19 research outputs found
A massive, Late Neolithic pit structure associated with Durrington Walls Henge
YesA series of massive geophysical anomalies, located south of the Durrington Walls henge monument, were identified during fluxgate gradiometer survey undertaken by the Stonehenge Hidden Landscapes Project (SHLP). Initially interpreted as dewponds, these data have been re-evaluated, along with information on similar features revealed by archaeological contractors undertaking survey and excavation to the north of the Durrington Walls henge. Analysis of the available data identified a total of 20 comparable features, which align within a series of arcs adjacent to Durrington Walls. Further geophysical survey, supported by mechanical coring, was undertaken on several geophysical anomalies to assess their nature, and to provide dating and environmental evidence. The results of fieldwork demonstrate that some of these features, at least, were massive, circular pits with a surface diameter of 20m or more and a depth of at least 5m. Struck flint and bone were recovered from primary silts and radiocarbon dating indicates a Late Neolithic date for the lower silts of one pit. The degree of similarity across the 20 features identified suggests that they could have formed part of a circuit of large pits around Durrington Walls, and this may also have incorporated the recently discovered Larkhill causewayed enclosure. The diameter of the circuit of pits exceeds 2km and there is some evidence that an intermittent, inner post alignment may have existed within the circuit of pits. One pit may provide evidence for a recut; suggesting that some of these features could have been maintained through to the Middle Bronze Age. Together, these features represent a unique group of features related to the henge at Durrington Walls, executed at a scale not previously recorded.The University of Bradford Research Development Fund and the University of St Andrews funded this open access publication.Supplementary data can be found at https://intarch.ac.uk/journal/issue55/4/supp-text.htm
Global overview of the management of acute cholecystitis during the COVID-19 pandemic (CHOLECOVID study)
Background: This study provides a global overview of the management of patients with acute cholecystitis during the initial phase of the COVID-19 pandemic. Methods: CHOLECOVID is an international, multicentre, observational comparative study of patients admitted to hospital with acute cholecystitis during the COVID-19 pandemic. Data on management were collected for a 2-month study interval coincident with the WHO declaration of the SARS-CoV-2 pandemic and compared with an equivalent pre-pandemic time interval. Mediation analysis examined the influence of SARS-COV-2 infection on 30-day mortality. Results: This study collected data on 9783 patients with acute cholecystitis admitted to 247 hospitals across the world. The pandemic was associated with reduced availability of surgical workforce and operating facilities globally, a significant shift to worse severity of disease, and increased use of conservative management. There was a reduction (both absolute and proportionate) in the number of patients undergoing cholecystectomy from 3095 patients (56.2 per cent) pre-pandemic to 1998 patients (46.2 per cent) during the pandemic but there was no difference in 30-day all-cause mortality after cholecystectomy comparing the pre-pandemic interval with the pandemic (13 patients (0.4 per cent) pre-pandemic to 13 patients (0.6 per cent) pandemic; P = 0.355). In mediation analysis, an admission with acute cholecystitis during the pandemic was associated with a non-significant increased risk of death (OR 1.29, 95 per cent c.i. 0.93 to 1.79, P = 0.121). Conclusion: CHOLECOVID provides a unique overview of the treatment of patients with cholecystitis across the globe during the first months of the SARS-CoV-2 pandemic. The study highlights the need for system resilience in retention of elective surgical activity. Cholecystectomy was associated with a low risk of mortality and deferral of treatment results in an increase in avoidable morbidity that represents the non-COVID cost of this pandemic
Prehistoric to post-medieval occupation at Dowd’s Farm, Hedge End, Hampshire
