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Topic Review
Palladium-Plated Copper Bonding Wire
Wire-bonding technology is the most commonly used chip interconnection technology in microelectronic packaging. Metal bonding wire is the key material for wire bonding and plays an important role in the reliability of electronic devices. Palladium-plated copper (PdCu) bonding wire has been widely used because of its low cost, good electrical and thermal conductivity, the fact that it is not easy to oxidize, and its high reliability.
  • 640
  • 21 Aug 2023
Topic Review
Palladium-Catalyzed Carboxylation Reactions
The efficient incorporation of carbon dioxide into an organic substrate (carboxylation) under catalytic conditions to give high value added molecules is one of the most important and fascinating areas of current organic synthesis. Carbon dioxide is a nonflammable, inexpensive and largely available C-1 feedstock. In fact, it allows converting an important waste (it is well known that carbon dioxide is produced in enormous amounts from the combustion of fossil fuels for the production of energy) into a variety of useful compounds, which can find application as fuels or in the pharmaceutical or material fields.
  • 936
  • 06 Jan 2022
Topic Review
Packaging Materials
The entry packaging materials is intended to summarize the recent progress in the work of fractal theory in packaging material to provide important insights into applied research on fractal in packaging materials. The fractal analysis methods employed for inorganic materials such as metal alloys and ceramics, polymers, and their composites are reviewed from the aspects of fractal feature extraction and fractal dimension calculation methods. Through the fractal dimension of packaging materials and the fractal in their preparation process, the relationship between the fractal characteristic parameters and the properties of packaging materials is discussed. The fractal analysis method can qualitatively and quantitatively characterize the fractal characteristics, microstructure, and properties of a large number of various types of packaging materials. 
  • 953
  • 06 Apr 2021
Topic Review
Paan
Paan (from Sanskrit: पर्ण, romanized: parṇá, lit. leaf, cognate with English fern) is a preparation combining betel leaf with areca nut widely consumed throughout South Asia and East Asia (mainly Taiwan). It is chewed for its stimulant effects. After chewing, it is either spat out or swallowed. Paan has many variations. Slaked lime (chuna) paste is commonly added to bind the leaves. Some preparations in the Indian subcontinent include katha paste or mukhwas to freshen the breath. Magahi paan is an expensive variety of betel which is grown in Aurangabad, Gaya and Nalanda districts of central Bihar. It is non-fibrous, sweeter, tastier and the softest of the lot. The origin and diffusion of betel chewing originates from and is closely tied to the Neolithic expansion of the Austronesian peoples. It was spread to the Indo-Pacific during prehistoric times, reaching Near Oceania at 3,400 to 3,000 BP; South India and Sri Lanka by 3,500 BP; Mainland Southeast Asia by 3,000 to 2,500 BP; Northern India by 1500 BP; and Madagascar by 600 BP. From India, it was also spread westwards to Persia and the Mediterranean. Paan (under a variety of names) is also consumed in many other Asian countries and elsewhere in the world by some Asian emigrants, with or without tobacco. It can be an addictive and stimulating formulation with adverse health effects, both with and without tobacco. The spit from chewing betel nuts, known as "buai pekpek" in Papua New Guinea, is often considered an eyesore. Because of this, many places have banned selling and chewing "buai".
  • 2.1K
  • 30 Sep 2022
Topic Review
P-Type Mn3O4 Nanosystems
Among oxide semiconductors, p-type Mn3O4 systems have been exploited in chemo-resistive sensors for various analytes, but their use in the detection of H2, an important, though flammable, energy vector, has been scarcely investigated. Herein, we report for the first time on the plasma assisted-chemical vapor deposition (PA-CVD) of Mn3O4 nanomaterials, and on their on-top functionalization with Ag and SnO2 by radio frequency (RF)-sputtering, followed by air annealing. The obtained Mn3O4-Ag and Mn3O4-SnO2 nanocomposites were characterized by the occurrence of phase-pure tetragonal α-Mn3O4 (hausmannite) and a controlled Ag and SnO2 dispersion. The system functional properties were tested towards H2 sensing, yielding detection limits of 18 and 11 ppm for Mn3O4-Ag and Mn3O4-SnO2 specimens, three orders of magnitude lower than the H2 explosion threshold. These performances were accompanied by responses up to 25% to 500 ppm H2 at 200 °C, superior to bare Mn3O4, and good selectivity against CH4 and CO2 as potential interferents. A rationale for the observed behavior, based upon the concurrence of built-in Schottky (Mn3O4/Ag) and p-n junctions (Mn3O4/SnO2), and of a direct chemical interplay between the system components, is proposed to discuss the observed activity enhancement, which paves the way to the development of gas monitoring equipments for safety end-uses.
