Mm In Diameter Research Articles

First Report of Fusarium ipomoeae Causing leaf rot on Hosta plantaginea in China.

Hosta plantaginea is an important horticultural plant with ornamental value and is widely cultivated in China. Since April 2022, leaf rot has been observed in the H. plantaginea plants in Wanzhou District, Chongqing City, China (31º14'58"N, 108º53'25"E), the initial symptom is a yellow and brown lesion on the edge of the leaf, in the late stage, brown blighted tissue caused leaves to curl and abscise. Ten typical diseased leaves were collected, the margins of infected tissues were cut into small pieces (5×5 mm) and were sterilized in 75% Ethanol for 30 s, 3% sodium hypochlorite for 3 min, rinsed three times with sterile water, then dried on sterile filter paper and placed to potato dextrose agar (PDA) medium at 25℃for 4 days. Thirteen isolates with morphological characteristics similar to those of Fusarium spp. (Nelson et al. 1983) were recovered. These isolates had white, pink and yellowish mycelia, two isolates produced irregular colonies, and remaining isolates showed round. Two of each type were selected for intensive study (yz2, yz11, yz9 and yz17). The colony of yz2 reached 62 mm in diameter on PDA medium after seven days, macroconidia were elongated sickle-shaped, 3-5 septa, and 12.92 to 21.49 × 3.42 to 5.90 μm in size, microconidia were oval and measured 5.69 to 12.95 × 3.41 to 9.80 μm in size, conidiophores were whorled and branched, yz9 attained 74 mm in diameter after nine days, macroconidia were curved sickle-shaped and apex cell acuminate, 26.9 to 57.2 × 2.4 to 7.1 μm, 3-5 septa. The microconidia were fusiform, 17.8 to 28.8 × 11.2 to 14.5 μm. Conidiophores variable in length. Genomic DNA was extracted from 7-day-old aerial mycelia of four strains (yz2, yz9, yz11 and yz17). The internal transcribed spacer (ITS) region (White et al. 1990), translation elongation factor (EF-1α) (Cao et al. 2014) and partial RNA polymerase second largest subunit (RPB2) (Wang et al. 2019) gene regions were amplified and multilocus phylogenetic analysis was conducted, their sequences were deposited in NCBI Genbank with the following accession numbers: the strains of yz2 and yz11 with OQ829372 and OR236201 for ITS, OQ848594 and OR282462 for EF-1α, OR492296 and OR492297 for RPB2; yz9 and yz17 with OQ829383 and OR236222 for ITS, OQ848595 and OR282463 for EF-1α, OR492295 and OR492298 for RPB2. The ModelFinder was used to select the best-fit model in PhyloSuite v1.2.2, the Bayesian Inference method (BI) analysis was used to estimate the system relationship, yz9 and yz17 were identified as Fusarium ipomoeae, yz2 and yz11 were identified as Fusarium tricinctum. To verify Koch's postulates, 8 healthy plants of H. plantaginea (two-year-old) grown were rinsed with sterile water, after 5 leaves per plant were stabbed with a sterilized needle, 4 plants were inoculated with conidial suspension (1×106 conidia mL-1), other plants injected with sterile water as control, then placed in a greenhouse maintained with 95% relative humidity at 25 ± 1°C. The symptoms on the leaves were similar to field after inoculation for 7 days, whereas all control leaves remained healthy. The same pathogen was re-isolated and re-identified based on multilocus phylogenetic analysis, fulfilling Koch's postulates. To our knowledge, this is the first report of F. ipomoeae causing leaf rot on H. plantaginea in China. In addition, F. ipomoeae was reported to cause leaf spot in Peanut (Xu et al. 2021), and F. tricinctum can cause fruit rot on navel orange in China (Yang et al. 2023). H. plantaginea as a horticultural plant is popular with some people, but it has long been threatened by Fusarium.spp. The finding can provide a theoretical basis for control leaf rot on H. plantaginea.

