Variation in seed dormancy and germination among populations of Silybum marianum (Asteraceae)

Milk thistle (Silybum marianum) is a medicinal plant; however, lack of consistency in past dormancy studies has hindered propagation of this species from seeds. We tested the germination responses of freshly harvested and after-ripened (stored for 2 and 7 months; 25°C at 50% relative humidity) seeds from three populations (P1, P2 and P3) in Iran at varying constant or alternating temperatures, with or without GA₃ and in light and continuous darkness. No germination occurred in freshly harvested seeds incubated at any condition without GA₃ application, indicating that all the seeds were dormant. Seeds from P1 and P2, which developed under relatively dry, warm conditions, germinated over a wider range of temperatures after 2 months of dry storage, indicating type 6 of non-deep physiological dormancy (PD). Seeds from P3, which developed under relatively wet, cool conditions, incubated at constant temperatures (especially on GA₃), exhibited an increase in maximum temperature for germination, indicating type 1 of non-deep PD. Light improved germination of after-ripened seeds, and GA₃ application substituted for the light requirement for germination. This is the first report that environmental conditions during seed development may be correlated with differences in the type of non-deep PD. We conclude that milk thistle seeds are positively photoblastic and photodormant and the germination responses of after-ripened seeds from different populations are different under darkness. Therefore, the impacts of genetic differences and maternal effects on the induction of dormancy during seed development should be considered in attempts to domesticate this medicinal plant.     

Modeling the Release of Betaine Extracted from Sugar Beet Molasses in the Structure of Fast-Dissolving Electrospun Fibers of Plantago ovata Seed Gum

Food Biophysics - This study aimed to extract betaine from sugar beet molasses using the cloud point method and encapsulate it in fast-dissolving fibers of Poly(vinyl alcohol) (PVA)/Plantago ovata...     

Cadmium-Induced Oxidative Stress in the Rat Testes: Protective Effects of Betaine

The aim of the present study was to evaluate the antioxidant effects of betaine against oxidative stress and pathological changes mediated by cadmium in the testes of rats. The adult male Wistar rats were allocated into three experimental groups as follows: the cadmium group received cadmium chloride at the dosage of 2 mg/kg intraperitoneally thereafter, the rats treated by physiological saline for 10 consecutive days. The betaine plus cadmium group received betaine at the dosage of 1.5 % w/w of the total diet orally for 10 consecutive days and cadmium chloride injected at the 2nd day of the betaine treatment. The control rats were injected physiological saline. Both testes of rats were removed for antioxidant assay and pathological changes evaluation on days 5 and 10 after cadmium toxicity. TBARS concentration (as a lipid peroxidation marker) was significantly higher in the cadmium group by day 10 compared to control and betaine plus cadmium groups, and it was significantly higher in cadmium group by day 5 in comparison with the controls. Catalase (CAT) and glutathione peroxidase activities decreased significantly by day 10 in cadmium group when compared to the controls. In contrast, CAT and superoxide dismutase activities increased significantly by day 10 in betaine plus cadmium group when compared to the cadmium group. In addition, the antioxidant effects of betaine could prevent testicular pathological changes in betaine plus cadmium group. The present data allow us to exploit the advantages of this nutrient agent in future studies.     

Antiproliferative activity and DNA binding studies of cyclometalated complexes of platinum(II) containing 2-vinylpyridine

BioMetals - The cytotoxic activity of four cyclometalated platinum(II) complexes [PtMe(vpy)(L)], containing 2-vinylpyridine (vpy) and the phosphine ligands (L) PMe2Ph (1a), PPh3 (1b), PMePh2 (1c),...     

A job-shop scheduling approach for optimising sugarcane rail operations

The sugarcane transport system is very complex and uses a daily schedule, consisting of a set of locomotives runs, to satisfy the requirements of the mill and harvesters. The total cost of sugarcane transport operations is very high; over 35% of the total cost of sugarcane production in Australia is incurred in cane transport. Producing efficient schedules for sugarcane transport can reduce the cost and limit the negative effects that this system can have on the raw sugar production system. In this paper, the sugarcane rail operations are formulated as a blocking job shop scheduling problem. A mixed integer programming approach is used to formulate the shop job scheduling problem. Mixed integer programming and constraint programming search techniques are integrated for solving the problem. A case study is solved to test the approach.     

