Strain-induced ferroelectric polarization reversal without undergoing geometric inversion in blue SiSe monolayer.

Ferroelectricity in two-dimensional (2D) systems generally arises from phonons and has been widely investigated. On the contrary, electronic ferroelectricity in 2D systems has been rarely studied. Using first-principles calculations, the ferroelectric behavior of the buckled blue SiSe monolayer under strain are explored. It is found that the direction of the out-of-plane ferroelectric polarization can be reversed by applying an in-plane strain. And such polarization switching is realized without undergoing geometric inversion. Besides, the strain-triggered polarization reversal emerges in both biaxial and uniaxial strain cases, indicating it is an intrinsic feature of such a system. Further analysis shows that the polarization switching is the result of the reversal of the magnitudes of the positive and negative charge center vectors. And the variation of buckling is found to play an important role, which results in the switch. Moreover, a non-monotonic variation of band gap with strain is revealed. Our findings throws light on the investigation of novel electronic ferroelectric systems.

MNI2CPC: A probabilistic cortex-to-scalp mapping for non-invasive brain stimulation targeting.

BACKGROUND: Synthesis of neural imaging information from many studies is valuable for identifying stable cortical targets for non-invasive brain stimulation (NIBS). Typically, these targets are specified in Montreal Neurological Institute (MNI) standard brain space. However, in practical NIBS applications, localizing MNI cortical targets often relies on the International 10-20 system or heuristic scalp approaches, which often lacks precision or applies only to specific targets. OBJECTIVE/HYPOTHESIS: We aim to establish a probabilistic mapping from any cortical target in MNI space to continuous proportional coordinate (CPC) standard scalp space (MNI2CPC) and assess the performance of this mapping for NIBS targeting. METHODS: The MNI2CPC mapping was calculated based on a large MRI dataset (n = 114). Its targeting error was evaluated via cross-individual validation using a leave-one-out approach, as well as through independent validation across race (n = 27) and across patient (n = 58) cohorts. RESULTS: The cross-individual validation demonstrated targeting errors of 4.03 ± 0.69 mm on the scalp and 3.30 ± 0.59 mm in the cortex. For independent cohorts, targeting errors were 4.71 ± 0.81 mm (scalp) and 3.85 ± 0.64 mm (cortex) across race, and 4.66 ± 0.77 mm (scalp) and 3.77 ± 0.61 mm (cortex) across patient. We publish a free online tool to enable querying of the CPC coordinate for any given MNI cortical target. The resulting CPC coordinates enable rapid and accurate manual localization on the scalp in a user-friendly manner. CONCLUSIONS: The MNI2CPC mapping developed in this study allows for manual localization of any MNI cortical target, which improves the accessibility and ease of application of NIBS in diverse settings.

High-status individuals are held to higher ethical standards.

Although there is evidence for the generosity of high-status individuals, there seems to be a strong perception that the elites are selfish and contribute little to others' welfare, and even less so than poorer people. We argue that this perception may derive from a gap between normative and empirical expectations regarding the behavior of the elites. Using large-scale survey experiments, we show that high-status individuals are held to higher ethical standards in both the US and China, and that there is a strong income gradient in normatively expected generosity. We also present evidence for a gap between people's normative expectations of how the rich should behave, and their empirical expectations of how they actually do: empirical expectations are generally lower than both normative expectations and actual giving.

Value of statistical life year in extreme poverty: a randomized experiment of measurement methods in rural Burkina Faso.