EVALUATION OF BOND STRENGTH BETWEEN DIFFERENT SYSTEMS FOR ADHESIVE CEMENTATION TO FELDSPATHIC PORCELAIN AND ZIRCONIUM OXIDE

Introduction: New systems for adhesive cementation have been increasingly developed and used in daily clinical practice for the cementation of ceramic prostheses. Differences in the chemical composition of various system components can influence the bond strength between the resin cement and the ceramic. Objective: This study aims to evaluate the bond strength between two ceramic systems—feldspathic porcelain and yttria-stabilized zirconium oxide—and three different systems for adhesive cementation: Rely X ARC, Multilink System, and Rely X UCem. Methodology: Thirty discs of Noritake feldspathic porcelain and thirty discs of zirconium oxide ceramic were fabricated, each measuring 7.5 mm in diameter by 3.0 mm in thickness, according to the manufacturers’ instructions. The discs were polished on a mechanical polisher with water sandpaper ranging from 320 to 1500 grit and embedded in ½ inch PVC tubes with self-curing acrylic resin. The feldspathic porcelain discs were conditioned with 10% hydrofluoric acid for 120 seconds, and the zirconium oxide discs were sandblasted with 40 psi alumina for 10 seconds at 10 mm. All discs were then washed and placed in an ultrasonic bath with distilled water for 10 minutes. The cementation systems were applied according to the manufacturers’ instructions (n=10) on an adhesion area of 5.0 mm in diameter, delimited by a tripartite metal matrix. The samples underwent 1,000 thermal cycles ranging from 5°C to 55°C. Shear bond strength tests were performed on an EMIC DL2000 testing machine with a 20 kN load cell and a speed of 0.5 mm/min. The mean values of the groups were as follows (in MPa): Feldspathic with Rely X ARC (G1) 6.21; Feldspathic with Multilink (G2) 8.98; Feldspathic with Rely X UCem (G3) 8.15; Zirconium Oxide with Rely X ARC (G4) 0.53; Zirconium Oxide with Multilink (G5) 9.25; Zirconium Oxide with Rely X UCem (G6) 4.37. Data were subjected to one-way ANOVA and Tukey tests. Results: There was no significant difference among the feldspathic porcelain groups. For zirconium oxide, Multilink showed higher bond strength values. Conclusion: The bond strength between the cements and feldspathic porcelain exceeded the intrinsic strength of this material, and Multilink showed the highest bond strength values regardless of the ceramic material.

Multiple ileal neuroendocrine tumors 10mm in diameter with lymph node metastasis detected on endoscopy:a case report

A 53-year-old man with an abnormal routine physical examination was referred to our hospital. Colonoscopy showed a 5-mm submucosal tumor that was 7cm proximal to the ileocecal valve. It was identified as a neuroendocrine tumor (NET) on biopsy. Preoperatively, we conducted a double balloon endoscopy to examine the entire small intestine. Another 7-mm submucosal tumor was found on the ileocecal valve, which was missed during the first colonoscopy. A final diagnosis of multiple ileal NETs (<10mm in diameter) was made, and the patient underwent ileocecal resection with lymphadenectomy. Histopathological evaluation of the surgical specimen verified the diagnosis of NET Grade 1 with submucosal invasion. Metastasis to lymph node #202 was also detected. He remained relapse-free for 5 years and 5 months after the operation. In conclusion, this was a case of multiple ileal NETs (<10mm in diameter) with lymph node metastasis that could not be detected preoperatively on contrast-enhanced computed tomography. This case highlights the significance of detailed endoscopic observation of the terminal ileum.

CHOLEDOCHOLITHIASIS IN A PATIENT CARRYING AN INTRAGASTRIC BALLOON. REMOVAL OR DIRECT ERCP?

CHOLEDOCHOLITHIASIS IN A PATIENT CARRYING AN INTRAGASTRIC BALLOON. REMOVAL OR DIRECT ERCP?

Assessment of Mechanical Properties and Antimicrobial Effects of Hyaluronic Acid Coating on Absorbable Suture Material: An In-vitro Study

