Associated factors of masked obesity in female college students / 中国学校卫生

Objective@#The status of masked obesity in female college students and the related factors were investigated to provide a theoretical reference for instructing the physical health education of female college students and improving their physical exercises.@*Methods@#Body composition tests were performed on 2 975 female college students, selected from 3 colleges in North China by using cluster sampling method during October to December in 2018, and their basic information and lifestyle were investigated using questionnaires.@*Results@#The incidence of masked obesity among female college students was 33.18%, of which 2.53% came from low-weight people. The difference in the incidence of masked obesity among female college students with different take-out frequencies was statistically significant (χ2=21.98, P<0.01). Compared with those who never take takeaway, people who take takeaway every day have an increased risk of masked obesity (OR=1.49, 95%CI=0.76-2.91). The difference in the incidence of masked obesity with the frequency of eating midnight snack was statistically significant (χ2=20.80, P<0.05). The difference in the incidence of masked obesity among female college students with different exercise time was statistically significant (χ2=18.49, P<0.01). Compared with exercise time above 60 min/d, female college students who are not exercising have an increased risk of masked obesity (OR=3.20, 95%CI=1.63-6.30). The difference in the incidence of masked obesity among female college students with different weight satisfaction was statistically significant (χ2=217.54, P<0.01). Compared with female college students who were satisfied with weight, female college students who were not satisfied with weight had an increased risk of masked obesity (OR=3.47, 95%CI=1.91-6.31). The difference in the incidence of masked obesity in different weightdown plans is statistically significant (χ2=186.40, P<0.01). Those who want to lose weight have a higher risk of developing masked obesity than those who want to gain weight (OR=18.11, 95%CI=5.54-50.13).@*Conclusion@#Female college students who drink a small amount of water, eat takeaways often, eat midnight snacks, do not exercise, and are not satisfied with their weight are more likely to develop masked obesity.

Terephthalate-based cobalt hydroxide: a new electrode material for supercapacitors with ultrahigh capacitance.

Searching for new electrode materials is one of the key tasks in developing high-performance supercapacitors. In this work, as a layered hydroxyl derivative, terephthalate-based cobalt hydroxide, Co2(OH)2(C8H4O4), is successfully prepared in situ on nickel foam through a simple hydrothermal route. The scanning electron microscopy results reveal that the products are composed of massive double-blade lath crystals grown along the a-axis. The as-obtained Ni-foam-supported Co2(OH)2(C8H4O4) is directly used as the positive electrode of supercapacitors without further treatment. The resulting Co2(OH)2(C8H4O4) electrode exhibits ultrahigh charge storage capacity with the specific capacity of 9.36 C cm-2 (1261 C g-1) at a current density of 10 mA cm-2 (0.5 A g-1) and good cycling stability with the capacity retention of 82.4% over 5000 cycles at a current density of 50 mA cm-2. In combination with activated carbon as the negative electrode in 3 M KOH aqueous electrolyte, the constructed asymmetric supercapacitor delivers a high energy density of 30.62 W h kg-1 at a power density of 221 W kg-1 within a voltage window of 1.5 V. These encouraging electrochemical performances enable the developed terephthalate-based cobalt hydroxide to be a promising electrode material for supercapacitor applications.

Hydrothermal growth of ferrous hydroxide terephthalate as a new positive electrode material for supercapacitors.

Ferrous hydroxide terephthalate, Fe(OH)(C8H5O4), is first prepared by an in situ hydrothermal growth method on nickel foam, which can be directly used as the positive electrodes for supercapacitors with superior pseudocapacitive behaviors. It displays high specific capacitance of 5.25 F cm-2 (656.3 F g-1) at 10 mA cm-2 (1.25 A g-1).

Fabrication of Bi19S27I3 nanorod cluster films for enhanced photodetection performance.

Thin-film photodetectors built from one-dimensional nanostructures have attracted extensive attention due to their significance in basic scientific research and potential technological applications. It is still desirable to develop new materials with a wide response range for application in photodetectors. In this work, a Bi19S27I3 nanorod cluster film has been successfully fabricated on various rigid substrates by a facile solvothermal method. The component nanorods exhibit an oriented growth along the [001] direction. The UV-Vis-NIR absorption spectrum shows a continuous strong absorption spanning the whole visible light to near-infrared region and presents a direct band gap of 0.83 eV for the prepared Bi19S27I3 nanorod clusters. The spectral photoresponse of the Bi19S27I3-based photodetector device demonstrates a broad photoresponse ranging from ultraviolet to near infrared. The photocurrent results reveal that the photodetector exhibits a more sensitive response towards near-infrared light than visible light. Furthermore, the photodetector based on the Bi19S27I3 nanorod cluster film shows significantly enhanced photodetection performance compared to Bi19S27I3 nanorod powder. The photocurrent and on-off ratio of the prepared nanorod cluster film are respectively up to 400 times and several times higher than those of the powder sample. The on-off ratios are about 265 and 66 under NIR illumination and 48 and 11 under visible light for the film and powder samples, respectively. These results suggest a great potential application of the prepared Bi19S27I3 nanorod cluster film in optoelectronic devices.