• Design & Manufacturing
• /
• v.17 no.2
• /
• pp.55-61
• /
• 2023

With femtosecond (fs) laser pulse irradiation on metals, various types of nano- and micro-scale structures can be naturally induced at the surface through laser-matter interaction. Two notable structures are laser-induced periodic surface structures (LIPSSs) and cone/spike structures, which are known to significantly modify the optical and physical properties of metal surfaces. In this work, we irradiate fs laser pulses onto various types of metals, cold-rolled steel, pickled & oiled steel, Fe-18Cr-8Ni alloy, Zn-Mg-Al alloy coated steel, and pure Cu which can be useful for precise molding and imprinting processes, and adjust the morphological profiles of LIPSSs and cone/spike structures for clear structural coloration and a larger range of surface wettability control, respectively, by changing the fluence of laser and the speed of raster scan. The periods of LIPSSs on metals used in our experiments are nearly independent of laser fluence. Accordingly, the structural coloration of the surface with LIPSSs can be optimized with the morphological profile of LIPSSs, controlled only by the speed of the raster scan once the laser fluence is determined for each metal sample. However, different from LIPSSs, we demonstrate that the morphological profiles of the cone/spike structures, including their size, shape, and density, can be manipulated with both the laser fluence and the raster scan speed to increase a change in the contact angle. By injection molding and imprinting processes, it is expected that fs laser-induced surface structures on metals can be replicated to the plastic surfaces and potentially beneficial to control the optical and wetting properties of the surface of injection molded and imprinted products.

• Journal of Digestive Cancer Research
• /
• v.2 no.1
• /
• pp.1-4
• /
• 2014

Palliative care for cancer aims to relieve the discomfort and pain from the cancer itself and associated conditions. Gastrointestinal cancers originate from the tube like structure of gastrointestinal tract and cause complications such as obstruction, bleeding, adhesion, invasion, and perforation to adjacent organ. Recent advances in interventional endoscopy enables endoscopy physicians to do safe and effective care for gastrointestinal cancer patients. Endoscopic palliation includes stent, hemostasis, nutritional support and targeted drug delivery. Self expandable metallic stent is one of the most important modalities in gastrointestinal palliation. Through the endoscopy or over the wire pre-placed by endoscopy, stents restore the gastrointestinal luminal patency and relieve the obstructive condition. Endoscopic hemostasis is another important palliation in gastrointestinal cancer patients. Epinephrine injection, argon plasma coagulation and thermal cauterization are usual modalities for hemostasis. Histoacryl glue and fibrin glue are also available. Hemostatic nanopowder spray is newly reported effective in benign disease and is supposed to be effective also in cancer bleeding. Enteral feeding tubes including gastro- or jejunostomy and nosoduodenal tubes are placed by using endoscopic guidance. Enteral feeding tubes role as the route of easily absorbable or semi-digested nutrients and effectively maintain both patients calorie requirements and gut microenvironment. Photodynamic therapy is the one of the outstanding medical employments of photo-physics. Especially for superficial cancers in esophagus, photodynamic therapy is very useful in cancer removal and maintaining organ structure. In biliary neoplasm, photodynamic therapy is well known to be effective in cancer ablation and biliary ductal patency restoration. Targeted drug delivery is the lastest issue in palliative endoscopy. Debates and questions are still on the table. In this article, the role of endoscopic interventions in palliative care for the gastrointestinal tumors will be thoroughly reviewed.

• Journal of Digestive Cancer Research
• /
• v.4 no.1
• /
• pp.21-28
• /
• 2016

Hepatocellular carcinoma (HCC) is rather unique. Most of HCC patients have underlying chronic liver diseases with or without cirrhosis and the prognosis of HCC depends on the liver function, as well as the tumor extent. Non-invasive diagnosis of HCC can be made with certain risk factors and specific imaging findings (e.g. hypervascularity). Patients with HCC can receive surgical resection, radiotherapy, and systemic chemotherapy as other solid malignancies. HCC has more treatment options such as liver transplantation, transarterial chemoembolization (TACE) and radiofrequency ablation (RFA). A variety of practice guidelines for HCC has been published by many academic societies. Different healthcare systems and availability of resources also affect the practice guidelines; therefore, practice guidelines have similarities and dissimilarities. Herein, we review the current status of practice guidelines for HCC and future perspectives for the improvement of guidelines are also discussed.

