Some gamma-ray bursts (GRBs) have a tera-electron volt (TeV) afterglow, but the early onset of this has not been observed. We report observations with the Large High Altitude Air Shower Observatory ...(LHAASO) of the bright GRB 221009A, which serendipitously occurred within the instrument's field of view. More than 64,000 photons >0.2 TeV were detected within the first 3000 seconds. The TeV flux began several minutes after the GRB trigger and then rose to a peak ~10 seconds later. This was followed by a decay phase, which became more rapid ~650 seconds after the peak. We interpret the emission using a model of a relativistic jet with half-opening angle of ~0.8°. This is consistent with the core of a structured jet and could explain the high isotropic energy of this GRB.
Abstract
Topological superconductors (TSCs) are unconventional superconductors with bulk superconducting gap and in-gap Majorana states on the boundary that may be used as topological qubits for ...quantum computation. Despite their importance in both fundamental research and applications, natural TSCs are very rare. Here, combining state of the art synchrotron and laser-based angle-resolved photoemission spectroscopy, we investigated a stoichiometric transition metal dichalcogenide (TMD), 2M-WS
2
with a superconducting transition temperature of 8.8 K (the highest among all TMDs in the natural form up to date) and observed distinctive topological surface states (TSSs). Furthermore, in the superconducting state, we found that the TSSs acquired a nodeless superconducting gap with similar magnitude as that of the bulk states. These discoveries not only evidence 2M-WS
2
as an intrinsic TSC without the need of sensitive composition tuning or sophisticated heterostructures fabrication, but also provide an ideal platform for device applications thanks to its van der Waals layered structure.
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A laminate structure with a nanostructured Cu–10Zn layer sandwiched between two coarse-grained Cu layers was produced by high-pressure torsion, rolling and annealing. Sharp interlayer ...interfaces with sufficient bonding strength were developed. Mechanical incompatibility between different layers during tensile deformation produced high strain hardening, which led to a tensile ductility higher than prediction by the rule-of-mixture. These observations provide insights into the architectural design and deformation studies of materials with gradient and laminate structures.
We demonstrate, both theoretically and experimentally, that cation vacancy can be the origin of ferromagnetism in intrinsic dilute magnetic semiconductors. The vacancies can be controlled to tune the ...ferromagnetism. Using Li-doped ZnO as an example, we found that while Li itself is nonmagnetic, it generates holes in ZnO, and its presence reduces the formation energy of Zn vacancy, and thereby stabilizes the zinc vacancy. Room temperature ferromagnetism with p type conduction was observed in pulsed laser deposited ZnO:Li films with certain doping concentration and oxygen partial pressure.
The c-Jun N-terminal kinases (JNKs) constitute one of the three major types of mitogen-activated protein kinases. Previous studies showed that JNK mediates multiple signaling transduction pathways ...implicated in cell proliferation, differentiation, inflammation, stress response and apoptosis in mammals. In the present study, we use goldfish as a model system and demonstrate that JNK kinases are necessary to promote embryonic survival and regulate eye development in vertebrates. During goldfish development, JNK1 and JNK2 are expressed at every stage from cleavage to hatching larvae. JNK3 is turned on at the gastrulation stage and then expressed at similar level to that of JNK2. JNK1 activity remains slightly fluctuated during different developmental stages. Inhibition of JNK activity caused massive apoptosis of blastula cells and significant death of goldfish embryos, which are associated with altered expression of the anti-apoptotic regulator, Mcl-1 and the proapoptotic regulator, Bak. These results provide novel information regarding the mechanisms by which JNKs promote embryonic survival. In addition, the embryos that survived inhibition of JNK activity displayed severe phenotype in the eye with clear microphthalmia and lens coloboma. To confirm that the observed phenotype is derived from JNK activity deficiency, we expressed JNK dominant negative mutant (DNM-JNK) in goldfish. Expression of DNM-JNK also caused similar phenotypes with altered expression of pax-6, Sox-2 and β-crystallin. Together, our results demonstrate that JNKs play important roles in promoting survival of vertebrate embryos and regulating development of vertebrate eye.
Background
The aim of this study was to evaluate whether adjuvant chemotherapy is associated with improved survival in patients with resectable gastric neuroendocrine carcinomas (G‐NECs) or mixed ...adenoneuroendocrine carcinomas (G‐MANECs).
Methods
The study included patients with G‐NECs or G‐MANECs who underwent surgery in one of 21 centres in China between 2004 and 2016. Propensity score matching analysis was used to reduce selection bias, and overall survival (OS) in different treatment groups was estimated by the Kaplan–Meier method.
Results
In total, 804 patients with resectable G‐NECs or G‐MANECs were included, of whom 490 (60·9 per cent) received adjuvant chemotherapy. After propensity score matching, OS in the chemotherapy group was similar to that in the no‐chemotherapy group. Among patients with G‐NECs, survival in the fluorouracil (5‐FU)‐based chemotherapy group and the non‐5‐FU‐based chemotherapy group was similar to that in the no‐chemotherapy group. Similarly, etoposide plus cisplatin or irinotecan plus cisplatin was not associated with better OS in patients with G‐NECs. Among patients with G‐MANECs, OS in the non‐5‐FU‐based chemotherapy group was worse than that in the no‐chemotherapy group. Patients with G‐MANECs did not have better OS when platinum‐based chemotherapy was
used.
Conclusion
There was no survival benefit in patients who received adjuvant chemotherapy for G‐NECs or G‐MANECs.
