Objective: To explore the occupational hazards caused by three kinds of welding operations, and to provide data support for individual protection. Methods: In October 2020, the welding fumes, metal elements and welding arc generated by three welding operations of argon gas shielded welding (JS80 welding wire) , manual welding (ZS60A welding rod) and carbon dioxide shielded welding (907A flux cored wire) were collected and measured in the welding laboratory. The samples were analyze and compare in the laboratory, and the differences of the occupational hazard factors of the three welding operations were judged. Results: The concentration of welding fume produced by carbon dioxide shielded welding, manual welding (ZS60A electrode) , and argon gas shielded welding (JS80 welding wires) were 6.80 mg/m(3), 6.17 mg/m(3), and 3.13 mg/m(3), respectively. The effective irradiance of the welding arc outside the welding mask from high to low is manual welding (ZS60A electrode) , carbon dioxide shielded welding (907A flux-cored welding wire) , and argon shielded welding (JS80 welding wire) , respectively 1 010.7, 740.9, 589.5 μW/cm(2). The long-wave ultraviolet UVA intensity generated by argon shielded welding (JS80 welding wire) is the largest, which is 1 500 μW/cm(2). The content of Mn in the three welding operations is the highest, and JS80 welding wire has the highest Mn content of 128493.2 mg/kg. 907A flux cored wire has the highest Ti content, which is 24355.5mg/kg. The electrode ZS60A has the highest Cu content, which is 24422.12 mg/kg. Conclusion: The intensity of occupational hazards is different in the three kinds of welding operations, so the methods of personal protective equipment, field exposure assessment and health monitoring should be more targeted.
Air Pollutants, Occupational/analysis* ; Argon/analysis* ; Carbon Dioxide/analysis* ; Gases/analysis* ; Occupational Exposure/analysis* ; Welding/methods*

PURPOSE: To report a case of central serous chorioretinopathy with peripapillary retinoschisis. CASE SUMMARY: A 64-year-old male presented with abnormal color vision of the left eye, which occurred 6 months prior to his visit. At the initial visit, a funduscopic examination revealed retinal elevation with suspected serous retinal detachment around the optic disc in the left eye. Spectral domain optical coherence tomography showed subretinal fluid on the nasal side of the optic disc and retinoschisis on the temporal side of the optic disc in the left eye. Fluorescein angiography revealed multiple leakages in the left eye. Indocyanine green angiography revealed choroidal vascular hyperpermeability in both eyes. Based on these results, the patient was diagnosed with chronic central serous chorioretinopathy and was treated with argon laser photocoagulation at the leakage points. After 8 weeks of laser therapy, optical coherence tomography indicated that there was no retinoschisis or subretinal fluid in the macula, nasal, or temporal sides of the optic disc. CONCLUSIONS: Peripapillary retinoschisis due to central serous chorioretinopathy improves with argon laser photocoagulation at leakage sites.
Angiography ; Argon ; Central Serous Chorioretinopathy ; Choroid ; Color Vision ; Fluorescein Angiography ; Humans ; Indocyanine Green ; Laser Therapy ; Light Coagulation ; Male ; Middle Aged ; Retinal Detachment ; Retinaldehyde ; Retinoschisis ; Subretinal Fluid ; Tomography, Optical Coherence

PURPOSE: We report two cases of intraocular lens (IOL) pupillary optic capture following IOL scleral fixation treated with argon laser iridotomy. CASE SUMMARY: (Case 1) A 69-year-old man presented with suddenly decreased visual acuity of the left eye. The best-corrected visual acuity was finger count (FC) 30 cm in the left eye. Slit lamp examination revealed subluxation of the left eye IOL. An IOL scleral fixation and anterior vitrectomy were performed and no specific findings were observed. During the follow-up period, pupillary optic capture was repeated without specific causes, such as trauma, or IOL decentration thus, argon laser iridotomy was performed. (Case 2) A 77-year-old man presented with a 3-day history of congestion of the left eye and decreased visual acuity. Best-corrected visual acuity was 0.4 logarithm of the minimum angle of resolution (logMAR) in the left eye. Slit lamp examination revealed subluxation of the left eye IOL. An IOL scleral fixation and anterior vitrectomy were performed, and no specific findings were observed. During the follow-up period, pupillary optic capture was found, and IOL repositioning and argon laser iridotomy were performed. CONCLUSIONS: Laser iridotomy can be used to prevent recurrence of pupillary optic capture in eyes with IOL scleral fixation without decentration or distortion.
Aged ; Argon ; Estrogens, Conjugated (USP) ; Fingers ; Follow-Up Studies ; Humans ; Lenses, Intraocular ; Recurrence ; Slit Lamp ; Visual Acuity ; Vitrectomy

