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Nitrogenase is the only enzyme that can cleave the triple bond in N2, making nitrogen available for all lifeforms. Previous computational studies have given widely diverging results regarding the reaction mechanism of the enzyme. For example, some recent studies have suggested that one of the μ2-bridging sulfide ligands (S2B) may dissociate from one of the Fe ions when protonated in the doubly

The technological evolution and widespread availability of wearables and handheld ECG devices capable of screening for atrial fibrillation (AF), and their promotion directly to consumers, has focused attention of health care professionals and patient organizations on consumer-led AF screening. In this Frontiers review, members of the AF-SCREEN International Collaboration provide a critical apprais

Prostate-specific antigen (PSA) is a serine protease secreted by hath normal prostate glandular celts and prostate cancer cells. The major proteolytic substrates for PSA are the gel-forming proteins in semen, semenogelin (Sg) I and II. On the basis of the PSA cleavage map for Sg I and II, a series of small peptides (ie., ≤ 7 amino acids) was synthesized and coupled at the COOH terminus to 7-amino-

Motivated by the novel coronavirus disease (COVID-19) pandemic, this paper aims to apply Gunter Stein's cautionary message of respecting the unstable to the problem of controlling the spread of an infectious disease. With this goal, we study the effect that delays and capacity constraints have in the test, trace, and isolate (TeTrIs) process, and how they impact its ability to prevent exponential

Bladder exstrophy is a rare congenital malformation leaving the urinary bladder open in the midline of the abdomen at birth. There is a clear genetic background with chromosome aberrations, but so far, no consistent findings apart from 22q11-duplications detected in about 2%–3% of all patients. Some genes are implicated like the LZTR1, ISL1, CELSR3, and the WNT3 genes, but most are not explained m

We consider a spectral problem associated with steady water waves of extreme form on the free surface of a rotational flow. It is proved that the spectrum of this problem contains arbitrary large negative eigenvalues and they are simple. Moreover, the asymptotics of such eigenvalues is obtained.

Background: Traumatic peripheral nerve injury is common and incurs significant cost to individuals and society. Healing following direct nerve repair or repair with autograft is slow and can be incomplete. Several bioengineered nerve wraps or devices have become available as an alternative to direct repair or autologous nerve graft. Nerve wraps attempt to reduce axonal escape across a direct repai

PURPOSE: To develop a psychometrically robust electronic patient reported outcome measure (ePROM) for refractive surgery. SETTING: Moorfields Eye Hospital, London, United Kingdom. DESIGN: Questionnaire development study. METHODS: Items were derived in 6 domains (spectacle dependence, visual quality, eye comfort, functional freedom, emotional wellbeing, and satisfaction with treatment) from existin

Ice-core timescales are vital for the understanding of past climate; hence they should be updated whenever significant amounts of new data become available. Here, the Greenland ice-core chronology GICC05 was revised for the last 3835 years by synchronizing six deep ice cores and three shallow ice cores from the central Greenland ice sheet. A new method was applied by combining automated counting o

The coronavirus disease (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has become a serious global healthcare crisis, so there is an emergence of identifying efficacious therapeutic options. In a setting where there is an unavailability of definitive medication along with the constant eruption of vaccine-related controversies, the drug-repositioning appr

The detection of electromagnetic (EM) emission following the gravitational wave (GW) event GW170817 opened the era of multi-messenger astronomy with GWs and provided the first direct evidence that at least a fraction of binary neutron star (BNS) mergers are progenitors of short Gamma-Ray Bursts (GRBs). GRBs are also expected to emit very-high energy (VHE, > 100 GeV) photons, as proven by the recen

Consider the subspace Wn of L2(C, dA) consisting of all weighted polynomials W(z)=P(z)·e-12nQ(z), where P(z) is a holomorphic polynomial of degree at most n- 1 , Q(z) = Q(z, z¯) is a fixed, real-valued function called the “external potential”, and dA=12πidz¯∧dz is normalized Lebesgue measure in the complex plane C. We study large n asymptotics for the reproducing kernel Kn(z, w) of Wn; this depend

Introduction: Etiological diagnosis of neurocognitive disorders of middle-old age relies on biomarkers, although evidence for their rational use is incomplete. A European task force is defining a diagnostic workflow where expert experience fills evidence gaps for biomarker validity and prioritization. We report methodology and preliminary results. Methods: Using a Delphi consensus method supported

Sheep wool was used in the production of textiles across Europe from prehistoric times onwards, but its origins remain unclear. Textiles are rarely preserved in the archaeological record, but further indirect evidence supports their use, such as the study of textile tools, osteology, and terminology. Moreover, new analytical methods, such as protein and DNA analysis, enable the identification of w

This article presents the investigation of two linen shirts which form part of the funerary dress of Bishop Peder Pedersen Winstrup (1605–1679), buried 1680 in Lund Cathedral, southern Sweden. When the grave was opened in 2013, it was discovered that the body had been naturally mummified, and that the funerary dress, including the linen, was well-preserved. Extant Early Modern linen garments are r

Quantitative reconstructions of past land cover are necessary to determine the processes involved in climate-human-land-cover interactions. We present the first temporally continuous and most spatially extensive pollen-based land-cover reconstruction for Europe over the Holocene (last 11g€¯700g€¯calg€¯yrg€¯BP). We describe how vegetation cover has been quantified from pollen records at a 11 spatia

Background: Previous research suggests that interactions between preschool teachers and children in early care and educational contexts can contribute to the child’s positive attachment development and socioemotional adjustment. Objective: Investigate how the transition process to preschool is organized and whether various ways of organizing it may differently influence family–teacher relationship