Spin-Charge Conversion in Chiral Polymers with Hopping Conduction.

Organic and biological materials are often chiral. Chiral polymers, as recent experiments indicate, facilitate spin-charge conversion: a charge current results in a spin polarization and vice versa, dubbed chirality-induced spin selectivity (CISS) and inverse CISS (ICISS). While CISS/ICISS in crystalline chiral systems such as tellurium can be understood in terms of their chirality- and spin-dependent band structure, such a picture becomes inapplicable to disordered chiral polymers, where carrier transport is via hopping rather than band conduction.

Inverse chirality-induced spin selectivity effect in chiral assemblies of π-conjugated polymers.

Coupling of spin and charge currents to structural chirality in non-magnetic materials, known as chirality-induced spin selectivity, is promising for application in spintronic devices at room temperature. Although the chirality-induced spin selectivity effect has been identified in various chiral materials, its Onsager reciprocal process, the inverse chirality-induced spin selectivity effect, remains unexplored. Here we report the observation of the inverse chirality-induced spin selectivity effect in chiral assemblies of π-conjugated polymers.

Revealing the Intrinsic Chiroptical Activity in Chiral Metal-Halide Semiconductors.

The combination of chirality and semiconducting properties has enabled chiral metal-halide semiconductors (MHS) to be promising candidates for spin- and polarization-resolved optoelectronic devices. Although several chiral MHS with rich chemical and structural diversity have been reported lately, the macroscopic origin of chiroptical activity remains elusive. Here, combining spectroscopic measurements and Mueller matrix analysis, we discover that the previously reported "apparent" anisotropy factor measured from circular dichroism (CD) in chiral MHS thin films is not an intrinsic chiroptical property, but rather, arising from an interference between the film's linear birefringence (LB) and linear dichroism (LD).

Omnidirectional exciton diffusion in quasi-2D hybrid organic-inorganic perovskites.

Exciton transport plays a central role in optoelectronic and photonic devices. In quasi-two-dimensional (2D) hybrid organic-inorganic perovskites (HOIPs), tightly bound excitons are found to diffuse within 2D layers rapidly with a non-monotonic temperature dependence. Surprisingly, the interlayer exciton diffusion is quite effective as well despite the large interlayer distance.

Quantized Exciton Motion and Fine Energy-Level Structure of a Single Perovskite Nanowire.

The quantum-confinement effect profoundly influences the exciton energy-level structures and recombination dynamics of semiconductor nanostructures but remains largely unexplored in traditional one-dimensional nanowires mainly due to their poor optical qualities. Here, we show that in defect-tolerant perovskite material of highly luminescent CsPbBr nanowires, the exciton's center-of-mass motion perpendicular to the axial direction is severely confined. This is reflected in the two sets of photoluminescence spectra emitted from a single CsPbBr nanowire, each of which consists of doublet peaks with linear polarizations perpendicular and parallel to the axial direction.

Rashba splitting in organic-inorganic lead-halide perovskites revealed through two-photon absorption spectroscopy.

The Rashba splitting in hybrid organic-inorganic lead-halide perovskites (HOIP) is particularly promising and yet controversial, due to questions surrounding the presence or absence of inversion symmetry. Here we utilize two-photon absorption spectroscopy to study inversion symmetry breaking in different phases of these materials. This is an all-optical technique to observe and quantify the Rashba effect as it probes the bulk of the materials.

Relationship Between Lifestyle Habits and Health-Related Quality of Life of Recently Diagnosed Breast Cancer Patients: A Comparison Between Younger and Older Women in China.

The aim of this study was to evaluate the relationship between lifestyle habits and health-related quality of life (HRQoL) among different ages who were initially diagnosed with breast cancer (within the first 2 weeks) and to determine the contribution of lifestyle habits factors on HRQoL. Patients with breast cancer were recruited from 22 hospitals in 11 provinces or municipalities in northern and eastern China. The Functional Assessment of Cancer Therapy-Breast Cancer (FACT-B) was used to measure HRQoL.

Magnetic-field manipulation of circularly polarized photoluminescence in chiral perovskites.

The introduction of chiral organic ligands into hybrid organic-inorganic perovskites (HOIPs) results in chiral perovskites, which exhibit natural optical activities (NOAs) such as circularly polarized luminescence (CPL). CPL can be observed in achiral HOIPs under a magnetic field as well. Here, we systematically study the temperature- and magnetic field-dependence of both circular polarization and total intensity in chiral HOIPs.

Exciton-acoustic phonon coupling revealed by resonant excitation of single perovskite nanocrystals.

Single perovskite nanocrystals have attracted great research attention very recently due to their potential quantum-information applications, which critically depend on the development of powerful optical techniques to resolve delicate exciton photophysics. Here we have realized resonant and near-resonant excitations of single perovskite CsPbI nanocrystals, with the scattered laser light contributing to only ~10% of the total collected signals. This allows us to estimate an ultranarrow photoluminescence excitation linewidth of ~11.

XRCC5/6 polymorphisms and their interactions with smoking, alcohol consumption, and sleep satisfaction in breast cancer risk: A Chinese multi-center study.

Background: X-ray repair cross-complementary 5 (XRCC5) and 6 (XRCC6) are critical for DNA repair. Few studies have assessed their association with breast cancer risk, and related gene-environment interactions remain poorly understood. This study aimed to determine the influence of XRCC5/6 polymorphisms on breast cancer risk, and their interactions with cigarette smoking, alcohol consumption, and sleep satisfaction.

