[Application of computational fluid dynamics in the evaluation of left ventricular function in cardiomyopathies and coronary disease].

Computational fluid dynamics (CFD) is an emerging technology applied in the field of cardiovascular medicine, which can obtain hemodynamic data by simulating the blood flow in the patient's heart for cardiac function assessment and disease diagnosis. Left ventricular function plays a key role in the occurrence and development of cardiomyopathies and coronary disease. CFD can reconstruct the left ventricular anatomic structures of patients to clarify pathophysiologic mechanisms and analyze hemodynamic parameters to evaluate left ventricular function, verify surgical efficacy, and guide surgical strategy, which has a positive effect on achieving early diagnosis and reducing mortality from cardiomyopathies and coronary disease. At present, there are still technical limitations in the large-scale clinical application of CFD, and various solutions are being developed and tested, and further improvement and refinement are needed.

[Comparison of different reconstruction procedures after distal gastrectomy in patients with gastric cancer].

Objective: To systematically compare the effect of Roux-en-Y with Billroth Ⅰ or Billroth Ⅱ in gastric cancer patients after distal gastrectomy by meta-analysis. Methods: Systematic search was conducted on the relevant electronic databases of Pubmed, Embase, Wanfang Database, CNKI and VIP from the established time to August 18, 2019. The randomized controlled trials about comparison of Roux-en-Y with Billroth Ⅰ or Billroth Ⅱ were strictly screened and analyzed by the software of Revman 5.3. Procedure and postoperative outcomes were analyzed, respectively. Results: A total of 783 relevant literatures were systematically retrieved, and 6 randomized controlled trials, including 954 patients, finally met the inclusion criteria after strict screening. The results of meta-analysis showed that operative time of Billroth Ⅰ was significantly shorter than that of Roux-en-Y (MD=-37.60, 95%CI:-50.79--24.40, P<0.001), intraoperative bleeding (MD=-21.64, 95%CI:-32.20--11.07, P<0.001) and the number of delayed gastric emptying (RR=0.52, 95%CI: 0.31-0.86, P=0.01) of Billroth Ⅰ were both significantly less than those of Roux-en-Y, while bile reflux (RR=8.17, 95%CI: 2.21-31.53, P=0.002) and residual gastritis (RR=1.75, 95%CI:1.43-2.14, P<0.000 01) of Billroth Ⅰ were both significantly higher than those of Roux-en-Y, other outcomes showed no significant difference. Compared with Roux-en-Y, operative time of Billroth Ⅱ was significantly shorter (MD=-19.73, 95%CI:-32.82--6.64, P=0.003), while bile reflux (RR=17.63, 95%CI: 4.50-69.02, P<0.001), residual gastritis (RR=1.94, 95%CI:1.15-3.26, P=0.01) and reflux esophagitis (RR=3.13, 95%CI: 1.31-7.45, P=0.01) of Billroth Ⅱ were all significantly higher, and there was no significant difference in other outcomes. Conclusion: Compared with Billroth Ⅰ and Billroth Ⅱ, the operation time of Roux-en-Y in gastric cancer patients undergoing distal gastrectomy is longer, but the incidences of bile reflux and residual gastritis are both lower, and the postoperative quality of life seems better.

The urogenital-hypogastric sheath: an anatomical observation on the relationship between the inferomedial extension of renal fascia and the hypogastric nerves.

PURPOSE: The study aimed to perform an anatomical observation on the inferomedial extension of the renal fascia (RF) to the pelvis and explore its relationship with the hypogastric nerves (HGNs). METHODS: Gross anatomy was performed on 12 formalin-fixed and 12 fresh cadavers. Sectional anatomy was performed on four formalin-fixed cadavers. RESULTS: Different from the traditional concept, both the anterior and posterior RF included the outer and inner layer with different inferomedial extensions. The multiple layers of RF extended downward to form a sandwich-like and compound fascia sheath with potential and expandable spaces which was named as "the urogenital-hypogastric sheath." Below the level of the origin of the inferior mesenteric artery, the bilateral urogenital-hypogastric sheath communicated with the counterpart in front of the great vessels in the midline and the superior hypogastric plexus ran into the urogenital-hypogastric sheath which carried the HGNs, ureters, and genital vessels downward to their terminations in the pelvis. In the retrorectal space, the urogenital-hypogastric sheath surrounded the fascia propria of the rectum posterolaterally as a layer of coat containing HGNs. CONCLUSION: The multiple layers of RF with different extensions are the anatomical basis of the formation of the urogenital-hypogastric sheath. As a special fascial structure in the retroperitoneal space and the pelvis, emphasis on its formation and morphology may be helpful for not only unifying the controversies about the relationship between the pelvic fascia and HGNs but also improving the intraoperative preservation of the HGNs by dissecting in the correct surgical plane.

