At present the model of the genetic code (the code of protein biosynthesis) proposed almost 50 years ago by M. Nirenberg and F. Crick has undergone severe erosion. Tactically, it is true that triplicity and the synony...At present the model of the genetic code (the code of protein biosynthesis) proposed almost 50 years ago by M. Nirenberg and F. Crick has undergone severe erosion. Tactically, it is true that triplicity and the synonymous degeneracy are unmistakable. But the Nirenberg-Crick postulate about unambiguous coding of amino acids, i.e., the strategy raises reasonable doubt. The reasons to doubt showed up very early: it turned out that the triplet UUU codes both phenylalanine and leucine, which was inconsistent with the declaration of the unambiguity of the DNA-RNA encoding of amino acids in proteins. On the other hand, the ambiguity automatically stems from the Wobble Hypothesis by F. Crick relating to the wobbling of the third nucleotide in codons, (random, undetermined behavior), which means the 3’-5’ codon-anticodon pair is not involved in the encoding, and represents a “steric crutch”. In fact, amino acids are coded not by triplet, but by doublet of nucleotides in a triplet, according to “Two-out-of-Three” rule by Ulf Lagerkvist. From this perspective, the codon families split into two classes: 32 codon-synonym triplets and 32 codon triplets with undetermined coding functions, that is inherent to one of the 32 codons UUU. These “undetermined” codons have called homonyms. They are ambiguous as they potentially and simultaneously encode two different amino acids, or amino acid and the stop function. However, the ambiguity is overcome in real protein biosynthesis. This is due to the sign orientations of ribosomes within mRNA contexts. This is the way the semantics of the codon-homonyms occur, as an exact analogy of the consciousness work in the human languages, abounding with homonyms. This turn in the understanding of the protein code, as actual text formation, leads to a strong idea of the genome as a quasi-intelligent biocomputer structure of living cells. Ignoring this leads to erroneous and dangerous works of genetic engineering, the most important results are Synthia bacteria with synthetic genome展开更多
A century old methodology for deriving statistical distribution using approximate Stirling’s formulation of the factorial becomes questionable. By avoiding the use of exaggerated approximations, a new picture of the ...A century old methodology for deriving statistical distribution using approximate Stirling’s formulation of the factorial becomes questionable. By avoiding the use of exaggerated approximations, a new picture of the energy distribution of fermions and bosons are presented. Energy distribution among fermions (or bosons) in systems with finite degeneracy are found to be degeneracy dependent. The presented point of view explains, successfully, presence of degeneracy pressure in ultra-cooled Fermi gas and predicts the minimum accessible temperature for finite degeneracy fermions system.展开更多
We achieve a highly degenerate and strongly interacting Fermi gas in a mixture of the two lowest hyperfine states of 6 Li by direct evaporative cooling in a high power crossed optical dipole trap. The trap is loaded f...We achieve a highly degenerate and strongly interacting Fermi gas in a mixture of the two lowest hyperfine states of 6 Li by direct evaporative cooling in a high power crossed optical dipole trap. The trap is loaded from a large atom number magneto-optical trap realized by a laser system of Z5-W intracavity-frequency-doubled light output at 671 nm. With this system, we also demonstrate the production of a molecular Bose-Einstein condensate （reBEC） of 6Li2, and observe the anisotropic expansion of Fermi gases in the so-called BEC-Bardeen-Cooper-Schrieffer crossover regime.展开更多
By coupling with a qubit, we demonstrate that qubit decoherence can unambiguously detect the occurrence of ground-state degeneracy in many-body systems. We first demonstrate universality using the two-band model. Cons...By coupling with a qubit, we demonstrate that qubit decoherence can unambiguously detect the occurrence of ground-state degeneracy in many-body systems. We first demonstrate universality using the two-band model. Consequently, several exemplifications, focused on topological condensed matter systems in one, two, and three dimensions, are presented to validate our proposal. The key point is that qubit decoherence varies significantly when energy bands touch each other at the Fermi surface. In addition, it can partially reflect the degeneracy inside the band. This feature implies that qubit decoherence can be used for reliable diagnosis of ground-state degeneracy.展开更多
文摘At present the model of the genetic code (the code of protein biosynthesis) proposed almost 50 years ago by M. Nirenberg and F. Crick has undergone severe erosion. Tactically, it is true that triplicity and the synonymous degeneracy are unmistakable. But the Nirenberg-Crick postulate about unambiguous coding of amino acids, i.e., the strategy raises reasonable doubt. The reasons to doubt showed up very early: it turned out that the triplet UUU codes both phenylalanine and leucine, which was inconsistent with the declaration of the unambiguity of the DNA-RNA encoding of amino acids in proteins. On the other hand, the ambiguity automatically stems from the Wobble Hypothesis by F. Crick relating to the wobbling of the third nucleotide in codons, (random, undetermined behavior), which means the 3’-5’ codon-anticodon pair is not involved in the encoding, and represents a “steric crutch”. In fact, amino acids are coded not by triplet, but by doublet of nucleotides in a triplet, according to “Two-out-of-Three” rule by Ulf Lagerkvist. From this perspective, the codon families split into two classes: 32 codon-synonym triplets and 32 codon triplets with undetermined coding functions, that is inherent to one of the 32 codons UUU. These “undetermined” codons have called homonyms. They are ambiguous as they potentially and simultaneously encode two different amino acids, or amino acid and the stop function. However, the ambiguity is overcome in real protein biosynthesis. This is due to the sign orientations of ribosomes within mRNA contexts. This is the way the semantics of the codon-homonyms occur, as an exact analogy of the consciousness work in the human languages, abounding with homonyms. This turn in the understanding of the protein code, as actual text formation, leads to a strong idea of the genome as a quasi-intelligent biocomputer structure of living cells. Ignoring this leads to erroneous and dangerous works of genetic engineering, the most important results are Synthia bacteria with synthetic genome
文摘A century old methodology for deriving statistical distribution using approximate Stirling’s formulation of the factorial becomes questionable. By avoiding the use of exaggerated approximations, a new picture of the energy distribution of fermions and bosons are presented. Energy distribution among fermions (or bosons) in systems with finite degeneracy are found to be degeneracy dependent. The presented point of view explains, successfully, presence of degeneracy pressure in ultra-cooled Fermi gas and predicts the minimum accessible temperature for finite degeneracy fermions system.
基金Supported by the National Natural Science Foundation of China under Grant No 11374101the Shanghai Pujiang Program under Grant No 13PJ1402500
文摘We achieve a highly degenerate and strongly interacting Fermi gas in a mixture of the two lowest hyperfine states of 6 Li by direct evaporative cooling in a high power crossed optical dipole trap. The trap is loaded from a large atom number magneto-optical trap realized by a laser system of Z5-W intracavity-frequency-doubled light output at 671 nm. With this system, we also demonstrate the production of a molecular Bose-Einstein condensate （reBEC） of 6Li2, and observe the anisotropic expansion of Fermi gases in the so-called BEC-Bardeen-Cooper-Schrieffer crossover regime.
文摘By coupling with a qubit, we demonstrate that qubit decoherence can unambiguously detect the occurrence of ground-state degeneracy in many-body systems. We first demonstrate universality using the two-band model. Consequently, several exemplifications, focused on topological condensed matter systems in one, two, and three dimensions, are presented to validate our proposal. The key point is that qubit decoherence varies significantly when energy bands touch each other at the Fermi surface. In addition, it can partially reflect the degeneracy inside the band. This feature implies that qubit decoherence can be used for reliable diagnosis of ground-state degeneracy.
