[Associations of Socioeconomic Factors,Nutrients Intake,and Gut Microbiota of Healthy Pregnant Women in the Third Trimester with Gestational Weight Gain].

Objective To investigate the associations of socioeconomic factors,nutrients intake,and gut microbiota of healthy pregnant women in the third trimester with gestational weight gain (GWG).Methods We recruited 98 pregnant women in the third trimester who had received antenatal care in the Department of Obstetrics Gynecology,Peking Union Medical College Hospital from October,2015 to May,2016. We collected socioeconomic information through a structured questionnaire covering age,ethnicity,height,pre-pregnancy weight,and education. Nutritional status of these pregnant women was assessed by a 24-hour dietary intake recall. The participants were provided with collective tubes for faecal sample collection at home;their weight before the delivery was recorded. The pre-pregnancy weight and GWG were classified according to World Health Organization body mass index (BMI) standard for adults and the Institute of Medicine GWG guidelines (2009),respectively. The gut microbiota of the participants were analyzed using a whole-metagenome shotgun sequencing method.Results Insufficient and excessive GWG accounted for 15.3% and 50.0% of the cohort,respectively. Appropriate GWG level was associated with intakes of fat (F=3.113,P=0.049),carbohydrates (F=3.750,P=0.027),and dietary fiber (F=4.499,P=0.014) but not with age (F=2.495,P=0.088),ethnicity (Χ 2=0.065,P=0.968),education (Χ 2=0.827,P=0.661),or pre-pregnancy BMI (F=0.121,P=0.887). Compared with the participants with appropriate GWG,those with excessive GWG had significantly higher abundance of Akkermansia muciniphila,Atopobium parvulum,and Alistipes indistinctus as well as lower abundance of Lactobacillus rhamnosus,Weissella unclassified,Eubacterium ventriosum,Ruminococcus torques,and Bacteroides uniformis. Compared with the participants with appropriate GWG,those with insufficient GWG had significantly higher abundance of Dialister invisus,Alistipes unclassified,Peptoniphilus harei,Escherichia unclassified,Parvimonas unclassified,Campylobacter ureolyticus,Lactobacillus crispatus,and Fusobacterium nucleatum and lower abundance of Eubacterium ventriosum.Conclusions Abnormal GWG is common in pregnant women. GWG is significantly associated with gut microbiota as well as with nutritional factors including fat,carbohydrate,and dietary fiber intake.

Stimulated emission and lasing from CdSe/CdS/ZnS core-multi-shell quantum dots by simultaneous three-photon absorption.

Three-photon pumped stimulated emission and coherent random lasing from colloidal CdSe/CdS/ZnS core-multishell quantum dots are achieved for the first time. These results can offer new possibilities in biology and photonics, as well as at their intersection of biophotonics.

Photophysical and electrochemical properties of donor-acceptor conjugated oligomers based on 3,4-ethylenedioxythiophene and deficient rings.

The photophysical and electrochemical properties of four novel donor-accepter (D-A) conjugated oligomers a-d based on 3,4-ethylenedioxythiophene (EDOT) and electrondeficient heterocycle rings were investigated. The UV-vis absorption spectroscopy, fluorescence emission spectroscopy and cyclic voltammertry studies suggest that the oligomers are expected to provide enhanced charge-transporting properties for the development of efficient electroluminescent materials. Furthermore, the third-order nonlinear optical (NLO) measurements made by Z-scan technique indicate that they have good third-order NLO response and are desired materias for fabricating nonlinear photonic devices. In the solid state of these oligomers, a strong tendency of self-assembled structure was also revealed by X-ray diffraction (XRD) patterns in powder.

[Preparation of palladium nanoparticles by laser ablation and its spectral properties study].

Palladium colloid was obtained via laser ablation under 1064 nm excitation from an Nd:YAG laser in redistilled deionized water. The Pd colloid consisted of "chemically pure" Pd nanoparticles, which were free from extraneous ions or other chemicals since no chemical reaction was involved in the preparation. There was no characteristic peak in UV/Vis spectrum of Pd colloid in the region of 200-800 nm. Hence, in contrast to the Au and Ag nanoparticles, the average size and the size distribution of the Pd nanoparticles could not be estimated from their UV/Vis adsorption spectral features. After the laser ablation, one drop (50 microL) of Pd colloid was deposited on the aluminum plate and dried naturally to form the Pd island films. This method resulted in the formation of a rough surface with a large number of separated Pd islands 20 microm in diameter. According to the SEM measurement, Pd nanoparticles with the average diameter of approximately 200 nm formed Pd island films. Surface-enhanced Raman scattering (SERS) activity of Pd colloid and Pd island films was evaluated by using 4-mercaptopyridine (4MPY) as a probe molecule. The SERS study revealed that Pd island film was a highly efficient SERS-active substrate while there was no SERS signal observed from Pd colloid. The surface enhancement factor of Pd island films for 4MPY was estimated, which could reach values as high as 8. 7 X 10(4) under 632.8 nm excitation. This value was comparable with the largest value of 10(4) cited in the literature. The SERS spectra of 4MPY molecules adsorbed on Pd surface showed that 4MPY molecules probably tilted from the Pd nanoparticle surface-via sulphur. By contrast, SERS spectrum of 4MPY adsorbed on Ag island films was recorded and analysed. From SERS data it was inferred that 4MPY molecules assumed the standing up orientation on the silver nanoparticle surface. It could be concluded that the 4MPY molecules were more perpendicular to the silver nanoparticle surface than to the Pd nanoparticle surface.