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RSC Advances Jun 2024This study investigates the potential and applicability of a novel solid magnetic catalyst constructed by incorporating molybdenum oxide (MoO) into zinc ferrite (ZnFeO)...
This study investigates the potential and applicability of a novel solid magnetic catalyst constructed by incorporating molybdenum oxide (MoO) into zinc ferrite (ZnFeO) to biodiesel production using Waste Frying Oil (WFO) as the residual raw material. The molybdenum amounts (5, 15, 25, 35 and 45%) present in the catalyst were studied and the catalyst demonstrated great characteristics and high acid properties, as well as superior magnetic and catalytic attributes. The one variable at time (OVAT) optimization method revealed that the application of the MoO/ZnFeO catalyst resulted in obtaining a biodiesel with 97.6% ± 0.727 conversion to fatty acid methyl esters (FAME) under the following optimized reaction conditions: temperature of 165 °C, methanol : WFO molar ratio of 40 : 1, catalyst amount of 6 wt% and reaction time of 3 h. In addition, the catalyst showed high reusability after six reaction cycles, with conversion to esters above 90%. Besides, the activation energy ( ) calculated in the kinetic study was 25.3 kJ mol. Moreover, the properties of the synthesized biodiesel met the standards set by the ASTM D6751 and EN 14214, which indicates the high MoO/ZnFeO potential for industrial application with low energy consumption as well as minimal negative environmental impact.
PubMed: 38952943
DOI: 10.1039/d4ra03580a -
RSC Advances Jun 2024We designed a unique oligomer form in which several helically twisted macrocycles (- or -helicity) are arranged through fusion. We investigated the optical rotation of a...
We designed a unique oligomer form in which several helically twisted macrocycles (- or -helicity) are arranged through fusion. We investigated the optical rotation of a series of fused oligomers of macrocycles with a difference in the number and arrangement of elements associated with point-chiral auxiliary. Some oligomers cooperatively attained a situation where an identical sense of twisting was preferred throughout the entire molecule. On the basis of these results, we estimated diastereomeric excess induced in each oligomer. We revealed that the molar optical rotation per element was modulated with a rotational angle between elements: an increase 0° rotational arrangement, a decrease 180° rotational arrangement, or a decrease cyclic arrangement. Alternatively, for other oligomers in which several diastereomeric conformers coexist, we uniquely attempted to consider the optical rotation based on the molecular structure through the assessment of a change ratio of the absorption dissymmetry factor before and after complexation with an achiral guest. We found that molar optical rotation could be different based on the arrangement, although actual measured values were similar.
PubMed: 38952942
DOI: 10.1039/d4ra03709j -
Turkish Journal of Orthodontics Jun 2024To evaluate the infrazygomatic crest (IZC) bone and develop guidelines for the optimum placement of orthodontic miniscrew implants (OMSIs) along the distobuccal root of...
Assessment of Bone Thickness at the Infra Zygomatic Crest Region for Various Orthodontic Miniscrew Implant (OMSI) Insertion Angles: A Cone-Beam Computed Tomographic Study.
OBJECTIVE
To evaluate the infrazygomatic crest (IZC) bone and develop guidelines for the optimum placement of orthodontic miniscrew implants (OMSIs) along the distobuccal root of the permanent maxillary first molar.
METHODS
Bone thickness of the IZC region of 50 young adults (25 males and 25 females) aged 18-30 years were evaluated using cone-beam computed tomography images. The infrazygomatic bone thickness along the distobuccal root of the permanent maxillary first molar was assessed at various insertion angles (40° to 75° i.r.t the maxillary occlusal plane) with an increment of 5°. Student's t-test was used to compare the IZC bone thickness and height at the orthodontic miniscrew insertion site for males and females on the right and left sides.
RESULTS
The bone thickness of the IZC region above the distobuccal root of the permanent maxillary first molar was estimated between 4.39±0.25 mm and 9.03±0.45 mm for insertion angles from 40° to 75° to the maxillary occlusal plane. The corresponding OMSI insertion heights were 17.71±0.61 mm to 13.69±0.75 mm, respectively, above the maxillary occlusal plane. There were statistically significant gender and side-wise variations in bone thickness at the IZC area and insertion height.
CONCLUSION
The safe position for OMSI placement at the IZC was 13.69-16 mm from the maxillary occlusal plane with an insertion angle between 55° and 75°. These parameters provide the optimum placement of OMSIs along the distobuccal root of the permanent maxillary first molar.
PubMed: 38952284
DOI: 10.4274/TurkJOrthod.2023.2023.14 -
JPMA. the Journal of the Pakistan... Jun 2024Recurrent rhinorrhoea that occurs chronically, needs to consider the possibility of a fistula in the nasal cavity, which has the potential to form a rhinolith. We report...
