Design of a novel carbon nanotube and metal-organic framework interpenetrated structure with enhanced microwave absorption properties.

The exploitation of carbon nanotube (CNT) and metal-organic framework (MOF) composite materials has been highly desirable in a number of applications. However, the construction of high dispersibility and stability CNT/MOF complex structures is still an enormous challenge. Herein, a novel assembly method is established for the construction of a CNT/Ni-MOF (0.1 CNT/MOF, 0.2 CNT/MOF, 0.3 CNT/MOF) interpenetrated structure by a solvothermal process. The MOFs can be robustly anchored on the surface of CNTs. Through a series of characterizations, the MOF can be comfortably integrated into the CNT fibers, which exhibits the enhancement of carrier mobility and fluorescence properties. The microwave absorption properties of the CNT/MOF are explored by a vector network analyzer. The 0.1 CNT/MOF has a maximum absorption of -9.2 dB at 18 GHz with a thickness of 5 mm, while the 0.2 CNT/MOF has a maximum absorption of -24.32 dB at 4.5 GHz with a thickness of 5 mm, a performance maximum. Therefore, the 0.2 CNT/MOF structures are potential candidates to ameliorate the microwave absorption properties.

Design of novel CNT/RGO/ZIF-8 ternary hybrid structure for lightweight and highly effective microwave absorption.

Carbon-nanotube-based composites are highly desirable for addressing the difficulties relevant to the quality of electromagnetic wave absorbers. The introduction of lightweight nanocomposites for constructing new structures has been widely studied due to the transformation in impedance matching and attenuation. In this paper, a novel carbon nanotube-graphene oxide-zeolitic imidazolate framework-8 (CNT/RGO/ZIF-8) ternary hybrid structure was successfully fabricated by a facile solvothermal process. The ZIF-8 was entangled initially by carbon nanotubes via the π-π interaction between organic ligands and benzene ring structure in CNT. Then, the CNT/ZIF-8 composite was immobilized on the surface of RGO by interacting with the active functional group of RGO. The structure and performance for CNT, CNT/ZIF-8, and CNT/RGO/ZIF-8 were compared to investigate the interaction mechanisms between components, and CNT/ZIF-8 exhibited a distinct improvement for microwave absorption performance. Furthermore, the introduction of RGO can accelerate the amelioration of absorption characteristics. The interfacial bonding between CNT, RGO, and ZIF-8 exerts a great influence on the absorbing quality. The mechanism of absorption of electromagnetic waves was explained by the synergistic effects of conduction loss, polarization behaviors, and eddy current. The unique structure could offer new insights to exploit advanced microwave-absorption materials.

Efficacy and safety of endoscopic drainage versus percutaneous drainage for pancreatic fluid collection; a systematic review and meta-analysis.

BACKGROUND/AIMS: Pancreatic fluid collections (PFC) are debris or fluid of the pancreas that needs to be drained out. This may result from surgery or necrotizing pancreatitis. This meta-analysis compared the outcomes of PFC through endoscopic and percutaneous interventions. METHODS: A medical database was searched up to June 2022, comparing the outcomes of endoscopic drainage (ED) and percutaneous drainage (PD) for the PFC. Eligible studies reporting clinical and technical success and adverse events were selected. RESULTS: Seventeen studies with 1170 patients were included for meta-analysis, of which 543 patients underwent ED and 627 underwent PD. The odd ratio (OR) of technical success was 0.81 (95% confidence interval (CI) 0.31, 2.1) and clinical success was in the favor of the ED group at OR 2.23 (95% CI 1.45, 3.41). Adverse events OR 0.62 (95% CI 0.27, 1.39) and stent migration OR 0.61 (95% CI 0.10, 3.88) were the same in both groups, but hospital stay pooled mean difference of 15.02 days (95% CI 9.86, 20.18), mortality OR 0.24 (95% CI 0.09, 0.67), and re-interventions OR 0.25 (95% CI 0.16, 0.40) favored ED. CONCLUSIONS: ED is safe and efficient for PFC with higher clinical success, lower mortality rate, hospital stay, and re-interventions compared with PD.

Safety and efficacy of lumen-apposing metal stents and double-pigtail plastic stents for endoscopic ultrasound-guided drainage of walled-off necrosis; a systematic review and meta-analysis.

