Removal of diminutive colorectal polyps: A prospective randomized clinical trial between cold snare polypectomy and hot forceps biopsy

AIMTo compare the efficacy and safety of cold snare polypectomy (CSP) and hot forceps biopsy (HFB) for diminutive colorectal polyps.METHODSThis prospective, randomized single-center clinical trial included consecutive patients ≥ 20 years of age with diminutive colorectal polyps 3-5 mm from December 2014 to October 2015. The primary outcome measures were en-bloc resection (endoscopic evaluation) and complete resection rates (pathological evaluation). The secondary outcome measures were the immediate bleeding or immediate perforation rate after polypectomy, delayed bleeding or delayed perforation rate after polypectomy, use of clipping for bleeding or perforation, and polyp retrieval rate. Prophylactic clipping after polyp removal wasn’t routinely performed.RESULTSTwo hundred eight patients were randomized into the CSP (102), HFB (106) and 283 polyps were evaluated (CSP: 148, HFB: 135). The en-bloc resection rate was significantly higher with CSP than with HFB [99.3% (147/148) vs 80.0% (108/135), P < 0.0001]. The complete resection rate was significantly higher with CSP than with HFB [80.4% (119/148) vs 47.4% (64/135), P < 0.0001]. The immediate bleeding rate was similar between the groups [8.6% (13/148) vs 8.1% (11/135), P = 1.000], and endoscopic hemostasis with hemoclips was successful in all cases. No cases of perforation or delayed bleeding occurred. The rate of severe tissue injury to the pathological specimen was higher HFB than CSP [52.6% (71/135) vs 1.3% (2/148), P < 0.0001]. Polyp retrieval failure was encountered CSP (7), HFB (2).CONCLUSIONCSP is more effective than HFB for resecting diminutive polyps. Further long-term follow-up study is required.

Risk factors for local recurrence and appropriate surveillance interval after endoscopic resection

BACKGROUND Risk factors for local recurrence after polypectomy, endoscopic mucosal resection(EMR), and endoscopic submucosal dissection(ESD) have not been identified.Additionally, the appropriate interval for endoscopic surveillance of colorectal tumors at high-risk of local recurrence has not been established.AIM To clarify the clinicopathological characteristics of recurrent lesions after endoscopic colorectal tumor resection and determine the appropriate interval.METHODS Three hundred and sixty patients(1412 colorectal tumors) who underwent polypectomy, EMR, or ESD and received endoscopic surveillance subsequently for more than one year to detect local recurrence were enrolled in this study. The clinicopathological factors associated with local recurrence were determined via univariate and multivariate analyses.RESULTS Local recurrence was observed in 31 of 360(8.6%) patients [31 of 1412(2.2%)lesions] after colorectal tumor resection. Piecemeal resection, tumor size of more than 2 cm, and the presence of villous components were associated with colorectal tumor recurrence after endoscopic resection. Of these three factors, the piecemeal resection procedure was identified as an independent risk factor for recurrence. Colorectal tumors resected into more than five pieces were associated with a high risk of recurrence since the average period from resection torecurrence in these cases was approximately 3 mo. The period to recurrence in cases resected into more than 5 pieces was much shorter than that in those resected into less than 4 pieces(3.8 ± 1.9 mo vs 7.9 ± 5.0 mo, P < 0.05).CONCLUSION Local recurrence of endoscopically treated colorectal tumors depends upon the outcome of first endoscopic procedure. Piecemeal resection was the only significant risk factor associated with local recurrence after endoscopic resection.

Numerical Prediction and Field Verification Test of Wind-Power Generation Potential in Nearshore Area Using a Moored Floating Platform

The offshore turbine system was installed on a floating platform moored in Hakata Bay, offshore of Fukuoka, Japan. An identical turbine system was also installed at the adjacent waterfront. The separation of the two turbines was 3.7 km. Wind flow tends to be more stable and the average wind speed is often larger in offshore areas than adjacent land areas at typical wind turbine hub height. This study focused on the wind condition of a nearshore area to clarify the advantages of nearshore wind farming. Prior to field experiment, wind conditions were predicted by using numerical simulation. It is useful for estimating topographical effect in nearshore areas. Next, field verification test was done by directly comparing wind data obtained from the identical wind turbine systems installed at an offshore location and the adjacent waterfront over the same extended period. The corresponding power output of these turbines was also compared. The data set exhibits 23% larger annual average wind speed at the offshore location and smaller turbulent intensity, resulting doubled annual power production.

Near Wake of a Horizontal Circular Cylinder in Stably Stratified Flows

The near wake of a circular cylinder in linearly stratified flows of finite depth was experimentally investigated by means of flow visualization and measurements of vortex shedding frequencies, at Reynolds numbers 3.5 × 103-1.2 × 104 and stratification parameters kd 0-2.0. The non-dimensional parameter kd is defined as kd = Nd/U, where N is the Brunt-Vaisala frequency, d, the diameter of the cylinder, and U, the approaching flow velocity. The study demonstrates that as kd increases from zero, the vortex shedding from a circular cylinder progressively strengthens, while the Strouhal number gradually becomes lower than that for homogeneous flow. This phenomenon can be explained by the effect of the increasingly stable stratification which enhances the two-dimensionality of the near-wake flow of the circular cylinder;the enhanced two-dimensionality of the flow strengthens the roll-up of the separated shear layer. Above a certain value of kd, however, vortex formation and shedding are strongly suppressed and the Strouhal number rises sharply. This observation is attributable to the development of stationary lee waves downstream of the circular cylinder because the lee waves strongly suppress vertical fluid motions.