Recurrent rhinorrhoea that occurs chronically, needs to consider the possibility of a fistula in the nasal cavity, which has the potential to form a rhinolith. We report the case of a 39-year-old man with complaints of recurrent rhinorrhoea since four years ago, accompanied by thick secretions, symptoms of post-nasal drips, and olfactory disturbances. The patient had a history of removing the left upper molar (molar I), which causes a fistula in the tooth extraction site, making it more likely for food and drink to enter the left nasal cavity. Anterior rhinoscopy examination revealed a white mass in the left inferior meatus and a purulent odour discharge. In addition, there were gingival defects of the first molar teeth, multi-sinusitis, and nasal septum deviation. Rinolith extraction was performed using functional endoscopic sinus surgery, submucosal resection, and repair of gingivo-nasal defects with rotational flaps. Follow-up for one week showed that the flap was in place and there were no complications.
Topics: Humans; Male; Adult; Rhinorrhea; Nose Diseases; Chronic Disease; Tooth Extraction; Endoscopy; Oral Fistula; Surgical Flaps
PubMed: 38948996
DOI: 10.47391/JPMA.9784 -
Imaging Science in Dentistry Jun 2024Non-secretory multiple myeloma (NSMM) is a rare cancer of plasma cells characterized by the absence of detectable monoclonal M protein in the blood or urine. A...
Non-secretory multiple myeloma (NSMM) is a rare cancer of plasma cells characterized by the absence of detectable monoclonal M protein in the blood or urine. A 57-year-old woman presented with mandibular pain but without intraoral swelling. Imaging studies revealed multiple osteolytic lesions in her mandible and pronounced root resorption of the left mandibular second molar. Biopsy results showed atypical plasmacytoid cells positive for anti-kappa, CD138, MUM1, and CD79a antibodies, but negative for anti-lambda and CD20. These results were indicative of a malignant plasma cell neoplasm. No abnormalities were revealed by free light chain assay or by serum or urine protein electrophoresis, leading to a diagnosis of NSMM. The patient began chemotherapy in conjunction with bisphosphonate therapy and achieved remission following treatment. This case underscores the critical role of dentists in the early detection and prevention of NSMM complications, as the disease can initially present in the oral cavity.
PubMed: 38948192
DOI: 10.5624/isd.20230257 -
Imaging Science in Dentistry Jun 2024Ameloblastic fibrodentinoma (AFD) is a rare benign odontogenic tumor that resembles an ameloblastic fibroma with dysplastic dentin. This report presents a rare case of...
Ameloblastic fibrodentinoma (AFD) is a rare benign odontogenic tumor that resembles an ameloblastic fibroma with dysplastic dentin. This report presents a rare case of mandibular AFD with imaging features in a young patient. Panoramic radiography and computed tomography revealed a well-defined lesion with internal septa and calcified foci, causing inferior displacement of the adjacent molars as well as buccolingual cortical thinning and expansion of the posterior mandible. The lesion was surgically removed via mass excision, and the involved tooth was extracted under general anesthesia. During the 5-year follow-up period, no evidence of recurrence was observed. Radiologic features of AFD typically reveal a moderately to well-defined mixed lesion with varying degrees of radiopacity, reflecting the extent of dentin formation. Radiologists should consider AFD in the differential diagnosis when encountering a multilocular lesion with little dense radiopacity, particularly if it is associated with delayed eruption, impaction, or absence of involved teeth, on radiographic images of young patients.
PubMed: 38948190
DOI: 10.5624/isd.20230247 -
Imaging Science in Dentistry Jun 2024This study was conducted to identify the typical sites and patterns of peri-implant bone defects on cone-beam computed tomography (CBCT) images, as well as to evaluate...
PURPOSE
This study was conducted to identify the typical sites and patterns of peri-implant bone defects on cone-beam computed tomography (CBCT) images, as well as to evaluate the detectability of the identified bone defects on panoramic images.
MATERIALS AND METHODS
The study population included 114 patients with a total of 367 implant fixtures. CBCT images were used to assess the presence or absence of bone defects around each implant fixture at the mesial, distal, buccal, and lingual sites. Based on the number of defect sites, the presentations of the peri-implant bone defects were categorized into 3 patterns: 1 site, 2 or 3 sites, and circumferential bone defects. Two observers independently evaluated the presence or absence of bone defects on panoramic images. The bone defect detection rate on these images was evaluated using receiver operating characteristic analysis.
RESULTS
Of the 367 implants studied, 167 (45.5%) had at least 1 site with a confirmed bone defect. The most common type of defect was circumferential, affecting 107 of the 167 implants (64.1%). Implants were most frequently placed in the mandibular molar region. The prevalence of bone defects was greatest in the maxillary premolar and mandibular molar regions. The highest kappa value was associated with the mandibular premolar region.
CONCLUSION
The typical bone defect pattern observed was a circumferential defect surrounding the implant. The detection rate was generally higher in the molar region than in the anterior region. However, the capacity to detect partial bone defects using panoramic imaging was determined to be poor.
