90 research outputs found
Effects of Compound Fertilization on Growth and Alkaloids of Datura (Datura innoxia Mill.) Plants
The effect of 0, 100, 200, 400, 600 and 800 kg haâ1 of Sangral, a complex chemical fertilizer at rates, on growth, alkaloid content, drug yield and nutrient uptake of datura (Datura innoxia Mill.) plants was studied during two successive seasons. The plant height, the number of branches and leaves/plant, the fresh and the dry weights increased with increasing fertilizer rates up to 800 kg haâ1; however, the maximum increase was recorded at 600 kg haâ1. Total alkaloid and drug (hyoscyamine + scopolamine) contents also increased with increasing the fertilization level to a peak value of 600 kg haâ1. It then, decreased at 800 kg haâ1 level. Plant leaves and fruits were the most valuable organs for alkaloid and drug accumulation followed by stems, roots and crowns, respectively. N, P and K in the leaves were linearly increased by increasing fertilizer level. It seems that compound fertilizers increase the availability of essential nutrient elements necessary for datura growth and metabolism, causing vigorous vegetation and high chemical production
Time-Resolved Photoluminescence of 6-Thienyl-Lumazine Flourophore In Cellulose Acetate Nanofibers For Detection Of Mercury Ions
Time-resolved photoluminescence measurements were used to characterize the photophysical properties of 6-thienyllumazine (TLm) fluorophores in cellulose acetate nanofibers (NFs) in the presence and absence of mercuric acetate salts. In solution, excited-state proton transfer (ESPT) from TLm to water molecules was observed at pH from 2 to 12. The insertion of the thienyl group into lumazine (Lm) introduces cis and trans conformers while keeping the same tautomerization structures. Global and target analysis was employed to resolve the true emission spectra of all prototropic, tautomeric, and rotameric species for TLm in water. However, in the NFs solid film no ESPT from TLm to a nearby water molecule was observed. The addition of NFs increases the excited-state lifetime of TLm in the solid state because of combined polarity/confinement effects. The solid-state fluorescence of TLm (in NFs) was quenched by mercuric acetate through different mechanismsâdynamic and staticâdepending on the applied pressureâatmospheric and vacuum, respectively. The new solid-state sensor is simple, ecofriendly, and instantly fabricated. 20 ÎŒmol TLm-loaded NFs is able to detect down to 200nmol of mercuric ions in aqueous media. The formation of the non-fluorescent ground-state complex between TLm molecules and mercuric ions inside the pores of NFs was achieved under vacuum condition
Time-Resolved Photoluminescence of 6-Thienyl-Lumazine Flourophore In Cellulose Acetate Nanofibers For Detection Of Mercury Ions
Time-resolved photoluminescence measurements were used to characterize the photophysical properties of 6-thienyllumazine (TLm) fluorophores in cellulose acetate nanofibers (NFs) in the presence and absence of mercuric acetate salts. In solution, excited-state proton transfer (ESPT) from TLm to water molecules was observed at pH from 2 to 12. The insertion of the thienyl group into lumazine (Lm) introduces cis and trans conformers while keeping the same tautomerization structures. Global and target analysis was employed to resolve the true emission spectra of all prototropic, tautomeric, and rotameric species for TLm in water. However, in the NFs solid film no ESPT from TLm to a nearby water molecule was observed. The addition of NFs increases the excited-state lifetime of TLm in the solid state because of combined polarity/confinement effects. The solid-state fluorescence of TLm (in NFs) was quenched by mercuric acetate through different mechanismsâdynamic and staticâdepending on the applied pressureâatmospheric and vacuum, respectively. The new solid-state sensor is simple, ecofriendly, and instantly fabricated. 20 ÎŒmol TLm-loaded NFs is able to detect down to 200nmol of mercuric ions in aqueous media. The formation of the non-fluorescent ground-state complex between TLm molecules and mercuric ions inside the pores of NFs was achieved under vacuum condition
Contribution of citizen science to improve knowledge on marine biodiversity in the Gulf Region
Monitoring marine biodiversity is costly and practical solutions have to be implemented to identify species and their preferred habitats, particularly in this era of rapid global change. Citizen science has proven to be effective and with high potential for monitoring efforts, and has been extensively applied to biodiversity. We have used the citizen science approach to engage the general public and stakeholders to contribute improving the current knowledge of sea snake biodiversity in Qatar and the Gulf Region. Logistic regression analysis using demographic data from interview surveys conducted in Qatar has indicated that the people having seen more sea snakes are older than 30 years and are Qatari citizens and/or fishermen from India. Of the ten species of sea snakes listed in the literature to be present in the Gulf Region, most of them have been reported for Qatar, Bahrain, United Arab Emirates and Saudi Arabia. However, the number of species present is often assumed based on their occurrence within the Arabian Gulf rather than on actual captures and appropriate identification. The creation of marine reference biological scientific collections to properly identify the species and make accurate biodiversity inventories is an urgent priority for the countries in the Gulf region. To this end, contributions by stakeholders and the general public for this study have proven to be very useful. However a larger networking with local and international scientists and stakeholders is still needed to adequately survey the country''s current biodiversity, identify research priorities and eventually provide the scientific input needed to assist biodiversity management related to renewable resource management and marine conservation in the Arabian Gulf Region