• Childhood Kidney Diseases
• /
• v.27 no.2
• /
• pp.105-110
• /
• 2023

Purpose: To analyze electrocardiograms (ECGs) of patients with a salt-losing tubulopathy (SLT) and to determine the frequency and risk factors for long QT and arrhythmia. Methods: A total of 203 patients aged <19 years with SLT, specifically Bartter syndrome and Gitelman syndrome, who had a 12-lead ECG were included in this retrospective study. We analyzed the presence of an arrhythmia or prolonged corrected QT (QTc) on ECGs obtained for these patients. Demographic and laboratory data were compared between patients with abnormal and normal ECG findings. Results: Out of the 203 SLT patients, 38 (18.7%) underwent electrocardiography and 10 (40.0%) of 25 patients with inherited SLT had abnormal ECG findings, including prolonged QTc and arrhythmias. The abnormal ECG group had significantly lower serum potassium levels than the normal group (median [interquartile range]: 2.50 mmol/L [2.20-2.83] vs. 2.90 mmol/L [2.70-3.30], P=0.036), whereas other serum chemistry values did not show significant differences. The cutoff level for a significant difference in QTc interval was serum potassium level <2.50 mmol/L. One cardiac event occurred in a 13-year-old boy, who developed paroxysmal supraventricular tachycardia and underwent cardiac ablation. No sudden cardiac deaths occurred in this cohort. Conclusions: The incidence of ECG abnormalities in patients with inherited SLT was 40.0%, whereas the ECG screening rate was relatively low (18.7%). Therefore, we recommend ECG screening in patients with inherited SLT, especially in those with serum potassium level <2.50 mmol/L.

• Journal of Chest Surgery
• /
• v.56 no.6
• /
• pp.414-419
• /
• 2023

Background: The recurrence of ventricular arrhythmias (VAs) in patients who have already undergone treatment with antiarrhythmic medication, catheter ablation, and the insertion of implantable cardioverter defibrillators is not uncommon. Recent studies have shown that bilateral cardiac sympathetic denervation (BCSD) effectively treats VAs. However, only a limited number of studies have confirmed the safety of BCSD as a viable therapeutic option for VAs. Methods: This single-center study included 10 patients, who had a median age of 54 years (interquartile range [IQR], 45-65 years) and a median ejection fraction of 58.5% (IQR, 56.2%-60.8%), with VAs who underwent video-assisted BCSD. BCSD was executed as a single-stage surgery for 8 patients, while the remaining 2 patients initially underwent left cardiac sympathetic denervation followed by right cardiac sympathetic denervation. We evaluated postoperative complications, the duration of hospital stays, and VA-related symptoms before and after surgery. Results: The median hospital stay after surgery was 2 days (IQR, 2-3 days). The median surgical time for BCSD was 113 minutes (IQR, 104-126 minutes). No significant complications occurred during hospitalization or after discharge. During the median follow-up period of 13.5 months (IQR, 10.5-28.0 months) from surgery, no VA-related symptoms were observed in 70% of patients. Conclusion: The benefits of a short postoperative hospitalization and negligible complications make BCSD a safe, alternative therapeutic option for patients suffering from refractory VAs.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.18 no.2
• /
• pp.311-326
• /
• 2024

The rapid development of neural network technology promotes the neural network model driven by big data to overcome the texture effect of complex objects. Due to the limitations in complex scenes, it is necessary to establish custom template matching and apply it to the research of many fields of computational vision technology. The dependence on high-quality small label sample database data is not very strong, and the machine learning system of deep feature connection to complete the task of texture effect inference and speculation is relatively poor. The style transfer algorithm based on neural network collects and preserves the data of patterns, extracts and modernizes their features. Through the algorithm model, it is easier to present the texture color of patterns and display them digitally. In this paper, according to the texture effect reasoning of custom template matching, the 3D visualization of the target is transformed into a 3D model. The high similarity between the scene to be inferred and the user-defined template is calculated by the user-defined template of the multi-dimensional external feature label. The convolutional neural network is adopted to optimize the external area of the object to improve the sampling quality and computational performance of the sample pyramid structure. The results indicate that the proposed algorithm can accurately capture the significant target, achieve more ablation noise, and improve the visualization results. The proposed deep convolutional neural network optimization algorithm has good rapidity, data accuracy and robustness. The proposed algorithm can adapt to the calculation of more task scenes, display the redundant vision-related information of image conversion, enhance the powerful computing power, and further improve the computational efficiency and accuracy of convolutional networks, which has a high research significance for the study of image information conversion.

• Clinical Endoscopy
• /
• v.56 no.1
• /
• pp.38-49
• /
• 2023

Background/Aims: Patients with Barrett's esophagus are at increased risk of developing esophageal adenocarcinoma. Endoscopic therapies aim to eradicate dysplastic and metaplastic tissues. Hybrid argon plasma coagulation (hybrid-APC) utilizes submucosal fluid injection to create a protective cushion prior to ablation that shields the submucosa from injury. We performed a pooled meta-analysis to evaluate the safety and efficacy of hybrid-APC. Methods: We conducted a systematic search of major electronic databases in April 2022. Studies that included patients with dysplastic and non-dysplastic Barrett's esophagus undergoing treatment with hybrid-APC were eligible for inclusion. Outcome measures included complete remission of intestinal metaplasia (CR-IM), stricture formation, serious adverse events, and number of sessions necessary to achieve CR-IM. Results: Overall pooled CR-IM rate for patients undergoing hybrid-APC was 90.8% (95% confidence interval [CI], 0.872-0.939; I²=0%). Pooled stricture rate was 2.0% (95% CI, 0.005-0.042; I²=0%). Overall serious adverse event rate was 2.7% (95% CI, 0.007-0.055; I²=0%). Conclusions: Results of the current meta-analysis suggest that hybrid-APC is associated with high rates of CR-IM and a favorable safety profile. Interpretation of these results is limited by the inclusion of retrospective cohort and case series data. Randomized controlled trials that standardize treatment and outcome evaluation protocols are necessary to understand how this treatment option is comparable to the current standards of care.

