Topic Review
Β-lactam Antibiotic
β-lactam antibiotics (beta-lactam antibiotics) are antibiotics that contain a beta-lactam ring in their molecular structure. This includes penicillin derivatives (penams), cephalosporins and cephamycins (cephems), monobactams, carbapenems and carbacephems. Most β-lactam antibiotics work by inhibiting cell wall biosynthesis in the bacterial organism and are the most widely used group of antibiotics. Until 2003, when measured by sales, more than half of all commercially available antibiotics in use were β-lactam compounds. The first β-lactam antibiotic discovered, penicillin, was isolated from a rare variant of Penicillium notatum (since renamed Penicillium chrysogenum). Bacteria often develop resistance to β-lactam antibiotics by synthesizing a β-lactamase, an enzyme that attacks the β-lactam ring. To overcome this resistance, β-lactam antibiotics can be given with β-lactamase inhibitors such as clavulanic acid.
  • 576
  • 24 Nov 2022
Topic Review
Zn-Pb Metallurgical Slags as Source of Metal Recovery
The mineralogical and chemical characteristics of zinc and lead smelting slags are presented, with particular reference to the slags formed during the simultaneous production of Zn and Pb by the Imperial Smelting Process. These slags, because of the presence of many metals in their composition, mainly in the form of crystalline phases, are a valuable source for their extraction. Slags from Zn-Pb metallurgy are processed on an industrial scale using pyrometallurgical and hydrometallurgical methods, alongside which a number of experiments conducted to recover metals as efficiently as possible, including bioleaching experiments.
  • 108
  • 03 Jan 2024
Topic Review
Zeolitic Imidazolate Framework
Zeolitic imidazolate frameworks (ZIFs) are a class of metal-organic frameworks that are topologically isomorphic with zeolites. ZIFs are composed of tetrahedrally-coordinated transition metal ions (e.g. Fe, Co, Cu, Zn) connected by imidazolate linkers. Since the metal-imidazole-metal angle is similar to the 145° Si-O-Si angle in zeolites, ZIFs have zeolite-like topologies. As of 2010, 105 ZIF topologies have been reported in the literature. Due to their robust porosity, resistance to thermal changes, and chemical stability, ZIF’s are being investigated for applications such as carbon capture.
  • 1.1K
  • 25 Oct 2022
Topic Review
Xeno Nucleic Acid
Xeno nucleic acid (XNA) is a synthetic alternative to the natural nucleic acids DNA and RNA as information-storing biopolymers that differs in the sugar backbone. As of 2011, at least six types of synthetic sugars have been shown to form nucleic acid backbones that can store and retrieve genetic information. Research is now being done to create synthetic polymerases to transform XNA. The study of its production and application has created a field known as xenobiology. Although the genetic information is still stored in the four canonical base pairs (unlike other nucleic acid analogues), natural DNA polymerases cannot read and duplicate this information. Thus the genetic information stored in XNA is "invisible" and therefore useless to natural DNA-based organisms.
  • 2.2K
  • 01 Nov 2022
Topic Review
Workflow of Materials Machine Learning for Perovskite Materials
Perovskite materials have been one of the most important research objects in materials science due to their excellent photoelectric properties as well as correspondingly complex structures. Machine learning (ML) methods have been playing an important role in the design and discovery of perovskite materials, while feature selection as a dimensionality reduction method has occupied a crucial position in the ML workflow.
  • 403
  • 26 Apr 2023
Topic Review
Wood Antimicrobial Behavior Test Method
Some wood species have antimicrobial properties and a variety of methods are used to investigate them. For testing the effect of antimicrobial compounds, direct and indirect methods are used. Meanwhile, the survival of microbes is also tested on surfaces (or material in contact with microbes) to validate the safety of surfaces.
  • 853
  • 29 Oct 2020
Topic Review
WO3 and Ionic Liquids -2
The possibility of using an IL to enhance WO3 dispersion on an inorganic support, ensuring the formation of composites with a very large number of exposed catalytic sites, is reported. In addition, in some cases the IL was demonstrated to be able to direct the morphology of WO3 particles.
  • 734
  • 29 Oct 2020
Topic Review
WO3 and Ionic Liquids -1
Although only recently ILs started to be used to enhance the performances of metal oxides based electrochemical gas sensors (with reference, in particular, to WO3 based sensors), the recognition of their role has been clearly asserted. In fact, not only ILs heavily influence the structure of WO3 nanoparticles when used in the synthetic step (nanoplates, nanorods, nanospheres, etc.), but their residues eventually present on nanoparticles surface can improve the sensed gas adsorption, thus yielding better performances. 
  • 657
  • 29 Oct 2020
Topic Review
William Freer Bale
William Freer Bale (1911 – 28 June 1982), biophysicist and educator, held key positions in the Atomic Energy Project at the University of Rochester. Pioneer in the study of radon exposure to miners.
  • 322
  • 10 Oct 2022
Topic Review
Westinghouse Lamp Plant
Coordinates: 40°46′53″N 74°11′45″W / 40.78137°N 74.19592°W / 40.78137; -74.19592 The Westinghouse Lamp Plant located in Bloomfield, New Jersey, was one of the lamp manufacturing plants of Westinghouse Electric Corporation. The plant had a major involvement in supplying uranium metal for the world's first self-sustaining chain reaction in Chicago (Chicago Pile-1) in the early phase of the Manhattan Project to create the first atomic bomb.
  • 392
  • 24 Nov 2022
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