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1.
Clin Oral Implants Res ; 35(2): 220-229, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38033198

RESUMO

OBJECTIVE: Optimal implant planning and placement allows the prosthesis to be well designed to achieve a satisfactory aesthetic and functional outcome. We aimed to compare deviations between implant planning and placement with the assistance of dynamic computer-assisted implant surgery (d-CAIS) or autonomous robotic computer-assisted implant surgery (r-CAIS) methods in a clinical setting. METHODS: The retrospective analysis of medical records between 2021 July and 2022 December was conducted to compare the implantation accuracy of the d-CAIS and r-CAIS system in partially edentulous patients through cone-beam computed tomography. Patient-reported outcomes (PROs) were recorded using a visual analogue scale (VAS). The Kolmogorov-Smirnov test was used to check the data distribution. Student's t-test or Mann-Whitney U-test was used as appropriate, with a defined significant difference (p < .05). RESULTS: Seventy-seven patients were analysed (124 implants), with 38 patients (62 implants) in the d-CAIS group and 39 patients (62 implants) in the r-CAIS group. The differences between d-CAIS and r-CAIS were 4.09 ± 1.79° versus 1.37 ± 0.92° (p < .001) in angular deviation; 1.25 ± 0.54 versus 0.68 ± 0.36 mm (p < .001) in coronal global deviation; 1.39 ± 0.52 versus 0.69 ± 0.36 mm (p < .001) in apical global deviation; the results of the PROMs showed no statistical difference between the two groups. CONCLUSIONS: r-CAIS allows more accurate implant placement than the d-CAIS technology. And both groups achieved overall satisfactory outcomes via VAS (Chinese Clinical Trial Registry ChiCTR2300072004).


Assuntos
Implantes Dentários , Procedimentos Cirúrgicos Robóticos , Cirurgia Assistida por Computador , Humanos , Implantação Dentária Endóssea/métodos , Estudos Retrospectivos , Cirurgia Assistida por Computador/métodos , Computadores , Tomografia Computadorizada de Feixe Cônico , Desenho Assistido por Computador , Imageamento Tridimensional
2.
BMC Oral Health ; 24(1): 296, 2024 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-38431564

RESUMO

BACKGROUND: Overerupted maxillary molars is common in adults, which can lead to insufficient intermaxillary vertical space ,great difficulty in prosthetic reconstruction ,and cause occlusal interference in movements.To reconstruct occlusal function, it is necessary to prepare enough space for prostheses. The aim of the present study was to evaluate the effect of space-adjustment occlusal splint on overerupted maxillary molars by clinical and electromyographic signals analysis. METHODS: Eighteen patients with overerupted maxillary molars were selected to wear space-adjustment occlusal splint suppressing overerupted maxillary molars for three months. Satisfaction was assessed by 5-point Likert; intermaxillary vertical space and the teeth transportation distance were measured in models; clinical periodontal status were evaluated by periodontal probing depth (PPT) and bleeding index (BI); electromyographic recordings of the masseter and anterior temporal muscles were monitored by Cranio-Mandibular K7 Evaluation System. RESULTS: All the patients were satisfied with the treatment effect (Likert scale ≧ 4). The intermaxillary space in edentulous areas after treatment showed statistically significant increasing when compared with those before treatment. PPT and BI showed no significant difference. No statistically significant differences were found in electromyographic activity of anterior temporal muscles, while a reduction of muscle activity in masseter in the contralateral side were detected in post-treatment evaluations compared with pre-treatment at mandibular rest position. CONCLUSIONS: Space-adjustment occlusal splint is an efficient treatment option on overerupted maxillary molars by intruding the maxillary molar to obtain adequate intermaxillary space for prostheses.


Assuntos
Dente Molar , Contenções , Adulto , Humanos , Dente Molar/cirurgia , Músculo Masseter/fisiologia , Músculo Temporal/fisiologia , Placas Oclusais , Eletromiografia
3.
J Transl Med ; 21(1): 668, 2023 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-37759285

RESUMO

Osteoporosis is a systemic bone disease characterized by low bone mass, microarchitectural deterioration, increased bone fragility, and fracture susceptibility. It commonly occurs in older people, especially postmenopausal women. As global ageing increases, osteoporosis has become a global burden. There are a number of medications available for the treatment of osteoporosis, categorized as anabolic and anti-resorptive. Unfortunately, there is no drugs which have dual influence on bone, while all drugs have limitations and adverse events. Some serious adverse events include jaw osteonecrosis and atypical femoral fracture. Recently, a novel medication has appeared that challenges this pattern. Romosozumab is a novel drug monoclonal antibody to sclerostin encoded by the SOST gene. It has been used in Japan since 2019 and has achieved promising results in treating osteoporosis. However, it is also accompanied by some controversy. While it promotes rapid bone growth, it may cause serious adverse events such as cardiovascular diseases. There has been scepticism about the drug since its inception. Therefore, the present review comprehensively covered romosozumab from its inception to its clinical application, from animal studies to human studies, and from safety to cost. We hope to provide a better understanding of romosozumab for its clinical application.