Antecedentes
El objetivo de este estudio fue evaluar si la quimioterapia adyuvante mejoraba la supervivencia en pacientes con carcinomas gástricos resecables neuroendocrinos (gastric neuroendocrine carcinomas, G‐NECs) y carcinomas adenoneuroendocrinos mixtos (mixed adenoneuroendocrine carcinomas, G‐MANECs).
Métodos
Se incluyeron pacientes con G‐NECs y G‐MANECs tratados quirúrgicamente en 21 centros en China entre 2004 y 2016. Se utilizó un análisis de emparejamiento por puntaje de propensión para reducir el sesgo de selección y el método de Kaplan‐Meier para estimar la supervivencia global (overall survival, OS) de los pacientes en los diferentes grupos de tratamiento.
Resultados
En total, se incluyeron en el estudio 804 pacientes con G‐NECs y G‐MANECs resecables y 490 pacientes (60,9%) recibieron quimioterapia adyuvante. Después del emparejamiento por puntaje de propensión, la OS del grupo con quimioterapia fue similar a la del grupo sin quimioterapia. En los pacientes con G‐NECs, la supervivencia en los grupos con quimioterapia basada en 5‐FU (fluorouracilo) y de quimioterapia sin 5‐FU fue similar a la del grupo sin quimioterapia. Asimismo, la combinación de etopósido y cisplatino o de irinotecán y cisplatino no se asoció con una mejor OS en pacientes con G‐NECs. En pacientes con G‐MANECs, la OS del grupo con quimioterapia sin 5‐FU fue peor que la del grupo sin quimioterapia. Los pacientes con G‐MANECs no presentaron una mejor OS cuando se administró quimioterapia basada en platinos.
Conclusión
La administración de quimioterapia adyuvante en pacientes con G‐NECs y G‐MANECs no mejoró la supervivencia.
This multicentre study enrolled 804 patients with resectable gastric neuroendocrine carcinomas and gastric mixed adenoneuroendocrine carcinomas. In propensity score matching analysis, there were no associations between the use of adjuvant chemotherapy and improved overall survival. Similar results were obtained in stratified analysis according to different chemotherapy regimens.
No benefit
Cholangiocarcinoma (CCA) continues to harbor a difficult prognosis and it is difficult to diagnose in its early stages. The molecular mechanisms of CCA oncogenesis and progression are poorly ...understood. This study aimed to identify candidate biomarkers for CCA. Integrated analysis of microarray data sets was performed to identify differentially expressed genes (DEGs) between CCA and normal tissues. Gene Ontology enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were then performed to identify the functions of DEGs. Furthermore, the protein-protein interaction (PPI) network of DEGs was constructed. The expressions of DEGs were validated in human CCA tissues by qRT-PCR. A set of 712 DEGs were identified in CCA compared with normal tissues, including 306 upregulated and 406 downregulated DEGs. It can be shown from the KEGG pathway analysis that some pathways may have important roles in pathology of CCA, including peroxisome proliferator-activated receptor signaling pathway, bile secretion, cell cycle, fat digestion and absorption. PPI network indicated that the significant hub proteins were PKM, SPP1 and TPM1. The abnormally overexpression PKM, SPP1 and TPM1 were closely related to oncogenesis and progression of CCA. PKM, SPP1, TPM1, COL1A1 and COL1A2 may serve as candidate biomarkers for diagnosis and prognosis of CCA.
Deformation twinning plays a vital role in accommodating plastic deformation of hexagonal-close-packed (hcp) metals, but its mechanisms are still unsettled under high strain rate shock compression. ...Here we investigate deformation twinning in shock-compressed Mg as a typical hcp metal with in situ, ultrafast synchrotron x-ray diffraction. Extension twinning occurs upon shock compression along ⟨112over ¯0⟩ and ⟨101over ¯0⟩, but only upon release for loading along ⟨0001⟩. Such deformation mechanisms are a result of the polarity of deformation twinning, which depends on directionality and relative magnitude of resolved shear stress and may be common for Mg and its alloys in a wide range of strain rates.
Heat shock proteins (Hsps) are important chaperones, which are involved in various signal pathways and regulate lots of physiological processes. Early research suggested that some Hsps are involved ...in insect development. However, few studies have been carried out to explore the roles of Hsps, especially in larval−pupal metamorphosis. In the present study, 49 Hsp unigenes were identified in the Spodoptera litura transcriptome and their mRNA expression profiles during midgut metamorphosis were examined using a tag‐based digital gene expression system. The genes with the most different levels of expression were then cloned and their expression patterns in midguts from sixth instar larvae to pupae were analysed using real time quantitative PCR. The responses of these genes to juvenile hormone (JH) and 20‐hydroxyecdysone (20E) were also studied. The results showed that the mRNA levels of 22 Hsp unigenes changed significantly during midgut metamorphosis. Amongst these 22 unigenes, hsp70, hsp20.4 and hsp20.8 were the most up‐regulated members, and hsp15.9, hsp19.3 and hsp22.0 were the most down‐regulated ones. Further studies showed that hsp70, hsp20.4 and hsp20.8 were remarkably up‐regulated by JH. In addition, 20E slightly increased the mRNA levels of both hsp20.4 and hsp20.8. However, hsp15.9, hsp19.3 and hsp22.0 did not respond to either JH or 20E. These results indicate that Hsp70 and small Hsps (sHsps) are probably the major players in midgut metamorphosis in S. litura. The current findings provide valuable insights into the roles of the Hsp superfamily in insect metamorphosis.
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