BACKGROUND: Value of a Statistical Life Year (VSLY) provides an important economic measure of an individual's trade-off between health risks and other consumption, and is a widely used policy parameter. Measuring VSLY is complex though, especially in low-income and low-literacy communities. METHODS: Using a large randomized experiment (N = 3027), we study methodological aspects of stated-preference elicitation with payment cards (price lists) in an extreme poverty context. In a 2 × 2 design, we systematically vary whether buying or selling prices are measured, crossed with the range of the payment card. RESULTS: We find substantial effects of both the pricing method and the list range on elicited VSLY. Estimates of the gross domestic product per capita multiplier for VSLY range from 3.5 to 33.5 depending on the study design. Importantly, all estimates are economically and statistically significantly larger than the current World Health Organization threshold of 3.0 for cost-effectiveness analyses. CONCLUSIONS: Our results inform design choice in VSLY measurements, and provide insight into the potential variability of these measurements and possibly robustness checks.

An Evolutionary Genomic Perspective on the Breeding of Dwarf Chickens.

The evolutionary history for dwarfism in chickens remains an enigma. Herein, we explore the evolution of the Serama, the smallest breed of chicken. Leveraging comparative population genomics, analyses identify several genes that are potentially associated with the growth and development of bones and muscles. These genes, and in particular both POU1F1 and IGF1, are under strong positive selection. Three allopatric dwarf bantams (Serama, Yuanbao, and Daweishan) with different breeding-histories, form distinct clusters and exhibit unique population structures. Parallel genetic mechanisms underlay their variation in body size. These findings provide insights into the multiple and complex pathways, depending on genomic variation, that chicken can take in response to aviculture selection for dwarfism.

Updated incidence rates and risk factors of esophageal cancer in Nan'ao Island, a coastal high-risk area in southern China.

Esophageal cancer (EC) is one of the most common cancers in China. The purpose of this study was to investigate the updated incidence rates and risk factors of EC in Nan'ao Island, where the EC incidence rate was chronically the highest in southern China. To calculate the annual incidence rate, data on 338 EC cases from Nan'ao Cancer Registry system diagnosed during 2005-2011 were collected. A case-control study was conducted to explore the EC risk factors. One hundred twenty-five alive EC patients diagnosed during 2005-2011 and 250 controls were enrolled into the case-control study. A pre-test questionnaire on demography, dietary factors, drinking water treatment, and behavioral factors was applied to collect information of all participants. The average EC incidence rates during 2005-2011 were 66.09/105, 94.62/105, 36.83/105 for both genders, males and females, respectively, in Nan'ao Island. The EC incidence rate in males was 2.40- to 4.55-fold higher than that in females in the period from 2006 to 2011 (P < 0.05). Considering the onset age, males tend to be much younger than females and reached peak incidence rate at a younger age (P < 0.05). Drinking water treatment by filter (odds ratio [OR] = 0.28, 95% confidence interval [95% CI] = 0.13-0.58) and fruit consumption (OR = 0.55, 95% CI = 0.32-0.94) reduced the risk for EC. On the contrary, the pickled vegetables consumption (OR = 2.64, 95% CI = 1.46-4.76) and liquor drinking (OR = 2.32, 95% CI = 1.21-4.44) increased the risk for EC. These results may be of importance for future research on EC etiology and prevention strategies.

Prognostic significance of residual or recurrent lymph nodes in the neck for patients with nasopharyngeal carcinoma after radiotherapy.

BACKGROUND: Nasopharyngeal carcinoma is the most frequently diagnosed primary tumor originating from the nasopharynx, and the preferred treatment modality is radiotherapy. AIMS: To identify nasopharyngeal carcinoma prognostic factors in patients with residual or recurrent cervical lymph node metastases after radiotherapy. PATIENTS AND METHODS: The clinicopathologic characteristics and prognoses of 67 nasopharyngeal carcinoma patients with residual or recurrent cervical lymph node metastases who were diagnosed and treated were analyzed retrospectively. The Chi-squared test and Cox proportional hazard regression model were used to investigate associations between survival and clinicopathological features. Cumulative survival plots were obtained using the Kaplan-Meier method. RESULTS: Data analysis using the Cox proportional hazard regression model revealed that the size of residual or recurrent lymph node metastases, level V lymph node involvement, number of involved levels, surgical procedure performed, and distant metastases were significantly associated with overall survival. Chi-squared analysis only determined a significant correlation between distant metastases and patient survival. Furthermore, the Kaplan-Meier analysis demonstrated that the 1-, 3-, and 5-year survival rates for patients were 86.6%, 52.2%, and 38.6%, respectively. Radical neck dissection resulted in substantially longer overall survival than modified neck dissection. CONCLUSION: The size of residual or recurrent lymph node metastases, level V lymph node involvement, number of involved levels, surgical procedure performed, and presence of distant metastases were prognostic factors for nasopharyngeal carcinoma patients with residual or recurrent cervical lymph node metastases after radiotherapy, with distant metastases being the most important determinant. Classical radical neck dissection is recommended for treating recurrent nodal disease in nasopharyngeal carcinoma.