Assuntos
Osteoporose , Animais , Feminino , Humanos , Idoso , Osteoporose/tratamento farmacológico , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais/uso terapêutico , Envelhecimento , Desenvolvimento Ósseo
4.
BMC Oral Health ; 23(1): 325, 2023 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-37231466

RESUMO

OBJECTIVE: Occlusal splints are always applied on individuals with bruxism to reduce tooth wear and relieve orofacial symptoms such as myofascial pain. The stomatognathic system is mainly composed of tooth, occlusion, masticatory muscles, and temporomandibular joint. The occlusion and masticatory muscles function are regarded as the important parameters for evaluating the stomatognathic system state objectively. However, the effects of occlusal splints on individuals with bruxism is rarely elucidated from accurate neuromuscular analysis and occlusion evaluation. The aim of the present study was to estimate the effects of three different splints (two clinically common full coverage occlusal splint and an modified anterior splint) on subjects with bruxism using K7-J5 neuromuscular analysis system and Dental Prescale II (DP2) to evaluate occlusion. METHODS: Sixteen subjects claimed to be suffering from nocturnal bruxism,with complete dentition and stable occlusal relationship, were selected for study.The intermaxillary space and the baselines of EMG-activity of the anterior temporalis and masseter were recorded for all the subjects. The participants was treated with three different splints, and outcomes were estimated by comfort index, occlusion and surface electromyography of anterior temporalis and masseter. RESULTS: At teeth clenched position, EMG data were significantly lower in the participants with use of modified anterior splint than with hard, soft occlusal splint or without splint (p < 0.05). The maximum bite force and bite area occur in subjects without use of splint, while the minimal occur in subjects with use of modified anterior splint. Intermaxillary space increased and masticatory muscles presented significant reduction of EMG data at rest position as a result of J5 (p < 0.05). CONCLUSION: Modified anterior splint seems to be more comfortable and effective in reducing occlusion force and electromyographic activity of anterior temporalis and masseter for subjects with bruxism.


Assuntos
Bruxismo , Contenções , Humanos , Bruxismo/complicações , Bruxismo/terapia , Oclusão Dentária , Músculos da Mastigação , Músculo Masseter/fisiologia , Eletromiografia
5.
BMC Oral Health ; 23(1): 89, 2023 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-36782192

RESUMO

BACKGROUND: Dynamic navigation systems have a broad application prospect in digital implanting field. This study aimed to explore and compare the dynamic navigation system learning curve of dentists with different implant surgery experience through dental models. METHODS: The nine participants from the same hospital were divided equally into three groups. Group 1 (G1) and Group 2 (G2) were dentists who had more than 5 years of implant surgery experience. G1 also had more than 3 years of experience with dynamic navigation, while G2 had no experience with dynamic navigation. Group 3 (G3) consisted of dentists with no implant surgery experience and no experience with dynamic navigation. Each participant sequentially placed two implants (31 and 36) on dental models according to four practice courses (1-3, 4-6, 7-9, 10-12 exercises). Each dentist completed 1-3, 4-6 exercises in one day, and then 7-9 and 10-12 exercises 7 ± 1 days later. The preparation time, surgery time and related implant accuracy were analyzed. RESULTS: Three groups placed 216 implants in four practice courses. The regressions for preparation time (F = 10.294, R2 = 0.284), coronal deviation (F = 4.117, R2 = 0.071), apical deviation (F = 13.016, R2 = 0.194) and axial deviation (F = 30.736, R2 = 0.363) were statistically significant in G2. The regressions for preparation time (F = 9.544, R2 = 0.269), surgery time (F = 45.032, R2 = 0.455), apical deviation (F = 4.295, R2 = 0.074) and axial deviation (F = 21.656, R2 = 0.286) were statistically significant in G3. Regarding preparation and surgery time, differences were found between G1 and G3, G2 and G3. Regarding implant accuracy, differences were found in the first two practice courses between G1 and G3. CONCLUSIONS: The operation process of dynamic navigation system is relatively simple and easy to use. The linear regression analysis showed there is a dynamic navigation learning curve for dentists with or without implant experience and the learning curve of surgery time for dentists with implant experience fluctuates. However, dentists with implant experience learn more efficiently and have a shorter learning curve.