The concept and pathological diagnostic criteria of gastric adenoma (dysplasia) differ between Western countries and Japan, and discrepancies between histopathological examinations before and after endoscopic resection may occur. Therefore, the natural history of adenoma should be interpreted and the treatment strategy of adenoma established. It is recommended that endoscopic resection be performed for high-grade dysplasia due to the potential higher risk of progression to carcinoma. For low-grade dysplasia, the risk of malignant transformation is relatively low. However, resection is considered the first approach for the purpose of diagnosis and treatment. If resection is not feasible, the alternative may be to use argon plasma coagulation for selected lesions that are less likely to be malignant. When Helicobacter pylori infection is detected, eradication therapy is recommended to reduce the risk of metachronous lesions. Post-resection follow-up should be performed within 1 year to detect synchronous lesions and then follow-up endoscopy at 1 or 2-year intervals may be considered for metachronous lesions.
Adenoma ; Argon Plasma Coagulation ; Diagnosis ; Endoscopy ; Follow-Up Studies ; Helicobacter pylori ; Japan ; Natural History ; Stomach

PURPOSE: Plasma activation of hydrophobic zirconia surfaces might be suitable to improve the bond strength of luting materials. The aim of this study was to analyze the influence of nonthermal argon-plasma on the shear bond strength (SBS) between zirconia and different combinations of 10-MDP adhesive systems and luting composites after artificial aging. MATERIALS AND METHODS: Two hundred forty Y-TZP specimens were ground automatically with 165 µm grit and water cooling. Half of the specimens received surface activation with nonthermal argon-plasma. The specimens were evenly distributed into three groups according to the adhesive systems ([Futurabond U, Futurabond M, Futurabond M + DCA], VOCO GmbH, Germany, Cuxhaven) and into further two subgroups according to the luting materials ([Bifix SE, Bifix QM], VOCO GmbH). Each specimen underwent artificial aging by thermocycling and water storage. SBS was measured in a universal testing machine. Statistical analysis was performed using ANOVA and Scheffè procedure with the level of significance set to 0.05. RESULTS: Surface activation with nonthermal plasma did not improve the bond strength between zirconia and the tested combinations of adhesive systems and luting materials. The plasma-activation trended to reveal higher bond strength if the self-etch luting material (Bifix SE) was used, irrespective of the adhesive system. CONCLUSION: Plasma-activation seems to be suitable to improve bond strength between zirconia and self-etch resin materials. However, further research is necessary to identify the influence of varying plasma-parameters.
Adhesives ; Aging ; Argon ; Germany ; Plasma ; Water

The argon plasma jet (Ar-PJ) is widely used in medical fields such as dermatology and dentistry, and it is considered a promising tool for cancer therapy. However, the in vivo effects of Ar-PJ for medical uses have not yet been investigated, and there are no biological tools to determine the appropriate clinical dosages of Ar-PJ. In this study, we used the caudal fin and embryo of zebrafish as novel in vivo tools to evaluate the biosafety of Ar-PJ. Typically, Ar-PJ is known to induce cell death in two-dimensional (2D) cell culture systems. By contrast, no detrimental effects of Ar-PJ were shown in our 3D zebrafish systems composed of 2D cells. The Ar-PJ-treated caudal fins grew by an average length of 0.7 mm, similar to the length of the normally regenerating fins. Remarkably, Ar-PJ did not affect the expression patterns of Wnt8a and β-Catenin, which play important roles in fin regeneration. In the embryo system, 85% of the Ar-PJ-treated embryos hatched, and the lateral length of these embryos was ~3.3 mm, which are equivalent to the lengths of normal embryos. In particular, vasculogenesis, which is the main cellular process during tissue regeneration and embryogenesis, occurred normally under the Ar-PJ dose used in this study. Therefore, our biosafety evaluation tools that use living model systems can be used to provide an experimental guideline to determine the clinically safe dosage of Ar-PJ.
Argon* ; Cell Culture Techniques ; Cell Death ; Dentistry ; Dermatology ; Embryonic Development* ; Embryonic Structures ; Female ; Plasma* ; Pregnancy ; Regeneration* ; Zebrafish*

BACKGROUND/AIMS: To date, the best therapeutic modality for gastric adenoma, especially low-grade adenoma, has not been established. The aim of this study was to assess the usefulness of argon plasma coagulation (APC) in treating gastric adenoma compared with endoscopic submucosal dissection (ESD). METHODS: We included 210 patients with gastric adenoma, who underwent treatment with either APC (97 patients) or ESD (113 patients). The clinical and pathologic characteristics, mean duration of hospital stay, complications, and recurrence rates between the two groups were compared. RESULTS: The mean adenoma size was 0.9 cm and 1.1 cm in the APC group and ESD group, respectively (p<0.001). The mean duration of hospital stay was significantly shorter in the APC group than in the ESD group (1.6 days vs. 5.8 days, p<0.001). Complications did not occur in the APC group. However, one case of perforation (0.9%) and 6 cases of bleeding (5.3%) occurred in the ESD group. The recurrence rates were 15.3% (15/97 patients) in the APC group and 3.5% (4/113 patients) in the ESD group (p=0.003). The proportion of hospitalization was less in the APC group (43.3%, 42/97) than in the ESD group (100.0%, 113/113) (p<0.001). Medical expense was less in the APC group (377,172 won) than in the ESD group (1,430,610 won) (p<0.001). CONCLUSIONS: The findings of this study suggest that APC is a safe treatment method for gastric adenoma without serious complications. However, regular endoscopic follow-up is necessary to detect any residual or recurrent lesions due to the relatively high rate of local recurrence after APC.
Adenoma* ; Argon Plasma Coagulation* ; Argon* ; Follow-Up Studies ; Hemorrhage ; Hospitalization ; Humans ; Length of Stay ; Methods ; Recurrence

