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During the period 1959-68, a total of 982 patients were submitted to treatment for arteriosclerotic vascular lesions in the lower limbs in Department M, Bispebjerg Hospital, Copenhagen. Conservative treatment solely was undertaken in 425 cases, while in addition 271 limbs were amputated after varying periods of conservative therapy or observation. Primary lumbar sympathectomy was undertaken in 25 patients. In the remaining 261 patients, indications were found for arterial reconstruction. In 25 cases explorative intervention only was undertaken. In the remaining 236 patients, 255 reconstructive interventions were undertaken during the period. These comprised 113 thrombendarterectomies, 71 of which were in vessels distal to the inguinal ligament, and 142 by-pass operations. In the latter procedures, five bifurcation prostheses were introduced, 40 simple prostheses with proximal anastomosis to the aorta or the iliac arteries, and 53 synthetic prostheses and 44 venous prostheses with proximal anastomoses to the femoral artery. Eight patients (3.4 percent) died postoperatively, while amputation had to be resorted to in 20 (8 percent). On discharge, pulsation distal to the site of operation was found in 61 percent of the patients discharged, one year later in 44 percent of the survivors and five years later in 23 percent. A total of 62 (24 percent) limbs were amputated on an average of 14 months after operation. 224 cases could be assessed after an average of 4 4/12 years. In 58 cases there was definite clinical improvement and pulsation distal to the site of operation. In 44 cases, pulsation had been present after operation and definite clinical improvement, but no pulsation distal to the reconstructed vessel was found at the follow-up examination. In 122 cases no evident beneficial effect of operation could be demonstrated at follow-up examination. The indications for operation and the incidence of operation are discussed, and the results compared with those of previous publications.

An updated version of the nested-grid GEOS-Chem model is developed allowing for higher horizontal (0.5°×0.667°) resolution as compared to global models. CO transport over a heavily polluted region, the Beijing-Tianjin-Hebei (BTH) city cluster in China, and the pattern of outflow from East China in summertime are investigated. Comparison of the nested-grid with global models indicates that the fine-resolution nested-grid model is capable of resolving individual cities with high associated emission intensities. The nested-grid model indicates the presence of a high CO column density over the Sichuan Basin in summer, attributable to the low-level stationary vortex associated with the Basin's topographical features. The nested-grid model provides good agreement also with measurements from a suburban monitoring site in Beijing during summer 2005. Tagged CO simulation results suggest that regional emissions make significant contributions to elevated CO levels over Beijing on polluted days and that the southeastward moving cyclones bringing northwest winds to Beijing are the key meteorological mechanisms responsible for dispersion of pollution over Beijing in summer. Overall CO fluxes to the NW Pacific from Asia are found to decrease by a factor of 3–4 from spring to summer. Much of the seasonal change is driven by decreasing fluxes from India and Southeast Asia in summer, while fluxes from East China are only 30% lower in summer than in spring. Compared to spring, summertime outflow from Chinese source regions is strongest at higher latitudes (north of 35° N). The deeper convection in summer transporting CO to higher altitudes where export is more efficient is largely responsible for enhanced export in summer.

We use aircraft observations of carbon monoxide (CO) from the NASA ARCTAS and NOAA ARCPAC campaigns in April 2008 together with multiyear (2003–2008) CO satellite data from the AIRS instrument and a global chemical transport model (GEOS-Chem) to better understand the sources, transport, and interannual variability of pollution in the Arctic in spring. Model simulation of the aircraft data gives best estimates of CO emissions in April 2008 of 26 Tg month−1 for Asian anthropogenic, 9.4 for European anthropogenic, 4.1 for North American anthropogenic, 15 for Russian biomass burning (anomalously large that year), and 23 for Southeast Asian biomass burning. We find that Asian anthropogenic emissions are the dominant source of Arctic CO pollution everywhere except in surface air where European anthropogenic emissions are of similar importance. Russian biomass burning makes little contribution to mean CO (reflecting the long CO lifetime) but makes a large contribution to CO variability in the form of combustion plumes. Analysis of two pollution events sampled by the aircraft demonstrates that AIRS can successfully observe pollution transport to the Arctic in the mid-troposphere. The 2003–2008 record of CO from AIRS shows that interannual variability averaged over the Arctic cap is very small. AIRS CO columns over Alaska are highly correlated with the Ocean Niño Index, suggesting a link between El Niño and Asian pollution transport to the Arctic. AIRS shows lower-than-average CO columns over Alaska during April 2008, despite the Russian fires, due to a weakened Aleutian Low hindering transport from Asia and associated with the moderate 2007–2008 La Niña. This suggests that Asian pollution influence over the Arctic may be particularly large under strong El Niño conditions.