Fe-based high temperature superconductivity with Tc=31K bordering an insulating antiferromagnet in (Tl,K)FexSe2 Crystals

Up to now, there have been two material families, the cuprates and the iron-based compounds with high-temperature superconductivity (HTSC). An essential open question is whether the two classes of materials share the same essential physics. In both, superconductivity (SC) emerges when an antiferromagnetical (AFM) ordered phase is suppressed. However, in cuprates, the repulsive interaction among the electrons is so strong that the parent compounds are "Mott insulators." By contrast, all iron-based parents are metallic. One perspective is that the iron-based parents are weakly correlated and that the AFM arises from a strong "nesting" of the Fermi surfaces. An alternative view is that the electronic correlations in the parents are still sufficiently strong to place the system close to the boundary between itinerancy and electronic localization. A key strategy to differentiate theses views is to explore whether the iron-based system can be tuned into a Mott insulator. Here we identify an insulating AFM in (Tl,K)FexSe2 by introducing Fe-vacancies and creating superconductivity in the Fe-planar. With the increasing Fe-content, the AFM order is reduced. When the magnetism is eliminated, a superconducting phase with Tc as high as 31K (and a Tc onset as high as 40K) is induced. Our findings indicate that the correlation effect plays a crucial role in the iron-based superconductors. (Tl,K)FexSe2, therefore, represents the first Fe-based high temperature superconductor near an insulating AFM.Comment: 20 pages, 8 figure

Superconductivity at 32K and anisotropy in Tl0.58Rb0.42Fe1.72Se2 crystals

Single crystals of Tl0.58Rb0.42Fe1.72Se2 are successfully grown with the superconducting transition temperatures Tconset=32K and Tczero=31.4K. The Hall coefficient exhibits a multi-band behavior, which is very similar to that of all other Fe-based superconductors. We found that the susceptibility at the normal state decreases with decreasing the temperature, indicating a strong antiferromagnetic (AFM) spin fluctuation at the normal state, which might be related to the superconductivity (SC). We also determined the upper critical fields in ab-plane and along c-axis. The anisotropy of the superconductivity determined by the ratio of Hc2ab and Hc2c is estimated to 5.0, which is larger than that in (Ba,K)Fe2As2 and BaFe2-xCoxAs2, but smaller than that in cuprate superconductors.Comment: 4 pages, 4 figure

A Mobile Application Penyikang Applied in Postpartum Pelvic Floor Dysfunction: A Cross-Sectional Study to Analyze the Factors Influencing Postpartum Pelvic Floor Muscle Strength and Women’s Participation in Treatment

Objectives. Postpartum pelvic floor muscle (PFM) injuries are the result of pregnancy and delivery, which lead to a series of symptoms requiring long-term follow-up. Mobile health platforms are progressively used for monitoring clinical conditions in medical subjects. This survey was a cross-sectional design based on collecting data from an application (Penyikang). We retrospectively analyzed the risk factors for weak postpartum PFM and further analyzed the factors influencing women’s participation in the treatment which may help to improve the app’s application in the future. Methods. We enrolled postpartum women who gave birth at the Women’s Hospital, Zhejiang University School of Medicine from August to November 2017; trained them to use the app; and collected the demographic and clinical information. This app requires users to fill questionnaires to assess their knowledge of pelvic floor dysfunction (PFD) and pelvic floor muscle training (PFMT) and experience with PFMT, and each therapy evaluation was restored. The relationship between the knowledge of PFMT/PFD, UI symptoms, and PFM strength was analyzed. Cluster analysis was used to define the degree of participation and identify the factors influencing the patients’ participation in intensive therapy and evaluation. Results. 1982 postpartum women who enrolled in the app program were defined as weak PFM. Younger maternal age, cesarean section, and without delivery injury were found as the prognostic factors to PFM strength (both type I and type II muscle fibers) (P<0.05), and higher educational level was also in favor of type II muscle fibers (P<0.05). Patient-reported UI symptoms were associated with weak PFM strength (P<0.05); there were no significant differences between knowledge of PFMT or PDF and PFM strength. Finally, patients with a higher degree of participation were more likely to accept the treatment (P<0.05). Conclusions. The mobile app provides a new applicative way to investigate postpartum PFD. The factors influencing women’s participation can help us focus on strategies to increase the patients’ compliance, and then we will apply the app into more areas to improve the prevention and treatment of postpartum PFD

Improvement of obesity-associated disorders by a small-molecule drug targeting mitochondria of adipose tissue macrophages

Adipose tissue macrophages are central to controlling inflammation in the context of obesity. Here the authors present a new infrared dye (IR-61) that accumulates in the mitochondria of these cells resulting in anti-inflammatory effects that counter obesity-associated pathology in mice