Co-infection and ICU-acquired infection in COIVD-19 ICU patients: a secondary analysis of the UNITE-COVID data set
Background: The COVID-19 pandemic presented major challenges for critical care facilities worldwide. Infections which develop alongside or subsequent to viral pneumonitis are a challenge under sporadic and pandemic conditions; however, data have suggested that patterns of these differ between COVID-19 and other viral pneumonitides. This secondary analysis aimed to explore patterns of co-infection and intensive care unit-acquired infections (ICU-AI) and the relationship to use of corticosteroids in a large, international cohort of critically ill COVID-19 patients.Methods: This is a multicenter, international, observational study, including adult patients with PCR-confirmed COVID-19 diagnosis admitted to ICUs at the peak of wave one of COVID-19 (February 15th to May 15th, 2020). Data collected included investigator-assessed co-infection at ICU admission, infection acquired in ICU, infection with multi-drug resistant organisms (MDRO) and antibiotic use. Frequencies were compared by Pearson's Chi-squared and continuous variables by Mann-Whitney U test. Propensity score matching for variables associated with ICU-acquired infection was undertaken using R library MatchIT using the "full" matching method.Results: Data were available from 4994 patients. Bacterial co-infection at admission was detected in 716 patients (14%), whilst 85% of patients received antibiotics at that stage. ICU-AI developed in 2715 (54%). The most common ICU-AI was bacterial pneumonia (44% of infections), whilst 9% of patients developed fungal pneumonia; 25% of infections involved MDRO. Patients developing infections in ICU had greater antimicrobial exposure than those without such infections. Incident density (ICU-AI per 1000 ICU days) was in considerable excess of reports from pre-pandemic surveillance. Corticosteroid use was heterogenous between ICUs. In univariate analysis, 58% of patients receiving corticosteroids and 43% of those not receiving steroids developed ICU-AI. Adjusting for potential confounders in the propensity-matched cohort, 71% of patients receiving corticosteroids developed ICU-AI vs 52% of those not receiving corticosteroids. Duration of corticosteroid therapy was also associated with development of ICU-AI and infection with an MDRO.Conclusions: In patients with severe COVID-19 in the first wave, co-infection at admission to ICU was relatively rare but antibiotic use was in substantial excess to that indication. ICU-AI were common and were significantly associated with use of corticosteroids
Clinical and organizational factors associated with mortality during the peak of first COVID-19 wave: the global UNITE-COVID study
Purpose: To accommodate the unprecedented number of critically ill patients with pneumonia caused by coronavirus disease 2019 (COVID-19) expansion of the capacity of intensive care unit (ICU) to clinical areas not previously used for critical care was necessary. We describe the global burden of COVID-19 admissions and the clinical and organizational characteristics associated with outcomes in critically ill COVID-19 patients. Methods: Multicenter, international, point prevalence study, including adult patients with SARS-CoV-2 infection confirmed by polymerase chain reaction (PCR) and a diagnosis of COVID-19 admitted to ICU between February 15th and May 15th, 2020. Results: 4994 patients from 280 ICUs in 46 countries were included. Included ICUs increased their total capacity from 4931 to 7630 beds, deploying personnel from other areas. Overall, 1986 (39.8%) patients were admitted to surge capacity beds. Invasive ventilation at admission was present in 2325 (46.5%) patients and was required during ICU stay in 85.8% of patients. 60-day mortality was 33.9% (IQR across units: 20%â50%) and ICU mortality 32.7%. Older age, invasive mechanical ventilation, and acute kidney injury (AKI) were associated with increased mortality. These associations were also confirmed specifically in mechanically ventilated patients. Admission to surge capacity beds was not associated with mortality, even after controlling for other factors. Conclusions: ICUs responded to the increase in COVID-19 patients by increasing bed availability and staff, admitting up to 40% of patients in surge capacity beds. Although mortality in this population was high, admission to a surge capacity bed was not associated with increased mortality. Older age, invasive mechanical ventilation, and AKI were identified as the strongest predictors of mortality
Early mobilisation in critically ill COVID-19 patients: a subanalysis of the ESICM-initiated UNITE-COVID observational study
Background
Early mobilisation (EM) is an intervention that may improve the outcome of critically ill patients. There is limited data on EM in COVID-19 patients and its use during the first pandemic wave.
Methods
This is a pre-planned subanalysis of the ESICM UNITE-COVID, an international multicenter observational study involving critically ill COVID-19 patients in the ICU between February 15th and May 15th, 2020. We analysed variables associated with the initiation of EM (within 72 h of ICU admission) and explored the impact of EM on mortality, ICU and hospital length of stay, as well as discharge location. Statistical analyses were done using (generalised) linear mixed-effect models and ANOVAs.