Assuntos
Implantes Dentários , Cirurgia Assistida por Computador , Humanos , Curva de Aprendizado , Cirurgia Assistida por Computador/métodos , Implantação Dentária Endóssea/métodos , Projetos de Pesquisa
6.
BMC Oral Health ; 22(1): 139, 2022 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-35473637

RESUMO

INTRODUCTION: The aim of this study was to verify whether the use of short implants could optimize stress distribution of bone surrounding implants in atrophic mandibles with different bone qualities. METHODS: A three-dimensional model of the atrophic mandible with three levels of bone quality was made using computer software. Short implants (6 mm) and standard implants (10 mm) were used in four designs: Design 1 "All-On four", Design 2 "All-On-four" with two short implants, Design 3 four vertical implants with two short implants, and Design 4 six short implants. The distal short implants were placed at the first molar position. All twelve models were imported into finite element analysis software, and 110 N oblique force was loaded on the left second premolar. Maximum principal stress values of peri-implant bone and the volumes of bone with over 3000 microstrians (overload)were analyzed. RESULT: Stress values and volumes of overload bone increased in all four groups with the decline of bone quality. The highest stress values were found in the cortical bone surrounding the Design 1 inclined implant in two lower bone quality mandibles, and the lowest in Design 3. However, Design 1 had less overload bone tissue than all three designs with short implants. CONCLUSION: Short implants placed posteriorly helped decrease stress values in peri-implant bone, while bone surrounding short implants had a high resorption risk in low bone quality mandible.


Assuntos
Implantes Dentários , Prótese Dentária Fixada por Implante , Análise do Estresse Dentário/métodos , Análise de Elementos Finitos , Humanos , Mandíbula/cirurgia
7.
Soft Matter ; 15(30): 6151-6159, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31317163

RESUMO

Digital light processing (DLP) three-dimensional (3D) printing technology has advantages of fast printing speed and high printing precision. It can print objects with small and complex geometrical features and has been widely used in jewelry manufacturing and dentistry. In DLP printing, it is common to use post-treatment with UV light irradiation to improve the final mechanical properties. However, it was found that the UV post-curing process can lead to shape distortion and thus reduction of dimension accuracy. In this paper, we combined photopolymerization reaction kinetics and Euler-Bernoulli beam theory to study UV post-curing induced shape distortion of thin structures prepared by DLP 3D printing. Experiments were conducted to characterize the evolution of mechanical behavior of printed samples during the post-printing process, which was correlated to printing parameters (printing time of single-layer, height of single-layer and printing UV intensity), post-curing UV light intensity and the thickness of the strip. Moreover, post-curing induced distortion was used for the fabrication of 3D structures.

8.
BMC Oral Health ; 19(1): 266, 2019 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-31791302

RESUMO

BACKGROUND: The aim of the study was to compare the efficacy of the autogenous tooth bone and xenogenic bone grafted in immediate implant placement with bone defect. METHODS: Thirty patients whose compromised anterior teeth need immediate implant placement were enrolled. Autogenous tooth bone made from the extracted teeth by chair-side or the xenogenic bone were used to repaired bone defect. Clinical examination, radiographic assessment about the horizontal bone change in the level of 0 mm, 3 mm and 6 mm below the implant neck and the marginal bone loss were made immediately, 6 and 12 months after implant placement. Questionnaire of the feelings about the surgery were made at the time of removing the sutures. RESULTS: All implants achieved the success criteria without any complications at the follow-up period. The percent of the horizontal bone change and the marginal bone loss at 6 and 12 months were almost the same between two groups (P > .05). The horizontal bone loss at the first or the latter 6 months was almost the same (P > .05). But the horizontal bone loss at the 6 mm level was less than the 0 mm and 3 mm levels at 6 and 12 months (P < .05). Meanwhile patients seem more satisfied with the autogenous tooth bone derived from the questionnaire. CONCLUSION: The bone volume change in the facial part of the implant after immediate placement is almost the same between two groups. Providing clinical evidence that the autogenous tooth bone made from compromised tooth can be an acceptable bone graft material.


