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Materials (Basel, Switzerland) May 2024The primary focus of the current paper centers on the microstructures and mechanical properties exhibited by a Ti-30Nb-12Zr-5Ta-2Sn-1.25Fe (wt. %) (TNZTSF) alloy that...
The primary focus of the current paper centers on the microstructures and mechanical properties exhibited by a Ti-30Nb-12Zr-5Ta-2Sn-1.25Fe (wt. %) (TNZTSF) alloy that has been produced through an intricate synthesis process comprising cold-crucible induction in levitation, carried out in an atmosphere controlled by argon, and cold-rolling deformation (CR), applying systematic adjustments in the total deformation degree (total applied thickness reduction), spanning from 10% to 60%. The microstructural characteristics of the processed specimens were investigated by SEM and XRD techniques, and the mechanical properties by tensile and microhardness testing. The collected data indicate that the TNZTSF alloy's microstructure, in the as-received condition, consists of a β-Ti phase, which shows polyhedral equiaxed grains with an average grain size close to 82.5 µm. During the cold-deformation processing, the microstructure accommodates the increased applied deformation degree by increasing crystal defects such as sub-grain boundaries, dislocation cells, dislocation lines, and other crystal defects, powerfully affecting the morphological characteristics. The as-received TNZTSF alloy showed both high strength (i.e., ultimate tensile strength close to σ = 705.6 MPa) and high ductility (i.e., elongation to fracture close to ε = 11.1%) properties, and the computed β-Ti phase had the lattice parameter a = 3.304(7) Å and the average lattice microstrain ε = 0.101(3)%, which are drastically influenced by the applied cold deformation, increasing the strength properties and decreasing the ductility properties due to the increased crystal defects density. Applying a deformation degree close to 60% leads to an ultimate tensile strength close to σ = 1192.1 MPa, an elongation to fracture close to ε = 7.9%, and an elastic modulus close to 54.9 GPa, while the computed β-Ti phase lattice parameter becomes a = 3.302(1) Å.
PubMed: 38793379
DOI: 10.3390/ma17102312 -
Materials (Basel, Switzerland) May 2024In this paper, Cu thin films were deposited on Si (100) substrates by the high-power impulse magnetron sputtering (HiIPMS) technique, and the effects of different duty...
In this paper, Cu thin films were deposited on Si (100) substrates by the high-power impulse magnetron sputtering (HiIPMS) technique, and the effects of different duty cycles (from 2.25% to 5.25%) on the plasma discharge characteristics, microstructure, and electrical properties of Cu thin films were investigated. The results of the target current test show that the peak target current remains stable under 2.25% and 3% duty cycle conditions. Under the conditions of a 4.5% and 5.25% duty cycle, the target peak current shows a decreasing trend. The average power of the target shows a rising trend with the increase in the duty cycle, while the peak power of the target shows a decreasing trend with the increase in the duty cycle. The results of OES show that with the increase in the duty cycle, the total peak intensity of copper and argon emissions shows an overall increasing trend. The duty cycle from 3% to 4.5% change in copper and argon emission peak total intensity change is not obvious. The deposition rate and surface morphology of the copper film were investigated by scanning electron microscopy, and the deposition rate of the copper film increased with the increase in the duty cycle, which was mainly due to the increase in the average power. The surface roughness of the copper film was evaluated by atomic force microscopy. X-ray diffraction (XRD) was used to analyze the grain size and texture of the Cu film, and the results showed that the average grain size of the Cu film increased from 38 nm to 59 nm on the (111) and (200) crystal planes. Four-probe square resistance test copper film resistivity in 2.25%, 3% low duty cycle conditions of the copper film resistivity is generally higher than 4.5%, 5.25% high duty cycle conditions, the copper film resistivity shows the trend of change is mainly affected by the copper film grain size and the (111) face of the double effect of the optimal orientation. The lowest resistivity of the copper film measured under the 4.5% duty cycle condition is 1.7005 μΩ·cm, which is close to the intrinsic resistivity of the copper film of 1.67 μΩ·cm.
PubMed: 38793378
DOI: 10.3390/ma17102311 -
Medicina (Kaunas, Lithuania) May 2024Besides classical stapedotomy, reverse stapedotomy has been used for many years in the management of otosclerosis. Our study aims to investigate whether reversing the...
