Multidimensional Ultrasound Evaluation of Diastasis Recti Abdominis During Different Gestational Periods.

OBJECTIVE: The purpose of this study is to explore the application value of two-dimensional ultrasound and shear wave elastography (SWE) in the multidimensional evaluation of diastasis recti abdominis (DRA) during different gestational periods. METHODS: A cohort of 202 gravidas that were examined in our hospital between June 2021 and September 2022 were selected for the purpose of the study, which included 26 cases with <14 weeks of pregnancy, 36 cases in the 14th-27th week of pregnancy, 36 cases in the 28th-34th week of pregnancy, 32 cases in the 35th-38th week of pregnancy, 45 cases at 42 days postpartum, and 27 cases at 3 months postpartum. The inter-rectus distance (IRD) and the thickness in each gestational period were measured, and Young's modulus of the rectus abdominis at different gestational periods was measured using SWE by two sonographers. The differences in IRD, thickness, and elasticity characteristics during different periods, and the correlation between rectus abdominis elasticity and IRD, thickness, body mass index (BMI), neonatal weight, and delivery mode were analyzed and compared. The consistency of SWE parameters obtained by different sonographers was also compared. RESULTS: There were significant differences in IRD, thickness, and Young's modulus during different gestational periods (P = .000, P < .001, P < .001). Early postpartum IRD and Young's modulus did not restore to the level of early pregnancy (P < .001, P < .001), while the thickness of rectus abdominis was not significantly different from that of early pregnancy (P = .211). The Young's modulus of rectus abdominis was negatively correlated with the IRD (r = .515), positively correlated with the thickness of rectus abdominis (r = .408), and weakly negatively correlated with maternal BMI (r = -.296). There was no significant correlation with neonatal weight or delivery mode (P = .147, .648). The Bland-Altman plot showed that the two sonographers had good consistency in evaluating the elasticity of rectus abdominis by SWE. CONCLUSION: The multidimensional evaluation of DRA by ultrasound is feasible and IRD and Young's modulus can be used to evaluate the postpartum recovery of DRA. The combination of the two can objectively reflect the severity of DRA morphology and function.

Ferroelectric phase-transition frustration near a tricritical composition point.

Phase transition describes a mutational behavior of matter states at a critical transition temperature or external field. Despite the phase-transition orders are well sorted by classic thermodynamic theory, ambiguous situations interposed between the first- and second-order transitions were exposed one after another. Here, we report discovery of phase-transition frustration near a tricritical composition point in ferroelectric Pb(Zr1-xTix)O3. Our multi-scale transmission electron microscopy characterization reveals a number of geometrically frustrated microstructure features such as self-assembled hierarchical domain structure, degeneracy of mesoscale domain tetragonality and decoupled polarization-strain relationship. Associated with deviation from the classic mean-field theory, dielectric critical exponent anomalies and temperature dependent birefringence data unveil that the frustrated transition order stems from intricate competition of short-range polar orders and their decoupling to long-range lattice deformation. With supports from effective Hamiltonian Monte Carlo simulations, our findings point out a potentially universal mechanism to comprehend the abnormal critical phenomena occurring in phase-transition materials.

An Ultrasound Model to Predict the Short-Term Effects of Endovascular Stent Placement in the Treatment of Carotid Artery Stenosis.

Purpose: The present study aimed to explore the predictive ability of an ultrasound linear regression equation in patients undergoing endovascular stent placement (ESP) to treat carotid artery stenosis-induced ischemic stroke. Methods: Pearson's correlation coefficient of actual improvement rate (IR) and 10 preoperative ultrasound indices in the carotid arteries of 64 patients who underwent ESP were retrospectively analyzed. A predictive ultrasound model for the fitted IR after ESP was established. Results: Of the 10 preoperative ultrasound indices, peak systolic velocity (PSV) at stenosis was strongly correlated with postoperative actual IR (r = 0.622; P < 0.01). The unstable plaque index (UPI; r = 0.447), peak eccentricity ratio (r = 0.431), and plaque stiffness index (ß; r = 0.512) moderately correlated with actual IR (P < 0.01). Furthermore, the resistance index (r = 0.325) and the dilation coefficient (r = 0.311) weakly correlated with actual IR (P < 0.05). There was no significant correlation between actual IR and the number of unstable plaques, area narrowing, pulsatility index, and compliance coefficient. In combination, morphological, hemodynamic, and physiological ultrasound indices can predict 62.39% of neurological deficits after ESP: fitted IR = 0.9816 - 0.1293ß + 0.0504UPI - 0.1137PSV. Conclusion: Certain carotid ultrasound indices correlate with ESP outcomes. The multi-index predictive model can be used to evaluate the effects of ESP before surgery.

Ultrasonography for Preoperative Diagnosis of Retroperitoneal Fibrosis.

This study aimed to assess the application of ultrasonography for preoperative diagnosis of retroperitoneal fibrosis (RPF). A total of 51 patients with clinically suspected RPF underwent transabdominal ultrasonography and ultrasound-guided histopathologic biopsy (tAU-UGHB). Retroperitoneal fibrosis was diagnosed in 35 patients; of these, 31 cases (88.6%) received a diagnosis using tAU-UGHB. The ultrasonographic images mainly showed solid, irregular isoechoic masses, which were present behind the retroperitoneum and surrounded the abdominal aorta, inferior vena cava, and ureters and had clear borders with the encapsulated structures. Compared with other retroperitoneal lesions, RPF lesions were mainly located below the initial level of the renal artery, and their internal flow signals were not rich (P < 0.05). Retroperitoneal fibrosis had characteristic ultrasonographic features, and color Doppler ultrasound-guided biopsy could be positioned accurately, safely, and efficiently; therefore, tAU-UGHB can be used as an effective modality for preoperative diagnosis of RPF.

[Isolation and identification of a low temperature hydrocarbon-degrading strain and its degradation characteristics].

A low-temperature hydrocarbon-degrading strain T7-2 was isolated from sea-mud of Bohai polluted area and identified as Rhodococcus erythropolis, which could use diesel oil as carbon source. The optimal temperature and pH for the strain utilizing ethanol was 15 degrees C and 7.8, and the optimal concentration of ethanol and the seed culture was 0.5% and 10(8) CFU/mL, respectively. Inoculated to artificial seawater which was added (NH4)2SO5 2.64 g/L, Na2HPO4 2.5 g/L and yeast extract 0.015 g/L after 7 days of culture at the temperature of 15 degrees C, the rate of degradation was 73.2%. The strain could degrade a large range of n-alkane from C12 to C36.