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1.
Methods Mol Biol ; 2740: 211-227, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38393478

RESUMO

Whole-mount immunofluorescence allows direct visualization of the cellular architecture within cells. Here, we apply this technique to mouse oocytes to visualize spindle morphology and microtubule attachments to kinetochores, using a technique we call "cold treatment," at various phases of the meiotic cell cycle. This method allows the analysis of spindle structures at different meiosis I stages and at metaphase II. An adaptation of the protocol to the cell cycle stage of interest is described.


Assuntos
Meiose , Fuso Acromático , Animais , Camundongos , Fuso Acromático/metabolismo , Metáfase , Microtúbulos/metabolismo , Cinetocoros , Oócitos/metabolismo
2.
J World Fed Orthod ; 13(2): 57-64, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38228450

RESUMO

Aligner orthodontics has gained significant popularity as an alternative to traditional braces because of its aesthetic appeal and comfort. The biomechanical principles that underlie aligner orthodontics play a crucial role in achieving successful outcomes. The biomechanics of aligner orthodontics revolve around controlled force application, tooth movement, and tissue response. Efficient biomechanics in aligner orthodontics involves consideration of attachment design and optimized force systems. Attachments are tooth-colored shapes bonded to teeth, aiding in torque, rotation, and extrusion movements. Optimized force systems ensure that forces are directed along the desired movement path, reducing unnecessary strain on surrounding tissues. Understanding and manipulating the biomechanics of aligner orthodontics is essential for orthodontists to achieve optimal treatment outcomes. This approach requires careful treatment planning, considering the mechanics required for each patient's specific malocclusion. As aligner orthodontics continues to evolve, advances in material science and treatment planning software contribute to refining biomechanical strategies, enhancing treatment efficiency, and expanding the scope of cases that can be successfully treated with aligners.


Assuntos
Má Oclusão , Braquetes Ortodônticos , Ortodontia , Humanos , Fenômenos Biomecânicos , Estética Dentária , Má Oclusão/terapia
3.
Infant Behav Dev ; 74: 101919, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38194729

RESUMO

Recent decades have seen a major rise in demand for daycare services for children aged 0 to 3 years, and this has increased research interest in the child-professional caregiver relationship at daycare centers: How does the relationship between children and their new caregivers develop over time? How long does it take for children to settle in at daycare? What variables can influence the settling-in process? These questions are all of the utmost salience and bear crucial implications for children, parents, and daycare practitioners. In this study, we set out to explore the relationship between infants and their new caregivers over the first two months in daycare, using the Professional Caregiver Attachment Diary. The study involved seven Italian daycare centres and 55 professional caregivers, who observed 148 children (M=17.8 months). The children's attachment behaviors were assessed at three time-points: when the children started attending daycare (T1), one month later (T2), and two months later (T3). We found that positive attachment behaviors (Secure and Non-Distressed) increased over time, whereas insecure behaviors (Avoidant and Resistant) decreased. Most of the change took place during the first month. Furthermore, children who had attended more daycare more regularly (with fewer days of absence) displayed fewer avoidant behaviors and a more rapid decrease in resistant behaviors than did children who were absent more frequently. The findings suggest that the PCAD may be usefully deployed to observe and analyze children while they are settling into a new daycare setting, especially in relation to their exploratory behaviors.


Assuntos
Cuidadores , Creches , Lactente , Criança , Humanos , Pais
4.
Expert Rev Med Devices ; 20(12): 1087-1103, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37934873

RESUMO

INTRODUCTION: Colorectal cancer (CRC) is the third most common malignancy and second leading cause of cancer-related mortality in the world. Adenoma detection rate (ADR), a quality indicator for colonoscopy, has gained prominence as it is inversely related to CRC incidence and mortality. As such, recent efforts have focused on developing novel colonoscopy devices and technologies to improve ADR. AREAS COVERED: The main objective of this paper is to provide an overview of advancements in the fields of colonoscopy mechanical attachments, artificial intelligence-assisted colonoscopy, and colonoscopy optical enhancements with respect to ADR. We accomplished this by performing a comprehensive search of multiple electronic databases from inception to September 2023. This review is intended to be an introduction to colonoscopy devices and technologies. EXPERT OPINION: Numerous mechanical attachments and optical enhancements have been developed that have the potential to improve ADR and AI has gone from being an inaccessible concept to a feasible means for improving ADR. While these advances are exciting and portend a change in what will be considered standard colonoscopy, they continue to require refinement. Future studies should focus on combining modalities to further improve ADR and exploring the use of these technologies in other facets of colonoscopy.