  • 839
  • 27 Jan 2021
Topic Review
P-Glycoprotein Transporter Modelling
ATP-binding cassette (ABC) transporters play a critical role in both drug bioavailability and toxicity, and with the discovery of the P-glycoprotein (P-gp), this became even more evident, as it plays an important role in preventing intracellular accumulation of toxic compounds. Intensive studies have been conducted to find new therapeutic molecules to reverse the phenomenon of multidrug resistance (MDR), that research has found is often associated with overexpression of P-gp, the most extensively studied drug efflux transporter; in MDR, therapeutic drugs are prevented from reaching their targets due to active efflux from the cell. The development of P-gp inhibitors is recognized as a good way to reverse this type of MDR, which has been the subject of extensive studies over the past few decades. Despite the progress made, no effective P-gp inhibitors to reverse multidrug resistance are yet on the market, mainly because of their toxic effects. Computational studies can accelerate this process, and in silico models such as quantitative structure-activity relationship (QSAR) models that predict the activity of compounds associated with P-gp (or analogous transporters) are of great value in the early stages of drug development, along with molecular modelling methods, which provide a way to explain how these molecules interact with the ABC transporter. 
  • 453
  • 21 Feb 2023
Topic Review
Oxygen Reduction Reaction Catalysts Derived from Biopolymers
Due to the limited reaction rate of the oxygen reduction reaction (ORR), it is considered as a limiting factor in the performance of fuel cells and metal-air batteries. Platinum is considered the benchmark catalyst for ORR; however, the scarcity of platinum, its high price, the drift phenomenon, its insufficient durability, and its susceptibility to gas poisoning are the reasons for the constant search for new ORR catalysts. Carbon-based catalysts show exceptional promise in this respect considering economic profitability and activity, and, in addition, they have favorable conductivity and often a large specific surface area.
  • 426
  • 13 Feb 2023
Topic Review
Oxonium Derivatives of nido-Carborane
Recent decades have demonstrated a growing interest in the chemistry of 7,8-dicarba-nido-undecaborante anion (nido-carborane) due to the wide possibilities of its application from medicine to catalysis. One of the main approaches to the modification of nido-carborane cluster is the ring-opening reactions of its cyclic oxonium derivatives with various nucleophiles, which opens practically unlimited prospects for the incorporation of nido-carborane into various macro- and biomolecules.
  • 529
  • 10 Feb 2022
Topic Review
Oxide Bioceramic Composites
Ceramic composites based on alumina and zirconia have found a wide field of application in the present century in orthopedic joint replacements, and their use in dentistry is spreading. The development of this class of bioceramic composites was started in the 1980s, but the first clinical applications of the total hip replacement joint were introduced in the market only in the early 2000s. Since then, several composite systems were introduced in joint replacements. These materials are classified as Zirconia-Toughened Alumina if alumina is the main component or as Alumina-Toughened Zirconia when zirconia is the main component. In addition, some of them may contain a third phase based on strontium exa-aluminate. The flexibility in device design due to the excellent mechanical behavior of this class of bioceramics results in a number of innovative devices for joint replacements in the hip, the knee, and the shoulder, as well in dental implants.
  • 473
  • 22 Sep 2021
Topic Review
Oxidative Strong Metal–Support Interactions
Oxidative Strong Metal–Support Interactions (OMSI) can be defined as a phenomenon occurring in a supported metal catalyst that is triggered by oxidative (or non-reductive) conditions with the typical features resembling that of SMSI, including 1) small-molecule of CO or H2 adsorption on metal will be significantly suppressed, 2) the support would encapsulate metal particles, 3) electron transfer from metal to the support, and 4) a reversal of the above phenomena following reduction treatment.
  • 1.1K
  • 27 Aug 2021
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