Introduction: The use of absorbable suture materials in surgical procedures is a critical aspect of wound closure and tissue repair. In recent years, there has been growing interest in exploring the potential benefits of incorporating Hyaluronic Acid (HA), a naturally occurring biopolymer, into these sutures. By shedding light on the interactions between HA and absorbable sutures, the present study seeks to provide valuable insights that could enhance the quality of surgical wound management. Aim: To assess the mechanical properties and antimicrobial effects of HA-coated and uncoated absorbable suture material. Materials and Methods: The in-vitro study was conducted at Saveetha Dental College, Saveetha Institute of Medical and Technical Sciences, Chennai, Tamil Nadu, India in a year 2022. A total of 70 samples of HA-coated and uncoated Vicryl 4-0 suture material were tested for tensile strength using an Instron machine. An anti-bacterial effect against Pseudomonas aeruginosa and Streptococcus mutans was assessed using a Mueller Hinton agar (MHA) plate, and the zone of inhibition was measured. Additionally, both the uncoated and HA-coated Vicryl 4-0 suture materials were analysed under the Scanning Electron Microscope (SEM) to determine the surface characteristics. An independent t-test was used to compare the tensile strength of coated and uncoated suture materials. Results: The mean tensile strength of uncoated and HAcoated suture material was 6.47±0.23 MPa and 3.78±1.02 MPa, respectively. The difference between both groups was statistically significant (p&lt;0.05). For Pseudomonas aeruginosa and Streptococcus mutans, the zone of inhibition was 8.0±0.5 mm in diameter and 9±0.5 mm in diameter, respectively, around coated Vicryl 4-0 suture material, whereas no zone of inhibition was observed for both Pseudomonas aeruginosa and Streptococcus mutans around uncoated suture material. SEM analysis showed superior surface characteristics of HA-coated suture thread when compared to uncoated suture thread. Conclusion: HA-coated suture material does not exhibit superior tensile strength when compared to the uncoated suture material. However, HA-coated suture material has potent antibacterial effects against Pseudomonas aeruginosa and Streptococcus mutans. Additionally, SEM analysis showed improved surface characteristics in favour of the coated suture material.

Determination of Needle Penetration Force and Pump Pressure for the Development of an Automated Trunk Injection System for HLB-Affected Citrus Trees

Highlights An equation was developed for estimating the needle penetration force required for trunk injection. A method to determine the required pump pressure for citrus tree trunk injection was developed. This information can be used for the development of a drill-free, pressurized, automated trunk injection system. Abstract. Targeted precisemanagement of intravascular diseases such as citrus Huanglongbing (HLB) involves the application of therapeutics via trunk injection.Although trunk injection has proven more effective than foliar spray and soil drenching, multiple studies have highlighted limitations for large-scale commercial tree crop applications because of the manual process involved, emphasizing the need for an automated injection system.The design of a trunk injection mechanism to efficiently dispense aqueous therapeutic materials to the trunk of HLB-affected citrus trees requires the characterization of the hydraulic properties of the trunk and the determination of the penetration force of a dispensing needle. This study developed an equation for estimating penetration force at maximum depth based on the needle diameter, depth of penetration, and specific gravity of the wood tissue, and presents a method for estimating injection pump pressure. Trunk hydraulic conductance was measured using a hydraulic conductance flow meter, and needle insertion and removal force were measured using a force gauge in an Instron universal testing machine. The average maximum force was 2517, 3739, and 5387 N for dowel pins 4.76, 6.35, and 7.93 mm in diameter at a 12 mm penetration depth. Average specific conductivity was 2.45, 0.34, and 0.15 kgs-1m-1MPa-1for trunk segments 0–12.7, 12.7–26.7, and 26.7–40.6 cm above the ground, with a corresponding estimated pump pressure of 0.14, 0.99, and 2.31 MPa, respectively. Keywords: Automated trunk injection, Drill-free, Huanglongbing, Plant diseases.

Pathological complete response after primary tumor surgery following chemoimmunotherapy and stereotactic radiosurgery of initially metastatic non-small-cell lung cancer

Introduction. Surgery of the primary tumor following extended course of chemoimmunotherapy has only recently been recognized as a feasible and safe option for selected groups of patients with initially unresectable non-small cell lung cancer. Case outline. Here we report a case of a 49-year-old female patient, who never smoked, that was diagnosed with metastatic non-small cell lung cancer. Lesions were evident in both lungs and the brain. She underwent stereotactic radiosurgery for brain metastases and combination therapy of chemotherapy, atezolizumab and bevacizumab. Response to therapy was both remarkable and durable. Ten cycles into treatment, magnetic resonance imaging of the brain revealed no metastatic lesions. Positron emission tomography / computed tomography revealed a single lesion in the right upper lobe 22 ? 23 mm in diameter. The patient underwent a right upper lobectomy. Pathohistological evaluation of the specimen revealed complete pathologic response. The patient recovered from surgery and continued chemoimmunotherapy. Four months post-surgery she is disease free and of excellent performance status. Conclusion. Primary tumor surgery following extensive chemoimmunotherapy regiment is feasible and could be considered as a treatment option. Further research is warranted to define a patient population that stands to benefit the most from this modality.

