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Six borazine-linked polymers (BLPs) have been synthesized through the thermolysis reaction of p -phenylenediamine, 1,3,5-tris-(4-aminophenyl)benzene, benzidine, or tetra-(4-aminophenyl)methane with boron tribromide or boron trichloride. Each product exists as an amorphous polymer whose chemical connectivity was confirmed by FT-IR and elemental analysis while thermogravimetric analysis revealed moderate thermal stabilities up to about 200 °C under nitrogen atmosphere. All BLPs possess high surface areas with chlorinated BLPs exhibiting higher values than brominated BLPs (1,174–1,569 vs. 503–849 m 2 /g, respectively). Gas storage capabilities were investigated as well. BLPs possess good hydrogen uptakes (0.68–1.75 wt% at 77 K) and zero-coverage isosteric heat of adsorption, Q st , (7.06–7.65 kJ/mol) as calculated by the virial method. The uptakes and heat of adsorption for carbon dioxide (51–141 mg/g at 273 K with Q st : 22.2–31.7 kJ/mol) are also attractive. BLPs do not, however, appear to exhibit significant methane storage capacities (1.9–15.2 mg/g at 273 K with Q st : 17.1–21.7 kJ/mol). Accordingly, CO 2 /CH 4 selectivity studies were performed using the ideal adsorbed solution theory and further supported by initial slope calculations. The results indicate that BLP-1(Br) and BLP-2(Br) exhibit very high CO 2 /CH 4 selectivities 23 and 26, respectively, which make them attractive for small gas separation applications.

In a randomized, controlled trial involving patients with membranous nephropathy, rituximab was noninferior to cyclosporine in inducing complete or partial remission of proteinuria at 12 months and was superior in maintaining proteinuria remission for up to 24 months.

In two trials in patients with moderate-to-severe plaque psoriasis, the anti–interleukin-17A monoclonal antibody secukinumab was more effective than placebo and etanercept. Infectious complications occurred more often with secukinumab than with placebo. Psoriasis is a chronic, immune-mediated inflammatory skin disease that is associated with substantial impairment of physical and psychological quality of life. 1 , 2 Our understanding of the pathogenesis of psoriasis was advanced by the discovery of the class of type 17 helper T (Th17) cells, which regulates innate and adaptive immunity. The proinflammatory cytokine interleukin-17A is the primary effector of Th17 cells, but it is also produced by other cell types in psoriatic lesions, including γδ T cells, neutrophils, and possibly mast cells. 3 – 7 Interleukin-17A stimulates keratinocytes to secrete chemokines and other proinflammatory mediators that recruit additional inflammatory cells, including neutrophils, . . .

Background Africa is the origin of modern humans within the past 300 thousand years. To infer the complex demographic history of African populations and adaptation to diverse environments, we sequenced the genomes of 92 individuals from 44 indigenous African populations. Results Genetic structure analyses indicate that among Africans, genetic ancestry is largely partitioned by geography and language, though we observe mixed ancestry in many individuals, consistent with both short- and long-range migration events followed by admixture. Phylogenetic analysis indicates that the San genetic lineage is basal to all modern human lineages. The San and Niger-Congo, Afroasiatic, and Nilo-Saharan lineages were substantially diverged by 160 kya (thousand years ago). In contrast, the San and Central African rainforest hunter-gatherer (CRHG), Hadza hunter-gatherer, and Sandawe hunter-gatherer lineages were diverged by ~ 120–100 kya. Niger-Congo, Nilo-Saharan, and Afroasiatic lineages diverged more recently by ~ 54–16 kya. Eastern and western CRHG lineages diverged by ~ 50–31 kya, and the western CRHG lineages diverged by ~ 18–12 kya. The San and CRHG populations maintained the largest effective population size compared to other populations prior to 60 kya. Further, we observed signatures of positive selection at genes involved in muscle development, bone synthesis, reproduction, immune function, energy metabolism, and cell signaling, which may contribute to local adaptation of African populations. Conclusions We observe high levels of genomic variation between ethnically diverse Africans which is largely correlated with geography and language. Our study indicates ancient population substructure and local adaptation of Africans.

From around 2750 to 2500 bc, Bell Beaker pottery became widespread across western and central Europe, before it disappeared between 2200 and 1800 bc . The forces that propelled its expansion are a matter of long-standing debate, and there is support for both cultural diffusion and migration having a role in this process. Here we present genome-wide data from 400 Neolithic, Copper Age and Bronze Age Europeans, including 226 individuals associated with Beaker-complex artefacts. We detected limited genetic affinity between Beaker-complex-associated individuals from Iberia and central Europe, and thus exclude migration as an important mechanism of spread between these two regions. However, migration had a key role in the further dissemination of the Beaker complex. We document this phenomenon most clearly in Britain, where the spread of the Beaker complex introduced high levels of steppe-related ancestry and was associated with the replacement of approximately 90% of Britain’s gene pool within a few hundred years, continuing the east-to-west expansion that had brought steppe-related ancestry into central and northern Europe over the previous centuries. Genome-wide data from 400 individuals indicate that the initial spread of the Beaker archaeological complex between Iberia and central Europe was propelled by cultural diffusion, but that its spread into Britain involved a large-scale migration that permanently replaced about ninety per cent of the ancestry in the previously resident population. Genomic insights into the Beaker culture Bell Beaker refers to a distinctive pottery style found across western and central Europe during the end of the Neolithic. Previous studies have had conflicting results on the origin and mechanisms of spread of the Beaker culture. David Reich and colleagues report genome-wide data from 400 Neolithic, Copper Age and Bronze Age Europeans, from 136 different archaeological sites, and including 226 Beaker-associated individuals. These individuals were highly genetically heterogeneous, which supports a model in which cultural transmission and human migration both had important roles in the spread of the Beaker culture, with the relative balance of these two processes varying by region. Elsewhere in this issue, David Reich and colleagues analyse genome-wide genomic data from 225 individuals who lived in southeastern European and the surrounding regions between 12000 and 500 bc . They analyse these data in combination with previous genomic datasets to update existing models of the early spread of farming into and across Europe.

