Systematic study of proton radioactivity of spherical proton emitters within various versions of proximity potential formalisms

In this work we present a systematic study of the proton radioactivity half-lives of spherical proton emitters within the Coulomb and proximity potential model. We investigate 28 different versions of the proximity potential formalisms developed for the description of proton radioactivity, $\mathcal{\alpha}$ decay and heavy particle radioactivity. It is found that 21 of them are not suitable to deal with the proton radioactivity, because the classical turning points $r_{\text{in}}$ cannot be obtained due to the fact that the depth of the total interaction potential between the emitted proton and the daughter nucleus is above the proton radioactivity energy. Among the other 7 versions of the proximity potential formalisms, it is Guo2013 which gives the lowest rms deviation in the description of the experimental half-lives of the known spherical proton emitters. We use this proximity potential formalism to predict the proton radioactivity half-lives of 13 spherical proton emitters, whose proton radioactivity is energetically allowed or observed but not yet quantified, within a factor of 3.71.Comment: 10 pages, 5 figures. This paper has been accepted by The European Physical Journal A (in press 2019

Small Molecule Inhibitors of Programmed Cell Death Ligand 1 (PD-L1):A Patent Review (2019–2021)

Introduction: The blockade of immune checkpoints, especially the PD-1/PD-L1 pathway with therapeutic antibodies, has shown success in treating cancers in recent years. Seven monoclonal antibodies (mAbs) targeting PD-1 or PD-L1 have been approved by FDA. However, mAbs exhibit several disadvantages as compared to small molecules such as poor permeation, high manufacturing costs, immunogenicity as well as lacking oral bioavailability. Recently, small-molecule inhibitors targeting PD-L1 have been disclosed with the ability to modulate the PD-1/PD-L1 pathway. Areas covered: The authors reviewed small molecules targeting PD-L1 that block the PD-1/PD-L1 protein–protein interaction for the treatment of various diseases. Expert opinion: Compared with mAbs, PD-1/PD-L1 small-molecule inhibitors show several advantages such as improved tissue penetration, low immunogenicity, well-understood formulation and lower manufacturing costs. They can serve as complementary or synergistically with mAbs for immune therapy. However, at this time most of the reported inhibitors are still inferior to therapeutic antibodies in their inhibitory activities due to smaller molecular weight. Therefore, better small molecules need to be developed to improve their potencies. Moreover, although several PD-L1 small-molecule inhibitors have shown excellent preclinical results, their safety and efficacy in the clinic still awaits further validation

The First Sinomastodon (Gomphotheriidae, Proboscidea) Skull From the Quaternary in China

The first Sinomastodon (Gomphotheriidae, Proboscidea) skull of the Early Pleistocene, collected from the Renzidong Cave deposits in Anhui Province, Eastern China, is described here as S. jiangnanensis sp. nov. As the only brevirostrine trilophodont gomphotheriid known from the Old World, Sinomastodon was mainly indigenous to China from the Early Pliocene to the Pleistocene. Compared with a few single Pleistocene teeth previously found in China, S. jiangnanensis sp. nov. is represented by a relatively complete skull, mandible and dentition, which is the first discovery of a Quaternary Sinomastodon skull from China. With a brevirostrine, elephant-like skull, no lower tusks, and simple bunodont and trilophodont intermediate molars, the new species is morphologically distinct from other gomphotheres and should belong to the genus Sinomastodon. The new species is more progressive than S. hanjiangensis and the Pliocene type species S. intermedius in its skull and mandible morphology, but is evidently more primitive than the Pleistocene S. yangziensis in its molar morphology. The faunal analysis suggests that the emergence of S. jiangnanensis sp. nov. in Jiangnan area and its southward migration may have been related to a cooling event at the beginning of the Quaternary in Eastern China

The First Sinomastodon (Gomphotheriidae, Proboscidea) Skull From the Quaternary in China

The first Sinomastodon (Gomphotheriidae, Proboscidea) skull of the Early Pleistocene, collected from the Renzidong Cave deposits in Anhui Province, Eastern China, is described here as S. jiangnanensis sp. nov. As the only brevirostrine trilophodont gomphotheriid known from the Old World, Sinomastodon was mainly indigenous to China from the Early Pliocene to the Pleistocene. Compared with a few single Pleistocene teeth previously found in China, S. jiangnanensis sp. nov. is represented by a relatively complete skull, mandible and dentition, which is the first discovery of a Quaternary Sinomastodon skull from China. With a brevirostrine, elephant-like skull, no lower tusks, and simple bunodont and trilophodont intermediate molars, the new species is morphologically distinct from other gomphotheres and should belong to the genus Sinomastodon. The new species is more progressive than S. hanjiangensis and the Pliocene type species S. intermedius in its skull and mandible morphology, but is evidently more primitive than the Pleistocene S. yangziensis in its molar morphology. The faunal analysis suggests that the emergence of S. jiangnanensis sp. nov. in Jiangnan area and its southward migration may have been related to a cooling event at the beginning of the Quaternary in Eastern China

Field emission enhancement of Au-Si nano-particle-decorated silicon nanowires

Au-Si nano-particle-decorated silicon nanowire arrays have been fabricated by Au film deposition on silicon nanowire array substrates and then post-thermal annealing under hydrogen atmosphere. Field emission measurements illustrated that the turn-on fields of the non-annealed Au-coated SiNWs were 6.02 to 7.51 V/μm, higher than that of the as-grown silicon nanowires, which is about 5.01 V/μm. Meanwhile, after being annealed above 650°C, Au-Si nano-particles were synthesized on the top surface of the silicon nanowire arrays and the one-dimensional Au-Si nano-particle-decorated SiNWs had a much lower turn-on field, 1.95 V/μm. The results demonstrated that annealed composite silicon nanowire array-based electron field emitters may have great advantages over many other emitters