Pore Structure and Pore Solution in Alkali Activated Fly Ash Geopolymer Concrete and Its Effect on ASR of Aggregates with Wide Silicate Contents

Alkali silica reaction (ASR) is detrimental to concrete. It is a time-dependent phenomenon, which can lead to strength loss, cracking, volume expansion, and premature failure of concrete structures. In essence, it is a particular chemical reaction involving alkali hydroxides and reactive form of silica present within the concrete mix. Geopolymer is a type of alkaline activated binder synthesized through polycondensation reaction of geopolymeric precursor and alkali polysilicates. In this thesis, three types of reactive aggregates with different chemical compositions were used. Systematic laboratory experiments and microstructural analysis were carried out for the geopolymer concrete and the OPC concrete made with the same aggregates. The result suggests that the extent of ASR reaction due to the presence of three reactive aggregates in geopolymer concrete is substantially lower than that in OPC based concrete, which is explained by the pore solution change and verified through their microstructural variations and FTIR images

Determinants of agriculture biodiversity in Western Terai landscape complex of Nepal

The study explored agriculture biodiversity around protected areas and identified factors affecting diversity of agriculture biodiversity in farming households. The study analyzed the data collected from household survey of about 907 farmers from Western-Terai Landscape Complex of Nepal. Intra-species and inter-species richness and evenness in agriculture landscape were estimated and compared across a spectrum of land-uses. The study identified different social, economic, technological and ecological factors affecting the richness of intra-species and inter-species diversity of agriculture biodiversity using generalized linear regression models. Technology index, information index, food security, animal holding, ethnicity, irrigation facility and land-use were found as major variables affecting agriculture. The results also indicated that buffer zones had higher diversity than other land-uses, indicating positive effects of protected-land on surrounding agriculture biodiversity. Results supported need of coordinated efforts to mainstream agriculture biodiversity conservation with landscape conservation plans and socio-economic developments of the region

Determinants of agriculture biodiversity in Western Terai landscape complex of Nepal

The study explored agriculture biodiversity around protected areas and identified factors affecting diversity of agriculture biodiversity in farming households. The study analyzed the data collected from household survey of about 907 farmers from Western-Terai Landscape Complex of Nepal. Intra-species and inter-species richness and evenness in agriculture landscape were estimated and compared across a spectrum of land-uses. The study identified different social, economic, technological and ecological factors affecting the richness of intra-species and inter-species diversity of agriculture biodiversity using generalized linear regression models. Technology index, information index, food security, animal holding, ethnicity, irrigation facility and land-use were found as major variables affecting agriculture. The results also indicated that buffer zones had higher diversity than other land-uses, indicating positive effects of protected-land on surrounding agriculture biodiversity. Results supported need of coordinated efforts to mainstream agriculture biodiversity conservation with landscape conservation plans and socio-economic developments of the region

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

Effect of Antiplatelet Therapy on Survival and Organ Support–Free Days in Critically Ill Patients With COVID-19

International audienc

Long-term (180-Day) outcomes in critically Ill patients with COVID-19 in the REMAP-CAP randomized clinical trial

Importance The longer-term effects of therapies for the treatment of critically ill patients with COVID-19 are unknown. Objective To determine the effect of multiple interventions for critically ill adults with COVID-19 on longer-term outcomes. Design, Setting, and Participants Prespecified secondary analysis of an ongoing adaptive platform trial (REMAP-CAP) testing interventions within multiple therapeutic domains in which 4869 critically ill adult patients with COVID-19 were enrolled between March 9, 2020, and June 22, 2021, from 197 sites in 14 countries. The final 180-day follow-up was completed on March 2, 2022. Interventions Patients were randomized to receive 1 or more interventions within 6 treatment domains: immune modulators (n = 2274), convalescent plasma (n = 2011), antiplatelet therapy (n = 1557), anticoagulation (n = 1033), antivirals (n = 726), and corticosteroids (n = 401). Main Outcomes and Measures The main outcome was survival through day 180, analyzed using a bayesian piecewise exponential model. A hazard ratio (HR) less than 1 represented improved survival (superiority), while an HR greater than 1 represented worsened survival (harm); futility was represented by a relative improvement less than 20% in outcome, shown by an HR greater than 0.83. Results Among 4869 randomized patients (mean age, 59.3 years; 1537 [32.1%] women), 4107 (84.3%) had known vital status and 2590 (63.1%) were alive at day 180. IL-6 receptor antagonists had a greater than 99.9% probability of improving 6-month survival (adjusted HR, 0.74 [95% credible interval {CrI}, 0.61-0.90]) and antiplatelet agents had a 95% probability of improving 6-month survival (adjusted HR, 0.85 [95% CrI, 0.71-1.03]) compared with the control, while the probability of trial-defined statistical futility (HR >0.83) was high for therapeutic anticoagulation (99.9%; HR, 1.13 [95% CrI, 0.93-1.42]), convalescent plasma (99.2%; HR, 0.99 [95% CrI, 0.86-1.14]), and lopinavir-ritonavir (96.6%; HR, 1.06 [95% CrI, 0.82-1.38]) and the probabilities of harm from hydroxychloroquine (96.9%; HR, 1.51 [95% CrI, 0.98-2.29]) and the combination of lopinavir-ritonavir and hydroxychloroquine (96.8%; HR, 1.61 [95% CrI, 0.97-2.67]) were high. The corticosteroid domain was stopped early prior to reaching a predefined statistical trigger; there was a 57.1% to 61.6% probability of improving 6-month survival across varying hydrocortisone dosing strategies. Conclusions and Relevance Among critically ill patients with COVID-19 randomized to receive 1 or more therapeutic interventions, treatment with an IL-6 receptor antagonist had a greater than 99.9% probability of improved 180-day mortality compared with patients randomized to the control, and treatment with an antiplatelet had a 95.0% probability of improved 180-day mortality compared with patients randomized to the control. Overall, when considered with previously reported short-term results, the findings indicate that initial in-hospital treatment effects were consistent for most therapies through 6 months