Initial clinical manifestations and early diagnosis of basal cell skin carcinoma

Background/Aim: Basal cell carcinoma (BCC) is the most common cancer of the skin. It is believed that increased UV radiation from the sun accounts for almost 90 % of the risk of BCC. There is a growing trend in the incidence of BCC in a younger population. The aim of study was to analyse the initial clinical symptoms of BCC that may be important for the early detection of this skin tumour. Method: The study was a prospective, multicentre study performed in the period from March 2017 to February 2022. A total of 69 respondents with BCC were analysed. Respondents applied for a targeted examination to examine a suspicious skin lesion (due to certain symptoms) or were diagnosed with BCC by accident, when examining other skin changes. Respondents were divided into 2 groups. The first, Group I (35 respondents), consisted of respondents with nodular BCC. The second, Group II (34 respondents), consisted of respondents with superficial spreading BCC. Initially, a careful history and data on the characteristics, shape and character of the tumour were taken from all respondents. Data on all (even the smallest) initial symptoms and relevant signs of evolution, as well as subjective problems related to the tumour were noted. All respondents underwent dermoscopy of suspected skin changes. Results: A significant difference was found between the examined groups in the characteristics of bleeding, crust formation and tendency to injury in lesions, where they occur more often in patients with nodular BCC. Symptoms such as burning and flaking occurred significantly more often in patients with superficial spreading BCC (p &lt; 0.01), as well as the diameter of lesions over 5 mm (p &lt; 0.05). Conclusion: Early clinical diagnosis of BCC is possible with a tumour diameter of only a few mm. The predominant initial (highly susceptible) symptoms of nodular BCC were initial bleeding and / or scab formation on the lesions, as well as propensity to injury. The superficial spreading form of BCC was often larger than 5 mm in diameter, with more frequent scaling of the lesion, as well as burning and stinging sensations in the tumour area. Itching was observed to be a very common previous occurrence in the BCC initial focus zone in subjects of both study groups. Dermsocopy is a highly reliable diagnostic method for early detection of BCC.

In-Motion Railcar Wheel Inspection using Magnetostrictive EMATs

Due to cyclic mechanical loading, railcar wheels are subject to the development of internal fatigue cracks in the rim underneath the tread surface. Off-line inspections are extremely laborious and require extended out-of-service time, and most existing in-line inspection systems that use conventional ultrasonics or electromagnetic acoustic transducer (EMAT) techniques have several drawbacks that limit their full-scale deployment in service. This paper discusses the work performed on the initial research and development of a proof-of-concept novel magnetostrictive EMAT sensor for in-motion railcar wheel inspection. Wheelsets with known internal discontinuities and a 3.7 m long panelized track were used to demonstrate the feasibility of the developed approach and methods. The results obtained from these tests have shown that the magnetostrictive EMAT sensor that generates 5 mm wavelength shear horizontal waves detects both surface defects and internal fatigue cracks with an excellent signal-to-noise ratio. Different wavelengths can also be added to the sensors to enhance or complement the detection of fatigue cracks at different depths. A total of four or five sensors located at standard concrete crosstie spacing along each rail would be able to provide complete coverage on wheels ranging from 711 to 965 mm in diameter with ±90° wheel coverage per sensor, and a theoretical inspection speed of 56 kph can be achieved using this approach.

Influence of Diabetes Mellitus and Universal Adhesive Application Mode on the Bond Strength of Composite Resin to Dentine.

