Enhanced water transport through a carbon nanotube controlled by the lateral pressure.

The transport of water through carbon nanotubes (CNTs) is now of great importance in bionanotechnology and of considerable interest for potential nanofluidic applications. In this paper, we show by molecular dynamics simulations that the permeation of single-file water molecules through a CNT can be significantly improved by means of tuning the direction of pressure difference, i.e. introducing an additional lateral pressure to the longitudinal one. The water flow exhibits an interesting maximum behavior with the change of lateral pressure, deciphered by the breakdown of single-file water chain inside the CNT. The translocation time decreases monotonously with the increase of lateral pressure and exhibits a clear bifurcation due to the longitudinal pressure, corresponding to the flow enhancement. Therefore, the lateral pressure will increase the difficulty for water entering, while promotes the water conduction inside the CNT, whose competition ultimately leads to the flow maximum behaviors. Along with the water reducing inside the CNT, the CNT switches between the filling and empty states with the unique distributions of water dipole orientation, density and H-bond number. Our results indicate that tuning the direction of pressure difference should be a significant new strategy for enhancing the water permeability, where the key lies in the breakdown of single-file water chain and are thus insightful for future studies.

Peroral endoscopic myotomy compared with pneumatic dilation for newly diagnosed achalasia.

BACKGROUND: This study retrospectively compared the safety and efficacy of two endoscopic techniques for treating newly diagnosed achalasia, pneumatic dilation (PD), and peroral endoscopic myotomy (POEM). METHODS: Demographics, clinical and manometric data, and outcomes were collected from the medical records of patients who received POEM or PD as the primary therapy for achalasia at our hospital from January 2012 to August 2015. RESULTS: Of 72 patients, 32 and 40 received POEM and PD, respectively. The two groups had similar preoperative features. On short-term follow-up, improvements in high-resolution esophageal manometry and barium esophagogram parameters were similar. For PD, the success rates at 3, 6, 12, 24, and 36 months were 95, 88, 75, 72, and 60%, respectively. For POEM, these were 96, 96, 96, 93, and 93% (P = 0.013, log-rank test). On subgroup analysis, the success rate was higher with POEM than that with PD in all 3 manometric subtypes, but only that of type III was statistically significant. POEM required significantly longer operative time and hospitalization than did PD (P < 0.001). Four POEM patients experienced subcutaneous emphysema. The rate of gastroesophageal reflux was higher in patients treated by POEM (18.8%) than that in PD (10%; P = 0.286). CONCLUSIONS: In the intermediate term, the remission rate of symptoms associated with POEM therapy was better than that with PD for newly diagnosed achalasia, especially in patients with type III achalasia. The short-term outcomes of the two therapies were similar.

Single-stage management with combined tri-endoscopic approach for concomitant cholecystolithiasis and choledocholithiasis.

OBJECTIVE: The aim of this study was to investigate the value of a single stage with combined tri-endoscopic (duodenoscopy, laparoscopy and choledochoscopy) approach for patients with concomitant cholecystolithiasis and choledocholithiasis. METHODS: Fifty-three patients with combined gallbladder stones and common bile duct stones from February 2014 to April 2015 were randomized assigned to two groups: 29 patients underwent single-stage surgery with combined duodenoscope, laparoscope and choledochoscope (combined tri-endoscopic group), and 29 patients underwent endoscopic sphincterotomy to remove common bile duct stones followed by laparoscopic cholecystectomy several days later (control group). The success rate of complete stone removal, procedure-related complication, hospital stay and the cost of hospitalization were compared between the two groups. RESULTS: Altogether, 53 patients (29 patients in combined tri-endoscopic group and 24 patients in control group) successfully underwent the surgery and ERCP procedure. Three patients in the control group developed post-ERCP pancreatitis. One case of bile leaking and one case of residual stone were noted in the combined tri-endoscopic group. There were no significant differences between the two groups with regard to both complete stone removal [96.6 % (28/29) vs. 100 % (24/24)] and procedure-related complication rate [3.4 % (1/29) vs. 12.5 % (3/24)] (p > 0.05). No open surgery was required in either group. There were significant differences between the two groups with regard to hospital stay (6.72 ± 1.3 days vs. 10.91 ± 1.6 days, p < 0.01) and cost of hospitalization (15,724 ± 1613 CNY vs. 19,829 ± 2433 CNY, p < 0.05). CONCLUSION: The single-stage combined tri-endoscopic approach for concomitant cholecystolithiasis and choledocholithiasis was just as safe and successful as the control group. In addition, it resulted in a shorter hospital stay and less cost.