Assuntos
Implantes Dentários para Um Único Dente , Perda do Osso Alveolar , Implantação Dentária Endóssea , Seguimentos , Humanos , Extração Dentária , Alvéolo Dental , Resultado do Tratamento
9.
Molecules ; 23(8)2018 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-30061494

RESUMO

Eucommia ulmoides Oliv. is widely regarded in China as a precious medicinal and commercial endemic tree. Due to cross-breeding or natural variation of E. ulmoides, the metabolite composition may vary significantly, making control of the medical quality difficult. In order to improve the rational development and utilization, the quality of seven varieties of E. ulmoides were evaluated based on metabolite profiles (total phenolic, total flavonoid, gutta-percha, aucubin, geniposidic acid, chlorogenic acid, geniposide, pinoresinol diglucoside, rutin, hyperoside, and astragalin), bioactivities (in vitro, in vivo antioxidant activities, and antibacterial activities) and HPLC fingerprint combined with chemometrics analysis. On this basis, the differences of medicinal parts (leaf and bark) were further carried out. For the traditional use of bark, Purple-leaf E. ulmoides was the most suitable. For the use of leaf, Qinzhong 1 and Purple-leaf E. ulmoides were appropriate. HPLC fingerprint analysis showed that significant differences in metabolite profiles exist among seven varieties of E. ulmoides. Combined with chemometrics analysis, seven varieties of E. ulmoides were divided into three groups from the use of leaf and bark. The analysis not only evaluated quality of seven varieties of E. ulmoides, but also could distinguish different varieties and different regions of origin. The results can provide theoretical basis for E. ulmoides resources utilization and cultivation of fine varieties.


Assuntos
Antibacterianos/isolamento & purificação , Antioxidantes/isolamento & purificação , Eucommiaceae/química , Metaboloma , Casca de Planta/química , Folhas de Planta/química , Antibacterianos/química , Antibacterianos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , China , Ácido Clorogênico/química , Ácido Clorogênico/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Eucommiaceae/classificação , Eucommiaceae/metabolismo , Flavonoides/química , Flavonoides/isolamento & purificação , Fungos/efeitos dos fármacos , Fungos/crescimento & desenvolvimento , Guta-Percha/química , Guta-Percha/isolamento & purificação , Glucosídeos Iridoides/química , Glucosídeos Iridoides/isolamento & purificação , Iridoides/química , Iridoides/isolamento & purificação , Quempferóis/química , Quempferóis/isolamento & purificação , Lignanas/química , Lignanas/isolamento & purificação , Fenóis/química , Fenóis/isolamento & purificação , Casca de Planta/metabolismo , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Folhas de Planta/metabolismo , Plantas Medicinais , Quercetina/análogos & derivados , Quercetina/química , Quercetina/isolamento & purificação , Rutina/química , Rutina/isolamento & purificação
10.
HPB (Oxford) ; 20(6): 477-486, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29526466

RESUMO

BACKGROUND: Controversy remains about the best pre-operative management of jaundice in patients with resectable pancreatic head cancer (RPC) undergoing planned pancreaticoduodenectomy (PD). OBJECTIVE: The aim of this study was to compare rates of post-operative complications in patients undergoing four pre-operative approaches (POA): preoperative biliary drainage with plastic stent (PBD-PS), metal stent (PBD-MS), and percutaneous transhepatic drain (PBD-PT), or no pre-operative biliary drainage (NPBD). METHOD: A study was included in the systematic review if it assessed the effects of PBD on post-operative outcomes in jaundiced patients with RPC. Endpoints were the rate of any post-operative complication, wound infection, intra-abdominal infection and post-operative bleeding. A network meta-analysis (NMA) was performed to rank the POAs from the best to worst, for each outcome. RESULTS: Thirty-two studies were included in the systematic review. Ten out of 32 studies included in the systematic review reported at least one of the 4 outcomes of interest and thus were used for NMA. The calculated odds ratios and P-scores ranked NPBD as the best approach. There was insufficient evidence to determine the best modality of PBD among PBD-PS, PBD-MS and PBD-PT. CONCLUSIONS: No preoperative biliary drainage may be the best management of preoperative jaundice in patients with RPC before PD. Further studies are needed to determine the best modality in patients that need PBD.


