Cesium nDJnD_{J}+6S1/26S_{1/2} Rydberg molecules and their permanent electric dipole moments

Cs$_2$ Rydberg-ground molecules consisting of a Rydberg, $nD_{J}$ (33 $\leq$ $n$ $\leq$ 39), and a ground state atom, 6$S_{1/2} (F=$3 or 4$)$, are investigated by photo-association spectroscopy in a cold atomic gas. We observe vibrational spectra that correspond to triplet $^T\Sigma$ and mixed $^{S,T}\Sigma$ molecular states. We establish scaling laws for the energies of the lowest vibrational states vs principal quantum number and obtain zero-energy singlet and triplet $s$-wave scattering lengths from experimental data and a Fermi model. Line broadening in electric fields reveals the permanent molecular electric-dipole moments; measured values agree well with calculations. We discuss the negative polarity of the dipole moments, which differs from previously reported cases.Comment: 5 pages, 4 figure

Effect of tenofovir disoproxil and telbivudine on the growth and development of infants by blocking mother-to-child transmission of hepatitis B virus

Purpose: To investigate the effect of tenofovir disoproxil and telbivudine on the growth and development of infants after blocking mother-to-child transmission (MTCT) of hepatitis B virus (HBV). Methods: Seventy pregnant women with chronic hepatitis B (CHB) were recruited and allocated to tenofovir disoproxil group (n = 35) and telbivudine group (n = 35) using random number table method. Tenofovir disoproxil group was given 300 mg tenofovir disoproxil orally four times daily, while telbivudine group was given telbivudine 600 mg orally four times daily. Results: After treatment, both groups showed no significant differences in serum HBV-DNA and ALT levels before delivery and 3 months after delivery (p > 0.05). Both groups showed no remarkable differences in the incidence of hypohydramnios, cholestasis, hypothyroidism, anemia, prolonged labor, fetal distress, and placental adhesions (p > 0.05). Both groups showed no significant differences in the rates of premature rupture of membranes, preterm birth, vaginal delivery, and cesarean section (p > 0.05). Both groups showed no significant differences in neonatal sex, gestational age at birth, weight, length, and Apgar scores (p > 0.05). The differences in the positive rates of HBVsAg, HBsAb, and HBeAg at birth and at 12 months were not statistically noticeable (p > 0.05). Conclusion: Tenofovir disoproxil and telbivudine reduce HBV-DNA levels, effectively blocks MTCT, and have a similar safety profile for infants. Further investigations to confirm t

Observation of Blackbody Radiation Enhanced Superradiance in Ultracold Rydberg Gases

An ensemble of excited atoms can synchronize emission of light collectively in a process known as superradiance when its characteristic size is smaller than the wavelength of emitted photons. The underlying superradiance depends strongly on electromagnetic (photon) fields surrounding the atomic ensemble. High mode densities of microwave photons from 300 K blackbody radiation (BBR) significantly enhance decay rates of Rydberg states to neighbouring states, enabling superradiance that is not possible with bare vacuum induced spontaneous decay. Here we report observations of the superradiance of ultracold Rydberg atoms embedded in a bath of room-temperature photons. The temporal evolution of the Rydberg |nD to |(n + 1)P superradiant decay of Cs atoms (n the principal quantum number) is measured directly in free space. Theoretical simulations confirm the BBR enhanced superradiance in large Rydberg ensembles. We demonstrate that the van der Waals interactions between Rydberg atoms change the superradiant dynamics and modify the scaling of the superradiance. In the presence of static electric fields, we find that the superradiance becomes slow, potentially due to many-body interaction induced dephasing. Our study provides insights into many-body dynamics of interacting atoms coupled to thermal BBR, and might open a route to the design of blackbody thermometry at microwave frequencies via collective, dissipative photon-atom interactions

Ultrasmall Organic Nanoparticles with Aggregation-Induced Emission and Enhanced Quantum Yield for Fluorescence Cell Imaging

The use of fluorescence probes for biomedical imaging has attracted significant attention over recent years owing to their high resolution at cellular level. The probes are available in many formats including small particle size based imaging agents which are considered to be promising candidates, due to their excellent stabilities. Yet, concerns over the potential cytotoxicity effects of inorganic luminescent particles have led to questions about their suitability for imaging applications. Exploration of alternatives inspired us to use organic fluorophores with aggregation-induced emission (AIE), prepared by functionalizing the amine group on tetraphenylethene with 3,5-bis­(trifluoromethyl)­phenyl isocyanate. The as-synthesized novel AIE fluorophore (TPE-F) display enhanced quantum yield and longer lifetime as compared with its counterparts (4,4′,4″,4‴-(ethene-1,1,2,2-tetrayl)­tetraaniline, TPE-AM). Furthermore, the TPE-F was encapsulated into small-size organic nanoparticles (NPs; dynamic light scattering size, ∼10 nm) with polysuccinimide (PSI). The biocompatibility, excellent stability, bright fluorescence, and selective cell targeting of these NPs enable the as-prepared TPE-F NPs to be suitable for specific fluorescence cell imaging

A Deep Catalogue of Protein-Coding Variation in 983,578 Individuals

Rare coding variants that substantially affect function provide insights into the biology of a gene1-3. However, ascertaining the frequency of such variants requires large sample sizes4-8. Here we present a catalogue of human protein-coding variation, derived from exome sequencing of 983,578 individuals across diverse populations. In total, 23% of the Regeneron Genetics Center Million Exome (RGC-ME) data come from individuals of African, East Asian, Indigenous American, Middle Eastern and South Asian ancestry. The catalogue includes more than 10.4 million missense and 1.1 million predicted loss-of-function (pLOF) variants. We identify individuals with rare biallelic pLOF variants in 4,848 genes, 1,751 of which have not been previously reported. From precise quantitative estimates of selection against heterozygous loss of function (LOF), we identify 3,988 LOF-intolerant genes, including 86 that were previously assessed as tolerant and 1,153 that lack established disease annotation. We also define regions of missense depletion at high resolution. Notably, 1,482 genes have regions that are depleted of missense variants despite being tolerant of pLOF variants. Finally, we estimate that 3% of individuals have a clinically actionable genetic variant, and that 11,773 variants reported in ClinVar with unknown significance are likely to be deleterious cryptic splice sites. To facilitate variant interpretation and genetics-informed precision medicine, we make this resource of coding variation from the RGC-ME dataset publicly accessible through a variant allele frequency browser