In order to examine whether repeated sciatic nerve blocks showed tachyphylaxis and continuity of sciatic nerve with spinal cord affected development of tachyphylaxis when assayed in vivo by duration of depression compound action potentials (CAP), rats were anesthetized with halothane, ventilated, monitored and supported with stable hemodynamics and temperature. Posterior tibial nerve distally and sciatic nerve in thigh were exposed, placed on bipolar silver electrodes for stimulation and recording respectively. Three sequential sciatic nerve blocks were performed between these electrodes using 0.15 ml of 3% chloroprocaine. Nine rats were chosen to observe the effects of repeated sciatic nerve blocks on CAP. In another 18 rats, a second investigator exposed the sciatic nerve near its origin at spinal cord and randomly performed nerve cut and sham (n=9), and closed the incision blinding the electrophysiologic investigator. The results showed that electrical stimulated tibial nerve induced sciatic nerve Aalpha/beta, Adelta, C fiber mediated CAP waves. CAP amplitudes were remained stable during whole experimental procedure. CAP amplitudes were decreased completely with 3% chloroprocaine blocked sciatic nerve and recovered fully. The duration of CAP depression were reduced with repeated blocks. There were no selective blocked effects on Aalpha/beta, Adelta, C fiber mediated CAP. With sciatic nerve cut proximally, there was no statistical significant tachyphylaxis with 3% chloroprocaine repeated blocked sciatic nerve, and the duration of first and third blocked Adelta fiber mediated CAP was 108+/-20 and 92+/-14 min respectively (P>0.05). In normal rats the duration of first and third blocked Adelta fiber mediated CAP was 110+/-20 and 75+/-16 min respectively (P<0.05). It was suggested that tachyphylaxis to local anesthetics can occur in rats repeated blocked sciatic nerve when assayed in vivo by duration of depression CAP. The continuity of sciatic nerve with spinal cord is one of the important factors affecting the development of tachyphylaxis.
Anesthetics, Local/*administration & dosage ; Nerve Block ; Procaine/administration & dosage ; Procaine/analogs & derivatives ; Sciatic Nerve ; *Tachyphylaxis/physiology

OBJECTIVE: To compare the polysaccharide contents of Dendrobium officinale in collection periods. METHODS: The contents of polysaccharide and mannose were determined by phenol-sulfuric acid method and HPLC. The ratio of peak area between mannose and glucose was worked out by HPLC. RESULTS: The polysaccharide content of Dendrobium officinale distributed from 26.52% to 46.78%, the mannose content was between 13.36% and 25.25%, and the ratio of peak area between mannose and glucose was 2.48-5.91. CONCLUSION: The polysaccharide contents of Dendrobii officinalis from different sources were diverse, all of which accorded with the standard of Chinese Pharmacopoeia: The content of polysaccharide in Dendrobium officinale from Yunnan province exceeded that from Zhejiang province, and the mannose content in biennial samples were higher than annual samples.

Objective    To study the effect of Tangeretin on non-small cell lung cancer (NSCLC) and the tumor stemness, and to find the molecular mechanism of its effect. Methods    We used cell counting and cell cloning experiments to study the effect of Tangeretin on the proliferation of NSCLC cells in vitro. The effect of Tangeretin on the invasion of NSCLC cells was detected by transwell assay. We detected the effect of Tangeretin on the proliferation of NSCLC cells in vivo by nude mouse tumor-bearing experiment. The effect of Tangeretin on tumor stemness of NSCLC cells was detected by self-renew assay, and CD133 and Nanog protein expressions. The expressions of PI3K/AKT/mTOR signaling pathway-related proteins were detected by Western blotting (WB). Results    Tangeretin had a good inhibitory effect on the proliferation of NSCLC cells in vivo and in vitro. Cell counting experiment, clonal formation experiment and nude mouse tumor-bearing experiment showed that Tangeretin could inhibit the proliferation activity, clonal formation ability, and tumor size of NSCLC cells in vivo. Self-renew experiments showed that Tangeretin could inhibit the self-renew ability of NSCLC cells. WB experiments showed that Tangeretin inhibited the expressions of tumor stemness markers CD133 and Nanog in NSCLC cells. Tangeretin could inhibit the activation of PI3K/AKT/mTOR signaling pathway-related proteins in NSCLC cells, and the activation of PI3K/AKT/mTOR signaling pathway could partially remit the inhibitory  effect of Tangeretin on tumor stemness of NSCLC cells. Conclusion    Tangeretin can inhibit the tumor stemness of NSCLC cells, which may be related to the regulation of PI3K/AKT/mTOR signaling pathway.