Assuntos
Adenoma , Neoplasias Colorretais , Humanos , Inteligência Artificial , Colonoscopia , Adenoma/diagnóstico , Adenoma/epidemiologia , Incidência , Tecnologia , Neoplasias Colorretais/diagnóstico , Detecção Precoce de Câncer/métodos
5.
Macromol Rapid Commun ; 44(24): e2300300, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37657944

RESUMO

Reconstructing functional sequence motifs of proteins, using statistical copolymers greatly reduces the information content, but simplifies synthesis significantly. Key amino acid residues involved in the adhesion of mussel foot proteins are identified. The side-chain functionalities of Dopa, lysine, and arginine are abstracted and incorporated into acrylate monomers to allow controlled radical polymerization. The resulting Dopa-acrylate (Y*-acr), arginine-acrylate (R-acr), and lysine-acrylate (K-acr) monomers are polymerized in different monomer ratios and compositions by reversible addition fragmentation transfer polymerization with a poly(ethylene glycol) (PEG) macrochain transfer agent. This results in two sets of PEG-block-copolymers with statistical mixtures and different monomer ratios of catechol/primary amine and catechol/guanidine side-chain functionalities, both important pairs for mimicking π-cation interactions. The coating behavior of these PEG-block-copolymers is evaluated using quartz crystal microbalance with dissipation energy monitoring (QCM-D), leading to non-covalent PEGylation of the substrates with clear compositional optima in the coating stability and antifouling properties. The coatings prevent non-reversible albumin or serum adsorption, as well as reduce cellular adhesion and fungal spore attachment.


Assuntos
Bivalves , Lisina , Animais , Adesivos , Polímeros , Di-Hidroxifenilalanina/química , Acrilatos , Arginina
6.
Interaçao psicol ; 27(1): 100-108, jan.-abr. 2023.
Artigo em Português | LILACS-Express | LILACS | ID: biblio-1512751

RESUMO

O Comprometimento Organizacional (CO) é um vínculo do indivíduo com a organização, sendo os três componentes mais aceitos desse estado psicológico o afetivo, instrumental e normativo. O construto foi introduzido na literatura há algumas décadas e interessa gestores e acadêmicos, porque está associada a resultados organizacionais desejáveis. Entretanto, apesar da longevidade, ainda existem questões na compreensão do fenômeno e faz-se necessário identificar as lacunas de pesquisa. Assim, o objetivo deste trabalho foi realizar revisão sistemática de literatura das revisões sistemáticas de literatura, metanálises e bibliometrias publicadas em português e inglês, entre 2009 e 2019, no portal de periódicos da Capes, em português e inglês. Foram identificados 15 trabalhos, nos quais foi possível verificar a prevalência das investigações de antecedentes em detrimento dos consequentes, havendo correspondência e congruências entre os achados dos preditores. Os autores dos estudos selecionados apontam limitações na concepção dos elementos constituintes do construto e sua dimensionalidade, o que reflete na medida. Os achados desta revisão indicam que o campo do CO se encontra em um estágio consolidado. Contudo, anseia por novas investigações que respondam aos questionamentos ainda existentes e auxiliem na execução de intervenções práticas nos mais diversos contextos organizacionais.


Organizational Commitment (OC) is an attachment of the individual of the organization, and the three most accepted components of this psychological state are affective, instrumental, and normative. The construct was introduced into the literature a few decades ago and interests managers and academics, for its association with desirable organizational outcomes. However, despite its longevity, there are still issues in understanding the phenomenon, for identifying research gaps. Thus, the aim of this work was to conduct a systematic literature review of systematic literature reviews, meta-analyses, and bibliometrics published in Portuguese and English, between 2009 and 2019, on the Capes journal portal. Fifteen studies were identified, in which it was possible to verify the prevalence of investigations of antecedents over consequents, with correspondence and congruences between the findings of the predictors. The authors of the selected studies point out limitations in the design of the construct's constituent elements and its dimensionality, which reflects on the measurement. The findings of this review indicate that the field of OC is at a consolidated stage. However, it looks forward to further research that answers the questions that still exist and assists in the execution of practical interventions in the most different organizational contexts.