Besides classical stapedotomy, reverse stapedotomy has been used for many years in the management of otosclerosis. Our study aims to investigate whether reversing the surgical steps in stapedotomy impacts vestibular function and hearing improvement. A cohort of 123 patients underwent either classic or reverse stapedotomy procedures utilizing a fiber-optic argon laser. Audiological assessments, following the guidelines of the Committee on Hearing and Equilibrium, were conducted, including pure tone average, air-bone (AB) gap, overclosure, and AB gap closure. Vestibular evaluation involved pre- and postoperative comparison of rotatory test parameters, including frequency, amplitude, and slow phase velocity of nystagmus. The study demonstrated an overall median overclosure of 3.3 (3.3, 5.0) dB and a mean AB gap closure of 20.3 ± 8.8 dB. Postoperative median AB gap was 7.5 (7.5, 11.3) dB in the reverse stapedotomy group and 10.0 (10.0, 12.5) dB in the classic stapedotomy group. While overclosure and AB gap closure were marginally superior in the reverse stapedotomy group, these differences did not reach statistical significance. No significant disparities were observed in the frequency, slow phase velocity, or amplitude of nystagmus in the rotational test. Although not always possible, reverse stapedotomy proved to be a safe surgical technique regarding postoperative outcomes. Its adoption may mitigate risks associated with floating footplate, sensorineural hearing loss, and incus luxation/subluxation, while facilitating the learning curve for less experienced ear surgeons.
Topics: Humans; Stapes Surgery; Male; Female; Middle Aged; Adult; Otosclerosis; Audiometry; Cohort Studies; Treatment Outcome; Audiometry, Pure-Tone; Aged; Vestibular Function Tests
PubMed: 38792986
DOI: 10.3390/medicina60050803 -
International Journal of Molecular... May 2024Epidermal melanin synthesis determines an individual's skin color. In humans, melanin is formed by melanocytes within the epidermis. The process of melanin synthesis...
Epidermal melanin synthesis determines an individual's skin color. In humans, melanin is formed by melanocytes within the epidermis. The process of melanin synthesis strongly depends on a range of cellular factors, including the fine-tuned interplay with reactive oxygen species (ROS). In this context, a role of cold atmospheric plasma (CAP) on melanin synthesis was proposed due to its tunable ROS generation. Herein, the argon-driven plasma jet kINPen MED was employed, and its impact on melanin synthesis was evaluated by comparison with known stimulants such as the phosphodiesterase inhibitor IBMX and UV radiation. Different available model systems were employed, and the melanin content of both cultured human melanocytes (in vitro) and full-thickness human skin biopsies (in situ) were analyzed. A histochemical method detected melanin in skin tissue. Cellular melanin was measured by NIR autofluorescence using flow cytometry, and a highly sensitive HPLC-MS method was applied, which enabled the differentiation of eu- and pheomelanin by their degradation products. The melanin content in full-thickness human skin biopsies increased after repeated CAP exposure, while there were only minor effects in cultured melanocytes compared to UV radiation and IBMX treatment. Based on these findings, CAP does not appear to be a useful option for treating skin pigmentation disorders. On the other hand, the risk of hyperpigmentation as an adverse effect of CAP application for wound healing or other dermatological diseases seems to be neglectable.
Topics: Humans; Melanins; Melanocytes; Plasma Gases; Epidermis; Ultraviolet Rays; Skin Pigmentation; Cells, Cultured; Reactive Oxygen Species; Biopsy; Melanogenesis
PubMed: 38791225
DOI: 10.3390/ijms25105186 -
BMJ Open Gastroenterology May 2024Dieulafoy's lesions (DLs) are a rare but potentially life-threatening source of gastrointestinal (GI) haemorrhage. They are responsible for roughly 1%-6.5% of all cases... (Review)
Review
OBJECTIVE
Dieulafoy's lesions (DLs) are a rare but potentially life-threatening source of gastrointestinal (GI) haemorrhage. They are responsible for roughly 1%-6.5% of all cases of acute non-variceal GI bleeding.Here, we describe retrospectively the clinical and endoscopic features, review the short-term and long-term outcomes of endoscopic management of bleeding DLs and we identify rate and risk factors, of recurrence and mortality in our endoscopic unit.
DESIGN
Data were collected from patients presenting with GI haemorrhagic secondary to DLs between January 2018 and August 2023. Patients' medical records as well as endoscopic databases were retrospectively reviewed. Demographic data, risk factors, bleeding site, outcomes of endoscopy techniques, recurrence and mortality rate were taken into account.
RESULTS
Among 1170 cases of GI bleeding, we identified only seven cases involving DLs. Median age was 74 years, with a male-to-female ratio of 2.5. 75% of patients had significant comorbidities, mainly cardiovascular diseases. Only anticoagulant and antiplatelet agents were significantly associated with DLs. All patients were presented with GI bleeding as their initial symptom. The initial endoscopy led to a diagnosis in 85% of the cases. Initial haemostasis was obtained in all patients treated endoscopically. Nevertheless, the study revealed early recurrence in two out of three patients treated solely with epinephrine injection or argon plasma coagulation. In contrast, one of three patients who received combined therapy, experienced late recurrence (average follow-up of 1 year). Pathological diagnosis was necessary in one case. One patient (14%) died of haemorrhagic shock. Average length of hospital stay was 3 days.
