[Research progress on the association between prenatal exposure to air pollutants and hypospadias in the offspring].

Recent epidemiological studies have increasingly found that pregnant women who are exposed to air pollutants (for example airborne particulate matter, nitrogen oxides, ozone, and sulfur dioxide) increase the risk of various birth defects in their offspring, such as congenital heart disease, neural tube defects, cleft lip and palate, and hypospadias. Hypospadias not only impairs the sexual function of infants but also causes major social and psychological problems during their growth period, therefore, the prevention and treatment of hypospadias infant carry substantial public health importance. However, the association between prenatal exposure to air pollution and hypospadias remains controversial. The study reviews the epidemiological research progress and potential biological mechanisms of prenatal maternal exposure to air pollutants such as particulate matter, nitrogen oxides, ozone, sulfur dioxide, and the risk of hypospadias in offspring. The study also summarizes the limitations of previous research and looks forward to future research directions, to provide scientific evidence for creating a healthy living environment for pregnant women, and reducing the risk of hypospadias in offspring.

[Association between cognitive impairment and main metals among oldest old aged 80 years and over in China].

Objective: To identify the main metals involved in cognitive impairment in the Chinese oldest old, and explore the association between these metal exposures and cognitive impairment. Methods: A cross-sectional study was conducted on 1 568 participants aged 80 years and older from Healthy Aging and Biomarkers Cohort Study (2017 to 2018). Fasting venous blood was collected to measure the levels of nine metals (selenium, lead, cadmium, arsenic, antimony, chromium, manganese, mercury, and nickel). The cognitive function of these participants was evaluated by using the Chinese version of the Mini-Mental State Examination (CMMSE). The random forest (RF) was applied to independently identify the main metals that affected cognitive impairment. The multivariate logistic regression model and restricted cubic splines (RCS) model were used to further verify the association of the main metals with cognitive impairment. Results: The age of 1 568 study subjects was (91.8±7.6) years old, including 912 females (58.2%) and 465 individuals (29.7%) with cognitive function impairment. Based on the RF model (the out-of-bag error rate was 22.9%), the importance ranking of variables was conducted and the feature screening of five times ten-fold cross-validation was carried out. It was found that selenium was the metal that affected cognitive function impairment, and the other eight metals were not included in the model. After adjusting for covariates, the multivariate logistic regression model showed that with every increase of 10 µg/L of blood selenium levels, the risk of cognitive impairment decreased (OR=0.921, 95%CI: 0.889-0.954). Compared with the lowest quartile(Q1) of blood selenium, the ORs (95%CI) of Q3 and Q4 blood selenium were 0.452 (0.304-0.669) and 0.419 (0.281-0.622) respectively. The RCS showed a linear dose-response relationship between blood selenium and cognitive impairment (Pnonlinear>0.05). Conclusion: Blood selenium is negatively associated with cognitive impairment in the Chinese oldest old.

Microstructure, mechanical properties and superelasticity of biomedical porous NiTi alloy prepared by microwave sintering.

Porous NiTi alloys were prepared by microwave sintering using ammonium hydrogen carbonate (NH4HCO3) as the space holder agent to adjust the porosity in the range of 22-62%. The effects of porosities on the microstructure, hardness, compressive strength, bending strength, elastic modulus, phase transformation temperature and superelasticity of the porous NiTi alloys were investigated. The results showed that the porosities and average pore sizes of the porous NiTi alloys increased with increasing the contents of NH4HCO3. The porous NiTi alloys consisted of nearly single NiTi phase, with a very small amount of two secondary phases (Ni3Ti, NiTi2) when the porosities are lower than 50%. The amount of Ni3Ti and NiTi2 phases increased with further increasing of the porosity proportion. The porosities had few effects on the phase transformation temperatures of the porous NiTi alloys. By increasing the porosities, all of the hardness, compressive strength, elastic modulus, bending strength and superelasticity of the porous NiTi alloys decreased. However, the compressive strength and bending strength were higher or close to those of natural bone and the elastic modulus was close to the natural bone. The superelastic recovery strain of the trained porous NiTi alloys could reach between 3.1 and 4.7% at the pre-strain of 5%, even if the porosity was up to 62%. Moreover, partial shape memory effect was observed for all porosity levels under the experiment conditions. Therefore, the microwave sintered porous NiTi alloys could be a promising candidate for bone implant.

Effect of micro-arc oxidation surface modification on the properties of the NiTi shape memory alloy.