Excavation at Dowd’s Farm, Hedge End, revealed evidence for Mesolithic to post-medieval activity. Mesolithic and Neolithic activity is attested by a small flint assemblage. A concentration of Bronze Age pits provides the first evidence for permanent occupation and an associated burnt tree-throw hole may suggest that tree clearance was being undertaken. Late Iron Age activity centred on two large ditched enclosures and an associated activity area, together with drainage, boundary and trackway ditches. Early medieval occupation focused on an area to the north of the existing farmhouse. Possible continuation of the field system established in the medieval period into the post-medieval period is suggested. Work on documentary sources has provided further evidence for occupation at Dowd’s Farm during the medieval and post-medieval periods
Synthesis of HCV Replicase Inhibitors: Base-Catalyzed Synthesis of Protected α‑Hydrazino Esters and Selective Aerobic Oxidation with Catalytic Pt/Bi/C for Synthesis of Imidazole-4,5-dicarbaldehyde
A robust convergent synthesis of
the prodrugs of HCV replicase
inhibitors <b>1</b>–<b>5</b> is described. The
central 5<i>H</i>-imidazoÂ[4,5-<i>d</i>]Âpyridazine
core was formed from acid-catalyzed cyclocondensation of an imidazole-4,5-dicarbaldehyde
(<b>20</b>) and a α-hydrazino ester, generated in situ
from the bis-BOC-protected precursors <b>25</b> and <b>33</b>. The acidic conditions not only released the otherwise unstable
α-hydrazino esters but also were the key to avoid facile decarboxylation
to the parent drugs from the carboxylic ester prodrugs <b>1</b>–<b>5</b>. The bis-BOC α-hydrazino esters <b>25</b> and <b>33</b> were prepared by addition of ester
enolates (from <b>23</b> and <b>32</b>) to di-<i>tert</i>-butyl azodicarboxylate via catalysis with mild inorganic
bases, such as Li<sub>2</sub>CO<sub>3</sub>. A selective aerobic oxidation
with catalytic 5% Pt–Bi/C in aqueous KOH was developed to provide
the dicarbaldehyde <b>20</b> from the diol <b>27</b>
Synthesis of HCV Replicase Inhibitors: Base-Catalyzed Synthesis of Protected α-Hydrazino Esters and Selective Aerobic Oxidation with Catalytic Pt/Bi/C for Synthesis of Imidazole-4,5-dicarbaldehyde
A robust convergent synthesis of the prodrugs of HCV replicase inhibitors 1-5 is described. The central 5H-imidazo[4,S-d]pyridazine core was formed from acid-catalyzed cyclocondensation of an imidazole-4,5-dicarbaldehyde (20) and a alpha-hydrazino ester, generated in situ from the bis-BOC-protected precursors 25 and 33. The acidic conditions not only released the otherwise unstable alpha-hydrazino esters but also were the key to avoid facile decarboxylation to the parent drugs from the carboxylic ester prodrugs 1-5. The bis-BOC alpha-hydrazino esters 25 and 33 were prepared by addition of ester enolates (from 23 and 32) to di-tert-butyl azodicarboxylate via catalysis with mild inorganic bases, such as Li2CO3. A selective aerobic oxidation with catalytic 5% Pt-Bi/C in aqueous KOH was developed to provide the dicarbaldehyde 20 from the diol 27
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A palaeoenvironmental context for Terminal Upper Palaeolithic and Mesolithic activity in the Colne Valley: Offsite records contemporary with occupation at Three Ways Wharf, Uxbridge
Multi-proxy analyses from floodplain deposits in the Colne Valley, southern England, have provided a palaeoenvironmental context for the immediately adjacent Terminal Upper Palaeolithic and Early Mesolithic site of Three Ways Wharf. These deposits show the transition from an open cool environment to fully developed heterogeneous floodplain vegetation during the Early Mesolithic. Several distinct phases of burning are shown to have occurred that are chronologically contemporary with the local archaeological record. The floodplain itself is shown to have supported a number of rare Urwaldrelikt insect species implying human manipulation of the floodplain at this time must have been limited or episodic. By the Late Mesolithic a reed-sedge swamp had developed across much of the floodplain, within which repeated burning of the in situ vegetation took place. This indicates deliberate land management practices utilising fire, comparable with findings from other floodplain sequences in southern Britain. With similar sedimentary sequences known to exist across the Colne Valley, often closely associated with contemporary archaeology, the potential for placing the archaeological record within a spatially explicit palaeoenvironmental context is great