Assuntos
Drenagem , Icterícia/terapia , Neoplasias Pancreáticas/cirurgia , Pancreaticoduodenectomia , Tomada de Decisão Clínica , Drenagem/efeitos adversos , Drenagem/instrumentação , Humanos , Icterícia/diagnóstico , Icterícia/etiologia , Metais , Neoplasias Pancreáticas/complicações , Neoplasias Pancreáticas/patologia , Pancreaticoduodenectomia/efeitos adversos , Plásticos , Complicações Pós-Operatórias/etiologia , Desenho de Prótese , Fatores de Risco , Stents , Resultado do Tratamento
11.
Biotechnol Bioeng ; 114(3): 503-515, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27617791

RESUMO

The enzymatic hydrolysis of cellulose is a thermodynamically challenging catalytic process that is influenced by both substrate-related and enzyme-related factors. In this study, a proteolysis approach was applied to recover and clean the partially converted cellulose at the different stages of enzymatic hydrolysis to monitor the hydrolysis rate as a function of substrate reactivity/accessibility and investigate surface characteristics of the partially converted cellulose. Enzyme-substrate interactions between individual key cellulase components from wild-type Trichoderma reesei and partially converted cellulose were followed and correlated to the enzyme adsorption capacity and dynamic sugar release. Results suggest that cellobiohydrolase CBH1 (Cel7A) and endoglucanases EG2 (Cel5A) adsorption capacities decreased as cellulose was progressively hydrolyzed, likely due to the "depletion" of binding sites. Furthermore, the degree of synergism between CBH1 and EG2 varied depending on the enzyme loading and the substrates. The results provide a better understanding of the relationship between dynamic change of substrate features and the functionality of various cellulase components during enzymatic hydrolysis. Biotechnol. Bioeng. 2017;114: 503-515. © 2016 Wiley Periodicals, Inc.


Assuntos
Celulase/metabolismo , Celulose/metabolismo , Adsorção , Celulase/química , Celulose/análise , Celulose/química , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Hidrólise , Ligação Proteica , Trichoderma/enzimologia
12.
Med Sci Monit ; 23: 4749-4759, 2017 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-28974670

RESUMO

BACKGROUND Surface characters of culture plates affect cellular behaviors such as cellular alignment and elongation. Microgrooves guide the cell growth along the grooves and spread. The aim of this study was to observe the effect of fibronectin (FN)-coated micro-grooved titanium plates on the alignment, spread, adhesion, and proliferation of human gingival fibroblasts (HGFs). MATERIAL AND METHODS Micro-grooved titanium plates were fabricated, and FN was immobilized onto the micro-grooved surfaces using silanization. HGFs were cultured on the smoothed or micro-grooved (with 35 µm width, 15 µm bridge, 10 µm depth) titanium plates, with or without the FN coating. We assessed the water contact angle and blood compatibility of the surfaces, and the earlier adhesion, adhesion strength, proliferation and morphology of the cells growing on the different titanium surfaces. RESULTS The results revealed that the blood hemolysis rates of different titanium surfaces were within the safety limits. HGFs aligned along the grooves, spread out more evidently, and showed significantly more adhesion in the FN-coated micro-grooved surface compared with other surfaces (p<0.05). CONCLUSIONS The micro-grooved surface coated with FN guides the HGFs to align along the grooves, and promotes cell spread, adhesion and proliferation, which might be used to improve the efficacy of dental implants.


Assuntos
Fibroblastos/citologia , Fibronectinas/fisiologia , Titânio/farmacologia , Adesão Celular/efeitos dos fármacos , Proliferação de Células , Células Cultivadas , Implantes Dentários , Fibroblastos/fisiologia , Fibronectinas/farmacologia , Gengiva/citologia , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura/métodos , Propriedades de Superfície , Aderências Teciduais
13.
Oncologist ; 20(6): 640-7, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25956404

