Influence of different magnetic forces on the effect of colonic anastomosis in rats.

BACKGROUND: Despite much work having been conducted on magnetic compression anastomosis (MCA) in the digestive tract, there are no reports on the influence of magnetic force on the anastomosis. AIM: To investigate the effect of different magnetic force magnets on the MCA of the digestive tract. METHODS: Two groups of magnets of the same sizes but different magnetic forces were designed and produced. A total of 24 Sprague-Dawley rats were randomly assigned into two groups (powerful magnet group and common magnet group), with 12 rats in each group. Two types of magnets were used to complete the colonic side-to-side anastomosis of the rats. The operation time and magnet discharge time were recorded. The anastomotic specimens were obtained 4 wk after the operation and then the burst pressure and diameter of the anastomosis were measured, and the anastomosis was observed via the naked eye and subjected to histological examination. RESULTS: The magnetic forces of the powerful and common magnet groups at zero distance were 8.26 N and 4.10 N, respectively. The colonic side-to-side anastomosis was completed in all 24 rats, and the operation success rate and postoperative survival rate were 100%. No significant difference was noted in the operation time between the two groups. The magnet discharge time of the powerful magnet group was slightly longer than that of the common magnet group, but the difference was not statistically significant (P = 0.513). Furthermore, there was no statistical difference in the burst pressure (P = 0.266) or diameter of magnetic anastomosis (P = 0.095) between the two groups. The gross specimens of the two groups showed good anastomotic healing, and histological observation indicated good mucosal continuity without differences on healing. CONCLUSION: In the rat colonic side-to-side MCA model, both the powerful magnet with 8.26 N and the common magnet with 4.10 N showed no significant impact on the anastomosis establishment process or its effect.

Numerical Simulation on the Hydrogen Storage Performance of Magnesium Hydrogen Storage Reactors.

Magnesium hydride (MH) is one of the most promising hydrogen storage materials. Under the hydrogen storage process, it will emit a large amount of heat, which limits the efficiency of the hydrogen storage reaction. In this paper, the hydrogen storage performance of the magnesium hydrogen storage reactor (MHSR) and the effect of structural parameters were studied by numerical simulation. The effect of different operating conditions on the hydrogen storage performance of the MHSR is analyzed. The volume energy storage rate (VESR) was taken as the comprehensive evaluation index (CEI). The results show that fins and heat exchange tubes can improve the heat transfer performance of the MHSR. Increasing fin thickness can reduce hydrogen storage time, but increasing fin spacing is the opposite. With the increase of fin thickness and fin spacing, VESR increases first and then decreases. With the increase of inlet temperature, the hydrogen storage time decreases first and then increases. When the inlet velocity is more than 5 m/s, the hydrogen storage time basically stays at 900 s. By optimizing the operating conditions, the hydrogen storage time can be shortened by 57.8%.

Clinical application of magnetic anchor technique in laparoscopic cholecystectomy: the first retrospective study in China.

Background and objectives: Magnetic anchor technique (MAT) is frequently used in laparoscopic cholecystectomy. However, there are few reports on its clinical application in China. In this study, we retrospectively analyzed the clinical application of MAT in laparoscopic cholecystectomy in China. Materials and methods: 25 patients (4 males, 21 females) who underwent laparoscopic cholecystectomy assisted by MAT at the First Affiliated Hospital of Xi'an Jiaotong University were enrolled from November 2020 to March 2021. Their records were retrospectively analyzed. The magnetic anchor device was independently designed and developed by the authors and consisted of the anchor magnet and magnetic grasping apparatus. Surgical time, intraoperative blood loss, intraoperative accidents, operator experience, postoperative incision pain score, postoperative complications, and other indicators were evaluated and analyzed. Results: All patients successfully underwent laparoscopic cholecystectomy, including 3 cases of MAT-assisted transumbilical single-port LC, 16 cases of MAT-assisted 2-port LC and 6 cases of conventional 3-port LC. The median operation time was 50 min (range 30-95 min); intraoperative bleeding was less than 30 ml. The median score of surgical incision on day 1 and 3 after the operation was 3 (range 1-4) and 1 (range 1-3), respectively. All patients had no intraoperative bile duct injury, vascular injury, postoperative bleeding, bile leakage, biliary stricture and other complications. No adverse events (such as injury to adjacent organs or failure of the magnetic anchor device) occurred either during or after the operation. Conclusions: The MAT-assisted laparoscopic cholecystectomy appears to be safe, feasible and effective and exhibits unique assistance in transumbilical single-port laparoscopic cholecystectomy.