Naturally regenerated forests and managed tree systems provide different levels of carbon, biodiversity, and livelihood benefits. Here, we show that tree cover gains in the moist tropics during 1982–2015 were 56% ± 3% naturally regenerated forests and 27% ± 2.6% managed tree systems, with these differences in forest type, not only natural conditions (climate, soil, and topography), driving observed carbon recovery rates. The remaining 17% ± 3% likely represents small, unmanaged tree patches within non-forest cover types. Achieving global forest restoration goals requires robust monitoring, reporting, and verification of forest types established by restoration initiatives. Tree cover gains in the moist tropics (1982–2015) were 56% naturally regenerated forests and 27% managed tree systems, with forest type influencing carbon recovery. Effective forest restoration requires robust tracking of forest types established by restoration efforts.

The genetic prehistory of human populations in Central America is largely unexplored leaving an important gap in our knowledge of the global expansion of humans. We report genome-wide ancient DNA data for a transect of twenty individuals from two Belize rock-shelters dating between 9,600-3,700 calibrated radiocarbon years before present (cal. BP). The oldest individuals (9,600-7,300 cal. BP) descend from an Early Holocene Native American lineage with only distant relatedness to present-day Mesoamericans, including Mayan-speaking populations. After ~5,600 cal. BP a previously unknown human dispersal from the south made a major demographic impact on the region, contributing more than 50% of the ancestry of all later individuals. This new ancestry derived from a source related to present-day Chibchan speakers living from Costa Rica to Colombia. Its arrival corresponds to the first clear evidence for forest clearing and maize horticulture in what later became the Maya region. The genetic prehistory of central America has not been well explored. Here, the authors find evidence from ancient DNA from twenty individuals who lived in Belize 9,600 to 3,700 years ago of a migration from the south that coincided with the first evidence for forest clearing and the spread of maize horticulture.

The roles of migration, admixture and acculturation in the European transition to farming have been debated for over 100 years. Genome-wide ancient DNA studies indicate predominantly Aegean ancestry for continental Neolithic farmers, but also variable admixture with local Mesolithic hunter-gatherers. Neolithic cultures first appear in Britain circa 4000  bc , a millennium after they appeared in adjacent areas of continental Europe. The pattern and process of this delayed British Neolithic transition remain unclear. We assembled genome-wide data from 6 Mesolithic and 67 Neolithic individuals found in Britain, dating 8500–2500  bc . Our analyses reveal persistent genetic affinities between Mesolithic British and Western European hunter-gatherers. We find overwhelming support for agriculture being introduced to Britain by incoming continental farmers, with small, geographically structured levels of hunter-gatherer ancestry. Unlike other European Neolithic populations, we detect no resurgence of hunter-gatherer ancestry at any time during the Neolithic in Britain. Genetic affinities with Iberian Neolithic individuals indicate that British Neolithic people were mostly descended from Aegean farmers who followed the Mediterranean route of dispersal. We also infer considerable variation in pigmentation levels in Europe by circa 6000  bc . DNA analyses of Mesolithic and Neolithic individuals indicates the British Neolithic transition was mediated by incoming continental farmers, with little gene flow from local hunter-gatherers.

Comorbid conditions appear to be common among individuals hospitalised with coronavirus disease 2019 (COVID-19) but estimates of prevalence vary and little is known about the prior medication use of patients. Here, we describe the characteristics of adults hospitalised with COVID-19 and compare them with influenza patients. We include 34,128 (US: 8362, South Korea: 7341, Spain: 18,425) COVID-19 patients, summarising between 4811 and 11,643 unique aggregate characteristics. COVID-19 patients have been majority male in the US and Spain, but predominantly female in South Korea. Age profiles vary across data sources. Compared to 84,585 individuals hospitalised with influenza in 2014-19, COVID-19 patients have more typically been male, younger, and with fewer comorbidities and lower medication use. While protecting groups vulnerable to influenza is likely a useful starting point in the response to COVID-19, strategies will likely need to be broadened to reflect the particular characteristics of individuals being hospitalised with COVID-19. Detailed knowledge of the characteristics of COVID-19 patients helps with public health planning. Here, the authors use routinely-collected data from seven databases in three countries to describe the characteristics of >30,000 patients admitted with COVID-19 and compare them with those admitted for influenza in previous years.