RESUMO

BACKGROUND: The effectiveness of adjuvant transarterial chemoembolization (TACE) for intrahepatic cholangiocarcinoma (ICC) after hepatectomy remains unclear. This study was performed to identify ICC patients who would benefit from adjuvant TACE. PATIENTS AND METHODS: The study included 553 patients who underwent hepatectomy for ICC between January 2008 and February 2011 at the Eastern Hepatobiliary Surgery Hospital and who were treated with or without TACE (122 with TACE and 431 without TACE). Survival risk stratification was performed using the established prognostic nomogram (ICC nomogram). The predictive performance was evaluated by concordance index and calibration. The tumor recurrence and overall survival (OS) rates were analyzed by the Kaplan-Meier method before and after propensity score matching (PSM). RESULTS: The predictive performance of the ICC nomogram was demonstrated by the well-fitted calibration curves and an optimal c-index of 0.71 for OS prediction. In the whole cohort, the 5-year recurrence and OS rates between the TACE and non-TACE groups were significantly different (5-year recurrence: 72.9% vs. 78.1%; OS: 38.4% vs. 29.7%). After 1:1 PSM, the TACE and non-TACE groups (122 patients each) had similar 5-year recurrence and OS rates (5-year recurrence: 72.9% vs. 74.2%; OS: 38.4% vs. 36.0%). By survival risk stratification based on ICC nomogram, only the patients in the lowest tertile (nomogram scores ≥77) benefited from adjuvant TACE (TACE vs. non-TACE groups: 90.4% vs. 95.9% for 5-year recurrence; 21.3% vs. 6.2% for 5-year OS). CONCLUSION: Adjuvant TACE following liver resection might be suitable for ICC patients with high ICC nomogram scores (≥77). IMPLICATIONS FOR PRACTICE: The accurate predictive performance of the established prognostic nomogram for intrahepatic cholangiocarcinoma (ICC) following liver resection was reconfirmed in an independent cohort with 553 patients. Based on the survival risk stratification using the nomogram, adjuvant transarterial chemoembolization following liver resection might be suitable only for ICC patients with high scores from the nomogram.


Assuntos
Quimioembolização Terapêutica , Colangiocarcinoma/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Recidiva Local de Neoplasia/tratamento farmacológico , Adulto , Idoso , Colangiocarcinoma/patologia , Colangiocarcinoma/cirurgia , Embucrilato/administração & dosagem , Embucrilato/análogos & derivados , Epirubicina/administração & dosagem , Feminino , Fluoruracila/administração & dosagem , Hepatectomia , Humanos , Estimativa de Kaplan-Meier , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/cirurgia , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/cirurgia , Estadiamento de Neoplasias , Prognóstico , Fatores de Risco
14.
ScientificWorldJournal ; 2014: 579328, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24592175

RESUMO

Fracturing by ductile damage occurs quite naturally in metal forming processes, and ductile fracture of strain-softening alloy, here 42CrMo steel, cannot be evaluated through simple procedures such as tension testing. Under these circumstances, it is very significant and economical to find a way to evaluate the ductile fracture criteria (DFC) and identify the relationships between damage evolution and deformation conditions. Under the guidance of the Cockcroft-Latham fracture criteria, an innovative approach involving hot compression tests, numerical simulations, and mathematic computations provides mutual support to evaluate ductile damage cumulating process and DFC diagram along with deformation conditions, which has not been expounded by Cockcroft and Latham. The results show that the maximum damage value appears in the region of upsetting drum, while the minimal value appears in the middle region. Furthermore, DFC of 42CrMo steel at temperature range of 1123~1348 K and strain rate of 0.01~10 s(-1) are not constant but change in a range of 0.160~0.226; thus, they have been defined as varying ductile fracture criteria (VDFC) and characterized by a function of temperature and strain rate. In bulk forming operations, VDFC help technicians to choose suitable process parameters and avoid the occurrence of fracture.


Assuntos
Força Compressiva , Aço/química , Ligas de Cromo/química , Dureza , Temperatura Alta
15.
NPJ Digit Med ; 7(1): 182, 2024 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-38971937

RESUMO

Computer-aided implant surgery has undergone continuous development in recent years. In this study, active and passive systems of dynamic navigation were divided into active dynamic navigation system group and passive dynamic navigation system group (ADG and PDG), respectively. Active, passive and semi-active implant robots were divided into active robot group, passive robot group and semi-active robot group (ARG, PRG and SRG), respectively. Each group placed two implants (FDI tooth positions 31 and 36) in a model 12 times. The accuracy of 216 implants in 108 models were analysed. The coronal deviations of ADG, PDG, ARG, PRG and SRG were 0.85 ± 0.17 mm, 1.05 ± 0.42 mm, 0.29 ± 0.15 mm, 0.40 ± 0.16 mm and 0.33 ± 0.14 mm, respectively. The apical deviations of the five groups were 1.11 ± 0.23 mm, 1.07 ± 0.38 mm, 0.29 ± 0.15 mm, 0.50 ± 0.19 mm and 0.36 ± 0.16 mm, respectively. The axial deviations of the five groups were 1.78 ± 0.73°, 1.99 ± 1.20°, 0.61 ± 0.25°, 1.04 ± 0.37° and 0.42 ± 0.18°, respectively. The coronal, apical and axial deviations of ADG were higher than those of ARG, PRG and SRG (all P < 0.001). Similarly, the coronal, apical and axial deviations of PDG were higher than those of ARG, PRG, and SRG (all P < 0.001). Dynamic and robotic computer-aided implant surgery may show good implant accuracy in vitro. However, the accuracy and stability of implant robots are higher than those of dynamic navigation systems.

