Effects of root-applied biochar on soil nitrogen transformation and root nitrogen metabolism of cucumber seedlings in facility continuous cropping soils.

The problem of soil barrier caused by excessive accumulation of nitrogen is common in continuous cropping soil of facility agriculture. To investigate the modulating effects of biochar amendment on soil nitrogen transformation in greenhouse continuous cropping systems, we conducted a pot experiment with two treatments, no biochar addition (CK) and 5% biochar addition (mass ratio). We analyzed the effects of biochar addition on soil microbial community structure, abundances of genes functioning in nitrogen cycling, root growth and nitrogen metabolism-related genes expressions of cucumber seedlings. The results showed that biochar addition significantly increased plant height, root dry mass, total root length, root surface area, and root volume of cucumber seedlings. Rhizosphere environment was improved, which enhanced root nitrogen absorption by inducing the up-regulation of genes expressions related to plant nitrogen metabolism. Biochar addition significantly increased soil microbial biomass nitrogen, nitrate nitrogen, and nitrite nitrogen contents. The abundances of bacteria that involved in nitrogen metabolism, including Proteobacteria, Cyanobacteria, and Rhizobiales (soil nitrogen-fixing bacteria), were also significantly improved in the soil. The abundances of genes functioning in soil nitrification and nitrogen assimilation reduction, and the activities of enzymes involved in nitrogen metabolisms such as hydroxylamine dehydrogenase, nitronate monooxygenase, carbonic anhydrase were increased. In summary, biochar addition improved soil physicochemical properties and microbial community, and affected soil nitrogen cycling through promoting nitrification and nitrogen assimilation. Finally, nitrogen adsorption capacity and growth of cucumber plant was increased.

Artificial intelligence for diagnosing microvessels of precancerous lesions and superficial esophageal squamous cell carcinomas: a multicenter study.

BACKGROUND: Intrapapillary capillary loop (IPCL) is an important factor for predicting invasion depth of esophageal squamous cell carcinoma (ESCC). The invasion depth is closely related to the selection of treatment strategy. However, diagnosis of IPCLs is complicated and subject to interobserver variability. This study aimed to develop an artificial intelligence (AI) system to predict IPCLs subtypes of precancerous lesions and superficial ESCC. METHODS: Images of magnifying endoscopy with narrow band imaging from three hospitals were collected retrospectively. IPCLs subtypes were annotated on images by expert endoscopists according to Japanese Endoscopic Society classification. The performance of the AI system was evaluated using internal and external validation datasets (IVD and EVD) and compared with that of the 11 endoscopists. RESULTS: A total of 7094 images from 685 patients were used to train and validate the AI system. The combined accuracy of the AI system for diagnosing IPCLs subtypes in IVD and EVD was 91.3% and 89.8%, respectively. The AI system achieved better performance than endoscopists in predicting IPCLs subtypes and invasion depth. The ability of junior endoscopists to diagnose IPCLs subtypes (combined accuracy: 84.7% vs 78.2%, P < 0.0001) and invasion depth (combined accuracy: 74.4% vs 67.9%, P < 0.0001) were significantly improved with AI system assistance. Although there was no significant differences, the performance of senior endoscopists was slightly elevated. CONCLUSIONS: The proposed AI system could improve the diagnostic ability of endoscopists to predict IPCLs classification of precancerous lesions and superficial ESCC.

Comparison of Interferon-α-based therapy and nucleos(t)ide analogs in preventing adverse outcomes in patients with chronic hepatitis B.

BACKGROUND: Whether interferon (IFN)-α therapy is better than nucleos(t)ide analogs (NAs) in the prevention of adverse outcomes, including hepatocellular carcinoma (HCC) in patients with chronic hepatitis B (CHB) is still uncertain or controversial. This study aimed to compare the cumulative incidence of adverse outcomes in patients with CHB on IFN-α- and NA-based therapies. METHODS: This was a retrospective study of patients with CHB on antivirals. Patients treated with IFN-α (IFN-α or peginterferon-α) with or without NAs were defined as the IFN-α group, and those only receiving NAs were defined as the NAs group. Propensity score matching (PSM) was used to minimize baseline bias. Cox regression models were performed to select possible factors related to adverse outcomes development. RESULTS: All 1247 patients were divided into the IFN-α (n = 877) and NAs (n = 370) groups. 26patients (20 and 6 in the NAs and IFN-α groups) developed adverse outcomes (decompensated cirrhosis, liver failure, HCC, liver transplantation and deaths) during a median follow-up of 5.2 years. The cumulative adverse outcomes occurrence at 10 years was significantly lower in the IFN-α group than in the NAs group in all (1.1% vs. 11.9%, P <0.001) and treatment-naïve (1.1% vs. 12.4%, P <0.001) patients. Similar trends were observed after PSM and differentiation of cirrhosis. Multivariate analysis before and after PSM showed that IFN-α-based treatment was independently associated with a lower adverse outcomes incidence (before/after PSM: P = 0.001/P = 0.002). HCC risk stratification analyses revealed that the superiority of IFN-α in preventing HCC was more significant in patients with high-risk HCC. CONCLUSIONS: IFN-α-based therapy was superior to NAs in preventing adverse outcomes in patients with CHB regardless of cirrhosis, and in reducing HCC in those with a high risk of HCC.