The risk of venous thromboembolism associated with midline catheters compared with peripherally inserted central catheters: A systematic review and meta-analysis.

BACKGROUND: Both midline catheters (MCs) and peripherally inserted central catheters (PICCs) can cause venous thromboembolism (VTE), but the prevalence associated with each is controversial. OBJECTIVE: To compare the risk of VTE between MCs and PICCs with a systematic review and meta-analysis. METHODS: The Web of Science Core Collection, PubMed, Scopus, Embase, the Cochrane Library and ProQuest were searched from inception to January 2020. All studies comparing the risk of VTE between MCs and PICCs were included. Selected studies were assessed for methodological quality using the Downs and Black checklist. Two authors independently assessed the literature and extracted the data. Any different opinion was resolved through third-party consensus. Meta-analyses were conducted to generate estimates of VTE risk in patients with MCs versus PICCs, and publication bias was evaluated with RevMan 5.3. RESULTS: A total of 86 studies were identified. Twelve studies were recruited, involving 40,871 patients. The prevalence of VTE with MCs and PICCs was 3.97% (310/7806) and 2.29% (758/33065), respectively. Meta-analysis showed that the prevalence of VTE with MCs was higher than that with PICCs (RR=1.53, 95% CI: 1.33-1.76, p < .00001). Subgroup analyses by age showed that the prevalence of VTE with MCs was higher than that with PICCs in the adult group (RR=1.75, 95% CI: 1.38-2.22, p < .00001), and higher than that with PICCs in the other subgroups (RR=1.42, 95% CI: 1.19-1.69, p = .0001). Subgroup analyses by nation showed that the prevalence of VTE with MCs was higher than that with PICCs (RR=1.50, 95% CI: 1.30-1.73, p < .00001) in US subgroup and higher than that with PICCs (RR=2.87, 95% CI: 1.24-6.65, p = .01) in the other nations. The sensitivity analysis shows that the results from this meta-analysis are robust and all studies have no significant publication bias. CONCLUSIONS: This study provides the first systematic assessment of the risk of VTE between MCs and PICCs. MCs are associated with a higher risk of VTE than PICCs in all patients and adults. The findings of this study have several important implications for future practice. However, the risk of VTE between MCs and PICCs in children is unclear.

A meta-analysis of the comparison of phlebitis between midline catheters and peripherally inserted central catheters in infusion therapy.

AIMS: To compare the risk of phlebitis between midline catheters and peripherally inserted central catheters in infusion therapy with a meta-analysis. DESIGN: This was a systematic literature review and meta-analysis. DATA SOURCES: Web of Science, PubMed, Scopus, Embase, Cochrane Library, ProQuest, CNKI, WanFang, VIP and SinoMed were searched from inception to May 2020. REVIEW METHODS: All studies comparing the risk of phlebitis between midline catheters and peripherally inserted central catheters were included. According to the inclusion and exclusion criteria, two authors independently assessed the literature and extracted the data. Meta-analyses were conducted to generate estimates of phlebitis risk in patients with midline catheters verse peripherally inserted central catheters, and publication bias was evaluated with RevMan 5.3. RESULTS: A total of seven studies were collected, involving 1377 participants. The incidence of phlebitis with midline catheters and peripherally inserted central catheters was 1.52% and 3.41%. Meta-analysis showed that the incidence of phlebitis has no significant difference between midline catheters and peripherally inserted central catheters. The sensitivity analysis shows that the results from this meta-analysis are fair in overall studies. All studies have no significant publication bias. CONCLUSION: This study provides the first systematic assessment of the risk of phlebitis between midline catheters and peripherally inserted central catheters. The incidence of phlebitis has no significant difference between them. There are many factors to consider when choosing vascular access devices.