CONCLUSION
Although rare, DLs may be responsible for active, recurrent and unexplained GI bleeding. Thanks to the emergence of endoscopic therapies, the recurrence rate has decreased and the prognosis has highly improved. Therefore, the endoscopic approach remains the first choice to manage bleeding DLs.
Topics: Aged; Aged, 80 and over; Female; Humans; Male; Middle Aged; Endoscopy, Gastrointestinal; Gastrointestinal Hemorrhage; Hemostasis, Endoscopic; Recurrence; Retrospective Studies; Risk Factors; Treatment Outcome; Stomach; Blood Vessels
PubMed: 38789268
DOI: 10.1136/bmjgast-2023-001299 -
Nanomaterials (Basel, Switzerland) May 2024Memristive structures are among the most promising options to be components of neuromorphic devices. However, the formation of HfO-based devices in crossbar arrays...
Memristive structures are among the most promising options to be components of neuromorphic devices. However, the formation of HfO-based devices in crossbar arrays requires considerable time since electroforming is a single stochastic operation. In this study, we investigate how Ar plasma immersion ion implantation (PI) affects the Pt/HfO (4 nm)/HfOXNY (3 nm)/TaN electroforming voltage. The advantage of PI is the simultaneous and uniform processing of the entire wafer. It is thought that Ar implantation causes defects to the oxide matrix, with the majority of the oxygen anions being shifted in the direction of the TaN electrode. We demonstrate that it is feasible to reduce the electroforming voltages from 7.1 V to values less than 3 V by carefully selecting the implantation energy. A considerable decrease in the electroforming voltage was achievable at an implantation energy that provided the dispersion of recoils over the whole thickness of the oxide without significantly affecting the HfOXNY/TaN interface. At the same time, Ar PI at higher and lower energies did not produce the same significant decrease in the electroforming voltage. It is also possible to obtain self-compliance of current in the structure during electroforming after PI with energy less than 2 keV.
PubMed: 38786787
DOI: 10.3390/nano14100831 -
Heliyon May 2024Designing a nearly zero energy building (NZEB) and more exclusively a positive energy building (PEB) hold significant importance these days. Achieving this objective...
Designing a nearly zero energy building (NZEB) and more exclusively a positive energy building (PEB) hold significant importance these days. Achieving this objective requires an effective blend of renewable systems and the energy efficient envelope. This study focuses on a villa situated in the southeast of Kerman, Iran with hot and dry summers. Commencing with the current energy-efficient design of the structure, the research conducted various analyses to explore the impacts of different strategies or alternative approaches that contribute to achieving a NZEB or PEB. The parameters examined in the analysis that pertain to the building envelope, encompass insulation scenarios, window-to-wall ratio, and glass types as passive strategies, along with the integration of wind turbine energy production as an active energy solution. The findings indicate that, under hot and dry conditions in this region, the optimal passive strategies for the case study involve a 40 % window-to-wall ratio, polyurethane insulation, and triple-layered glass with argon. This combination results in a noteworthy reduction in total annual energy consumption, decreasing from 24,344.56 kWh to 11,909.64 kWh. To offset the remaining energy requirements and transform the building into a positive energy structure, a wind turbine was employed. This integrated approach not only aligns with the specific climatic conditions of the area but also demonstrates the feasibility of achieving a positive energy building which resulted in a surplus energy of 1,414.13 kWh.
PubMed: 38770335
DOI: 10.1016/j.heliyon.2024.e30694 -
Clinical and Experimental Hepatology Mar 2024Managing patients with liver cirrhosis and gastric hyperplastic polyps (GHPs) is challenging. Despite being the standard technique for resection of GHPs, hot snare...