Application of artificial intelligence in gastrointestinal disease: a narrative review.

OBJECTIVE: We collected evidence on the application of artificial intelligence (AI) in gastroenterology field. The review was carried out from two aspects of endoscopic types and gastrointestinal diseases, and briefly summarized the challenges and future directions in this field. BACKGROUND: Due to the advancement of computational power and a surge of available data, a solid foundation has been laid for the growth of AI. Specifically, varied machine learning (ML) techniques have been emerging in endoscopic image analysis. To improve the accuracy and efficiency of clinicians, AI has been widely applied to gastrointestinal endoscopy. METHODS: PubMed electronic database was searched using the keywords containing "AI", "ML", "deep learning (DL)", "convolution neural network", "endoscopy (such as white light endoscopy (WLE), narrow band imaging (NBI) endoscopy, magnifying endoscopy with narrow band imaging (ME-NBI), chromoendoscopy, endocytoscopy (EC), and capsule endoscopy (CE))". Search results were assessed for relevance and then used for detailed discussion. CONCLUSIONS: This review described the basic knowledge of AI, ML, and DL, and summarizes the application of AI in various endoscopes and gastrointestinal diseases. Finally, the challenges and directions of AI in clinical application were discussed. At present, the application of AI has solved some clinical problems, but more still needs to be done.

New anti-reflux plastic stent to reduce the risk of stent-related cholangitis in the treatment of biliary strictures.

BACKGROUND: There is little data available on the role of new anti-reflux plastic stents (ARPSs). AIM: To compare the use of ARPSs with that of traditional plastic stents (TPSs) for patients with biliary strictures. METHODS: Consecutive patients with biliary strictures who underwent first endoscopic biliary stenting between February 2016 and May 2019 were included. The onset of stent-related cholangitis, stent patency, clinical success, and other adverse events were evaluated. RESULTS: Sixty-seven patients in the ARPS group and 66 patients in the TPS group were included in the final analyses. Fewer patients experienced stent-related cholangitis in the ARPS group than that in the TPS group (8 patients vs 18 patients; P = 0.030). The median time till the onset of first stent-related cholangitis was later in the ARPS group than that in the TPS group (128.5 d vs 76 d; P = 0.039). The cumulative median stent patency in the ARPS group was 185 d, which was significantly longer than that in the TPS group (133 d; P = 0.001). The clinical success rates and other adverse events did not significantly differ between both groups. CONCLUSION: Placement of new ARPS might be a safe and effective optional therapeutic strategy to reduce the risk of stent-related cholangitis and prolong stent patency.

Peroral endoscopic myotomy for management of gastrointestinal motility disorder.

Achalasia is a type of esophageal motility disorder, consisting of relaxation dysfunction of the lower esophagus and disturbed esophageal peristalsis. Related clinical symptoms include dysphagia, regurgitation, chest pain, and weight loss. Traditional treatment options include endoscopic botulinum toxin injection, endoscopic pneumatic dilation, and laparoscopic Heller's myotomy. These therapies mainly relieve symptoms by reducing the pressure on the lower esophageal sphincter and reducing blood flow resistance at the esophagogastric junction. Based on endoscopic submucosal dissection and natural orifice transluminal endoscopic surgery, peroral endoscopic myotomy (POEM) is a purely endoscopic method of myotomy with minimal invasiveness and a low rate of adverse events when performed by experienced operators. Since then, numerous studies have shown the significant clinical efficacy and safety of POEM. The purpose of this article is to introduce different modified POEMs, special indications for different POEMs, and their advantages as well as disadvantages.

Biliary spontaneous dislodgement spiral stent for patients who underwent mechanical lithotripsy.