Results
Mobilisation data from 4190 patients from 280 ICUs in 45 countries were analysed. 1114 (26.6%) of these patients received mobilisation within 72 h after ICU admission; 3076 (73.4%) did not. In our analysis of factors associated with EM, mechanical ventilation at admission (OR 0.29; 95% CI 0.25, 0.35; pâ=â0.001), higher age (OR 0.99; 95% CI 0.98, 1.00; pââ€â0.001), pre-existing asthma (OR 0.84; 95% CI 0.73, 0.98; pâ=â0.028), and pre-existing kidney disease (OR 0.84; 95% CI 0.71, 0.99; pâ=â0.036) were negatively associated with the initiation of EM. EM was associated with a higher chance of being discharged home (OR 1.31; 95% CI 1.08, 1.58; pâ=â0.007) but was not associated with length of stay in ICU (adj. difference 0.91 days; 95% CI â 0.47, 1.37, pâ=â0.34) and hospital (adj. difference 1.4 days; 95% CI â 0.62, 2.35, pâ=â0.24) or mortality (OR 0.88; 95% CI 0.7, 1.09, pâ=â0.24) when adjusted for covariates.
Conclusions
Our findings demonstrate that a quarter of COVID-19 patients received EM. There was no association found between EM in COVID-19 patients' ICU and hospital length of stay or mortality. However, EM in COVID-19 patients was associated with increased odds of being discharged home rather than to a care facility.
Trial registration ClinicalTrials.gov: NCT04836065 (retrospectively registered April 8th 2021)
COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study
Background:
The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms.
Methods:
International, prospective observational study of 60â109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms.
Results:
âTypicalâ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (â€â18 years: 69, 48, 23; 85%), older adults (â„â70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each Pâ<â0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country.
Interpretation:
This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men
DETERMINATION OF WATER REQUIREMENTS AND IRRI-GATION SCHEDULING FOR DATE PALM OFFSHOOT
The current study was carried out at the Agricultural and Veterinary Research Station, Faculty of Agriculture and Veterinary Medicine, Qassim University, Kingdom of Saudi Arabia during the two seasons 2003/2004 and 2003/2004. The objectives of this study are to investigate the effect of irrigation scheduling methods with different amounts of applied water on date palme offshoot growth, Determination offshoot consumptive use, crop coefficient, actual water requirements and the suitable soil moisture tension in the root zone before irrigation. The irrigation was scheduling by three methods, evapotranspiration calculation method, soil moisture depletion method and farmer method (control). The evapotranspiration calculation method (ETo) included ten treatments as a percentage of evapotranspiration (0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0 ETo). The soil moisture depletion method included five treatments of soil moisture depletion as a percentage of field capacity (50%Fc, 60%Fc, 70% Fc, 80% Fc and 90% Fc). The results showed that scheduling irrigation of the offshoot by evapotranspiration calculation method (ETo) or by soil moisture depletion method, the amount of applied water decreased and the offshoot growth and the water use efficiency increased; compared with the farmer scheduling method. The daily and seasonal gross irrigation requirements for date palm offshoots were 51.3 l/day and 2191 m3/hec.year, while the farmer applied 19960 m3/h.year. So, the farmer added seven times as much as the actual gross irrigation requirements. The maximum water use efficiency were 2.5 kg/m3 and 1.44 kg/m3 for the treatments 0.1 ETo and 50% Fc, respectively. The suitable soil moisture tension in the root zone before irrigation were 21.5 to 22 C-bar and 22.5 to 23 C-bar for 60 cm and 90 cm depths, respectively
Searching for natural herbicides in methanol extracts of eight plant species
Abstract Background Plant extracts could turn out to be natural herbicides to be used in weed control. This study was conducted to study the phytotoxic effects of methanol extracts obtained from Tamarix mannifera, Alhagi maurorum, Echinops spinosissimus, Haloxylon salicornicum, Lactuca virosa, Neurada procumbens, Ochradenus bacctus, and Cyperus conglomerates plants on germination and growth of Phalaris minor, Echinochloa crusgalli, Portulaca oleracea, and Lactuca sativa. Results In laboratory trial, extracts of eight plants at 0, 5, 10, 20, and 40âg/L were evaluated on germination of seeds of four target species. The inhibitory effect of tested extracts varied among the examined seeds, and P. minor was the most sensitive. Extracts of T. mannifera and L. virosa showed the greatest effect on seed germination and seedling growth of studied seeds. Using the extract of T. mannifera at 40âg/L completely inhibited the germination and seedling growth of P. minor and shoot length of P. oleracea as well as root length of E. crusgalli and L. sativa. At this concentration, L. virosa nearly had a complete inhibition effect on germination and seedling growth of P. minor and P. oleracea. In the greenhouse trial, extracts from tested plants at four concentrations (0, 30, 60, and 90âg/L) were used in a phytotoxic bioassay against 6-week-old L. sativa and three target weeds. The growth of 6-week-old weeds tended to be less sensitive to the tested extracts than the weed germination. The significant injury effect was observed only when T. mannifera extract at 60 and 90âg/L was sprayed on P. minor, E. crusgalli, and L. sativa plants. Conclusions Among tested species, T. mannifera and L. virosa could be used for developing new natural herbicide
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