Bis(2,6-dichloro­benz­yl)selane

The title mol­ecule, C14H10Cl4Se, features a selenide bridge between two dichloro­benzyl units. The dihedral angle between the two benzene rings is 107.9 (16)°. In the crystal, weak π–π face-to-face aromatic inter­actions are observed [centroid–centroid distance between two adjacent (but crystallographically different) phenyl rings = 3.885 (5) Å], providing some packing stability. Short Cl⋯Cl contacts of 3.41 (2) Å are observed

(3S,12R,20S,24R)-20,24-Ep­oxy­dammarane-3,12,25-triol

In the title mol­ecule, C30H52O4, the three six-membered rings are in chair conformations, the cyclo­pentane ring is in an envelope form and the tetra­hydro­furan ring has a conformation inter­mediate between half-chair and sofa. In the crystal, mol­ecules are linked by inter­molecular O—H⋯O hydrogen bonds into helical chains along [100]. Two intra­molecular O—H⋯O hydrogen bonds are also present. One C atom of the tetrahydrofuran ring and its attached H atoms are equally disordered over two sets of sites

The role and safety of UVA and UVB in UV-induced skin erythema

BackgroundDifferent wavelengths of ultraviolet (UV) light cause skin damage through different mechanisms. Minimal erythema dose (MED) is usually used to clinically evaluate skin sensitivity to ultraviolet radiation by inducing skin erythema using ultraviolet B (UVB) or ultraviolet A (UVA) + UVB.AimsIn this study, we detected changes in the blood flow at the MED erythema caused by UVB and UVA + UVB radiation through optical coherence tomography (OCT) to explain the role of different bands of ultraviolet rays in erythema induction.MethodsTwo MED irradiation areas on the subjects' back were irradiated with UVB alone or UVA + UVB (UVA: UVB = 8:1). The absolute energy of UVB remained the same in UVB and UVA+UVB. At 24 h after the irradiation, the changes in the blood flow in the MED area were detected using OCT.ResultsCompared with the blank control, the maximum blood flow depth, blood flow peak, and total blood flow of UVB-MED and UVA+UVB-MED were significantly increased. Notably, the maximum blood flow depth and blood flow peak of UVB-MED were higher than UVA+UVB-MED. There was no significant difference in total blood perfusion between UVA+UVB-MED and UVB-MED. Under the same UVB energy, the skin erythema caused by UVA + UVB was weaker than UVB alone.ConclusionsThe analysis of local blood flow by OCT showed that the peak and maximum depth of local blood flow caused by UVB alone were significantly higher than UVA + UVB

Did the S.A.R.S. epidemic weaken the integration of Asian stock markets? Evidence from smooth time-varying cointegration analysis

The purpose of this study is to examine the effect of the Severe Acute Respiratory Syndrome (S.A.R.S.) epidemic on the long-run relationship between China and four Asian stock markets. To this end, we first employ the advanced smooth time-varying cointegration model to investigate the existence of a time-varying cointegration relation among these markets and then employ the difference-indifferences approach to analyse whether or not the S.A.R.S. epidemic impacted the long-run relation between China and these four markets during the period 1998–2008, covering 5 years before and after the S.A.R.S. outbreak. Our results support the existence of a time-varying cointegration relation in the aggregate stock price indices, and that the S.A.R.S. epidemic did weaken the long-run relationship between China and the four markets. Therefore, stockholders and policy makers should be concerned about the influence of catastrophic epidemic diseases on the financial integration of stock market in Asia

USE JD-R THEORY TO EXPLORE THE RELATIONSHIP BETWEEN EMPLOYEE EXPERIENCE AND EMPLOYEE ENGAGEMENT—TAKING JOB DEMANDS AS THE MODERATING VARIABLE

Past research has proven that employee experience has a positive impact on employee engagement. Based on the conceptual framework of Job Demands-Resources model (JD-R) model, this study regards efficient employee experience as a job resource to explore the impact of "employee experience" and” job demands” on employee engagement in organizations. Work requirements are further divided into challenge demand and hindrance demand. This study adopts the experimental design of the scenario method and uses two two-factor independent sample designs, namely 2x2(employee experience is high / employee experience is low x challenging job demands is high / challenging job demands is low) and 2x2(employee experience is high / employee experience is low x hindering job demands is high / hindering job demands is low).A total of 176 valid questionnaires were collected. The research results found that when employee experience is high, employee engagement is higher than when employee experience is low. Employee experience and job demands have an interactive effect on employee engagement. When employee experience is high, employee engagement will be higher when challenging job demands are added than when hindering job demands are added. It is expected that the results of this study can help in theoretical and practical application

COMPARISON OF TORSO TWIST BETWEEN SLAP HIT AND ORDINARY HIT IN SOFTBALL BATTING

Softball batters take advantage of slap hit, by positioning the batters much closer to the first base. The purpose of this study was to compare the difference of torso twist between a slap hit and an ordinary hit in softball batting. Ten female college softball batters performed slap hits and ordinary hits. Reflective markers were placed on specific landmarks for each subject and VICON motion analysis system was used to record the hits. Slap hits showed less backward rotation during the torso wind-up phase while ordinary hit showed more forward rotation during the torso follow-through phase. No difference on trunk rotation was found at impact. The findings of this study suggested that the restricted backward torso twist during the wind-up phase and the limited forward torso twist during the follow-through phase should be taken into consideration in slap hits

Sodium alginate and Chitosan aided design of form-stable Polyrotaxane based phase change materials with ultra-high latent heat.

We prepared a series of highly porous Polyrotaxane/sodium alginate, and Polyrotaxane/Chitosan foam alloys according to a sustainable pathway by using water as the only solvent. The foam alloys were further used as supporter materials for poly (ethylene glycol) (PEG) encapsulation, to fabricate shape-stable bio-based phase change materials (PCMs). The pore morphology and the internal interface between PEG and foam alloys were characterized by scanning electron microscope (SEM). Due to the good compatibility between foam alloys and PEG, the PCM performed perfect anti-leakage properties. The introduction of sodium alginate or Chitosan ensures the shape stability of the PCMs during the phase transition. The PCMs performed good cycle stability and showed ultra-high latent heat (171.6 J g−1–189.5 J g−1). Finally, we compared the typical indicators of this work with those reported in the literature, and the comparison highlighted that the present PCMs have the significant advantages: high melting enthalpy, convenient preparation and outstanding sustainability. Notably, the work provided a sustainable idea for the design of anti-leakage and shape-stable PEG-based PCMs.pre-print1327 K