Efficacy and safety of convalescent plasma for severe COVID-19 based on evidence in other severe respiratory viral infections: a systematic review and meta-analysis

BACKGROUND:The safety and efficacy of convalescent plasma in severe coronavirus disease 2019 (COVID-19) remain uncertain. To support a guideline on COVID-19 management, we conducted a systematic review and meta-analysis of convalescent plasma in COVID-19 and other severe respiratory viral infections.METHODS:In March 2020, we searched international and Chinese biomedical literature databases, clinical trial registries and prepublication sources for randomized controlled trials (RCTs) and nonrandomized studies comparing patients receiving and not receiving convalescent plasma. We included patients with acute coronavirus, influenza and Ebola virus infections. We conducted a meta-analysis using random-effects models and assessed the quality of evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.RESULTS:Of 1099 unique records, 6 studies were eligible, and none of these included patients with COVID-19. One nonrandomized study (n = 40) on convalescent plasma in severe acute respiratory syndrome coronavirus (SARS-CoV) provided uninformative results regarding mortality (relative risk [RR] 0.10, 95% confidence interval [CI] CI 0.01 to 1.70). Pooled estimates from 4 RCTs on influenza (n = 572) showed no convincing effects on deaths (4 RCTs, RR 0.94, 95% CI 0.49 to 1.81), complete recovery (2 RCTs, odds ratio 1.04, 95% CI 0.69 to 1.64) or length of stay (3 RCTs, mean difference −1.62, 95% CI −3.82 to 0.58, d). The quality of evidence was very low for all efficacy outcomes. Convalescent plasma caused few or no serious adverse events in influenza RCTs (RR 0.85, 95% CI 0.56 to 1.29, low-quality evidence).INTERPRETATION:Studies of non-COVID-19 severe respiratory viral infections provide indirect, very low-quality evidence that raises the possibility that convalescent plasma has minimal or no benefit in the treatment of COVID-19 and low-quality evidence that it does not cause serious adverse events.

Coronavirus disease 2019 (COVID-19) has been diagnosed in nearly 3 million individuals around the globe, of whom around 0.2 million have died.¹ Many patients with COVID-19 develop severe acute respiratory illness requiring admission to intensive care units (ICU) and often mechanical ventilation.² The case fatality rate in COVID-19 may be as high as 2.3% overall² and from 10% to 40% among severely affected individuals. ^3,4 There is an urgent need for effective therapies.Emerging epidemiologic and clinical data show both similarities and differences between severe COVID-19 and severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS).⁵ Similarly, treatment strategies for severe influenza infections tested during the H1N1 pandemic and H5N1 and H7N9 outbreaks could inform the care of patients with severe COVID-19.⁶Of the treatment options proposed for COVID-19,⁷ convalescent plasma has evidence suggesting a mortality benefit for Ebola virus infection.⁸ This intervention has also been tested in other severe acute viral respiratory infections.^6,9,10 “Convalescent plasma” refers to plasma obtained from individuals recently recovered from a viral illness, which is expected to contain the highest levels of polyclonal antibodies directed against the virus.¹¹ Similarly, “hyperimmune plasma” is collected from donors exhibiting high titres of neutralizing antibodies, independent of time elapsed since viral illness. Authors have used the terms interchangeably, and because viral neutralization is only one of the postulated mechanisms by which antibodies exert their antiviral effect, the importance of the distinction between the 2 products remains unclear (Figure 1).Open in a separate windowFigure 1:Potential mechanisms of action of anti–severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies in coronavirus disease 2019 (COVID-19). This figure illustrates the normal entry of SARS-CoV-2 in a host cell, in which membrane fusion is mediated by the interaction between the SARS-CoV-2 spike glycoprotein (red) and the angiotensin-converting enzyme 2 (ACE2) receptor (green) on the host cell, either through the cytoplasmic or endosomal route. Antibodies directed against the receptor-binding domain (RBD) of the spike protein can interfere with its interaction with the ACE2 receptor and prevent viral entry in the host cell (panel A). Antibodies directed against epitopes outside the RBD can also exert antiviral functions through other mechanisms (panels B, C and D). The relative importance of these various functions in rescuing patients from an active SARS-CoV-2 infection is unknown. Importantly, neutralization assays generally used to qualify hyperimmune products measure only 1 of the 4 mechanisms depicted here and do not necessarily correlate with the others.Clinicians have typically administered convalescent plasma to patients with viral infections whose condition deteriorated despite supportive care.⁶ Although the primary postulated mechanism of action of convalescent plasma is reduction in viremia (passive immunity),¹² an increase in host immune response (active immunity) has also been proposed.¹³ We describe in Figure 1 the possible mechanisms by which convalescent plasma inhibits severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).Systematic summaries of the available evidence regarding safety and effectiveness can inform the use of convalescent plasma in patients with COVID-19. We therefore conducted a systematic review to summarize the evidence for convalescent plasma to support a guideline on COVID-19 management.¹⁴ Because we anticipated a paucity of direct evidence addressing the use of convalescent plasma in COVID-19, we summarized the available evidence addressing convalescent plasma in the treatment of SARS, MERS and influenza, including H1N1, H7N9 and H5N1, as well as addressing possible adverse effects in patients with Ebola disease.