The setting and adjustment of ventilator parameters need to rely on a large amount of clinical data and rich experience. This paper explored the problem of difficult decision-making of ventilator parameters due to the time-varying and sudden changes of clinical patient's state, and proposed an expert knowledge-based strategies for ventilator parameter setting and stepless adaptive adjustment based on fuzzy control rule and neural network. Based on the method and the real-time physiological state of clinical patients, we generated a mechanical ventilation decision-making solution set with continuity and smoothness, and automatically provided explicit parameter adjustment suggestions to medical personnel. This method can solve the problems of low control precision and poor dynamic quality of the ventilator's stepwise adjustment, handle multi-input control decision problems more rationally, and improve ventilation comfort for patients.
Humans ; Ventilators, Mechanical ; Respiration, Artificial ; Neural Networks, Computer

For the detection and identification of abnormal nodular tissues on the body surface, a microwave sensor structure loaded with a spiral resonator is proposed in this paper, a sensor simulation model is established using HFSS software, the structural parameters are optimized, and the actual sensor is fabricated. The S21 parameters of the tissue were obtained when nodules appeared by simulation, and the characteristic relationship between the difference of S21 parameters with position was analyzed and tested experimentally. The results showed that when nodules were present in normal tissues, the curve of S21 parameter difference with position change had obvious inverted bimodal characteristics, and the extreme value of S21 parameter difference appeared when the sensor was directly above the nodules, which was easy to identify the position of nodules. It provides an objective detection tool for the identification of abnormal nodular tissues on the body surface.
Microwaves ; Recognition, Psychology ; Computer Simulation ; Software

Objective    To explore the potential role of tumor spread through air spaces (STAS) as a prognostic indicator of non-small cell lung cancer (NSCLC) through meta-analysis. Methods    PubMed, EMbase and Web of Science, from inception to February 2022 were searched by computer about the research of the 5-year overall survival (OS) and recurrence free survival (RFS) of NSCLC patients with or without STAS. The Newcastle-Ottawa scale (NOS) was used to evaluate the quality of each study. Results    Totally 13 published articles were included with 4 647 patients, and 1 424 (30.6%) patients had STAS. The NOS score of all studies≥6 points. The meta-analysis showed that compared with the NSCLC patients without STAS, those with STAS had a worse prognosis of 5-year RFS, and the combined HR was 1.89 (95%CI 1.61-2.23); they had a shorter 5-year OS, and the combined HR was 2.25 (95%CI 1.79-2.84). There was no statistical heterogeneity among studies. Conclusion    The presence of STAS may be a poor prognostic factor for patients with NSCLC, and enough attention should be paid. The STAS should be recorded in the pathological report to guide the comprehensive treatment and evaluate the prognosis of patients.

This study aims to investigate whether displacement force on stents can accurately represents the displacement of the stent after endovascular aneurysm repair (EVAR) by comparing the measured stent displacement with the displacement forces calculated by computational fluid dynamics (CFD). And the effect of cross-limb and parallel-limb EVAR on stent displacements is further studied. Based on our objective, in this study, ten cross-limb EVAR patients and ten parallel-limb EVAR patients in West China Hospital of Sichuan University were enrolled. Patient-specific models were first reconstructed based on the computed tomography angiography images, then the stent displacements were measured, and the displacement forces acting on the stents were calculated by CFD. Finally, the cosα value of the angle between the displacement force and the displacement vector was used to analyze the matching degree between the displacement and the displacement force. The results showed that the displacement forces on cross-limb stents and parallel-limb stents were (2.67 ± 2.14) N and (1.36 ± 0.48) N, respectively. Displacements of stent gravity center, stent displacements relative to vessel, and vessel displacements of cross-limb and parallel-limb stents were (4.43 ± 2.81) mm and (6.39 ± 2.62) mm, (0.88 ± 0.67) mm and (1.11 ± 0.71) mm, (3.55 ± 2.88) mm and (5.28 ± 2.52) mm, respectively. The mean cosα for cross-limb and parallel-limb stents were 0.02 ± 0.66 and - 0.10 ± 0.73, respectively. This study indicates that the displacement force on the stent can't accurately represent the displacement of the stent after EVAR. In addition, the cross-limb EVAR is probably safer and more stable than the parallel-limb EVAR.
Aortic Aneurysm, Abdominal/surgery* ; Blood Vessel Prosthesis ; Blood Vessel Prosthesis Implantation ; Endovascular Procedures/methods* ; Humans ; Prosthesis Design ; Retrospective Studies ; Stents ; Treatment Outcome