Managing patients with liver cirrhosis and gastric hyperplastic polyps (GHPs) is challenging. Despite being the standard technique for resection of GHPs, hot snare polypectomy (HSP) is risky in the setting of coagulation disorders associated with liver cirrhosis. The aim of the study was to assess the efficacy and safety of endoscopic band ligation (EBL), compared to HSP in resecting GHPs in cirrhotic patients. One hundred consecutive adults with liver cirrhosis and sessile or pedunculated GHPs were enrolled from December 2018 to December 2020. Cases were non-blindly randomized (1 : 1) to two groups to have GHPs managed by either EBL (group I) or HSP (group II). Data of demographic, clinical, and pathological factors, hospitalization expenses and outcomes of both treatment maneuvers were collected and statistically analyzed. Upper endoscopy was repeated for all patients at 3, 6 and 12 months after treatment for recurrence detection. Between the two procedures, the mean operational time was significantly shorter in the EBL than the HSP group (15.1 ±3.80 min vs. 36.6 ±6.72 min, < 0.001). Concerning complications, 94% of EBL cases had reported no complications compared to 78% with HSP. Bleeding occurred only with HSP (20%) with urgent need for adrenaline and/or argon plasma coagulation ( = 0.003). Regarding cost, it was significantly lower in EBL than HSP (280 ±2.02 EGP vs. 390 ±181.8 EGP, < 0.001). However, the recurrence rate of GHPs and number of needed sessions were not significantly different. EBL proved to be a safer, more rapid, and economic maneuver when compared to HSP on resecting GHPs in patients with liver cirrhosis.
PubMed: 38765908
DOI: 10.5114/ceh.2024.136216 -
Cureus Apr 2024We report two cases of diffuse unilateral subacute neuroretinitis (DUSN) where multimodal imaging was used to assist in locating the nematode. The first case presented...
We report two cases of diffuse unilateral subacute neuroretinitis (DUSN) where multimodal imaging was used to assist in locating the nematode. The first case presented with clusters of migrating choroiditis with a suspicious tiny visualized worm noted on serial fundus photography. The second case had an atypical presentation with extensive exudative retinal detachment and a suspicious coiled worm in the subretinal space noted on optical coherence tomography. Both cases received oral albendazole for six weeks while the first case received additional argon laser photocoagulation to the suspected nematode. Both cases showed resolution of the ocular inflammation upon completion of treatment with no further recurrences. DUSN should be suspected in young and healthy patients with unexplained unilateral inflammatory eye disease with severe loss of vision. This series highlights the challenges faced in identifying the nematode in cases with suspected DUSN.
PubMed: 38765355
DOI: 10.7759/cureus.58510 -
World Journal of Gastrointestinal... May 2024Intraductal papillary neoplasm of the bile duct (IPNB) is a premalignant biliary-type epithelial neoplasm with intraductal papillary or villous growth. Currently...
BACKGROUND
Intraductal papillary neoplasm of the bile duct (IPNB) is a premalignant biliary-type epithelial neoplasm with intraductal papillary or villous growth. Currently reported local palliative therapeutic modalities, including endoscopic nasobiliary drainage, stenting and biliary curettage, endoscopic biliary polypectomy, percutaneous biliary drainage, laser ablation, argon plasma coagulation, photodynamic therapy, and radiofrequency ablation to relieve mechanical obstruction are limited with weaknesses and disadvantages. We have applied percutaneous transhepatic cholangioscopy (PTCS)-assisted biliary polypectomy (PTCS-BP) technique for the management of IPNB including mucin-hypersecreting cast-like and polypoid type tumors since 2010.
AIM
To assess the technical feasibility, efficacy, and safety of PTCS-BP for local palliative treatment of IPNB.
METHODS
Patients with mucin-hypersecreting cast-like or polypoid type IPNB and receiving PTCS-BP between September 2010 and December 2019 were included. PTCS-BP was performed by using a half-moon type snare with a soft stainless-steel wire, and the tumor was snared and resected with electrocautery. The primary outcome was its feasibility, indicated by technical success. The secondary outcomes were efficacy, including therapeutic success, curative resection, and clinical success, and safety.
RESULTS
Five patients (four with mucin-hypersecreting cast-like type and one with polypoid type IPNB) were included. Low- and high-grade intraepithelial neoplasia (HGIN) and recurrent IPNB with invasive carcinoma were observed in one, two, and two patients, respectively. Repeated cholangitis and/or obstructive jaundice were presented in all four patients with mucin-hypersecreting cast-like type IPNB. All five patients achieved technical success of PTCS-BP. Four patients (three with mucin-hypersecreting cast-like type and one with polypoid type IPNB) obtained therapeutic success; one with mucin-hypersecreting cast-like type tumors in the intrahepatic small bile duct and HGIN had residual tumors. All four patients with mucin-hypersecreting IPNB achieved clinical success. The patient with polypoid type IPNB achieved curative resection. There were no PTCS-BP-related serious adverse events.
CONCLUSION
PTCS-BP appears to be feasible, efficacious, and safe for local palliative treatment of both mucin-hypersecreting cast-like and polypoid type IPNB.
PubMed: 38764829
DOI: 10.4251/wjgo.v16.i5.1821