Carbon K-edge x-ray emission spectroscopy of gas phase ethylenic molecules

We report on the C K-edge x-ray absorption spectra and the resonant (RXES) and non-resonant (NXES) x-ray emission spectra of ethylene, allene and butadiene in the gas phase. The RXES and NXES show clear differences for the different molecules. Overall both types of spectra are more structured for ethylene and allene, than for butadiene. Using density functional theory–restricted open shell configuration interaction single calculations, we simulate the spectra with remarkable agreement with the experiment. We identify the spectral features as being due to transitions involving localised 1s orbitals. For allene, there are distinct spectral bands that reflect transitions predominantly from either the central or terminal carbon atoms. These results are discussed in the context of ultrafast x-ray studies aimed at detecting the passage through conical intersections in polyatomic molecules

Associations of modern initial antiretroviral drug regimens with all-cause mortality in adults with HIV in Europe and North America: a cohort study

Background: Over the past decade, antiretroviral therapy (ART) regimens that include integrase strand inhibitors (INSTIs) have become the most commonly used for people with HIV starting ART. Although trials and observational studies have compared virological failure on INSTI-based with other regimens, few data are available on mortality in people with HIV treated with INSTIs in routine care. Therefore, we compared all-cause mortality between different INSTI-based and non-INSTI-based regimens in adults with HIV starting ART from 2013 to 2018. Methods: This cohort study used data on people with HIV in Europe and North America from the Antiretroviral Therapy Cohort Collaboration (ART-CC) and UK Collaborative HIV Cohort (UK CHIC). We studied the most common third antiretroviral drugs (additional to nucleoside reverse transcriptase inhibitor) used from 2013 to 2018: rilpivirine, darunavir, raltegravir, elvitegravir, dolutegravir, efavirenz, and others. Adjusted hazard ratios (aHRs; adjusted for clinical and demographic characteristics, comorbid conditions, and other drugs in the regimen) for mortality were estimated using Cox models stratified by ART start year and cohort, with multiple imputation of missing data. Findings: 62 500 ART-naive people with HIV starting ART (12 422 [19·9%] women; median age 38 [IQR 30–48]) were included in the study. 1243 (2·0%) died during 188 952 person-years of follow-up (median 3·0 years [IQR 1·6–4·4]). There was little evidence that mortality rates differed between regimens with dolutegravir, elvitegravir, rilpivirine, darunavir, or efavirenz as the third drug. However, mortality was higher for raltegravir compared with dolutegravir (aHR 1·49, 95% CI 1·15–1·94), elvitegravir (1·86, 1·43–2·42), rilpivirine (1·99, 1·49–2·66), darunavir (1·62, 1·33–1·98), and efavirenz (2·12, 1·60–2·81) regimens. Results were similar for analyses making different assumptions about missing data and consistent across the time periods 2013–15 and 2016–18. Rates of virological suppression were higher for dolutegravir than other third drugs. Interpretation: This large study of patients starting ART since the introduction of INSTIs found little evidence that mortality rates differed between most first-line ART regimens; however, raltegravir-based regimens were associated with higher mortality. Although unmeasured confounding cannot be excluded as an explanation for our findings, virological benefits of first-line INSTIs-based ART might not translate to differences in mortality. Funding: US National Institute on Alcohol Abuse and Alcoholism and UK Medical Research Council

Always Contact a Vascular Interventional Specialist Before Amputating a Patient with Critical Limb Ischemia

Patients with severe critical limb ischemia (CLI) due to long tibial artery occlusions are often poor candidates for surgical revascularization and frequently end up with a lower limb amputation. Subintimal angioplasty (SA) offers a minimally invasive alternative for limb salvage in this severely compromised patient population. The objective of this study was to evaluate the results of SA in patients with CLI caused by long tibial occlusions who have no surgical options for revascularization and are facing amputation. We retrospectively reviewed all consecutive patients with CLI due to long tibial occlusions who were scheduled for amputation because they had no surgical options for revascularization and who were treated by SA. A total of 26 procedures in 25 patients (14 males; mean age, 70 ± 15 [SD] years) were evaluated. Technical success rate was 88% (23/26). There were four complications, which were treated conservatively. Finally, in 10 of 26 limbs, no amputation was needed. A major amputation was needed in 10 limbs (7 below-knee amputations and 3 above-knee amputations). Half of the major amputations took place within 3 months after the procedure. Cumulative freedom of major amputation after 12 months was 59% (SE = 11%). In six limbs, amputation was limited to a minor amputation. Seven patients (28%) died during follow-up. In conclusion, SA of the tibial arteries seem to be a valuable treatment option to prevent major amputation in patients with CLI who are facing amputation due to lack of surgical options

The adaptation of mechanically softened gutta-percha to the canal walls in the presence or absence of smear layer: a scanning electron microscopic study

The objective of this study was to compare the adaptation of mechanically softened gutta-percha to the root canal wall in the presence and absence of smear layer. The root canals of 20 freshly extracted human maxillary incisors were cleaned and shaped. Prior to obturation, 10 root canals were irrigated with 20 ml of 50% citric acid followed by 20 ml of 5.25% sodium hypochlorite. All canals were obturated with mechanical compaction of gutta-percha and AH-26 sealer. After 72h, each tooth was fractured in half. Scanning electron microscopy demonstrated that the sealer had formed a continuous layer in contact with the canal walls, becoming progressively thinner towards the apex. The sealer pentrated into the dentinal tubules along with projections of gutta-percha only in those teeth without smear layer.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71864/1/j.1365-2591.1995.tb00312.x.pd