• Annals of Hepato-Biliary-Pancreatic Surgery
• /
• v.28 no.1
• /
• pp.1-13
• /
• 2024

Hepatocellular carcinoma (HCC) is the sixth most diagnosed cancer worldwide. Healthcare resource constraints may predispose treatment delays. We aim to review existing literature on whether delayed treatment results in worse outcomes in HCC. PubMed, Embase, The Cochrane Library, and Scopus were systematically searched from inception till December 2022. Primary outcomes were overall survival (OS) and disease-free survival (DFS). Secondary outcomes included post-treatment mortality, readmission rates, and complications. Fourteen studies with a total of 135,389 patients (delayed n = 25,516, no delay n = 109,873) were included. Age, incidence of male patients, Child-Pugh B cirrhosis, and Barcelona Clinic Liver Cancer Stage 0/A HCC were comparable between delayed and no delay groups. Tumor size was significantly smaller in delayed versus no delay group (mean difference, -0.70 cm; 95% confidence interval [CI]: -1.14, 0.26; p = 0.002). More patients received radiofrequency ablation in delayed versus no delay group (OR, 1.22; 95% CI: 1.16, 1.27; p < 0.0001). OS was comparable between delayed and no delay in HCC treatment (hazard ratio [HR], 1.13; 95% CI: 0.99, 1.29; p = 0.07). Comparable DFS between delayed and no delay groups (HR, 0.99; 95% CI: 0.75, 1.30; p = 0.95) was observed. Subgroup analysis of studies that defined treatment delay as > 90 days showed comparable OS in the delayed group (HR, 1.04; 95% CI: 0.93, 1.16; p = 0.51). OS and DFS for delayed treatment were non-inferior compared to no delay, but might be due to better tumor biology/smaller tumor size in the delayed group.

• Journal of Digestive Cancer Research
• /
• v.7 no.1
• /
• pp.26-30
• /
• 2019

Pancreatic cancer has a very poor prognosis. Complete surgical resection remains the only current curative treatment. Locally advanced pancreatic cancer (LAPC) is considered as unresectable because of involvement of celiac and/or mesenteric vessels. The treatment of LAPC is a challenge. Current guidelines suggest systemic therapy. However, the majority of patients will never experience conversion to surgical resection. Thus, in these patients, ablation is an alternative therapy for local control, which causes local destruction while ideally avoiding injury to surrounding healthy tissue. Irreversible electroporation (IRE) is an energy delivery system, effective in ablating tumors by inducing irreversible membrane destruction of cells. IRE demonstrated to be safe in previous studies. However, it is not free from complications, even serious. Here, we reported two cases of the IRE in LAPC patients.

• Journal of Oral Medicine and Pain
• /
• v.30 no.4
• /
• pp.457-464
• /
• 2005

The purpose of our study was to investigate whether the intrapulpal temperature during cavity preparation of enamel or dentin with Er:YAG laser still remained in range of safety for dental pulp protection when combined with appropriate water flow rate. The effect of different pulse repetition rates at the same pulse energy during ablation was evaluated as well. Caries-free, restoration-free extracted human molar teeth were prepared for the specimen and divided two experimental groups of enamel and dentin. Each group comprised 5 specimens and each of tooth specimens were embedded into a resin block each and measuring probe was placed on the irradiated pulpal walls. For experiments of dentin ablation, enamel layers were prepared to produce dentin specimen with a same dentin thickness of 2 mm. A pulse energy of Er:YAG laser was set to 300 mJ and three different pulse repetition rates of 20 Hz, 15 Hz and 10 Hz were employed. Laser beam was delivered with 3 seconds and less per application over enamel and dentin surfaces constant sized by $3\;mm{\times}2\;mm$ and water spray added during irradiation was a rate of 1.6 ml/min. Temperature change induced by Er:YAG laser irradiation was monitored and recorded While enamel was ablated, there was no significant difference of temperature related to pulse repetition rates(p=0.358) and temperature change at any pulse repetition rate was negligible. Significant statistical difference in temperature changes during cavity preparation in dentin existed among three different pulse groups(p=0.001). While temperature rise was noticeable when the dentinal wall was perforated, actual change of temperature due to Er:YAG laser irradiation was not enough to compromise safety of dental pulp when irradiation was conjugated with appropriate water spray. Conclusively, it can be said that cavity preparation on enamel or dentin with an Er:YAG laser is performed safely without pulp damage if appropriate volume of water is sprayed properly over the irradiated site.