The geometric bone model of patients is an important basis for individualized biomechanical modeling and analysis, formulation of surgical planning, design of surgical guide plate, and customization of artificial joint. In this study, a rapid three-dimensional (3D) reconstruction method based on statistical shape model was proposed for femur. Combined with the patient plain X-ray film data, rapid 3D modeling of individualized patient femur geometry was realized. The average error of 3D reconstruction was 1.597-1.842 mm, and the root mean square error was 1.453-2.341 mm. The average errors of femoral head diameter, cervical shaft angle, offset distance and anteversion angle of the reconstructed model were 0.597 mm, 1.163°, 1.389 mm and 1.354°, respectively. Compared with traditional modeling methods, the new method could achieve rapid 3D reconstruction of femur more accurately in a shorter time. This paper provides a new technology for rapid 3D modeling of bone geometry, which is helpful to promote rapid biomechanical analysis for patients, and provides a new idea for the selection of orthopedic implants and the rapid research and development of customized implants.
Humans ; Imaging, Three-Dimensional/methods* ; Tomography, X-Ray Computed/methods* ; Femur/surgery* ; Femur Head ; Lower Extremity

For patients with aortic valve disease who require replacement of their native valve, surgical aortic valve replacement (SAVR) has been the standard of care. Due to the hemorrhage and thromboembolic risks of long-term anticoagulation therapy for mechanical prosthesis, bioprosthetic aortic valve replacement (AVR) has a trend to be used in younger patients, which raising the concern for the durability of bioprosthetic valves. The newly published 5-year outcomes of PERIGON trial, with no structural valve deterioration, again demonstrated the favorable durability of the new generation bioprosthetic valves, further providing the evidence of using bioprosthetic AVR in younger patients. At the meantime, the rapid progress of transcatheter aortic valve implantation (TAVI) has brought a new treatment option. For younger patients with low risks, choosing SAVR or TAVI becomes a critical decision. This paper reviews the outcomes of PERIGON trial and its implications to the clinical practice and research of bioprosthetic AVR.

Objective: To explore the association between the consumption of chemical fertilizers and the risk of low birth weight (LBW), to provide references for prevention programs on LBW and to improve the birth outcomes. Methods: Stratified multivariate logistic regression method was used in this study involving 153 preterm LBW infants, 179 term LBW infants and 204 normal control infants that were randomly selected from the birth monitoring data between October 2007 and September 2012 in Pingding county, Shanxi province. Associations between the risk of LBW and maternal exposure to chemical fertilizers during pregnancy were identified. A normal control group was set up to compare results between preterm and term LBW groups. Results: Totally, 18 749 infants were born between 2007 and 2012, with the total incidence rates of LBW as 48.5‰, preterm LBW as 19.4‰, and term LBW as 29.1‰. Concerning the case control study on preterm LBW, after adjustment for confounding factors, the risk of preterm LBW appeared 2.51 (95%CI: 1.05-5.99) times higher in villages with annual consumption of chemical fertilizer ≥100 tons than those villages that using chemical fertilizer less than 50 tons. No significant statistical associations were found between the amounts of household chemical fertilizer consumption and the risks of preterm LBW. Regarding the case control study on term LBW, after adjustment for confounding factors, in villages with ≥100 tons annual consumption of chemical fertilizers, the risk of term LBW was 4.03 (95%CI: 1.63-9.92) times of the risk in villages where the annal use of chemical fertilizers was less than 50 tons. There was no significant association between household consumption of chemical fertilizers and the risk of term LBW. Conclusions: Maternal exposure to chemical fertilizers during pregnancy was associated with the risk of LBW. Our findings suggested that the amount of chemical fertilizer consumption in rural areas seemed also associated with the risks of other adverse pregnancy outcomes. Women should avoid the chance of exposure to chemical fertilizers during pregnancy and the consumption of chemical fertilizers should be carefully managed.
Adult ; Case-Control Studies ; Environmental Exposure/adverse effects* ; Female ; Fertilizers/adverse effects* ; Humans ; Infant ; Infant, Low Birth Weight ; Infant, Newborn ; Maternal Exposure ; Pregnancy ; Premature Birth/epidemiology* ; Random Allocation ; Risk Factors