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Objective to analyze the uterine artery and spiral artery blood flow parameters in patients with unexplained recurrent spontaneous abortion (URSA) with different pregnancy outcomes, to compare the predictive value of uterine artery and spiral artery blood flow parameters in pregnancy outcome, and to explore the possible mechanism of URSA and the effect of different drug regimens on pregnancy outcome in URSA patients. Methods a retrospective cohort study was conducted to analyze the clinical data of 174 pregnant women with unexplained recurrent abortion and 144 pregnant women without adverse pregnancy history. According to the pregnancy outcome, the pregnant women with unexplained recurrent abortion were divided into normal pregnancy outcome group (URSA-N,n = 138) and adverse pregnancy outcome group (URSA-A,n = 36). The pregnant women in the control group were divided into normal pregnancy outcome group (CON-N,n = 129) and adverse pregnancy outcome group (CON-A,n = 15). The blood flow parameters of uterine artery and spiral artery in mid-luteal phase, 11–13 weeks of gestation, 15–17 weeks of gestation and 19–21 weeks of gestation were compared, and the predictive value of uterine artery blood flow parameters and spiral artery blood flow parameters on pregnancy outcome was compared. the effects of aspirin and aspirin combined with low molecular weight heparin on pregnancy outcome in patients with unexplained recurrent abortion were evaluated. Results there was no significant difference in age and body mass index (BMI) between URSA group and CON group. The number of spontaneous abortion and BMI in URSA-N group were less than those in URSA-A group. There was no significant difference in age and BMI between CON groups. The spiral artery blood flow parameters of URSA-N group and CON-N group were lower than those of URSA-A group and CON-A group at mid-luteal phase, 11–13 weeks, 15–17 weeks and 19–21 weeks of gestation, respectively. The uterine artery blood flow parameters (mRI, mPI, mS/D) in the middle luteal period, uterine artery pulse index (mPI) at 11–13 weeks of gestation, peak systolic flow rate/diastolic (mS/D) flow rate at 15–17 weeks of gestation in URSA-N group were lower than those in URSA-A group, and the uterine artery blood flow parameters (mRI, mPI, mS/D) of the CON-N group were lower than those of the CON-A group at the middle luteal stage and weeks 11–13 of gestation. The area under the ROC curve of spiral artery blood flow parameters (mRI,mPI,mS/D) was larger than that of uterine artery. There were significant differences in the efficacy of different drugs between the URSA-N group and the URSA-A group, and aspirin combined with low molecular weight heparin could improve the pregnancy outcome.The area under the ROC curve of spiral artery blood flow parameters (mRI,mPI,mS/D) was larger than that of uterine artery. There were significant differences in pregnancy outcomes among different treatment schemes, and aspirin combined with low molecular weight heparin could improve the pregnancy outcome. The area under the ROC curve of spiral artery blood flow parameters (mRI,mPI,mS/D) was larger than that of uterine artery. There were significant differences in the efficacy of different drugs between the URSA-N group and the URSA-A group, and aspirin combined with low molecular weight heparin could improve the pregnancy outcome. Conclusion the blood flow parameters (mRI,mPI,mS/D) of uterine artery and spiral artery in adverse pregnancy outcome group are higher than those in normal pregnancy outcome group. Abnormal blood flow parameters of uterine artery and spiral artery may be one of the causes of URSA and adverse pregnancy outcome. Spiral artery blood flow parameters are more valuable than uterine artery blood flow parameters in predicting pregnancy outcome. Aspirin combined with low molecular weight heparin can improve the pregnancy outcome of URSA patients more than aspirin alone.

Background: To nd appropriate Nickel-Titanium instruments for lingual canals in mandibular rst premolars with two canals.Methods: A total of 42 extracted mandibular rst premolars with two canals were selected after micro-CT scanning. The teeth were matched and divided into three groups, and three types of Nickel-Titanium instruments (M3, HyFlex CM and XP-endo Shaper) were used to prepare the lingual canals of the sample teeth. After instrumentation, micro-CT scanning was used again to reconstruct the three-dimensional (3D) teeth model, and then it was geometrically aligned with the original model before instrumentation. Two-dimensional (2D) and three-dimensional parameters of teeth models were measured to evaluate the ability of cleaning and maintaining the original canal shape by the three different instruments.Results: Compared with HyFlex CM and XP-endo Shaper, the apical transportation of M3 was signi cantly greater within the apical 3 mm (P < 0.05), while there was no signi cant difference between HyFlex CM and XP-endo Shaper (P > 0.05). There was no signi cant difference in centering ability among three types of instruments (P > 0.05). In general, HCM group and XPS group performed better than M3 group in the 2D and 3D analysis (P < 0.05).Conclusions: Preparation of the lingual canal in mandibular rst premolar was more challenging than that of the main buccal canal. All the three nickel-titanium instruments are safe for canal preparation, and generally, the HyFlex CM and XP-endo Shaper performed better than the M3.

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Let p ∈ (0, 1] n be a n-dimensional vector and A a dilation. Let H p A (R n ) denote the anisotropic mixed-norm Hardy space defined via the radial maximal function. Using the known atomic characterization of H p A (R n ) and establishing a uniform estimate for corresponding atoms, the authors prove that the Fourier transform of f ∈ H p A (R n ) coincides with a continuous function F on R n in the sense of tempered distributions. Moreover, the function F can be controlled pointwisely by the product of the Hardy space norm of f and a step function with respect to the transpose matrix of A. As applications, the authors obtain a higher order of convergence for the function F at the origin, and an analogue of Hardy-Littlewood inequalities in the present setting of H p A (R n ).