Objective To optimize the solid-phase synthesis process of phosphorodiamidate morpholino oligonucleotide(PMO)and determine the optimal reaction conditions.Methods The PMO tetramer PMO-TTTT was synthesized according to the reported reaction conditions,followed by purification through a semi-preparative high-performance liquid chromatography(HPLC)process.PMO-TTTT was structurally verified using nuclear magnetic resonance(NMR)and high-resolution mass spectrometry.With purified PMO-TTTT as a reference,a calibration curve was established,which subsequently guided the optimization of the reaction conditions for the solid-phase coupling reaction process,including the organic base,additives,duration of reaction and temperature.Under the optimized reaction condition,the anti-influenza A virus PMO sequence,PMO-flu,was synthesized and purified using a nucleic acid purification device.Results The optimal parameters for PMO solid-phase synthesis were determined.The organic base was N-ethylmorpholine,the additive was lithium iodide,the best temperature was 30 ℃,and the duration was 90 minutes.Conclusion The PMO solid-phase synthesis process has been established.LiI has been screened as a potent coupling reaction additive which could significantly boosts the efficiency of PMO solid-phase synthesis.

Objective: To analyze the influence of atmospheric particulate matters (PM_2.5 and PM₁₀) on low-birth-weight (LBW) infants at different periods of gestation. Methods: We conducted a systematic literature search for 2 471 articles related to particulate matter and LBW published from January 1st 2000 to January 1st 2016 using the PubMed, Cochrane Library, Web of Science, Science Direct, Chinese Web of Knowledge, Wanfang and Weipu, and the keywords were" air pollution" , "adverse birth outcomes" , "adverse pregnancy outcomes" , "low birth weight/LBW" . According to criteria, 27 literatures were selected and included. Metafor package of the R 3.1.1 Software was used to check the heterogeneity and merge the effect value of the selected literatures, and sensitivity analysis and publication bias were detected and adjusted. Results: A total of 2 471 studies selected form the databases, 27 enrolled in this analysis according to the inclusion and exclusion criteria. Each 10 μg/m³ increase in PM_2.5 was associated with combined OR values of 1st trimester, 2nd trimester, 3rd trimester and entire gestation at 1.02(95% CI: 0.87-1.19), 1.03 (95% CI: 0.91-1.16) , 1.07 (95%CI: 1.04-1.11) and 1.09 (95%CI: 1.04-1.15), respectively. And 10 μg/m³ increase in PM₁₀ was associated with combined OR values of 1st trimester, 2nd trimester, 3rd trimester and entire gestation at 1.66 (95%CI: 1.06-2.61), 1.58 (95%CI:1.28-1.95) , 1.38 (95%CI: 1.23-1.56) and 1.04 (95%CI: 0.99-1.09), respectively. After adjusting the bias of publication, each 10 μg/m³ increase in PM_2.5 was associated with the risk of low birth weight at 1.11 (95%CI: 1.02-1.21). Conclusion This meta analysis supports an adverse impact of maternal exposure to particulate air pollution on low birth weight, varying in effects by exposure period.

Objective:To investigate the repair effect of electrospun gelatin polycaprolactone (GT/PCL) nanofiber aerogels (NFA) combined with cartilage extracellular matrix (ECM) for treatment of cartilage injuries in rabbits.Methods:Firstly, the GT/PCL electrospun membrane was prepared by electrospinning and was ground into the short fiber at high speed. ECM was extracted and separated from fresh bovine articular cartilage, which mixed with the short fiber solution (10 ∶1). Subsequently, it was used to prepared GT/PCL/ECM (NFA) three-dimensional scaffold. Finally, the physical characteristics of the three different scaffolds (GT/PCL, ECM and GT/PCL/ECM) were detected by scanning electron microscope and Fourier-transform infrared (FTIR) spectrometer, including the composition, microstructure, swelling rate, porosity, compressive strength and degradation rates. And the biocompatibility research was getting on by co-culturing the scaffold with chondrocytes. Fifteen male New Zealand white rabbits were divided into blank control group (Group A, n=5), ECM group (group B, n=5) and composite scaffold(GT/PCL/ECM)group (Group C, n=5) according to the random number table. An injury model was established and three types of bio-scaffold materials were implanted into different groups. At 3 weeks, the cartilage repair was evaluated among groups by semi quantitative global MRI scoring system (WORMS). After the animals were killed, the knee joints of each group were scored by the international society for cartilage repair histological score (ICRs); the ICRs histological score was performedby HE staining and safranine green staining. Results:Three scaffolds showed a porous three-dimensional structure under the scanning electron microscope. FIRT showed that GT and PCL were introduced into the scaffolds successfully. The GT/PCL NAF was loose and unable to be characterized by materials science. The swelling rate of GT/PCL/ECM scaffold [(1, 092.0±32.2)%] was higher than that of ECM scaffold [(933.6±16.3)%] ( P<0.01). The porosity of GT/PCL/ECM scaffold [(92.3±2.3)%] was higher than that of ECM scaffold [(85.9±2.2)%] ( P<0.05). The compressive strength of ECM scaffold [(2.7±0.1)kPa] and of GT/PCL/ECM scaffold [(2.4±0.1)kPa] showed no statistical difference ( P>0.05). The degradation rate of ECM scaffold was higher than that of GT/PCL/ECM scaffold, but the difference was not statistically significant ( P>0.05). The cytotoxicity rating of GT/PCL/ECM scaffold was grade I, indicating that its biocompatibility was better. At 3 weeks, the MRI WORMS score in Group C [(49.0±11.4)points] was significantly higher than that in Group B [(40.0±6.7)points] and that in Group A [(24.0±6.5) points] ( P<0.05 or 0.01); the general ICRS score of group C was [(7.4±1.1) points], which was significantly higher than that of group B [(4.6±1.1)points] and group A [(3.0±1.2)points] ( P<0.01); The ICRS histological scores of group C and group B were [(6.8±0.8)points] and [(4.2±0.8)points] respectively compared with group A [(2.8±0.8)points] were significantly higher ( P<0.05 or 0.01). Conclusion:GT/PCL/ECM (NFA) scaffold has similar tissue structure to natural cartilage and is superior to traditional ECM scaffold in physical properties and biocompatibility, which provides a stable environment for chondrocyte adhesion and growth, promotes collagen regeneration, and thus accelerates the repair of cartilage injury.