Efficacy and safety of EUS-guided coil embolization combined with endoscopic cyanoacrylate injection versus balloon-occluded retrograde transvenous obliteration for gastric varices with high-risk ectopic embolism: A multicenter and retrospective cohort study.

Background and Objectives: Gastric varices (GV) with spontaneous portosystemic shunt (SPSS) are associated with ectopic embolism in endoscopic cyanoacrylate. This study targeted to assess the efficacy and safety of EUS-guided coil embolization combined with endoscopic cyanoacrylate injection versus balloon-occluded retrograde transvenous obliteration (BRTO) for GV with high-risk ectopic embolism. Materials and Methods: We retrospectively analyzed six tertiary hospitals' 104 patients with GV at high-risk ectopic embolism (the narrowest diameter of SPSS was greater than or equal to 5 mm and the maximum diameter usually >8 mm) who underwent EUS-guided coil embolization combined with endoscopic cyanoacrylate injection or BRTO from January 2014 to December 2020. The outcomes included rebleeding, survival, and complications. Results: The EUS group and BRTO group contained 59 and 45 patients, respectively. The technical success rate between the two groups was similar (96.6% vs. 95.6%, P = 1.000). During the follow-up, both groups' 5-day rebleeding rate and 6-week mortality rate were 0%. One-year all-cause rebleeding rate (20.0% vs. 18.9%, P = 0.900) and 1-year mortality rate (2.0% vs. 0%, P = 1.000) in the EUS group were similar to the BRTO group. One patient experienced ectopic embolism in the EUS group, while the BRTO group did not. Both groups had similar mean days (16.0 [interquartile range (IQR), 12.0-19.0] vs. 16.5 [IQR, 11.8-26.0], P = 0.165) and cost of hospitalization (¥ 45950.6 [IQR, 39330.2-55768.2] vs. ¥ 51205.8 [IQR, 31628.8-74251.5], P = 0.680). Multivariate analysis showed that the narrowest diameter of the shunt (odds ratio [OR] = 1.86; 95% confidence interval [CI]: 1.062-3.258; P = 0.03) and content of hemoglobin (OR = 0.941; 95% CI: 0.892-0.992; P = 0.025) were the prognostic factors for survival. Conclusions: The efficacy and safety of EUS-guided coil embolization combined with endoscopic cyanoacrylate injection for GV with high-risk ectopic embolism are comparable to BRTO.

Cronkhite-Canada Syndrome Associated With Superficial Esophageal Carcinoma: A Case Report and Literature Review.

Introduction: Cronkhite-Canada syndrome is a rare disease characterized by generalized gastrointestinal polyposis, alopecia, skin pigmentation, and onychotrophia with no generally recognized mechanism of pathogenesis. There is a tendency of malignant transformation or coexistence of gastrointestinal malignancies in patients with Cronkhite-Canada syndrome. Case Description: The patient was a 67-year-old man who complained of dyspepsia, hair loss, skin hyperpigmentation, and pedal edema. Lab tests showed hypoalbuminemia. Endoscopic findings included superficial esophageal carcinoma and numerous polyps in the stomach, duodenum, and colon. The patient was treated with endoscopic submucosal dissection for the esophagus lesion, endoscopic mucosal resection for colon polyps, and glucocorticoids for Cronkhite-Canada syndrome. Conclusion: Esophagus cancer is a rare comorbidity of Cronkhite-Canada syndrome. Endoscopic examination and surveillance are critical for patients with Cronkhite-Canada syndrome for malignant gastrointestinal tumors.