In this paper, the effects of micro-arc oxidation (MAO) surface modification (alumina coatings) on the phase transformation behavior, shape memory characteristics, in vitro haemocopatibility and cytocompatibility of the biomedical NiTi alloy were investigated respectively by differential scanning calorimetry, bending test, hemolysis ratio test, dynamic blood clotting test, platelet adhesion test and cytotoxicity testing by human osteoblasts (Hobs). The results showed that there were no obvious changes of the phase transformation temperatures and shape memory characteristics of the NiTi alloy after the MAO surface modification and the coating could withstand the thermal shock and volume change caused by martensite-austenite phase transformation. Compared to the uncoated NiTi alloys, the MAO surface modification could effectively improve the haemocopatibility of the coated NiTi alloys by the reduced hemolysis ratio, the prolonged dynamic clotting time and the decreased number of platelet adhesion; and the rough and porous alumina coatings could obviously promote the adherence, spread and proliferation of the Hobs with the significant increase of proliferation number of Hobs adhered on the surface of the coated NiTi alloys (P < 0.05).

Load- and displacement-controlled finite element analyses on fusion and non-fusion spinal implants.

This study used finite element (FE) analysis with the load-controlled method (LCM) and the displacement-controlled method (DCM) to examine motion differences at the implant level and adjacent levels between fusion and non-fusion implants. A validated three-dimensional intact (INT) L1-L5 FE model was used. At the L3-L4 level, the INT model was modified to surgery models, including the artificial disc replacement (ADR) of ProDisc II, and the anterior lumbar interbody fusion (ALIF) cage with pedicle screw fixation. The LCM imposed 10 Nm moments of four physiological motions and a 150 N preload at the top of L1. The DCM process was in accordance with the hybrid testing protocol. The average percentage changes in the range of motion (ROM) for whole non-operated levels were used to predict adjacent level effects (ALE%). At the implant level, the ALIF model showed similar stability with both control methods. The ADR model using the LCM had a higher ROM than the model using the DCM, especially in extension and torsion. At the adjacent levels, the ALIF model increased ALE% (at least 17 per cent) using the DCM compared with the LCM. The ADR model had an ALE% close to that of the INT model, using the LCM (average within 6 per cent), while the ALE% decreased when using the DCM. The study suggests that both control methods can be adopted to predict the fusion model at the implant level, and similar stabilization characteristics can be found. The LCM will emphasize the effects of the non-fusion implants. The DCM was more clinically relevant in evaluating the fusion model at the adjacent levels. In conclusion, both the LCM and the DCM should be considered in numerical simulations to obtain more realistic data in spinal implant biomechanics.

[Optimization of the processing technology of Aconitum kusnezoffii Reichb. by orthogonal test].

A study on the processing technology of Aconitum kusnezoffii by orthogonal test was carried out by assaying as criteria the changes in contents of the total alkaloids and ester type alkaloids before and after processing. The optimum experimental conditions were obtained after treating the experimental data with a formula for the multiple criteria, and the optimal processing results were achieved by having the material macerated with water, cut into thick pieces and then steamed under high pressure (127 degrees C, 0.15MPa) for 3 hours.

[Studies on the sweet principles from the leaves of Cyclocarya paliurus (Batal.) Iljinskaya].

Four intensely sweet compounds (I-IV) were obtained from the leaves of Cyclocarya paliurus (Batal.) Iljinskaya. The structure of compound I was elucidated by chemical and spectroscopic methods as 20,24-epoxy-dammarane-(3 beta,12 beta,24R)-12-O-alpha-L-rhamnopyranosyl-25- hydroxyl-3-O-alpha-(5'-O-acetyl)-L-arabinofuranoside. It is a new natural product, named cyclocarioside A, and is the main sweet principle of this plant, possessing about 200 times the sweetness intensity of sugar.

[Studies on the active constituents of Momordica charantia L].

Five compounds were isolated from the seeds of Momordica charantia. This paper reports their structure determination by spectral (IR, UV, HNMR, CNMR, and MS) and chemical methods. The structures of I, II, III, IV and V were elucidated as vacine, mycose, 3-O-(beta-D-glucopyranosyl)-24 beta-ethyl-5 alpha-cholesta-7, trans-22E, 25 (27)-trien-3 beta-ol, momorcharaside A and momorcharaside B respectively. Mycose was the first time found in this plant and compound III was the first time found in the genus Momordica. IV and V were new compounds. IV exhibited obvious inhibition of DNA and RNA syntheses in S 180 tumor cells in preliminary pharmacological studies.