Refractory case of ulcerative colitis with idiopathic thrombocytopenic purpura successfully treated by Janus kinase inhibitor tofacitinib:A case report

BACKGROUND Concomitant ulcerative colitis (UC) and idiopathic thrombocytopenic purpura(ITP) is a rare phenomenon. The management of UC with ITP can be challenging,since a decreased platelet count augments UC.CASE SUMMARY A 24-year-old man with UC and steroid-resistant ITP experienced UC flare.Although continuous infusion of cyclosporine was initiated, UC did not improve.The administration of tofacitinib subsequently led to the induction of remission.The patient has maintained remission of UC and ITP for over one year ontofacitinib treatment. Whole transcriptomic sequencing was performed forinflamed rectal mucosae obtained before and after the initiation of Janus kinase(JAK) inhibitor, suggesting that distinct molecular signatures seemed to beregulated by JAK inhibitors and other conventional therapies including tumornecrosis factor lockers.CONCLUSION Tofacitinib should be considered in refractory cases of UC with ITP.

Improving the Power Generation Performance of a Solar Tower Using Thermal Updraft Wind

The purpose of this study is to improve the efficiency of the power generation system of a solar tower using fluid dynamics. The power generation system of a solar tower can be designed and constructed at relatively low cost. However, the energy output tends to be low for its physical size compared with other renewable energy production systems. The technical and scientific improvement of these types of generation systems has lost its momentum since the shutdown of the wellknown Spanish pilot plant “Manzanares Solar Chimney” in 1989, although it still has the potential to play a role in renewable energy in the future. We have focused on the tower component of the system to seek possible enhancements of the power output of the internal turbine. As a result of our fluid dynamic shape optimization, a diffuser-shaped tower was employed to increase the internal flow speed of a scaled model. The results show a remarkable improvement in the power output of the internal wind turbine.

Erratum to “Improving the Power Generation Performance of a Solar Tower Using Thermal Updraft Wind” [Energy and Power Engineering Vol. 6 No. 11 (October 2014) 362-370]

The original online version of this article (Masataka Motoyama, Kenichiro Sugitani, Yuji Ohya, et al. (2014) “Improving the Power Generation Performance of a Solar Tower Using Thermal Updraft Wind”, 2014, 6, 362-370. http://dx.doi.org/10.4236/epe.2014.611031) was published in October, 2014.The author wishes to correct the following error in text and Figures 9-11.

Castor oil as booster for colon capsule endoscopy preparation reduction: A prospective pilot study and patient questionnaire

BACKGROUND Preparation for colon capsule endoscopy(CCE)requires a large liquid laxative volume for capsule excretion,which compromises the procedure's tolerability.AIM To assess the safety and utility of castor oil-boosted bowel preparation.METHODS This prospective cohort study including 20 patients(age range,16-80 years;six men and 14 women)suspected of having colorectal disease was conducted at Kindai University Hospital from September 2017 to August 2019.All patients underwent CCE because of the following inclusion criteria:previous incomplete colonoscopy in other facility(n=20),history of abdominal surgery(n=7),or organ abnormalities such as multiple diverticulum(n=4)and adhesion after surgery(n=6).The exclusion criteria were as follows:Dysphagia,history of allergic reactions to the drugs used in this study(magnesium citrate,polyethylene glycol,metoclopramide,and castor oil),possibility of pregnancy,possibility of bowel obstruction or stenosis based on symptoms,or scheduled magnetic resonance imaging within 2 wk after CCE.The primary outcome was the capsule excretion rate within the battery life,as evaluated by the total large bowel observation rate,large bowel transit time,and bowel creasing level using a fivegrade scale in different colorectal segments.The secondary outcomes were complications,colorectal lesion detection rates,and patients’tolerability.RESULTS The castor oil-based regimen was implemented in 17 patients.Three patients cancelled CCE because they could tolerate castor oil,but not liquid laxatives.The capsule excretion rate within the battery life was 88%(15/17).The mean large bowel transit time was 236 min.Approximately 70%of patients had satisfactory colon cleansing levels.CCE detected colon polyps(14/17,82%)and colonic diverticulum(4/12,33%).The sensitivity,specificity,and diagnostic accuracy rates for detecting colorectal polyps(size≥6 mm)were 76.9%,75.0%,and 76.4%,respectively.The sensitivity,specificity,and diagnostic accuracy rates for detection of diverticulum were 100%each.Twelve patients(71%)rated CCE as more than“good”,confirming the new regimen’s tolerability.No serious adverse events occurred during this study.CONCLUSION The castor oil-based regimen could reduce bowel preparation dose and improve CCE tolerability.