The aim of the current study was to evaluate the influence of diabetes mellitus and the mode of applying a universal adhesive on the shear bond strength of composite resin to dentin. Forty teeth were extracted from diabetic individuals who had been living with diabetes for a period of 5 to 15 years. These forty teeth were divided into two groups: twenty molars from patients with type 1 diabetes and twenty molars from patients with type 2 diabetes. The remaining twenty sound human molars were collected from non-diabetic patients. The collected teeth were assigned into 3 groups, and each group was further divided into 2 subgroups. Group A (n = 20): non-diabetic (ND) where sub group IA: Universal adhesive applied in the total-etch mode (n = 10) and sub group IIA: Universal adhesive applied in the self-etch mode (n = 10). Group B (n = 20): diabetic type 1 (D1) where sub group IB: Universal adhesive applied in the total-etch mode (n = 10) and sub group IIB: Universal adhesive applied in the self-etch mode (n = 10). Group C (n = 20): diabetic type 2 (D2). Where Sub group IC: Universal adhesive applied in the total-etch mode (n = 10) and sub group IIC: Universal adhesive applied in the self-etch mode (n = 10). A Teflon mold measuring 3mm in diameter was attached to the dentin surface, used to build Filtek Z550 to a height of 3mm. The specimens were fixed to the universal testing to measure shear bond strength. There was a statistically significant difference of Mean ±SD of shear bond strength among the three tested groups. In group A, the Mean ±SD were (21.710 ± 0.638), it was decreased in group B to (14.626 ± 0.726) and group C to (17.740 ± 0.668). Subgroup I had lower shear bond strength values than subgroup II in all tested groups. The difference between each subgroup in groups A, B, and C was significant. 1. Diabetes mellitus has an adverse effect on the shear bond strength of composite to dentine. 2. Type 1 diabetes mellitus significantly reduces the shear bond strength of composite resin to dentin. 3. Shear bond strength of the universal adhesive was higher when applied to dentin using the self-etch mode, as compared to the total etch mode, in all groups, regardless of whether the participants had diabetes or not. Key words:Diabetes Mellitus, Universal Adhesive, Application Mode, Shear bond Strength, Dentine, Composite.

Gastric polyps: a retrospective cohort analysis of 23,668 endoscopies indicates changing epidemiological and phenotypic characteristics.

Growing adoption of endoscopic procedures in clinical practice has gradually increase the detection rate of gastric polypoid lesions. To identify the epidemiologic characteristics of gastric polyps as well as changes of these parameters during a 15-year period. We reviewed all the upper endoscopies archived in our database reporting a polypoid lesion from 2003 to 2018. Demographic data, indication for endoscopy, morphological characteristics of polyps, histology, and presence of Helicobacter pylori were collected. We compared the abovementioned data between 2 periods: 2003-2010 and 2010-2018. A total of 989 (4.2%) patients from 23,668 reviewed were identified to harbour a polypoid lesion. Mean patient age was 63.2 years, with 58.8% being female. Most polyps (65.2%) were less than 5 mm in diameter and located in the fundus. Hyperplastic polyps (HPs) were the predominant type (28.6%) while fundic gland polyps (FGPs) were found in 24.1% of patients. Adenomas were the least common type (2.7%). Other pathology was identified in 43.3%. Comparison between the 2 periods revealed a rise of FGPs against HPs with a concomitant shift of location from antrum to fundus and an increase in the number of polyps per patient. FGPs and HPs were the most common polyps found in our cohort, with a change of their pattern during the 15 years. It is imperative to acknowledge the distinct characteristics of gastric polyps so as to properly assess the malignant potential that some of them, or their surrounding gastric mucosa, harbour.

Endoscopic treatment of an esophageal perforation in eosinophilic esophagitis by insertion of a self-expanding metal stent.

We present the case of a 29-year-old patient with multiple allergies, mild asthma and rhinoconjunctivitis who reported a history of esophageal impactions after ingestion of solid foods. These episodes resolved spontaneously at home and by self-induced vomiting and never required endoscopic removal. The patient presented to the emergency department due to a sensation of food impaction lasting more than 12 hours after eating meat the night before, which did not subside with the intake of liquids or self-induced vomiting. Endoscopic evaluation was requested for foreign body extraction. A meat bolus impacted in the distal esophagus was easily removed using a Roth basket, revealing a severe esophageal stricture that prevented passage of the endoscope into the gastric cavity. Furthermore, in the same area where the foreign body was previously located, a deep esophageal tear was seen. Given the high suspicion of perforation, the patient was examined, and thoracic and cervical crepitation was observed. It was decided to immediately insert, with only endoscopic control, a partially covered Ultraflex® esophageal stent measuring 18 mm in diameter and 15 cm in length. After insertion, clinical improvement and cessation of crepitation were observed.