Discrimination of Semen cassiae from two related species based on the multivariate analysis of high-performance liquid chromatography fingerprints.

A simple and efficient high-performance liquid chromatography fingerprint method was developed to discriminate Semen cassiae from two related species: Cassia obtusifolia L. (CO) and Cassia tora L. (CT), the seeds of which are abbreviated as COS and CTS, respectively. 22 major bioactive ingredients in 42 samples (20 COS and 22 CTS) collected from different provinces of China were identified. The statistical methods included similarity analysis and partial least-squares discriminant analysis. The pattern analysis method was specific and could be readily used for the comprehensive evaluation of Semen cassiae samples. Therefore, high-performance liquid chromatography fingerprint in combination with pattern analysis provided a simple and reliable method for discriminating between COS and CTS.

Five new anthraquinones from the seed of Cassia obtusifolia.

A phytochemical investigation on the seeds of Cassia obtusifolia led to the isolation of five new anthraquinones, including one aglycon and four glycosides. The structures were elucidated by analysis of extensive spectroscopic data and the results of acid hydrolysis. All these isolates were evaluated for their inhibitory effects against α-glucosidase, and 1 showed potent activity with IC50 value of 185 ± 15 µM.

Towards a better understanding of medicinal uses of Carthamus tinctorius L. in traditional Chinese medicine: a phytochemical and pharmacological review.

ETHNOPHARMACOLOGICAL RELEVANCE: Carthamus tinctorius L. (Compositae), a widely used traditional Chinese medicine, was known as Hong hua (Chinese: ), safflower. Safflower with a wide spectrum of pharmacological effects has been used to treat dysmenorrhea, amenorrhea, postpartum abdominal pain and mass, trauma and pain of joints, etc. The present paper reviews the advancements in investigation of botany and ethnopharmacology, phytochemistry, pharmacology and toxicology of safflower. Finally, the possible tendency and perspective for future investigation of this plant are discussed, too. MATERIALS AND METHODS: The information on safflower was collected via piles of resources including classic books about Chinese herbal medicine, and scientific databases including Pubmed, Google Scholar, ACS, Web of science, CNKI and others. RESULTS: Over 104 compounds from this plant have been isolated and identified, and quinochalcones and flavonoids are considered as the characteristic and active constituents of safflower. Safflower with its active compounds possesses wide-reaching biological activities, including dilating coronary artery, improving myocardial ischemia, modulating immune system, anticoagulation and antithrombosis, antioxidation, antiaging, antihypoxia, antifatigue, antiinflammation, anti-hepatic fibrosis, antitumor, analgesia, etc. CONCLUSIONS: As an important traditional Chinese medicine, it is important to investigate the pharmacological effects and molecular mechanisms of this plant based on modern realization of diseases' pathophysiology. More bioactive components should be identified using bioactivity-guided isolation strategies, and the possible mechanism of action as well as potential synergistic or antagonistic effects of multi-component mixtures derived from safflower need to be evaluated integrating pharmacological, pharmacokinetic, bioavailability-centered and physiological approaches. Further studies on safflower can lead to the development of new drugs and therapeutics for various diseases, and how to utilize it better should be paid more attention to.