Additive effects of simulated climate changes,elevated CO2, and nitrogen deposition on grassland diversity

Biodiversity responses to ongoing climate and atmospheric changes will affect both ecosystem processes and the delivery of ecosystem goods and services. Combined effects of co-occurring global changes on diversity, however, are poorly understood. We examined plant diversity responses in a California annual grassland to manipulations of four global environmental changes, singly and in combination: elevated CO2, warming, precipitation, and nitrogen deposition. After 3 years, elevated CO2 and nitrogen deposition each reduced plant diversity, whereas elevated precipitation increased it and warming had no significant effect. Diversity responses to both single and combined global change treatments were driven overwhelmingly by gains and losses of forb species, which make up most of the native plant diversity in California grasslands. Diversity responses across treatments also showed no consistent relationship to net primary production responses, illustrating that the diversity effects of these environmental changes could not be explained simply by changes in productivity. In two- to four-way combinations, simulated global changes did not interact in any of their effects on diversity. Our results show that climate and atmospheric changes can rapidly alter biological diversity, with combined effects that, at least in some settings, are simple, additive combinations of single-factor effects.     

COVID-19 risk index (CRI): a simple and validated emergency department risk score that predicts mortality and the need for mechanical ventilation

Journal of Thrombosis and Thrombolysis - Although certain risk factors have been associated with morbidity and mortality, validated emergency department (ED) derived risk prediction models specific...     

CXCR4 blockade and Sphingosine‐1‐phosphate activation facilitate engraftment of haematopoietic stem and progenitor cells in a non‐myeloablative transplant model

Both immunosuppressive and cytoreductive effects of γ‐irradiation contribute to engraftment of allogeneic haematopoietic stem and progenitor cells. We hypothesized that a release of host stem and progenitor cells from the niche prior to conditioning would permit engraftment after less intensive conditioning. Administration of AMD3100 and SEW2871 on days ?4 to ?2 followed by irradiation on day ?1 in a non‐myeloablative zebrafish transplant model resulted in a reduced radiation minimum dose of 10 Gy from 15 Gy being sufficient for engraftment. Targeting the SDF‐1 (CXCL12)/CXCR4‐ and S1P/S1P₁‐axis increased the efficacy of allografting in an experimental transplant model.     

Admission respiratory status predicts mortality in COVID‐19

COVID‐19 has significant case fatality. Glucocorticoids are the only treatment shown to improve survival, but only among patients requiring supplemental oxygen. WHO advises patients to seek medical care for “trouble breathing,” but hypoxemic patients frequently have no respiratory symptoms. Our cohort study of hospitalized COVID‐19 patients shows that respiratory symptoms are uncommon and not associated with mortality. By contrast, objective signs of respiratory compromise—oxygen saturation and respiratory rate—are associated with markedly elevated mortality. Our findings support expanding guidelines to include at‐home assessment of oxygen saturation and respiratory rate in order to expedite life‐saving treatments patients to high‐risk COVID‐19 patients.     

Age related macular degeneration surgery

Age related macular degeneration (ARMD) is a disease in which the retinal pigment epithelium (RPE) is damaged in the central retinal area. In the exudative form, the vision loss is due to choroidal neovascularization, while in the nonexudative or atrophic form, there is a vision loss because of the retinal pigment epithelium atrophy. Treatment which proved to be efficient in lowering the risk of severe vision loss in the exudative form includes laser photocoagulation, photodynamic therapy, transpupilary thermotherapy and as surgical treatment, the controversial subretinal membrane extraction. In all these situations the RPE is damaged by the disease itself and by the therapeutic procedure too. Retinal translocation is a surgical procedure that intends to remove the neurosensory retina from an area with damaged RPE to an healthy RPE area, through a 360 degrees retinotomy or through a limited one. This paper present some ARMD cases treated by subretinal membrane extraction and one by limited retinal translocation. The question which is still remaining is which are the risks and benefits for the following treatment procedures: laser photocoagulation, photodynamic therapy, transpupilary thermotherapy and surgical approach?     

Internal tamponade in proliferative diabetic retinopathy surgery

Vitreous hemorrhage has been the most common indication of posterior vitrectomy in diabetic retinopathy. Now, the leader is tractional retinal detachement and many others: rhegmatogenous retinal detachement, fibrovascular proliferations membranes, huge premacular hemorrhage. During vitrectomy procedure it may be necessary internal tamponade using air, expanding gases, silicon oil and/or perfluorocarbon liquids.