The use of D- and L,D- cloprostenol to reduce diastral period of estrus cycle in mares

In order to determine the minimum effective drug doses, the levels of decrease in progesterone concentration followed the injections of D and L, D - cloprostenol (the dosage 25 - 250 μg) were compared. The effect of treatment on the reduction of estrus duration and the time before ovulation were studied. It has been shown that the level of progesterone 24 hours after the first injection (at any dose except 50 μg of L, Dcloprostenol) decreased by 76-81%. Complete luteolysis was achieved (0.24-0.45 ng/ml) at any kind of treatment in 72 hours after injection. A significant difference in the average duration of estrus (when using large doses) and the period from injection to ovulation (when using small and large doses) was found between groups of mares that were injected with a follicle diameter of 22-28 or 29-37 mm in both the first and in the second half of diestrus. The study showed that the use of D-cloprostenol once in reduced doses (25 - 50 μg) or D, L-cloprostenol twice 50 μl in the presence of follicles more than 29 mm in diameter will decrease the risk of reducing the duration of estrus.

Muco-bioadhesive gel containing basil extract (Ocimum basilicum) in the management of recurrent aphthous stomatitis: a randomized clinical and immunological study

Background Recurrent aphthous ulcer (RAU) is a widespread highly prevalent disorder that impairs the life quality of the affected persons and leads to difficulties in daily activities such as talking, eating, and oral hygiene maintenance. Aim To evaluate the efficiency of basil extract (Ocimum basilicum) loaded in poly (vinylacohol)–borate hydrogel for topical application in the treatment of RAU. Patients and methods Twenty patients with a clear history of frequent eruption of RAU, their ages ranges between 18 and 45 years, and presented with mucosal ulcer (2 days or less duration and ≥4 mm in diameter). The patients were randomly allocated into two groups, group I (test group): 10 patients treated with mucoadhesive gel containing 2% of basil extract. Group II (placebo group): 10 patients treated with placebo gel. The healing period, pain scale, and the size of the ulcer were evaluated. Salivary endocan was collected at baseline and 5 days after materials application. Results There was no significant difference between the test and control group, while there were statistically significant differences between them and the healthy group at baseline clinically and immunologically. At 5 days there was a significant reduction in the degree of pain sensation, healing period, ulcer size, and decrease in the level of salivary endocan for both groups with statistically significant differences between them observed in the test group more than the control group in all tested parameters. Conclusion Using the muco-bioadhesive gel containing basil extract (O. basilicum) shows promise as a therapy for the management of patients with RAU.

Wet bio-amniotic membrane plugging combined with transplantation in the treatment of small corneal perforations.

Wet bio-amniotic membrane plugging combined with transplantation is a novel option that combined amniotic membrane plugging with amniotic membrane transplantation for the treatment of small corneal perforations. This study aimed to evaluate the efficacy of wet bio-amniotic membrane plugging in the treatment of small corneal perforations and compared it with that of the penetrating keratoplasty procedure. Forty patients (41 eyes) with small corneal perforations <3 mm in diameter treated at our hospital between July 2018 and January 2021 were retrospectively included. Among them, 21 eyes were treated with wet bio-amniotic membrane plugging (wet bio-amniotic membrane plugging group), and 20 eyes were treated with penetrating keratoplasty procedure (penetrating keratoplasty procedure group). The best-corrected visual acuity, anterior chamber formation, corneal thickness, primary disease control, postoperative complications, and graft survival rate were assessed. No significant difference in baseline characteristics was found between the wet bio-amniotic membrane plugging and penetrating keratoplasty procedure groups (p>0.05). The postoperative control rates of primary diseases in the wet bio-amniotic membrane plugging and penetrating keratoplasty procedure groups were 95.2% and 90.0%, respectively (p=0.481). Visual acuity was improved 6 months after the operation in the wet bio-amniotic membrane plugging group and was improved at postoperative 1 month in the penetrating keratoplasty procedure group. The formation time of the anterior chamber in the wet bio-amniotic membrane plugging group was significantly shorter than that in the penetrating keratoplasty procedure group (p=0.023). The corneal thickness of the two groups significantly increased 12 months after the operation; however, the degree of thickening in the penetrating keratoplasty procedure group was higher than that in the wet bio-amniotic membrane plugging group (p<0.001). During the follow-up, postoperative complications were not different between the two groups (p>0.999). The results suggest that wet bio-amniotic membrane plugging is effective and safe in the treatment of small corneal perforations. Thus, it can be used as an emergency treatment alternative to penetrating keratoplasty procedure for small corneal perforations.