7.
Materials (Basel) ; 16(15)2023 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-37569951

RESUMO

The objective of this study was to compare the distribution of stress in the maxillary bone, dental implants, and prosthetic components supporting implant-supported maxillary overdentures with partial palatal coverage, in both splinted and unsplinted designs. Two models of maxillary overdentures were designed using the Exocad Dental CAD program, which included cancellous and cortical bone. The complete denture design and abutments (locator abutments in the unsplinted and Hader bar with Vertix attachments placed distally in the splinted variant) were also designed. The denture material was PEEK (Polyetheretherketone), and the method used to analyze patient-specific 3D X-ray scans was 3D QCT/FEA (three-dimensional quantitative computed tomography-based finite element analysis). Loading was divided into three load cases, in the frontal region (both incisors of the denture) and distal region (both molars and first premolar of the denture). The forces applied were 150 N with an oblique component with a buccal inclination of 35° in the frontal region, and 600 N with a buccal inclination of 5° (molars) or solely vertical (premolar) in the distal region. The model with locator abutments showed higher stresses in all load cases in both analyzed implant variants and in the maxilla. The differences in stress distribution between the splinted and unsplinted variants were more significant in the distal region. According to the results of the present study, the amount of stress in bone tissue and dental implant parts was smaller in the splinted, bar-retained variant. The findings of this study can be useful in selecting the appropriate prosthetic design for implant-supported maxillary overdentures with partial palatal coverage.

8.
Animals (Basel) ; 13(13)2023 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-37444018

RESUMO

This study investigates the impact of empathy on the relationship between human-dog attachment and human quality of life. A survey involving 263 dog owners was conducted to gather data on attachment to dogs, empathy, and human quality of life in Korea. The findings indicate significant correlations between attachment to dogs, human empathy, and quality of life. Specifically, both general attachment and concerns for animal rights/welfare demonstrate meaningful parallel double-mediation effects. However, cognitive empathy does not show a significant double-mediation effect on human quality of life. These findings emphasize the importance of attachment and empathy towards dogs in enhancing the quality of life of both humans and dogs. The study suggests a shift in perceiving dogs as independent individuals rather than mere substitutes for humans. Future research should focus on emotional factors, particularly affective empathy, to further enhance the quality of life for both humans and dogs through improved relationships.

9.
BMC Oral Health ; 23(1): 495, 2023 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-37461004

RESUMO

OBJECTIVE: To assess the possibility of extrusion of a maxillary central incisor with the use of buccal and lingual pressure columns in the absence of attachments, and to evaluate the forces and moments experienced by the teeth using both thermoformed and 3D-printed clear aligners. MATERIALS AND METHODS: A three-axis force and moment sensor (Aidin Robotics, Anyang, South Korea) was used to measure the forces and moments during extrusion of an upper left central incisor (UL1) and any forces experienced by the upper right central incisor (UR1) using thermoformed aligners and 3D-printed aligners. For the thermoformed aligners, the materials used were ATMOS® (American Orthodontics, Sheboygan, WI) and Zendura FLX® (Bay Materials LLC, Fremont, CA). 3D-printed aligners were fabricated using TC-85 clear photocurable resin (Graphy Inc., Seoul, South Korea). For each material type, three conditions were tested: Group 1: No attachment or pressure columns (control); Group 2: Attachment only; and Group 3: Pressure columns only. Each group was planned for 0.5 mm of extrusion on the UL1. RESULTS: All force readings collected demonstrated statistically significant differences when compared by materials and when compared by groups, with a P value of < 0.001. In the absence of attachment or pressure columns (Group 1), ATMOS® and TC-85 groups exerted extrusive force on the UL1. However, significantly lower forces and moments were exerted by the TC-85 group in comparison to the ATMOS® and Zendura FLX® groups. In the presence of attachment (Group 2), all three ATMOS®, Zendura FLX® and TC-85 groups exerted extrusive force on the UL1, with the TA group showing different directions of faciolingual force, mesiodistal force and faciolingual inclination on the UR1 when compared to the other two thermoformed groups. Whereas in the presence of pressure columns (Group 3), only the TC-85 3D-printed aligner group exerted extrusive force. Thermoformed aligners generated significantly higher mean forces and moments than 3D-printed aligners. Significant levels of unintended forces and moments were present in all groups. CONCLUSIONS: Force levels generated during extrusion with clear aligners are significantly lower with those 3D-printed using TC-85 than with those thermoformed using ATMOS® or Zendura FLX®. Attachments consistently generated extrusive forces, and may be an effective adjunct in achieving extrusion of incisors. Extrusion may be achieved without the use of attachments by utilizing pressure columns in 3D-printed aligners using TC-85. While different strategies can generate extrusive forces, there are significant unintended forces and moments.