Hemocompatibility improvement of decellularized spleen matrix for constructing transplantable bioartificial liver.

Thrombogenicity is the predominant obstacle to successful implantation of decellularized spleen matrix (DSM). The aim of this study was to construct a transplantable functional bioartificial liver (BAL) with the use of DSM. This was achieved by layer-by-layer electrostatic immobilization technique by using poly dimethyl diallyl ammonium chloride and heparin. After heparin immobilization, DSM gradually turned from translucent into completely opaque milky white. Toluidine blue staining showed strong positive staining of the entire coated DSM. In vitro diluted blood perfusion test showed that the splenic arterial pressure of the heparin-coated DSM was much lower than that of the non-coated DSM (p < 0.01). Then, we heterotopically transplanted the modified DSM into rat hepatic injury model for 6 h to evaluate the hemocompatibility in vivo. Overall, HE staining and vWF immunohistochemistry all confirmed that heparin-coated DSM has a satisfactory anticoagulant effect. Based on the heparin-coated DSM, BALs were built with the use of rat primary hepatocytes. Our results demonstrate that these heparin-coated BALs satisfied anticoagulant effects even after 6 h. Immunofluorescence of ALB and G6PC also showed that hepatocytes in heparin-coated BAL have significantly higher cell viability and function than the non-coated group. However, serum analysis did not indicate a significant difference between the two groups but a slight trend of improvement with respect to serum albumin (p = 0.156) and aspartate transaminase (p = 0.140). In conclusion, we demonstrated that the BAL constructed by heparin-coated DSM can exert satisfactory short-term anticoagulant effects and can compensate for a certain degree of liver function.

Impact of cigarette smoking on recurrence of hyperlipidemic acute pancreatitis.

AIM: To investigate the impact of cigarette smoking on the recurrence rate and recurrence-free survival in patients with hyperlipidemic acute pancreatitis (HLAP). METHODS: A total of 863 patients were admitted to our hospital for acute pancreatitis (AP) from January 2013 to March 2016, of whom 88 diagnosed with HLAP were enrolled in this retrospective study. Demographic data, medical history, previous episodes of pancreatitis, consumption of alcohol and cigarettes, as well as biochemical and hematological data were carefully recorded for univariate and multivariate analyses. During follow-up, the information on current smoking status and recurrent AP was gathered. Recurrence-free survival (RFS) was calculated using the Kaplan-Meier method, and the differences between groups were compared using the log-rank test. RESULTS: No significant differences were observed between the three groups in age or medical history of hyperlipidemia, fatty liver, diabetes mellitus, hypertension, or AP. The current smokers had a remarkably higher recurrence rate and a greater incidence of repeated episodes of AP (50.0% and 77.8%, respectively) than non-smokers (9.8% and 39.0%), and these two percentages were reduced to 9.1% and 36.4% for patients who gave up smoking. The median follow-up time was 13.5 mo and HLAP recurred after hospital discharge in 23 (26.1%) patients. Multivariate analysis identified current smoking (HR = 6.3, P = 0.020) as an independent risk factor contributing to HLAP recurrence. Current smokers had significantly worse RFS than non-smokers (23 mo vs 42 mo), but no significant difference was documented between ex-smokers (34 mo) and non-smokers. The RFS was not significantly different between light and heavy smokers. CONCLUSION: Smoking is associated with worse RFS and an increased rate of HLAP recurrence. Continued smoking correlates with a compromised survival and smoking cessation should be recommended.