Effect of Ceramic Thickness on the Bond Strength to Resin-Luting Agents before and after Thermal Cycling.

This study investigated microshear bond strength (µSBS) of two (2) dual-cured resin-luting agents (RelyX™ Ultimate and RelyX™ U200) when photoactivated through varying thicknesses of lithium disilicate, with or without thermal cycling. Discs of IPS e.max Press of 0.5, 1.5, and 2 mm in thickness were obtained. Elastomer molds (3.0 mm in thickness) with four cylinder-shaped orifices 1.0 mm in diameter, were placed onto the ceramic surfaces and filled with resin-luting agents. A Mylar strip, glass plate, and load of 250 grams were placed over the filled mold. The load was removed and the resin-luting agents were photoactivated through the ceramics using a single-peak LED (Radii Plus.) All samples were stored in distilled water at 37oC for 24 h. Half of the samples were subjected to thermal cycling (3,000 cycles; 5ºC and 55ºC). All samples were then submitted to µSBS test using a universal testing machine (Instron 4411) at a crosshead speed of 0.5 mm/min. Data were submitted to three-way ANOVA and Tukey post-hoc test (α=0.05). The mean µSBS at 24 h was significantly higher than after thermal cycling (p<0.05). No statistical difference was found between resin-luting agents (p > 0.05). The mean µSBS for groups photoactivated through 0.5 mm ceramic were significantly higher than 1.5 mm and 2.0 mm (p < 0.05). In conclusion, increased ceramic thicknesses reduced the bond strength of tested resin-luting agents to lithium disilicate. No differences were found between resin-luting agents. Thermal cycling reduced the bond strength of both resin-luting agents.

Effect of interlayer temperature and cold wire addition in Wire Arc Additive Manufacturing on carbon steel

Wire Arc Additive Manufacturing (WAMM) consists in the manufacture of metallic preforms from the deposition of multilayer weld beads on a substrate, that is, from a three-dimensional model, the object is divided into layers defining the trajectories in which the addition of metal will be made, with the use of a robotic manipulator. The objective of this work is to study the influence of the addition of cold wire and the effect of interlayer temperature in the WAAM process, comparing it with the deposition made with a single wire, observing mechanical properties such as tensile strength, hardness, in addition to the cooling time for different interlayer temperatures and the geometry of the manufactured parts. A GMAW (Gas Metal Arc Welding) system was used coupled to a robotic manipulator, with multiple wires of 1.6 mm in diameter for the energized wire and 1.0 mm for the cold wire, both classified as ER70S-6. In order to manufacture the specimens for the tensile test, 20 layers were superimposed in a straight line, forming a wall, varying the interlayer temperature between each layer, using 100°C, 150°C and directly, with no waiting interval between layers. In general, a shorter cooling time was observed for the walls manufactured with the addition of cold wire when compared to depositions with a single wire. In addition, it was noted that the cold wire also influences the height and thickness of the pieces. In the mechanical tests, the cold wire did not significantly influence the hardness values. The highest values were found in the 100°C samples. For the tensile tests, it was observed that, in general, the addition of cold wire tended to increase the maximum tensile strength of the samples.

Evaluation of time-dependent ion-release and antibacterial activity of three adhesive resin cements