BACKGROUND: The incidence of post-endoscopic retrograde cholangiopancreatography (ERCP) cholangitis (PEC) in patients who underwent mechanical lithotripsy (ML) for large stone removal is high (up to 13.3%). One of the main causes is remaining small fragments or sludge that can impair normal biliary drainage. Endoscopic placement of a nasobiliary tube or a conventional plastic biliary stent has been commonly used under such conditions, but the patient may suffer from significant discomfort after the placement of a nasobiliary tube, while additional endoscopy is required for stent removal. We developed a biliary spontaneous dislodgement spiral stent (BSDSS) to overcome those shortcomings. AIM: To evaluate the feasibility, safety, and effectiveness of inserting a BSDSS for patients who underwent ML for large stone removal. METHODS: We conducted a single-center, retrospective, cohort study at West China Hospital, Sichuan University. A total of 91 consecutive patients with large biliary stones (≥ 10 mm) in the common bile duct who underwent ML between November 2017 and July 2018 were included. The 49 eligible patients were divided into the BSDSS group and the nasobiliary tube group. Technical success, post-ERCP adverse events (including PEC, post-ERCP pancreatitis, stone recurrence, BSDSS retention, self-extraction and dislocation of the nasobiliary tube), drainage time, and postoperative stay were measured and compared. RESULTS: Twenty-one patients in the BSDSS group and 28 patients in the nasobiliary tube group were included in the analyses. The baseline characteristics and clinical information were similar in the two groups. Insertions of BSDSS and nasobiliary tube were technically successful in all 49 patients. There was no significant difference in the incidence of overall post-ERCP adverse events between the two groups (4.8% in the BSDSS group vs 17.9% in the nasobiliary tube group, P = 0.219). The median duration of drainage time (3 d in the BSDSS group vs 4 d in the nasobiliary tube group) and length of postoperative stay (4 d in the BSDSS group vs 5 d in the nasobiliary tube group) also did not differ (P = 0.934, and P = 0.223, respectively). CONCLUSION: Endoscopic placement of a BSDSS appears to be feasible, safe and effective for patients who underwent ML for large stone removal.

Risk factors for distal migration of biliary plastic stents and related duodenal injury.

BACKGROUND: The risk factors of duodenal injury from distal migrated biliary plastic stents remain uncertain. The aim of this study was to determine the risk factors of distal migration and its related duodenal injury in patients who underwent placement of a single biliary plastic stent for biliary strictures. METHODS: We retrospectively reviewed all patients with biliary strictures who underwent endoscopic placement of a single biliary plastic stent from January 2006 to October 2017. RESULTS: Two hundred forty-eight patients with 402 endoscopic retrograde cholangiopancreatography procedures were included. The incidence of distal migration was 6.2%. The frequency of duodenal injury was 2.2% in all cases and 36% in cases with distal migration. Benign biliary strictures (BBS), length of the stent above the proximal end of the stricture (> 2 cm), and duration of stent retention (< 3 months) were independently associated with distal migration (p = 0.018, p = 0.009, and p = 0.016, respectively). Duodenal injury occurred more commonly in cases with larger angle (≥ 30°) between the distal end of the stent and the centerline of the patient's body (p = 0.018) or in cases with stent retention < 3 months (p = 0.031). CONCLUSIONS: The risk factors of distal migration are BBS and the length of the stent above the proximal end of the stricture. The risk factor of duodenal injury due to distal migration is large angle (≥ 30°) between the distal end of the stent and the centerline of the patient's body. Distal migration and related duodenal injury are more likely to present during the early period after biliary stenting.

New antireflux plastic stent for patients with distal malignant biliary obstruction.

BACKGROUND: Endoscopic biliary stenting is a well-established palliative treatment for patients with unresectable distal malignant biliary obstruction (MBO). However, the main problem with stent placement is the relatively short duration of stent patency. Although self-expanding metal stents (SEMSs) have a longer patency period than plastic stents (PSs), the higher costs limit the wide use of SEMSs. A PS with an antireflux valve is an attractive idea to prolong stent patency, but no ideal design for an antireflux PS (ARPS) has been proposed. We developed a new ARPS with a "duckbilled" valve attached to the duodenal end of the stent. AIM: To compare the patency of ARPSs with that of traditional PSs (TPSs) in patients with unresectable distal MBO. METHODS: We conducted a single-center, prospective, randomized, controlled, double-blind study. This study was conducted at the West China Hospital of Sichuan University. Consecutive patients with extrahepatic MBO were enrolled prospectively. Eligible patients were randomly assigned to receive either an ARPS or a TPS. Patients were followed by clinic visits or telephone interviews every 1-2 mo until stent exchange, death, or the final study follow-up in October 2018. The primary outcome was the duration of stent patency. Secondary outcomes included the rate of technical success, the rate of clinical success, adverse events, and patient survival. RESULTS: Between February 2016 and December 2017, 38 patients were randomly assigned to two groups, with 19 patients in each group, to receive ARPSs or TPSs. Stent insertion was technically successful in all patients. There were no significant differences between the two groups in the rates of clinical success or the rates of early or late adverse events (P = 0.660, 1.000, and 1.000, respectively). The median duration of stent patency in the ARPS group was 285 d [interquartile range (IQR), 170], which was significantly longer than that in the TPS group (median, 130 d; IQR, 90, P = 0.005). No significant difference in patient survival was noted between the two groups (P = 0.900). CONCLUSION: The new ARPS is safe and effective for the palliation of unresectable distal MBO, and has a significantly longer stent patency than a TPS.

