A Detailed Examination of the Gender Wage Gap in United States

The purpose of this paper is to study the recent trend of the gender wage gap in United States and underlying reasons that cause the change. The data I use is from 2000 to 2014. I use OLS method to estimate the coefficients of variables and Oaxaca and Blinder decomposition method to study the gender wage gap. The research result shows that the gender wage gap in United States has a clear downward trend in this period. Also, I find that occupational segregation benefits women and reduces the gender wage gap. The sticky floor effect and glass ceiling effect both exist, but the latter one is more significant. The findings suggest that the government should encourage women to invest more in education, especially in fields of study that require high skills

Trojan Horse nanotheranostics with dual transformability and multifunctionality for highly effective cancer treatment.

Nanotheranostics with integrated diagnostic and therapeutic functions show exciting potentials towards precision nanomedicine. However, targeted delivery of nanotheranostics is hindered by several biological barriers. Here, we report the development of a dual size/charge- transformable, Trojan-Horse nanoparticle (pPhD NP) for delivery of ultra-small, full active pharmaceutical ingredients (API) nanotheranostics with integrated dual-modal imaging and trimodal therapeutic functions. pPhD NPs exhibit ideal size and charge for drug transportation. In tumour microenvironment, pPhD NPs responsively transform to full API nanotheranostics with ultra-small size and higher surface charge, which dramatically facilitate the tumour penetration and cell internalisation. pPhD NPs enable visualisation of biodistribution by near-infrared fluorescence imaging, tumour accumulation and therapeutic effect by magnetic resonance imaging. Moreover, the synergistic photothermal-, photodynamic- and chemo-therapies achieve a 100% complete cure rate on both subcutaneous and orthotopic oral cancer models. This nanoplatform with powerful delivery efficiency and versatile theranostic functions shows enormous potentials to improve cancer treatment

MqsR/MqsA Toxin/Antitoxin System Regulates Persistence and Biofilm Formation in Pseudomonas putida KT2440

Bacterial toxin/antitoxin (TA) systems have received increasing attention due to their prevalence, diverse structures, and important physiological functions. In this study, we identified and characterized a type II TA system in a soil bacterium Pseudomonas putida KT2440. This TA system belongs to the MqsR/MqsA family. We found that PP_4205 (MqsR) greatly inhibits cell growth in P. putida KT2440 and Escherichia coli, the antitoxin PP_4204 (MqsA) neutralizes the toxicity of the toxin MqsR, and the two genes encoding them are co-transcribed. MqsR and MqsA interact with each other directly in vivo and MqsA is a negative regulator of the TA operon through binding to the promoter. Consistent with the MqsR/MqsA pair in E. coli, the binding of the toxin MqsR to MqsA inhibits the DNA binding ability of MqsA in P. putida KT2440. Disruption of the mqsA gene which induces mqsR expression increases persister cell formation 53-fold, while overexpressing mqsA which represses mqsR expression reduces persister cell formation 220-fold, suggesting an important role of MqsR in persistence in P. putida KT2440. Furthermore, both MqsR and MqsA promote biofilm formation. As a DNA binding protein, MqsA can also negatively regulate an ECF sigma factor AlgU and a universal stress protein PP_3288. Thus, we revealed an important regulatory role of MqsR/MqsA in persistence and biofilm formation in P. putida KT2440

Density functional theory study of single-molecule ferroelectricity in Preyssler-type polyoxometalates

A detailed study on the single-molecule ferroelectric property of Preyssler-type polyoxometalates (POMs), [M3+P5W30O110]12− (M = La, Gd, and Lu), is performed by density functional theory calculations. Linked to one H2O molecule, the cation (M3+) encapsulated in the cavity of the Preyssler framework is off-centered, and it generates a permanent dipole, which is essential for a ferroelectric ground state. Accompanied with a 180° rotation of H2O, the switching of M3+ between two isoenergetic sites on both sides of the cavity results in a calculated barrier of 1.15 eV for Gd3+, leading to the inversion of electric polarization. The height of the barrier is in good agreement with the experimentally measured barrier for the Tb3+ ion, whose ionic radius is similar to Gd3+. The total polarization value of the crystal is estimated to be 4.7 µC/cm2 as calculated by the modern theory of polarization, which is quite close to the experimental value. Considering that the order of contributions to the polarization is M3+–H2O > counter-cations (K+) > [P5W30O110]15−, the interconversion of M3+–H2O between the two isoenergetic sites is predicted to be the main origin of ferroelectricity with a polarization contribution of 3.4 µC/cm2; the K+ counter-cations contribute by 1.2 µC/cm2 and it cannot be disregarded, while the framework appears to contribute negligibly to the total polarization. Our study suggests that a suitable choice of M3+–H2O could be used to tune the single-molecule ferroelectricity in Preyssler-type polyoxometalates