Aim This in-vitro study aimed to evaluate time-dependent ion-release and antibacterial activity of three self-adhesive resin cements. Materials and methods Sixty cement discs of the three tested self-adhesive resin cements were fabricated according to the manufacturer’s instructions in a plastic transparent mold, their dimensions were 6 mm in diameter and 2 mm in height. They were divided into three main experimental groups according to the self-adhesive resin cement type: group A (Thera-Cem), group B (G-Cem), and group C (RelyX Unicem 2) (20 each). Then, each main group was further subdivided into subgroup 1 (n = 10) for antibacterial assessment against Streptococcus mutans and subgroup 2 (n = 10) for ion-release assessment of fluoride and calcium. Direct contact test was used to monitor the bacterial outgrowth. Fluoride and calcium ions release were measured by ion chromatography and atomic absorption spectrometer respectively. All results were analyzed by one-way analysis of variance then multiple comparison Tukey’s test. Results All the evaluated cements exhibited antibacterial effects against S. mutans; fluoride and calcium were released by all the three cements in varying concentrations after aging. Conclusion Based on the results of this in-vitro study and within its limitations, it can be concluded that self-adhesive resin cements seem to provide promising antibacterial and remineralizing effects as being bioactive materials.

EFFECTS OF PIPE DIAMETER ON INTERFACIAL AND WALL FRICTION FACTORS OF SWIRLING ANNULAR FLOWS IN A VERTICAL PIPE

Interfacial and wall friction factors, &lt;i&gt;f&lt;sub&gt;i&lt;/sub&gt;&lt;/i&gt; and &lt;i&gt;f&lt;sub&gt;w&lt;/sub&gt;&lt;/i&gt;, of swirling annular flows in a vertical pipe of 20 mm in diameter D were measured for comparison with those in a vertical pipe of &lt;i&gt;D &lt;/i&gt;&amp;#61; 30 mm. A three-fluid model was applied to evaluate the friction factors. Measurements were carried out in two sections, one near the swirler and the other far downstream the swirler. The swirl intensity of the flow was evaluated by the interfacial swirl number si defined by the ratio of the azimuthal to the axial components of interfacial wave velocity. The interfacial swirl numbers were smaller in the smaller pipe. The ratio of &lt;i&gt;f&lt;sub&gt;i&lt;/sub&gt;&lt;/i&gt; in swirling annular flows to that in non-swirling annular flows decreased to unity with decreasing &lt;i&gt;s&lt;sub&gt;i&lt;/sub&gt;&lt;/i&gt;* which is the arithmetic mean value of &lt;i&gt;s&lt;sub&gt;i&lt;/sub&gt;&lt;/i&gt; for 0 &amp;le; &lt;i&gt;z&lt;/i&gt;* (&amp;#61; &lt;i&gt;z/D&lt;/i&gt;) &amp;le; 3.8, where &lt;i&gt;z&lt;/i&gt; is the axial coordinate in the test section, and is higher in &lt;i&gt;D &lt;/i&gt;&amp;#61; 20 mm than in &lt;i&gt;D &lt;/i&gt;&amp;#61; 30 mm. The ratio of &lt;i&gt;f&lt;sub&gt;w&lt;/sub&gt;&lt;/i&gt; in swirling annular flows to that in non-swirling annular flows decreased to less than unity with decreasing &lt;i&gt;s&lt;sub&gt;i&lt;/sub&gt;&lt;/i&gt;* and is higher in &lt;i&gt;D &lt;/i&gt;&amp;#61; mm than in &lt;i&gt;D &lt;/i&gt;&amp;#61;30 mm.

A New Architecture Paradigm for Tool Wear Prediction during AISI 9840 Drilling Operation

In conventional machining processes based on the chip removal mechanism, the progressive wear of the tool determines a change of the geometric characteristics of the cutting edge. Tool wear is a complex phenomenon and related tool life depends on several factors, such as cutting parameters, lubrication, and tool-workpiece relative trajectories. Tool wear progression affects the quality of the machined parts, making the tool replacement necessary even before its breakage. Moreover, in industrial practice, tool replacement cannot depend on the subjectivity of the operator, thus, the definition of an optimized strategy for cutting tool wear monitoring before tool failure is mandatory. This work compares Random Forest and Neural Network models for predicting tool wear in drilling. For the development of predictive models, tool life tests were performed by drilling through holes on AISI 9840 steel parts, with a coated tungsten carbide drill of 8 mm of diameter and by using constant cutting parameters. Flank wear of the tool was monitored. A set of statistical features computed from the vibration signals, the acoustic emission signals, the power signals and the torque signals constitute the input of the algorithms. The classification accuracy was 88% and 91% for Neural Network and Random Forest models respectively. In order to correctly define the tool replacement policy during production, the developed Random Forest model has been implemented in an industry, through production management software, achieving promising results.