Non-precious metal single-atom catalysts (NPM-SACs) with unique electronic structures and coordination environments have gained much attention in electrocatalysis owing to their low cost, high atomic utilization, performance. NPM-SACs on carbon support (NPM-SACs/CS) are promising because of the substrate a large surface area, excellent electrical conductivity, chemical stability...

The emergence of single atom sites as a frontier research area in catalysis has sparked extensive academic and industrial interest, especially for energy, environmental chemicals production processes. Single catalysts (SACs) have shown remarkable performance variety catalytic reactions, demonstrating high selectivity to the products long lifespan, stability more importantly atomic metal utiliza...

The unique structures of single-atom catalysts (SACs) endow them with widespread energy applications. This review summarized the achievements multifarious synchrotron-radiation characterization methods in studying local environments SACs.

This paper investigates an idea that was put forward (and hinted at in Fitch, 2000) by Tecumseh Fitch at the Cradle of Language conference in Stellenbosch, South Africa. The idea is that air sacs may have played an important role in early hominid vocalizations. Many other primates have air sacs, notably chimpanzees, gorillas and orangutans. It is therefore likely that our latest common ancestor...

—The vertebrae of sauropod dinosaurs are characterized by complex architecture involving laminae, fossae, and internal chambers of various shapes and sizes. These structures are interpreted as osteological correlates of a system of air sacs and pneumatic diverticula similar to that of birds. In extant birds, diverticula of the cervical air sacs pneumatize the cervical and anterior thoracic vert...

A possible function of laryngeal air sacs in apes and gibbons was investigated by examining the relationships between air sac distribution, call rate, call duration and body weight in a phylogenetic context. The results suggest that lack of sacs in the smaller gibbons and in humans is a derived feature. Call parameters in primates, such as rate and duration, scaled to resting breathing rate (an...

The Shortest Approximate Common Superstring (SACS) problem is : Given a set of strings f={w1, w2, ... , wn}, where no wi is an approximate substring of wj, i ≠ j, find a shortest string Sa, such that, every string of f is an approximate substring of Sa. When the number of the strings n>2, the SACS problem becomes NP-complete. In this paper, we present a greedy approximation SACS algorithm. Our ...

Electrochemical water splitting is regarded as the most promising approach to produce hydrogen. However, sluggish electrochemical reactions occurring at anode and cathode, namely, oxygen evolution reaction (OER) hydrogen (HER), respectively, consume a tremendous amount of energy, seriously hampering its wide application. Recently, single-atom catalysts (SACs) have been proposed effectively enha...

AIMS The present study aimed to determine whether yolk sacs with abnormal sonographic appearance are associated with adverse perinatal outcomes in both early and late gestation. MATERIAL AND METHODS A total of 305 viable singleton pregnancies with gestational age of 6 to 9 weeks were prospectively evaluated with respect to perinatal outcomes and sonographic characteristics of the yolk sacs. ...

The lymphatic vasculature drains lymph fluid from the tissue spaces of most organs and returns it to the blood vasculature for recirculation. Before reaching the circulatory system, antigens and pathogens transported by the lymph are trapped by the lymph nodes. As proposed by Florence Sabin more than a century ago and recently validated, the mammalian lymphatic vasculature has a venous origin a...