A Nanometer Water Pump Induced by the Brownian and Non-Brownian Motion of a Graphene Sheet on a Membrane Surface.

Energy-saving water pump and efficient semipermeable membranes are the cores of reverse osmosis technology. Applying nanotechnology to improve the performance is a fashion in recent years. Based on the competitive effect of water's spontaneous infiltration of two sides of a carbon nanotube, we design a water pump that makes use of the natural permeability by weakening one side's competitiveness based on a small graphite sheet laying on the membrane. According to molecular dynamic simulations, continues net flux is observed. The motion mode of the sheet is the key for the performance. For the pure Brownian motion without any dynamical load, we find two water molecules per nanosecond flux, while the flux induced by the unidirectional motion can be several times enhanced, depending on the external force. The Brownian motion is similar to the physical mechanism of osmotic pressure, and the unidirectional motion shows great performance that has huge applications for reverse osmosis. Our work creatively proposes a new strategy to pump water molecules crossing though a nanochannel, inspiring for nanofluidic device designers.

A low prevalence of H pylori and endoscopic findings in HIV-positive Chinese patients with gastrointestinal symptoms.

AIM: To compare the prevalence of H pylori infection, peptic ulcer, cytomegalovirus (CMV) infection and Candida esophagitis in human immunodeficiency virus (HIV)-positive and HIV-negative patients, and evaluate the impact of CD4 lymphocyte on H pylori and opportunistic infections. METHODS: A total of 151 patients (122 HIV-positive and 29 HIV-negative) with gastrointestinal symptoms were examined by upper endoscopy and biopsy. Samples were assessed to determine the prevalence of H pylori infection, CMV, candida esophagitis and histologic chronic gastritis. RESULTS: The prevalence of H pylori was less common in HIV-positive patients (22.1%) than in HIV-negative controls (44.8%; P < 0.05), and the prevalence of H pylori displayed a direct correlation with CD4 count stratification in HIV-positive patients. In comparison with HIV-negative group, HIV-positive patients had a lower incidence of peptic ulcer (20.7% vs 4.1%; P < 0.01), but a higher prevalence of chronic atrophy gastritis (6.9% vs 24.6%; P < 0.05)ìCandida esophagitis and CMV infection. Unlike HIV-negative group, H pylori infection had a close relationship to chronic active gastritis (P < 0.05). In HIV-positive patients, chronic active gastritis was not significantly different between those with H pylori infection and those without. CONCLUSION: The lower prevalence of H pylori infection and peptic ulcer in HIV-positive patients with gastrointestinal symptoms suggests a different mechanism of peptic ulcerogenesis and a different role of H pylori infection in chronic active gastritis and peptic ulcer. The pathogen of chronic active gastritis in HIV-positive patients may be different from the general population that is closely related to H pylori infection.

Dual inhibition of 5-LOX and COX-2 suppresses esophageal squamous cell carcinoma.

COX-2 and 5-LOX are up-regulated in ESCC. This study aims to determine the efficacy of COX-2 inhibitor, 5-LOX inhibitor and their combination on ESCC. Nimesulide can suppress cell growth and promote apoptosis, accompanied with a decrease of PGE(2) production. AA861 has the similar effect with a down-regulation of LTB(4). In animal experiment, the tumor volumes in drug-treated groups were significantly smaller with the lowest rates of Ki-67 positive cells. In conclusion, either COX-2 inhibitor or 5-LOX inhibitor can suppress ESCC. Dual inhibition of COX-2 and 5-LOX pathway may present a superior anticancer efficacy to either inhibition of COX-2 or 5-LOX alone.