BACKGROUND: Patients with walled-off necrosis (WON) are still challenging to treat safely and effectively. Recently, double-pigtail plastic stents (DPS), bi-flanged metallic stents (BFMS), and lumen-apposing metal stents (LAMS) have been employed with endoscopic ultrasound-guided (EUS-guided) drainage. However, there is little solid evidence to support the effectiveness and safety of using stents. This study aims to compare the outcomes of the LAMS and the PS. METHOD: Till July 2022, a thorough database search was done, and studies that met the criteria were chosen. By using the RevMan software, the technical and clinical success and other secondary outcomes were calculated. Subgroup analysis was performed between the LAMS and the BFMS. RESULTS: Fifteen studies (two randomized controlled trials and thirteen observational) with 687 patients receiving metal stents and 771 patients receiving plastic stents were selected for final analysis. There was no significant risk of bias or publication bias. The odds ratios (OR) for technical and clinical success were 0.36 (95% confidence interval (95% CI) 0.08, 1.52) and 2.26 (95%CI 1.62, 3.15), respectively. The OR for overall adverse events was 0.74 (95% CI 0.41, 1.34). In subgroup analysis, the LAMS and the BFMS showed the same outcomes. CONCLUSION: Compared to DPS, LAMS had better clinical outcomes and fewer side effects when treating patients with WON.

What is the best endoscopic treatment option for the walled-off necrosis (WON)?A brief comparison of lumen-apposing metal stents (LAMS), bi-flanged metallic stents (BFMS) and double-pigtail plastic stents (DPS) for the treatment of WON patients.How can we limit the adverse events and provide better treatment.

Clinicopathological characteristics and prognosis of gastrointestinal vascular tumours.

To evaluate the clinicopathological characteristics and prognosis of gastrointestinal vascular tumours. By reviewing the information from the electronic medical record system and pathology database of Hangzhou First People's Hospital affiliated with Zhejiang University School of Medicine and Jiaxing First People's Hospital from June 2008 to December 2019, 31 patients pathologically diagnosed with vascular tumours were included in this study. The age of onset, sex differences, clinical manifestations, imaging and endoscopic characteristic manifestations, pathological characteristics, treatment methods and prognosis were analysed. The pathological classification was haemangiolymphangioma, haemangioma, and lymphangioma in 8, 14, and 9 cases, respectively. The age of onset was 44-66 years, with no significant difference according to sex (P = 0.583); 32.26% (10/31) of patients had no noticeable symptoms, 37.5% (12/31) of patients had gastrointestinal bleeding, and 6.45% (2/31) of patients, all with lymphangioma, had intestinal obstruction. The lesions were located in and below the duodenum. Endoscopy showed colour differences. Both endoscopic and surgical treatments were safe and effective. The mean survival time was 57.06 ± 35.64 months. Regarding vascular tumours without typical symptoms, the main pathological classification is haemangioma. Vascular tumours are often clinically identified because of bleeding or obstruction and can be treated with endoscopy or surgery. Clinical follow-up is recommended because no invasive manifestations or instances of recurrence were observed.

Correlation of Cleanliness among Different Bowel Segments during Colonoscopy: A Retrospective Study.

OBJECTIVE: To analyze the correlation of intestinal cleanliness in each segment of the Boston Intestinal Preparation Scale. METHODS: From February 2017 to October 2019, the data of patients who underwent colonoscopy in the Department of Gastroenterology, Hangzhou First People's Hospital, Zhejiang University School of Medicine, were collected. Statistical analysis was performed according to the Boston Intestinal Preparation Scale score, and the correlation of intestinal cleanliness in each region was obtained. RESULTS: A total of 1739 patients were included. The overall score of BBPS was 6.77 ± 1.88. The scores of each region were 2.04 ± 0.84 (right lateral colon), 2.25 ± 0.68 (transverse colon), and 2.48 ± 0.64 (left colon). The difference between the regions was statistically significant (P < 0.05). The bowel cleanliness showed a gradual deterioration trend, and there was a positive correlation between colon cleanliness in each region. The accuracy of the transverse colon in predicting the right colon (AUC = 0.809) is higher than that of the left colon (AUC = 0.735), and the accuracy of predicting the cleanliness of the right colon intestinal tract by the cleanliness of the left colon intestinal tract is relatively low. CONCLUSION: Intestinal cleanliness gradually deteriorates from the direction of the insert. It is not reliable to predict the right side of poor cleanliness by using the left colon intestinal cleanliness (BBPS 0-1 score). It should continue to further endoscopy. When the cleanliness of the transverse colon is poor, then stopping further endoscopy is considered.