Comparison of computed tomography and magnetic resonance imaging in the evaluation of facet tropism and facet arthrosis in degenerative cervical spondylolisthesis.

The aim of this study was to determine the reliability of magnetic resonance imaging (MRI) in the assessment of facet tropism and facet arthrosis of spondylolisthesis levels in degenerative cervical spondylolisthesis as compared to computed tomography (CT). The discrepancies in the interpretation of CT and MRI data in the evaluation of facet tropism and arthrosis have given rise to questions regarding the reliability of comparisons of the two techniques. Using a 4-point scale, 3 blinded readers independently graded the severity of facet tropism and facet arthrosis of 79 cervical facet joints on axial T2-weighted and sagittal T1 and T2-weighted turbo spin echo images as well as the corresponding axial CT scans. All results were subjected to the kappa coefficient statistic for strength of agreement. In the assessment of the severity of facet arthrosis, intermethod agreement (weighted κ) between CT scanning with a moderate inter-rater reliability (range κ = 0.43-0.57) and MRI with fair inter-rater reliability (range κ = 0.23-0.38) was 0.76 and 0.43 for the severity of facet tropism and facet arthrosis, respectively. Intra-rater reliability for the severity of facet arthrosis was moderate to substantial for CT and was moderate for MRI scans. Intra-rater reliability for the severity of facet tropism was substantial to very good for CT and substantial for MRI scans. MRI can reliably determine the presence or degree of facet tropism but not facet arthrosis. Therefore, for a comprehensive assessment of cervical facet joint degeneration, both a CT and an MRI scan should be performed.

Distribution and speciation of mercury in surficial sediments from main mangrove wetlands in China.

The purpose of this study was to establish the distribution, speciation and bioavailability of mercury in mangrove sediments. A systemic survey of surficial sediments from 13 mangrove wetlands of China was carried out. Hg concentrations ranged from 2.3-903.6ngg(-1), with an average value of 189.4ngg(-1). Of the 13 areas surveyed, the Hg content in sediments was similar to background levels in 6 areas but was much higher in the other seven areas. Hg levels were affected by natural and anthropogenic factors, including terrestrial pollutants, geomorphic properties, and indirectly by economic status. Hg levels were positively correlated with organic matter, pH, and silt and clay fractions, but Hg was negatively correlated with sand fraction. In most mangrove wetlands, Hg existed primarily in the form of volatile Hg. Hg is easily bioaccumulated in mangrove wetlands and may be the natural source of Hg emissions to the atmosphere.

[Experimental morphological study of injection nerve injuries in rabbits].

The sciatic nerve of 16 rabbits were examined with the optical and electron microscope 2, 24, 72 hours and 7 days after injecting penicillin (200,000 U) into nerve or its peripheral in experiment group and control group. The experiment group showed successively nerve fiber tumefaction, myelin sheath lamellar separation and degeneration partly, the construction of axonal change abnormality myelin and axonal obvious degeneration from 2 hours to 7 days. The control group showed perinerve edema, hyperemia, epineurium hyperplasia, the nerve fiber of near epineurium had mild pathologic changes.

[Study on the inflation pressure of air tourniquets in surgery of the upper extremities].

52 patients were studied under two different inflation pressure so as to find out the proper inflation pressure in the upper extremity operation. Analyzing the hemostasis effect and EMG of the upper extremity under different inflation pressre, it suggested that when the air tourniquet is used in the upper extremity operation the traditionally used pressure (33.3-40.0 kPa) of the air tourniquet should be changed according to the patient's condition. Usually good hemotasis effect could be obtained under the pressure of 4.0-6.6 kPa, which is more than the systolic pressure of the brachial artery.