Correlation effects in the electronic structure of the Ni-based superconducting KNi2S2

The LDA plus Gutzwiller variational method is used to investigate the groundstate physical properties of the newly discovered superconducting KNi2S2. Five Ni-3d Wannier-orbital basis are constructed by the density-functional theory, to combine with local Coulomb interaction to describe the normal state electronic structure of Ni-based superconductor. The band structure and the mass enhanced are studied based on a multiorbital Hubbard model by using Gutzwiller approximation method. Our results indicate that the correlation effects lead to the mass enhancement of KNi2S2. Different from the band structure calculated from the LDA results, there are three energy bands across the Fermi level along the X-Z line due to the existence of the correlation effects, which induces a very complicated Fermi surface along the X-Z line. We have also investigated the variation of the quasi-particle weight factor with the hole or electron doping and found that the mass enhancement character has been maintained with the doping.Comment: 12 pages, 6 figure

Chinese ‘low-tar’ cigarettes do not deliver lower levels of nicotine and carcinogens

BackgroundLow-tar cigarette smoking is gaining popularity in China. The China National Tobacco Corporation (CNTC) promotes low-tar cigarettes as safer than regular cigarettes.MethodsA total of 543 male smokers smoking cigarettes with different tar yields (15 mg, regular cigarettes, 10-13 mg low-tar cigarettes and < 10 mg low-tar cigarettes) were recruited in Shanghai, China, who then completed a questionnaire on smoking behaviour and provided a urine sample for analysis of the nicotine metabolites cotinine and trans-3'-hydroxycotinine. A total of 177 urine samples were selected at random for the analysis of the carcinogens polycyclic aromatic hydrocarbon metabolites (PAHs) (1-hydroxypyrene, naphthols, hydroxyfluorenes and hydroxyphenanthrenes) and the tobacco specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-butanone (NNK) metabolites, 4-(methylnitrosamino)-1-(3-pyridyl)-butanol (NNAL) and NNAL-glucuronide. Values were normalised by creatinine to correct for possible distortions introduced by dilution or concentration of the urine.ResultsSmokers of low-tar cigarettes smoked fewer cigarettes per day (p=0.001) compared to smokers of regular cigarettes. Despite this lower reported consumption, levels of cotinine, trans-3'-hydroxycotinine and PAHs in urine of people smoking low-tar cigarettes were not correlated with nominal tar delivery of the cigarettes they smoked. Urine concentrations of NNAL were higher in smokers of lower tar than higher tar cigarettes.ConclusionsChinese low-tar cigarettes do not deliver lower doses of nicotine and carcinogens than regular cigarettes, therefore it is unlikely that there would be any reduction in harm. CNTC's promotion of low-tar cigarettes as 'less harmful' is a violation of the World Health Organization Framework Convention on Tobacco Control, which China ratified in 2005

Ethnopharmacokinetic- and Activity-Guided Isolation of a New Antidepressive Compound from Fructus Aurantii Found in the Traditional Chinese Medicine Chaihu-Shugan-San: A New Approach and Its Application

Aims. We aimed to identify an antidepressive compound found in traditional Chinese medicine (TCM) by a new approach called ethnopharmacokinetic- and activity-guided isolation (EAGI). Methods. The new approach targets an unknown chromatographic peak produced by an absorbed compound found in oral Chaihu-Shugan-San (CSS) taken by patients with depression. Once the compound was isolated from Fructus Aurantii (FA), spectral data was employed to identify the compound. The effects of this compound, FA, and CSS on depressive behaviors were investigated. Results. The identified compound was merazin hydrate (MH) according to the new approach. MH, FA, and CSS significantly reduced immobility time and increased locomotor activity. The effects of MH, FA and CSS were similar to Fluoxetine at high doses. Conclusion. MH, a compound whose antidepressive effect is similar to FA and CSS, was isolated for the first time from FA via targeting its corresponding unknown chromatographic peak, and its antidepressive effect was compared with FA or CSS. These findings highlight the potential for drug R&D and pharmacological research of ∼100,000 TCMs

Perpendicular in-plane negative magnetoresistance in ZrTe5

The unique band structure in topological materials frequently results in unusual magneto-transport phenomena, one of which is in-plane longitudinal negative magnetoresistance (NMR) with the magnetic field aligned parallel to the electrical current direction. This NMR is widely considered as a hallmark of chiral anomaly in topological materials. Here we report the observation of in-plane NMR in the topological material ZrTe5 when the in-plane magnetic field is both parallel and perpendicular to the current direction, revealing an unusual case of quantum transport beyond the chiral anomaly. We find that a general theoretical model, which considers the combined effect of Berry curvature and orbital moment, can quantitatively explain this in-plane NMR. Our results provide new insights into the understanding of in-plane NMR in topological materials