Intraductal papillary mucinous neoplasm of the bile duct (IPMN-B) is frequently found and has recently been recognized as a precancerous lesion leading to invasive carcinoma characterized by papillary growth of the ductal epithelium with rich mucin production and cystic dilatation of the hepatic duct. Surgical resection is the treatment of choice to avoid malignant transformation. Despite a growing number of studies on IPMN-B, there are few reports of its treatment aside from surgery. A 75-year-old woman was incidentally diagnosed as IPMN-B. Considering the patient's age, comorbidity, and preference, we recommended an argon plasma coagulation (APC) as local ablation therapy rather than surgical resection. There was no evidence of remnant tumor on percutaneous transhepatic cholangioscopy 4 weeks after the ablation of tumor mass by using APC. We report a rare case of IPMN-B successfully treated with APC.
Aged ; Argon Plasma Coagulation* ; Argon* ; Bile Duct Neoplasms ; Bile Ducts* ; Bile* ; Comorbidity ; Dilatation ; Epithelium ; Female ; Hepatic Duct, Common ; Humans ; Mucins*

Intraductal papillary mucinous neoplasm of the bile duct (IPMN-B) is frequently found and has recently been recognized as a precancerous lesion leading to invasive carcinoma characterized by papillary growth of the ductal epithelium with rich mucin production and cystic dilatation of the hepatic duct. Surgical resection is the treatment of choice to avoid malignant transformation. Despite a growing number of studies on IPMN-B, there are few reports of its treatment aside from surgery. A 75-year-old woman was incidentally diagnosed as IPMN-B. Considering the patient's age, comorbidity, and preference, we recommended an argon plasma coagulation (APC) as local ablation therapy rather than surgical resection. There was no evidence of remnant tumor on percutaneous transhepatic cholangioscopy 4 weeks after the ablation of tumor mass by using APC. We report a rare case of IPMN-B successfully treated with APC.
Aged ; Argon Plasma Coagulation* ; Argon* ; Bile Duct Neoplasms ; Bile Ducts* ; Bile* ; Comorbidity ; Dilatation ; Epithelium ; Female ; Hepatic Duct, Common ; Humans ; Mucins*

PURPOSE: The purpose of this study was to investigate the electrochemical characteristics of nanotubular Ti-25Nb-xZr ternary alloys for dental implant materials. MATERIALS AND METHODS: Ti-25Nb-xZr alloys with different Zr contents (0, 3, 7, and 15 wt.%) were manufactured using commercially pure titanium (CP-Ti), niobium (Nb), and zirconium (Zr) (99.95 wt.% purity). The alloys were prepared by arc melting in argon (Ar) atmosphere. The Ti-25Nb-xZr alloys were homogenized in Ar atmosphere at 1,000℃ for 12 hours followed by quenching into ice water. The microstructure of the Ti-25Nb-xZr alloys was examined by a field emission scanning electron microscope. The phases in the alloys were identified by an X-ray diffractometer. The chemical composition of the nanotube-formed surfaces was determined by energy-dispersive X-ray spectroscopy. Selforganized TiO₂ was prepared by electrochemical oxidation of the samples in a 1.0 M H₃PO₄+0.8 wt.% NaF electrolyte. The anodization potential was 30 V and time was 1 hour by DC supplier. Surface wettability was evaluated for both the metallographically polished and nanotube-formed surfaces using a contact-angle goniometer. The corrosion properties of the specimens were investigated using a 0.9 wt.% aqueous solution of NaCl at 36℃±5℃ using a potentiodynamic polarization test. RESULT: Needle-like structure of Ti-25Nb-xZr alloys was transform to equiaxed structure as Zr content increased. Nanotube formed on Ti-25Nb-xZr alloys show two sizes of nanotube structure. The diameters of the large tubes decreased and small tubes increased as Zr content increased. The lower contact angles for nanotube formed Ti-25NbxZr alloys surfaces showed compare to non-nanotube formed surface. The corrosion resistance of alloy increased as Zr content increased, and nanotube formed surface showed longer the passive regions compared to non-treatment surface. CONCLUSION: It is confirmed that corrosion resistance of alloy increased as Zr content increased, and nanotube formed surface has longer passive region compared to without treatment surface.
Alloys* ; Argon ; Atmosphere ; Corrosion ; Dental Implants* ; Freezing ; Ice ; Nanotubes ; Niobium ; Spectrum Analysis ; Titanium ; Water ; Wettability ; Zirconium