Assuntos
Incisivo , Aparelhos Ortodônticos Removíveis , Humanos , Desenho de Aparelho Ortodôntico , Técnicas de Movimentação Dentária , Projetos de Pesquisa
10.
J Clin Periodontol ; 50(11): 1530-1538, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37518848

RESUMO

AIM: To evaluate the long-term survival, incidence of prosthetic/technical and biological complications and the oral-health-related quality of life in patients with an edentulous mandible who were fitted with overdentures on two immediately loaded implants in the symphyseal area. MATERIALS AND METHODS: Forty-six patients with edentulous mandibles received two immediately loaded implant-retained dentures with either two Locator attachments or egg-shaped bar attachments. Implant outcomes were recorded after a period of observation of 9 years and included prosthetic complications, modified gingiva index (mGI), modified plaque index (mPI), oral health impact profile (OHIP-G) and radiographic estimation of bone loss. RESULTS: In 2020/2021, 27 patients with 54 implants were still available for follow-up. In total, nine implants in six patients were lost. Survival was 89.1% in the bar group and 91.3% in the Locator group. Implant success was 84.6% in the Locator group and 76.9% in the bar group. The mPI values were significantly higher in the bar group than in the Locator group, whereas no difference was seen in the mGI values. During the observation period, 152 prosthetic complications occurred, but the OHIP-G score did not differ significantly. CONCLUSIONS: There was no difference in implant survival between Locator or joint bar attachments over a 9-year observation period. Joint bar attachments were associated with slightly more complications, while patients in the Locator group were able to maintain better oral hygiene. The study was registered in the German Register of Clinical (Trials DRKS00004245).

11.
Spec Care Dentist ; 2023 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-37431228

RESUMO

BACKGROUND: The rehabilitation of maxillectomy defects is a challenging endeavour that necessitates customizing the procedure for each patient. The successful treatment for these patients requires a combined conventional and contemporary treatment options. The high-tech prosthodontic treatment option for these defects and distal extension cases are combining fixed and removable partial dentures with precision/semi-precision attachments. It will enhance retention, stability, esthetics and functional ability of the prosthesis. METHODS: Three post-Covid Mucormycosis patients reported after localised debridement and partial maxillectomy for definitive rehabilitation. For partial Maxillectomy patients, DMLS designed cast partial denture along with semi-precision attachments (Preci-vertix and OT strategy Rhein For patient with localized defect, DMLS designed cast partial denture was planned. For both patients the defect area was kept as hollow cavity (Closed or Open), in order to reduce the weight of the prosthesis. RESULTS AND CONCLUSION: The prosthodontic rehabilitation of these patient can be a simple and economical treatment options and it improves the stomatognathic functions and quality of life of the patient. The major hurdles during rehabilitation are retention and stability as there is no basal seat and hard tissue support. Hence, we tried a combined conventional and digital techniques in order to provide prosthesis with precise fit and accuracy as well as reducing the treatment time and visits of the patients.

12.
Cureus ; 15(5): e38683, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37292565

RESUMO

Successful full-mouth rehabilitation requires contemporary and advanced treatment planning, especially in distal extension cases. Multiple treatment modalities are available in those cases. Treatment outcome in these patients remains challenging. Though implants are one of the treatment options in such scenarios, fixed removable partial dentures with precision attachments are the best treatment options for patients who cannot afford expensive treatment. We have made an attempt to describe a case report of a long-span edentulous arch by incorporating the ideas and information received from Chat Generative Pre-trained Transformer (GPT).

