A central question in the high temperature cuprate superconductors is the fate of the parent Mott insulator upon charge doping. Here we use scanning tunneling microscopy to investigate the local electronic structure of lightly doped cuprate in the antiferromagnetic insulating regime. We show that the doped charge induces a spectral weight transfer from the high energy Hubbard bands to the low energy in-gap states. With increasing doping, a V-shaped density of state suppression occurs at the Fermi level, which is accompanied by the emergence of checkerboard charge order.The new STM perspective revealed here is the cuprates first become a charge ordered insulator upon doping. Subsequently, with further doping, Fermi surface and high temperature superconductivity grow out of it.High temperature superconductivity in the cuprates is widely believed to originate from adding charge carriers into an antiferromagnetic (AF) Mott insulator (1). Elucidating the properties of the doped Mott insulator is among the most crucial issues concerning the mechanism of superconductivity. From the electronic structure point of view, the key question is how the large Mott-Hubbard gap, or more precisely the charge transfer gap, evolves into the d-wave superconducting (SC) gap upon charge doping. This has turned out to be a formidable challenge, both theoretically and experimentally, due to the presence of strong AF fluctuations and electron correlations. A major obstacle lying between the parent Mott insulator and the optimally doped cuprate is the pseudogap phase, which exhibits a normal state gap as revealed by early spectroscopic studies (2-4). More recently, imaging and diffraction techniques show that electrons in the pseudogap phase have strong propensity towards charge (5-16) or spin order (5,(17)(18)(19). Currently neither the gap-like density of state (DOS) suppression nor the charge/spin density wave is well understood (4).Most previous experiments on the pseudogap phase focused on the underdoped regime with finite transition temperature (T c ), and aimed to address its relationship with the SC phase by probing the strength of the two orders across T c (4). Recent scanning tunneling microscopy (STM) and x-ray spectroscopy experiments provide increasing evidence that the charge order associated with the pseudogap compete with superconductivity because its feature gets suppressed as the sample enters the SC phase below T c (4,11,16). However, due to the lack of spectroscopic data spanning the energy range of both the pseudogap and charge transfer gap, less is known about lightly doped, non-SC regime standing next to the parent To address these questions, here we carry out STM investigations on lightly doped Bi 2 Sr 2-x La x CuO 6+ (La-Bi2201) in the AF insulating regime. La-Bi2201 is an ideal cuprate system which not only has a well-cleaved surface, but also can be doped towards the Mott insulating limit by varying the . Figure 1A 1C displays spatially resolved tunneling spectra dI/dV(r, V), which is roughly proportional to ...

Objective To quantify the background incidence rates of 15 prespecified adverse events of special interest (AESIs) associated with covid-19 vaccines. Design Multinational network cohort study. Setting Electronic health records and health claims data from eight countries: Australia, France, Germany, Japan, the Netherlands, Spain, the United Kingdom, and the United States, mapped to a common data model. Participants 126 661 070 people observed for at least 365 days before 1 January 2017, 2018, or 2019 from 13 databases. Main outcome measures Events of interests were 15 prespecified AESIs (non-haemorrhagic and haemorrhagic stroke, acute myocardial infarction, deep vein thrombosis, pulmonary embolism, anaphylaxis, Bell’s palsy, myocarditis or pericarditis, narcolepsy, appendicitis, immune thrombocytopenia, disseminated intravascular coagulation, encephalomyelitis (including acute disseminated encephalomyelitis), Guillain-Barré syndrome, and transverse myelitis). Incidence rates of AESIs were stratified by age, sex, and database. Rates were pooled across databases using random effects meta-analyses and classified according to the frequency categories of the Council for International Organizations of Medical Sciences. Results Background rates varied greatly between databases. Deep vein thrombosis ranged from 387 (95% confidence interval 370 to 404) per 100 000 person years in UK CPRD GOLD data to 1443 (1416 to 1470) per 100 000 person years in US IBM MarketScan Multi-State Medicaid data among women aged 65 to 74 years. Some AESIs increased with age. For example, myocardial infarction rates in men increased from 28 (27 to 29) per 100 000 person years among those aged 18-34 years to 1400 (1374 to 1427) per 100 000 person years in those older than 85 years in US Optum electronic health record data. Other AESIs were more common in young people. For example, rates of anaphylaxis among boys and men were 78 (75 to 80) per 100 000 person years in those aged 6-17 years and 8 (6 to 10) per 100 000 person years in those older than 85 years in Optum electronic health record data. Meta-analytic estimates of AESI rates were classified according to age and sex. Conclusion This study found large variations in the observed rates of AESIs by age group and sex, showing the need for stratification or standardisation before using background rates for safety surveillance. Considerable population level heterogeneity in AESI rates was found between databases.

The layered transition-metal dichalcogenide 1T-TaS 2 has been recently found to undergo a Mottinsulator-to-superconductor transition induced by high pressure, charge doping, or isovalent substitution. By combining scanning tunneling microscopy measurements and first-principles calculations, we investigate the atomic scale electronic structure of the 1T-TaS 2 Mott insulator and its evolution to the metallic state upon isovalent substitution of S with Se. We identify two distinct types of orbital texturesone localized and the other extended-and demonstrate that the interplay between them is the key factor that determines the electronic structure. In particular, we show that the continuous evolution of the charge gap visualized by scanning tunneling microscopy is due to the immersion of the localized-orbital-induced Hubbard bands into the extended-orbital-spanned Fermi sea, featuring a unique evolution from a Mott gap to a charge-transfer gap. This new mechanism of Mottness collapse revealed here suggests an interesting route for creating novel electronic states and designing future electronic devices.

Molecular mechanisms underlying breast cancer lymph node metastasis remain unclear. Using single-cell sequencing, we investigated the transcriptome profile of 96,796 single cells from 15 paired samples of primary tumors and axillary lymph nodes. We identified nine cancer cell subclusters including CD44 + / ALDH2 + /ALDH6A1 + breast cancer stem cells (BCSCs), which had a copy-number variants profile similar to that of normal breast tissue. Importantly, BCSCs existed only in primary tumors and evolved into metastatic clusters infiltrating into lymph nodes. Furthermore, transcriptome data suggested that NECTIN2-TIGIT-mediated interactions between metastatic breast cancer cells and tumor microenvironment (TME) cells, which promoted immune escape and lymph node metastasis. This study is the first to delineate the transcriptome profile of breast cancer lymph node metastasis using single-cell RNA sequencing. Our findings offer novel insights into the mechanisms underlying breast cancer metastasis and have implications in developing novel therapies to inhibit the initiation of breast cancer metastasis.