Intra-Site Structure of the Early Ahmarian Site of Al-Ansab 1, AH 1 (Jordan)

The Early Ahmarian represents an Early Upper Palaeolithic cultural unit, which spans throughout the Levant to the Sinai Peninsula. At least 40 sites belong to this unit. Both open-air and cave sites provide different amounts of archaeological material at various spatial resolutions. The team of the Collaborative Research Centre 806 “Our Way to Europe” excavated the site of Al-Ansab 1, Wadi Sabra, since 2009. The site provides one of the largest lithic assemblages of the Early Ahmarian. Analysis of intra-site distributions and patterns has been conducted for a small number of sites, providing scarce information on the spatial makeup of Early Ahmarian occupation layers. The internal structure testifies to repeated settlement without task specialisation. While this has been described for the sites on the Sinai Peninsula, the situation has been unclear for locations placed in the escarpments of the Transjordanian Highlands. At Al-Ansab 1, we can observe the repeated, relatively ephemeral occupation of a specific location in the Wadi Sabra for the execution of various tasks such as processing of faunal elements and raw material exploitation. Our results correlate to a pattern of mobility observable at other Early Ahmarian sites such as Abu Noshra II. These sites are usually attributed to relatively small and highly mobile bands of hunter-gatherers. Analysing these patterns of intra-site and regional spatial behaviour in the context of environmental patterning highlights potential external drivers to the expression of human occupation at sites such as Al-Ansab 1, archaeological horizon 1.

La Embajada de Estados Unidos en Madrid y la arquitectura moderna de posguerra

Between 1950 and 1955, the United States Embassy in Madrid was planned and built on the former Huerta de Cánovas estate. This building has already been studied in its pioneering and controversial implementation in the Paseo de la Castellana. Some reference has also been made to the link between Mariano Garrigues, the Spanish architect who directed the construction works, and North America. This article goes deeper, however, into some issues that have not yet been explained; in particular, the aim is to reveal how a prototype of the International Style was adapted to local circumstances. For this purpose, both foreign sources related to the North American architectural office (Foreign Building Operations, FBO) and local sources related to the Spanish architect are used. Likewise, graphic analyses are carried out to complement the available information and to focus on aspects of the site, construction, and spatial organization. The analysis is not limited to the general aspects of the building. Its link with post-war modern architecture is increased with considerations of site, structure and furnishing. The final assessment falls somewhere between absolute adherence to modern ideals and local mediation.

Crystallization of 3-hexulose-6-phosphate synthase

The crystal structures can reveal detailed information about the overall structure, active site structure, and functional mechanism of enzymes. This study focused on the crystallization of 3-hexulose-6-phosphate synthase from Methylomonas aminofaciens 77a, to produce higher resolution crystals for precise structural characterization. 3-Hexulose-6-phosphate synthase is from Methylomonas aminofaciens 77a (EC 4.1.2.43). It belongs to the orotidine 5'-monophosphate decarboxylase superfamily, and acts as a key enzyme for a ribulose-monophosphate cycle of formaldehyde fixation and detoxification. 3-Hexulose-6-phosphate synthase catalyzes the aldol condensation of formaldehyde with D-ribulose-5-phosphate. For the maximum activity, 3-hexulose-6-phosphate synthase requires Mg2+ or Mn2+ as ligands. MaHPS crystallized at the concentration of 7 mg/mL and conditions consisting of 0.2 M MgCl2, 18% PEG 3350 at pH = 7.0.

POTENTIAL OF TAIPING CITY AS A HERITAGE TOURISM ATTRACTION IN PERAK

The existence of various monuments and buildings built since the early 1900s needs to be preserved as heritage tourist attractions. Taiping is one of the cities that has the potential to be promoted as a popular heritage tourism destination in Perak. To that end, the purpose of this study was to identify the types and categories of various buildings and monuments that have the potential to be used as heritage tourism attractions in the city; by examining the perceptions of local people on the potential of Taiping and to suggest strategies and measures preserve and conserve the heritage of the city. This study uses a mixture of quantitative and qualitative methods. The results show that there are various monuments and old buildings being the potential to be heritage tourist attractions, including Rock Garden, Chinese Pagoda, F.M.S Station, Peking Hotel, railway station, Rest House 1894, clock tower, Silver Museum, and First Galeria. Among the things that need to be given attention in order to make Taiping a heritage tourist attraction are the level of cleanliness and cheerfulness of the environment, provision of basic facilities, maintenance and conservation of heritage site structure, promotional aspect, and security level in the area. Various strategies and measures are proposed to make Taiping a popular heritage tourism destination in Perak in particular and Malaysia in general.

Iron-Imprinted Single-Atomic Site Catalyst-Based Nanoprobe for Detection of Hydrogen Peroxide in Living Cells

Fe-based single-atomic site catalysts (SASCs), with the natural metalloproteases-like active site structure, have attracted widespread attention in biocatalysis and biosensing. Precisely, controlling the isolated single-atom Fe-N-C active site structure is crucial to improve the SASCs’ performance. In this work, we use a facile ion-imprinting method (IIM) to synthesize isolated Fe-N-C single-atomic site catalysts (IIM-Fe-SASC). With this method, the ion-imprinting process can precisely control ion at the atomic level and form numerous well-defined single-atomic Fe-N-C sites. The IIM-Fe-SASC shows better peroxidase-like activities than that of non-imprinted references. Due to its excellent properties, IIM-Fe-SASC is an ideal nanoprobe used in the colorimetric biosensing of hydrogen peroxide (H2O2). Using IIM-Fe-SASC as the nanoprobe, in situ detection of H2O2 generated from MDA-MB-231 cells has been successfully demonstrated with satisfactory sensitivity and specificity. This work opens a novel and easy route in designing advanced SASC and provides a sensitive tool for intracellular H2O2 detection.