13.
Arch Pediatr ; 30(5): 314-320, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37321950

RESUMO

BACKGROUND: Orthorexia nervosa (ON), defined as the pathological obsession for pure foods, remains a novelty in the field of eating disorders. Many studies in the literature have shown that attachment styles correlate with the development of eating disorders. Patients with eating disorders were found to be more avoidant and anxious and less secure than individuals who do not have eating disorders. However, studies on the relationship between attachment styles and ON remain limited, particularly in adolescents. This study assessed the relationship between attachment styles and ON in Lebanese adolescents (15-18 years), along with evaluating the indirect effect of self-esteem on this association. METHODS: This study used a cross-sectional design and was carried out during May-June 2020 with 555 students (15-18 years) enrolled. The Düsseldorf Orthorexia Scale was utilized to screen for ON tendencies. A linear regression was conducted taking the DOS score as the dependent variable. The PROCESS Macro was used to test the indirect effect of self-esteem between attachment styles and ON. RESULTS: Higher fearful and preoccupied attachment styles, female gender, and more physical activity were significantly associated with more ON tendencies, whereas higher self-esteem was significantly associated with less ON tendencies. When adjusting for all sociodemographic characteristics and other attachment styles, none of the attachment styles remained significantly correlated with ON tendencies. Self-esteem mediated the association between secure attachment style and ON and between dismissive attachment style and ON. CONCLUSIONS: The rise in ON warrants further studies and investigations to raise awareness and plan behavioral interventions in order to treat it.


Assuntos
Transtornos da Alimentação e da Ingestão de Alimentos , Ortorexia Nervosa , Humanos , Adolescente , Feminino , Estudos Transversais , Autoimagem , Ansiedade , Inquéritos e Questionários
14.
Zoomorphology ; : 1-16, 2023 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-37360222

RESUMO

The greater rhea, Rhea americana, is a wild ratite of high scientific importance and significant and zootechnical value, especially considering the current development state of Brazilian poultry production, where research aimed at increasing the productivity of these animals has become extremely relevant. Studies concerning fetal attachments and embryonic development are paramount, as they can provide essential information concerning reproductive and nutritional animal management. However, a lack of information on greater rhea fetal morphology is noted. Therefore, the aim of the present study was to establish a standard model for fetal attachments in this species. Greater rhea eggs were incubated from 0 to 36 days, and macroscopic and microscopic embryonic attachment characterizations were performed. Histologically, all embryonic annexes exhibit germ layers, namely the ectoderm (outer layer), mesoderm (middle layer) and endoderm (inner layer). The findings indicate that greater rhea development patterns are similar to other birds.

15.
Biomedicines ; 11(6)2023 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-37371776

RESUMO

Dental-implant-supported reconstructions provide comfort and improvements in prosthetic function, adaptation, and stability over conventional treatment options. The objective of this study was to evaluate the effect of different denture cleansing solutions and their influence on the deterioration and loss of retention of overdenture attachments in a 12-month clinical-use simulation. In this way, ten specimens each of different brands of retentive caps made of Teflon (OT Equator® (Rhein83, Bologna, Italy), Locator® (Zest Anchors, Escondido, CA, USA), Kerator® (KJ Meditech, Gwangiu, Republic of Korea), and Locator R-Tx® (Zest Anchors, Escondido, CA, USA)) were immersed in five different cleaning solutions (Kukident® (P&G Tech, Oxford Parkway, UK), Benfix® (Laboratorios URGO S.L., Guipúzcoa, Spain), Corega® (Stafford Miller, Waterford, Ireland), and Protefix® (Neuhofer Weiche, Parchim, Germany)), and tap water was used as the control group, in a simulation that lasted 12 months. Data were analyzed using two-way ANOVA and a Tukey HSD. Furthermore, a Levene Test and Shapiro-Wilk tests were performed to assess the validation of the ANOVA assumptions. The statistical analysis was performed using R version 4.2.2 software with the significance level set to p < 0.05. There were significant statistical differences between the different manufacturers regarding the retention forces of the attachment's retentive caps (F = 322.066, p < 0.001). For the cleaning solution groups, different statistical results between Kukident® (P&G Tech, Oxford Parkway, UK) (p < 0.05) and Benfix® (Laboratorios URGO S.L., Guipúzcoa, Spain) (p < 0.05) were observed. There were no significant statistical differences between Corega® (Stafford Miller, Ireland), Protefix® (Neuhofer Weiche, Parchim, Germany), and tap water, even though the retention forces decreased in all of them.