A multi-center investigation of breast-conserving surgery based on data from the Chinese Society of Breast Surgery (CSBrS-005).

Background: Although breast-conserving surgery is one of the standard treatments for breast cancer, few studies have assessed its recent implementation in China. We aimed to clarify the current real-world status of breast-conserving surgery in China.

Methods: This cross-sectional survey relied on data collected by the Chinese Society of Breast Surgery (CSBrS) to examine patients who underwent this surgery between January 2018 and December 2018.

Chirality-Induced Spin-Orbit Coupling, Spin Transport, and Natural Optical Activity in Hybrid Organic-Inorganic Perovskites.

Hybrid organic-inorganic perovskites (HOIPs) with chiral organic ligands exhibit highly spin-dependent transport and strong natural optical activity (NOA). Here we show that these remarkable features can be traced to a chirality-induced spin-orbit coupling (SOC), = σ, which connects the carrier's spin (σ), its wave vector (), and the material's helicity (τ) along the screw direction with strength α controlled by the geometry of the organic ligands. This SOC leads to a macroscopic spin polarization in the presence of an electrical current and is responsible for the observed spin-selective transport.

Transition from Doublet to Triplet Excitons in Single Perovskite Nanocrystals.

Lead halide perovskite nanocrystals (NCs) have emerged as novel semiconductor nanostructures possessing great potential for optoelectronic, photovoltaic, and quantum information processing applications. Success in these applications requires a comprehensive understanding of the perovskite NCs' electronic structures, which mysteriously exhibit either doublet or triplet peaks of exciton luminescence at the single-particle level. Here we show that the transition from doublet- to triplet-exciton peaks can be triggered in single CsPbI NCs from the same batch of samples when they are stored in the ambient environment.

Molecular fingerprint of precancerous lesions in breast atypical hyperplasia.

Objective: To identify atypical hyperplasia (AH) of the breast by shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS), and to explore the molecular fingerprinting characteristics of breast AH.

Methods: Breast hyperplasia was studied in 11 hospitals across China from January 2015 to December 2016. All patients completed questionnaires on women's health.

Resonant free-carrier absorption in 2D hybrid organic-inorganic perovskites: The Rashba effect or small polarons?

The Rashba effect, which shifts the conduction band extremum from wavevector k = 0 to |k| = k ≠ 0 with an energy gain of E, has been frequently invoked to explain outstanding optoelectronic properties in hybrid organic-inorganic perovskites (HOIPs). For two-dimensional (2D) layered HOIPs, the only direct experimental evidence of the Rashba effect to date is resonant free-carrier absorption (FCA), which has been attributed to direct optical transition between the Rashba subbands at |k| = k ≠ 0 with photon energy ℏω = 4E. Here, we show that in layered perovskites, small polarons induced by a strong short-range coupling between electrons and optical phonons can also give rise to a resonant FCA at ℏω = 4E, with E being the polaron binding energy.

Ultrafast acoustic phonon scattering in CHNHPbI revealed by femtosecond four-wave mixing.

Carrier scattering processes are studied in CHNHPbI using temperature-dependent four-wave mixing experiments. Our results indicate that scattering by ionized impurities limits the interband dephasing time (T) below 30 K, with strong electron-phonon scattering dominating at higher temperatures (with a time scale of 125 fs at 100 K). Our theoretical simulations provide quantitative agreement with the measured carrier scattering rate and show that the rate of acoustic phonon scattering is enhanced by strong spin-orbit coupling, which modifies the band-edge density of states.

Optical deformation potential and self-trapped excitons in 2D hybrid perovskites.

Self-trapped excitons (STEs) in two-dimensional (2D) hybrid organic-inorganic perovskites (HOIPs) emit broadband white light, suggesting the great potential of 2D HOIPs in low-cost lighting and display applications. A prerequisite for understanding STEs' properties is a correct identification of the underlying interaction that leads to the STEs. Here, we show that the long-range polar coupling between electrons and optical phonons is quenched in 2D HOIPs' tightly bound excitons and cannot effect STEs.

Controlling Magnetoresistance by Oxygen Impurities in Mq3-Based Molecular Spin Valves.

The understanding of magnetoresistance (MR) in organic spin valves (OSVs) based on molecular semiconductors is still incomplete after its demonstration more than a decade ago. Although carrier concentration may play an essential role in spin transport in these devices, direct experimental evidence of its importance is lacking. We probed the role of the charge carrier concentration by studying the interplay between MR and multilevel resistive switching in OSVs.

Plasmonic circular dichroism of vesicle-like nanostructures by the template-less self-assembly of achiral Janus nanoparticles.

Chiral nanostructures have been attracting extensive interest in recent years primarily because of the unique materials properties that can be exploited for diverse applications. In this study, gold Janus nanoparticles, with hexanethiolates and 3-mercapto-1,2-propanediol segregated on the two hemispheres of the metal cores (dia. 2.

Factors associated with insufficient awareness of breast cancer among women in Northern and Eastern China: a case-control study.

Objectives: To investigate the awareness and knowledge level of breast cancer among Chinese participants.

Design: Case-control study.

Settings: This study was based on the database of the minister-affiliated hospital key project of the Ministry of Health of the People's Republic of China that included 21 Chinese hospitals between April 2012 and April 2013.