Short-term effect of a negative colonoscopy in patients with functional constipation.

The yield of colonoscopy for neoplasia among patients with chronic constipation is very low. However, a negative colonoscopy may benefit these patients by decreasing anxiety and thereby alleviating constipation symptoms. We performed a prospective study to characterize the effect of a negative colonoscopy in patients with functional constipation. Seventy-five patients with chronic constipation were enrolled, and 69 patients were diagnosed with functional constipation through the Rome III criteria. After excluding patients whose constipation symptoms were affected by medications (e.g., laxatives, prokinetics), 45 patients were included in the study. Among the 45 patients, the average health-related anxiety score decreased from 21.0 to 15.6 at 1 week after colonoscopy (P < 0.01). Sustained improvement was observed in anxiety scores at 1 month (14.0), 2 months (12.4), and 6 months (11.2). Mean constipation symptom score was also decreased at 1 week (8.7), 1 month (8.0), 2 months (7.6), and 6 months (6.8) compared with the precolonoscopy period (11.5; P < 0.01). These results suggest that a negative colonoscopy in patients with functional constipation is associated with a decline in health-related anxiety and constipation symptom scores. (Registration number: ChiCTR-OOh-16008488).

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In this study, we examined the effects of biochar addition on the soil nutrition and microbial community diversity in continuous cultivated cucumber soils, using 95% soils of planting cucumbers for 6 and 10 years mixed with 5% biochar as treatment and no biochar addition as control, all plants cultivated in the pots. The results showed that adding biochar increased per plant yield of cucumber by 11.4% and 62.8% compared with continuous cropping soil of 6 years and 10 years, respectively. Biochar addition significantly decreased two continuous cropping soils bulk density, increased the content of soil organic matter, available P content, cation exchange capacity (CEC) and soil pH. Meanwhile, biochar addition remarkably improved the abundance of bacteria, ratio of bacteria/fungi, but reduced the abundance of fungi and fusarium oxysporum, which made fungal type soil turn to bacterial type soil. For 10 years continuous cropping soils of adding biochar, the abundance of soil bacteria and bacteria/fungi ratio were 2.00 and 3.64 times to that in the control, respectively, and the abundance of fungi and fusarium oxysporum were decreased by 54.8% and 55.9%, respectively. Biochar addition significantly enhanced soil microbial activities, soil microbial Shannon and McIntosh indexes of 10 years soil by 1.50, 2.14 and 1.31 times, respectively. For continuous cropping soil of 10 years, biochar addition significantly increased microbial utilization abilities of carbohydrate, amino acid, phenolic acid and amine by 1.62, 1.81, 1.74 and 1.93 times, respectively. There were remarkable influences of soil bulk density, available P content, CEC, and pH value to changes of soil microbial community. In conclusion, biochar addition optimized the riphzosphere environment, increased cucumber yield, and alleviated continuous cropping obstacles by improving soil physical and chemical properties, as well as soil microbial community.

A pilot single-center prospective randomized trial to assess the short-term effect of a flashing warning light on reducing fluoroscopy time and radiation exposure during ERCP.

BACKGROUND AND AIMS: ERCP has the risk of exposure to ionizing radiation. Performers may unconsciously increase fluoroscopy time (FT) because of a lack of radiation protection awareness. This study investigates whether a flashing warning light adopted as a behavioral intervention for performers reduces FT and radiation exposure during ERCP. METHODS: We conducted a prospective randomized trial of 200 therapeutic ERCPs. A flashing warning light was placed on top of the endoscopy monitor. Cases were consecutively enrolled and randomly assigned to 2 groups in a 1:1 ratio. In the warning light group, the light was on when the fluoroscopy foot pedal was depressed; in the control group, the light was off. Fluoroscopy and procedure-related data were recorded. RESULTS: The median FT and dose-area product (DAP) for the warning light group versus the control group were 142.5 seconds versus 175.0 seconds (P = .045) and 856.8 µGy∙m2 versus 1054.4 µGy∙m2 (P = .043). In a multivariable analysis, the use of the warning light was found to reduce FT by 15.4% (-27.0 seconds; P = .042). DAP reduction because of the decreased FT was 15.2% (160.3 µGy∙m2). The reduction in patient effective dose per case was .42 mSv, equivalent to 21 chest radiographs. No adverse events or interference with the procedures because of the warning light were noted. CONCLUSIONS: The use of a flashing warning light is a feasible way to reduce FT and radiation exposure during ERCP. (Clinical trial registration number: ChiCTR-IPR-14005349.).