Highly selective and robust single-atom catalyst Ru1/NC for reductive amination of aldehydes/ketones

Single-atom catalysts (SACs) have emerged as a frontier in heterogeneous catalysis due to the well-defined active site structure and the maximized metal atom utilization. Nevertheless, the robustness of SACs remains a critical concern for practical applications. Herein, we report a highly active, selective and robust Ru SAC which was synthesized by pyrolysis of ruthenium acetylacetonate and N/C precursors at 900 °C in N2 followed by treatment at 800 °C in NH3. The resultant Ru1-N3 structure exhibits moderate capability for hydrogen activation even in excess NH3, which enables the effective modulation between transimination and hydrogenation activity in the reductive amination of aldehydes/ketones towards primary amines. As a consequence, it shows superior amine productivity, unrivalled resistance against CO and sulfur, and unexpectedly high stability under harsh hydrotreating conditions compared to most SACs and nanocatalysts. This SAC strategy will open an avenue towards the rational design of highly selective and robust catalysts for other demanding transformations.

Insights into the Structural Dynamics of Pt/CeO2 Single-Site Catalysts during CO Oxidation

Despite their high atomic dispersion, single site catalysts with Pt supported on CeO2 were found to have a low activity during oxidation reactions. In this study, we report the behavior of Pt/CeO2 single site catalyst under more complex gas mixtures, including CO, C3H6 and CO/C3H6 oxidation in the absence or presence of water. Our systematic operando high-energy resolution-fluorescence-detected X-ray absorption near-edge structure (HERFD-XANES) spectroscopic study combined with multivariate curve resolution with alternating least squares (MCR-ALS) analysis identified five distinct states in the Pt single site structure during CO oxidation light-off. After desorption of oxygen and autoreduction of Pt4+ to Pt2+ due to the increase of temperature, CO adsorbs and reduces Pt2+ to Ptδ+ and assists its migration with final formation of Ptx+ clusters. The derived structure–activity relationships indicate that partial reduction of Pt single sites is not sufficient to initiate the conversion of CO. The reaction proceeds only after the regrouping of several noble metal atoms in small clusters, as these entities are probably able to influence the mobility of the oxygen at the interface with ceria.

Highly Sensitive Fluorescent Detection of Acetylcholine Based on the Enhanced Peroxidase-Like Activity of Histidine Coated Magnetic Nanoparticles

Inspired by the active site structure of natural horseradish peroxidase having iron as a pivotal element with coordinated histidine residues, we have developed histidine coated magnetic nanoparticles (His@MNPs) with relatively uniform and small sizes (less than 10 nm) through one-pot heat treatment. In comparison to pristine MNPs and other amino acid coated MNPs, His@MNPs exhibited a considerably enhanced peroxidase-imitating activity, approaching 10-fold higher in catalytic reactions. With the high activity, His@MNPs then were exploited to detect the important neurotransmitter acetylcholine. By coupling choline oxidase and acetylcholine esterase with His@MNPs as peroxidase mimics, target choline and acetylcholine were successfully detected via fluorescent mode with high specificity and sensitivity with the limits of detection down to 200 and 100 nM, respectively. The diagnostic capability of the method is demonstrated by analyzing acetylcholine in human blood serum. This study thus demonstrates the potential of utilizing His@MNPs as peroxidase-mimicking nanozymes for detecting important biological and clinical targets with high sensitivity and reliability.

Public Baseline and shared response structures support the theory of antibody repertoire functional commonality

The naïve antibody/B-cell receptor (BCR) repertoires of different individuals ought to exhibit significant functional commonality, given that most pathogens trigger an effective antibody response to immunodominant epitopes. Sequence-based repertoire analysis has so far offered little evidence for this phenomenon. For example, a recent study estimated the number of shared (‘public’) antibody clonotypes in circulating baseline repertoires to be around 0.02% across ten unrelated individuals. However, to engage the same epitope, antibodies only require a similar binding site structure and the presence of key paratope interactions, which can occur even when their sequences are dissimilar. Here, we search for evidence of geometric similarity/convergence across human antibody repertoires. We first structurally profile naïve (‘baseline’) antibody diversity using snapshots from 41 unrelated individuals, predicting all modellable distinct structures within each repertoire. This analysis uncovers a high (much greater than random) degree of structural commonality. For instance, around 3% of distinct structures are common to the ten most diverse individual samples (‘Public Baseline’ structures). Our approach is the first computational method to find levels of BCR commonality commensurate with epitope immunodominance and could therefore be harnessed to find more genetically distant antibodies with same-epitope complementarity. We then apply the same structural profiling approach to repertoire snapshots from three individuals before and after flu vaccination, detecting a convergent structural drift indicative of recognising similar epitopes (‘Public Response’ structures). We show that Antibody Model Libraries derived from Public Baseline and Public Response structures represent a powerful geometric basis set of low-immunogenicity candidates exploitable for general or target-focused therapeutic antibody screening.