PubMed: 38948187
DOI: 10.5624/isd.20230258 -
Imaging Science in Dentistry Jun 2024Preoperative identification of the intraosseous posterior superior alveolar artery (PSAA) is critical when planning sinus surgery. This study was conducted to determine...
PURPOSE
Preoperative identification of the intraosseous posterior superior alveolar artery (PSAA) is critical when planning sinus surgery. This study was conducted to determine the distance between the cementoenamel junction and the PSAA, as well as to identify factors influencing the detection of the PSAA on cone-beam computed tomography (CBCT).
MATERIALS AND METHODS
In total, 254 CBCT scans of maxillary sinuses, acquired with 2 different scanners, were examined to identify the PSAA. The distance from the cementoenamel junction (CEJ) to the PSAA was recorded at each maxillary posterior tooth position. Binomial logistic regression and multiple linear regression were employed to evaluate the effects of scanner type, CBCT parameters, sex, and age on PSAA detection and CEJ-PSAA distance, respectively. -values less than 0.05 were considered to indicate statistical significance.
RESULTS
The mean CEJ-PSAA distances at the second molar, first molar, second premolar, and first premolar positions were 17.0±4.0 mm, 21.8±4.1 mm, 19.5±4.7 mm, and 19.9±4.9 mm for scanner 1, respectively, and 17.3±3.5 mm, 16.9±4.3 mm, 18.5±4.1 mm, and 18.4±4.3 mm for scanner 2. No independent variable significantly influenced PSAA detection. However, tooth position (b=-0.67, <0.05) and scanner type (b=-1.3, <0.05) were significant predictors of CEJ-PSAA distance.
CONCLUSION
CBCT-based estimates of CEJ-PSAA distance were comparable to those obtained in previous studies involving cadavers, CT, and CBCT. The type of CBCT scanner may slightly influence this measurement. No independent variable significantly impacted PSAA detection.
PubMed: 38948184
DOI: 10.5624/isd.20230160 -
ACS Omega Jun 2024This study aimed to investigate heterogeneous catalytic filaments of calcium oxide (CaO) for fused deposition modeling three-dimensional (3D) printers. The CaO catalysts...
This study aimed to investigate heterogeneous catalytic filaments of calcium oxide (CaO) for fused deposition modeling three-dimensional (3D) printers. The CaO catalysts were blended with acrylonitrile butadiene styrene (ABS) plastic to form catalytic filaments. A single-screw filament extruder was used to prepare the filaments, following which their mechanical properties, thermal properties, morphology, catalytic characteristics in biodiesel production, and reusability were evaluated. In accordance with the results, a maximum CaO catalyst content of 15 wt % was recommended to be blended in the ABS pellet. The hardness and compressive strength of these catalytic filaments were shown to be improved. Subsequently, the catalytic filaments with the highest CaO content (15 wt %) were used to produce methyl ester from pretreated sludge palm oil through the transesterification process. To determine the recommended conditions for achieving the highest purity of methyl ester in biodiesel, the process parameters were optimized. A methyl ester purity of 96.58 wt % and a biodiesel yield of 79.7 wt % could be achieved under the recommended conditions of a 9.0:1 methanol to oil molar ratio, 75.0 wt % catalytic filament loading, and 4.0 h reaction time. Furthermore, the reusability of the 15 wt % CaO catalytic filaments was evaluated in a batch process with multiple transesterification cycles. The results indicated that the purity of methyl ester dropped to 95.0 wt % only after the fourth cycle. The method used in this study for preparing and characterizing CaO catalytic filaments can potentially serve as a novel approach for constructing biodiesel reactors using 3D printing technology.
PubMed: 38947778
DOI: 10.1021/acsomega.4c03063 -
Cureus May 2024Dental anatomy exhibits considerable variation with the presence of additional canals being a common occurrence. The upper second molar typically presents with three...
Dental anatomy exhibits considerable variation with the presence of additional canals being a common occurrence. The upper second molar typically presents with three canals and three roots; however, variations such as the existence of an extra canal or a root can pose challenges during endodontic treatment. Maxillary molar is characterized by an additional canal located within the palatal root, often exhibiting complex configurations and variations in morphology. Access refinement is critical to gaining adequate visibility and facilitating instrumentation. Meticulous exploration of the pulp chamber floor and careful examination of radiographs from different angles are essential for accurate diagnosis. Careful negotiation and cleaning of the extra canal with appropriate files and irrigants are essential to remove pulp tissue and debris effectively. Furthermore, obturation of the canal space with biocompatible materials is crucial to ensure a three-dimensional seal and prevent bacterial ingress. Clinically, the inability to detect and treat the extra palatal canal can lead to persistent infection, incomplete debridement, and compromised treatment outcomes. This case report delves into the significance of this anatomical variation, diagnostic modalities, and effective management strategies.
PubMed: 38947704
DOI: 10.7759/cureus.61266