16.
J World Fed Orthod ; 12(3): 105-111, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37142480

RESUMO

BACKGROUND: Deep overbite has been shown to be difficult to correct with clear aligners. Optimized deep bite attachments are reported to facilitate deep bite correction with aligners. The aim of this retrospective study was to quantify the efficacy of deep bite correction with aligners when using optimized versus conventional attachments. METHODS: This was a retrospective cohort study. The pretreatment and post-treatment intraoral scans of patients with deep overbite treated with Invisalign clear aligners were accessed. Patients were divided into two groups: group A, patients treated with conventional attachments, and group B, patients treated with optimized attachments. Pre and post-treatment overbite and the planned overbite reduction were measured and compared between groups. Descriptive statistics were computed, and statistical significance was set at P < 0.05. RESULTS: Seventy-eight patients were included. There was no statistically significant difference in overbite reduction between patients who had conventional versus optimized attachments. The amount of overbite reduction observed post-treatment was found to be no more than 33-40% of the planned amount of overbite reduction across all patients and groups. CONCLUSIONS: Deep overbite correction with aligners remains difficult regardless of the type of attachment used. Optimized attachments are no more effective than using conventional attachments in reducing deep overbite. The amount of overbite reduction expected with clear aligners is significantly lower than the planned overbite reduction. PRACTICAL IMPLICATIONS: When correcting deep bite with clear aligners, the attachment type does not improve the success rate. Clinicians should plan to overcorrect deep bite reduction to expect only 33% to 40% of their planned final overbite to be actually expressed.


Assuntos
Aparelhos Ortodônticos Removíveis , Sobremordida , Humanos , Sobremordida/terapia , Estudos Retrospectivos
17.
J World Fed Orthod ; 12(3): 112-117, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37164825

RESUMO

BACKGROUND: Clear aligners are reported to control anterior open bites. Despite this, anterior extrusion remains difficult with aligners. Optimized extrusion attachments on incisors may facilitate anterior extrusion to correct open bite with Invisalign. The aim of this retrospective study was to compare the efficacy of anterior open bite correction with Invisalign when using optimized extrusion versus conventional attachments. METHODS: This was a retrospective cohort study. The pre- and post-treatment intraoral scans of patients with anterior open bite treated with Invisalign aligners were assessed. Patients were divided into two groups: group A, patients with horizontal conventional attachments and group B, patients with optimized extrusion attachments on incisors. The pre and post-treatment overbite and the planned overbite change were measured and compared between the groups. Descriptive statistics were computed and statistical significance was set at P < 0.05. RESULTS: A total of 86 patients were included. Both groups showed significant increases in overbite, but there was no difference in the open bite correction efficacy in patients with conventional versus optimized attachments. Shorter treatment times for open bite closure were reported for patients with optimized attachments. CONCLUSIONS: Anterior open bite can be corrected regardless of the attachment type. Optimized attachments are no more effective than using conventional attachments in incisor extrusion to correct open bite. Patients with anterior open bite with optimized attachments observed shorter treatment times for overbite correction. When correcting anterior open bite with Invisalign, the attachment type does not improve the success rate. Optimized extrusion attachments on incisors may shorten the treatment time compared to conventional attachments.


Assuntos
Má Oclusão Classe II de Angle , Mordida Aberta , Aparelhos Ortodônticos Removíveis , Sobremordida , Humanos , Mordida Aberta/terapia , Sobremordida/terapia , Estudos Retrospectivos
18.
J Anat ; 243(3): 431-447, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37186281

RESUMO

Computational musculoskeletal modeling represents a valuable approach to examining biological systems in physical anthropology. Probabilistic modeling builds on computational musculoskeletal models by associating mathematical distributions of specific musculoskeletal features within known ranges of biological variability with functional outcomes. The purpose of this study was to determine if overlap in rotator cuff muscle force predictions would occur between species during the performance of an evolutionarily relevant horizontal bimanual arm suspension task. This necessitated creating novel probabilistic models of the human and chimpanzee glenohumeral joint through augmentation of previously published deterministic models. Glenohumeral musculoskeletal features of anthropological interest were probabilistically modeled to produce distributions of predicted human and chimpanzee rotator cuff muscle force that were representative of the specific anatomical manipulations. Musculoskeletal features modeled probabilistically included rotator cuff origins and deltoid insertion, glenoid inclination, and joint stability. Predicted human rotator cuff muscle force distributions were mostly limited to alternating between infraspinatus and teres minor, with both 100% and 0% muscle force predicted for both muscles. The chimpanzee model predicted low-to-moderate muscle force across all rotator cuff muscles. Rotator cuff muscle force predictions were most sensitive to changes of muscle origins and insertions. Results indicate that functional rotator cuff overlap is unlikely between chimpanzees and humans without greater modifications of the glenohumeral musculoskeletal phenotypes. The results also highlight the low efficacy of the human upper extremity in overhead, weight-bearing tasks, and propensity for rotator cuff injury.


