63 research outputs found
Synthesis based on cyclohexadienes. Part 24. A new total synthesis of pupukean-2-one and a facile entry to copa and ylanga type sesquiterpene skeletons
A novel tandem 5-exo-trig allyl and 3-exo-trig radical cyclisation and rearrangement to copa and ylanga type sesquiterpene skeletons from easily prepared cyclohexadienes is reported. A new total synthesis of pupukean-2-one 8, which belongs to a novel class of sesquiterpenes, involving a 5-exo-trig allyl radical cyclisation as the key step is also reported
Synthesis based on cyclohexadienes. Part 23. Total synthesis of 5-epi-pupukean-2-one
A new strategy for the construction of the isotwistane skeleton is reported from easily available cyclohexadienes which involves stereoselective alkylation of a bicyclooctenone derivative and a decarboxylative 5-exo-trig radical cyclisation as the key steps in the total synthesis of 5-epi-pupukean-2-one
Synthesis based on cyclohexadienes. Part 22. Formal syntheses of patchouli alcohol and norpatchoulenol
The preparation of 6-endo-formyl-1,3,3-trimethylbicyclo[2.2.2]octan-2-one 7 and 6-endo-acetyl-1,3,3-trimethylbicyclo[2.2.2]octan-2-one 8, the two key intermediates for the synthesis of patchouli alcohol 1 and norpatchoulenol 2, is reported by a simple and short method from 2-methylbenzoic acid
Finite Element Analysis of Propeller Shaft for Automotive and Naval Application
The Drive shaft is mainly used for power transmission from the engine to the rear differential. Parts are created by using creo software and the assembled model is exported to analysis Parasolid file and various analysis are performed. Structural analysis of drive shaft to with stand a torque of 10000nm at one where other side is fixed. Use of conventional steel for manufacturing of drive shaft has many disadvantages such as low specific stiffness and strength. Conventional drive shaft is made up into two parts to increase its fundamental natural bending frequency. Two-piece drive shaft increases the weight of drive shaft which is not desirable in today’s market. Many methods are available at present for the design optimization of structural systems and these methods based on mathematical programming techniques involving gradient search and direct search. These methods assume that the design variables are continuous. But in practical structural engineering optimization, almost all the design variables are discret
Diagnostic pathways and direct medical costs incurred by new adult pulmonary tuberculosis patients prior to anti-tuberculosis treatment - Tamil Nadu, India.
BACKGROUND: Tuberculosis (TB) patients face substantial delays prior to treatment initiation, and out of pocket (OOP) expenditures often surpass the economic productivity of the household. We evaluated the pre-diagnostic cost and health seeking behaviour of new adult pulmonary TB patients registered at Primary Health Centres (PHCs) in Vellore district, Tamil Nadu, India. METHODS: This descriptive study, part of a randomised controlled trial conducted in three rural Tuberculosis Units from Dec 2012 to Dec 2015, collected data on number of health facilities, dates of visits prior to the initiation of anti-tuberculosis treatment, and direct OOP medical costs associated with TB diagnosis. Logistic regression analysis examined the factors associated with delays in treatment initiation and OOP expenditures. RESULTS: Of 880 TB patients interviewed, 34.7% presented to public health facilities and 65% patients sought private health facilities as their first point of care. The average monthly individual income was 39.74. Overall, patients experienced a median of 6 days (3-11 IQR) of time to treatment initiation and 21 days (10-30 IQR) of health systems delay. Age ≤ 40 years (aOR: 1.73; CI: 1.22-2.44), diabetes (aOR: 1.63; CI: 1.08-2.44) and first visit to a private health facility (aOR: 17.2; CI: 11.1-26.4) were associated with higher direct OOP medical costs, while age ≤ 40 years (aOR: 0.64; CI: 0.48-0.85) and first visit to private health facility (aOR: 1.79, CI: 1.34-2.39) were associated with health systems delay. CONCLUSION: The majority of rural TB patients registering at PHCs visited private health facilities first and incurred substantial direct OOP medical costs and delays prior to diagnosis and anti-tuberculosis treatment initiation. This study highlights the need for PHCs to be made as the preferred choice for first point of contact, to combat TB more efficiently.Eunice Kennedy Shriver National Institute of Child Health and Human Developmen
Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19
IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19.
Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19.
DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022).
INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days.
MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes.
RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively).
CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes.
TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570
Recent advances in cascade Enyne/RCM in organic synthesis
A concise highlight on recent advances in cascade/enyne RCM reactions of a range of substrates is discussed. Some of the reported strategies led to total synthesis of biologically active natural products
A concise total synthesis of (+)-cladospolide D
A short and convergent total synthesis of (+)-cladospolide D is delineated, which involves olefin cross metathesis and furan oxidation to access the γ-oxo-α,β-unsaturated acid and Yamaguchi lactonization to construct the 12-membered ring as key steps
An expedient enyne metathesis approach to dysidiolide
A short and efficient enyne metathesis route is reported for the construction of a key intermediate required in the synthesis of dysidiolide thus completing its formal synthesis.© Elsevie
First enantioselective total synthesis of the angucyclinone-type antibiotic YM-181741
A simple and efficient strategy for angucyclinone antibiotics is described with the disclosure of first total synthesis of YM-181741
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