Assuntos
Lesões do Manguito Rotador , Articulação do Ombro , Humanos , Animais , Manguito Rotador/fisiologia , Pan troglodytes , Articulação do Ombro/fisiologia , Escápula , Fenômenos Biomecânicos
19.
Glob Chall ; 7(4): 2100140, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37020619

RESUMO

This paper presents a piezoelectric wind energy harvester that operates by a galloping mechanism with different shaped attachments attached to a bluff body. A comparison is made between harvesters that consist of different shaped attachments on a bluff body; these include triangular, circular, square, Y-shaped, and curve-shaped attachments. Simulation of the pressure field and the velocity field variation around the different shaped bluff bodies is performed and it is found that a high pressure difference creates a high lift force on the bluff body with curve-shaped attachments. A theoretical model based on a galloping mechanism is presented, which is verified by experiments. It is observed that the proposed harvester with curve-shaped attachments provides the best performance, where the harvester with a curve-shaped attachments provides the highest voltage and power output compared to the other shaped harvesters examined in this study. This paper provides a new concept for improving the power performance of the piezoelectric wind energy harvesters with modifications made on the bluff body.

20.
Tissue Eng Part A ; 29(15-16): 439-448, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37073459

RESUMO

The temporomandibular joint (TMJ) disc complex (i.e., the TMJ disc and its six attachments) is crucial to everyday functions such as mastication and speaking. The TMJ can be afflicted by many conditions, including disc displacement and defects. Pathologies of the TMJ disc complex most commonly present first as anterior disc displacement, which the field hypothesizes may implicate the two posterior attachments. As a result of anterior disc displacement, defects may develop in the lateral disc complex. Tissue engineering is poised to improve treatment paradigms for these indications of the TMJ disc complex by engineering biomimetic implants, but, first, gold-standard design criteria for such implants should be established through characterization studies. This study's objective was to characterize the structural, mechanical, biochemical, and crosslinking differences among the two posterior attachments and the lateral disc in the Yucatan minipig, a well-accepted TMJ animal model. In tension, it was found that the posterior inferior attachment (PIA) was significantly stiffer and stronger by 2.13 and 2.30 times, respectively, than the posterior superior attachment (PSA). It was found that collagen in both attachments was primarily aligned mediolaterally; however, the lateral disc was much more aligned and anisotropic than either attachment. Among the three locations, the PSA exhibited the greatest degree of heterogeneity and highest proportion of fat vacuoles. The PIA and lateral disc were 1.93 and 1.91 times more collagenous, respectively, by dry weight (DW) than the PSA. The PIA also exhibited 1.78 times higher crosslinking per DW than the PSA. Glycosaminoglycan per DW was significantly higher in the lateral disc by 1.48 and 5.39 times than the PIA and PSA, respectively. Together, these results establish design criteria for tissue-engineering of the TMJ disc complex and indicate that the attachments are less fibrocartilaginous than the disc, while still significantly contributing to the mechanical stability of the TMJ disc complex during articulation. These results also support the biomechanical function of the PIA and PSA, suggesting that the stiffer PIA anchors the disc to the mandibular condyle during articulation, while the softer PSA serves to allow translation over the articular eminence. Impact Statement Characterization of the temporomandibular joint (TMJ) disc complex (i.e., the disc and its attachments) has important implications for those aiming to tissue-engineer functional replacements and can help elucidate its biomechanical function. For example, the findings shown here suggest that the stiffer posterior inferior attachment anchors the disc during articulation, while the softer posterior superior attachment allows translation over the articular eminence.


Assuntos
Colágeno , Disco da Articulação Temporomandibular , Animais , Suínos , Disco da Articulação Temporomandibular/patologia , Porco Miniatura , Glicosaminoglicanos , Engenharia Tecidual
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