16.
Sci Rep ; 14(1): 3009, 2024 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-38321110

RESUMO

Currently, the classification of bone mineral density (BMD) in many research studies remains rather broad, often neglecting localized changes in BMD. This study aims to explore the correlation between peri-implant BMD and primary implant stability using a new artificial intelligence (AI)-based BMD grading system. 49 patients who received dental implant treatment at the Affiliated Hospital of Stomatology of Fujian Medical University were included. Recorded the implant stability quotient (ISQ) after implantation and the insertion torque value (ITV). A new AI-based BMD grading system was used to obtain the distribution of BMD in implant site, and the bone mineral density coefficients (BMDC) of the coronal, middle, apical, and total of the 1 mm site outside the implant were calculated by model overlap and image overlap technology. Our objective was to investigate the relationship between primary implant stability and BMDC values obtained from the new AI-based BMD grading system. There was a significant positive correlation between BMDC and ISQ value in the coronal, middle, and total of the implant (P < 0.05). However, there was no significant correlation between BMDC and ISQ values in the apical (P > 0.05). Furthermore, BMDC was notably higher at implant sites with greater ITV (P < 0.05). BMDC calculated from the new AI-based BMD grading system could more accurately present the BMD distribution in the intended implant site, thereby providing a dependable benchmark for predicting primary implant stability.


Assuntos
Densidade Óssea , Implantes Dentários , Humanos , Inteligência Artificial , Próteses e Implantes , Torque , Benchmarking
17.
Sci Total Environ ; 876: 162631, 2023 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-36894093

RESUMO

Global energy issue raised the necessity to develop second-generation biofuels, and biorefinery of cellulosic biomass becomes a promising solution. Various pretreatments were used to overcome the cellulose nature of recalcitrance and improve the enzymatic digestibility, but the lack of mechanism understanding hindered the development of efficient and cost-effective technologies of cellulose utilization. Using structure-based analysis, we demonstrate that the improved hydrolysis efficiency caused by ultrasonication was ascribed to the changed cellulose properties rather than the increased dissolubility. Further, isothermal titration calorimetry (ITC) analysis suggested that enzymatic digestion of cellulose is an entropically favored reaction driven by hydrophobic forces other than an enthalpically favored reaction. The changes in cellulose properties and thermodynamic paramenters due to ultrasonication accounted for the improved accessibility. Ultrasonication-treated cellulose showed porous, rough and disordered morphology, accompanying with the loss of crystalline structure. Despite the unaffected unit cell structure, ultrasonication expanded the crystalline lattice by increasing grain sizes and average cross-sectional area, resulting in the transformation from cellulose I to cellulose II, with the decreased crystallinity, better hydrophilicity and increased enzymatic bioaccessibility. Furthermore, FTIR combined with two-dimensional correlation spectroscopy (2D-CoS) verified that the sequential shift of hydroxyl group and intramolecular/intermolecular hydrogen bonds, the functional groups governing cellulose crystal structure and stability, accounted for the ultrasonication-induced transition of cellulose crystalline structure. This study provides a comprehensive picture of cellulose structure and property response caused by mechanistic treatments and will open up avenues to develop novel pretreatments for efficient utilization.


Assuntos
Celulose , Celulose/química , Ligação de Hidrogênio , Biomassa , Hidrólise
18.
J Dent ; 137: 104642, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37517786

RESUMO

OBJECTIVES: This study aims to compare the surgical efficiency (preparation and operation time) and accuracy of implant placement between robots with different human-robot interactions. METHODS: The implant robots were divided into three groups: semi-active robot (SR), active robot (AR) and passive robot (PR). Each robot placed two implants (#31 and #36) on a phantom, practising 10 times. The surgical efficiency and accuracy of implant placement were then evaluated. RESULTS: Sixty implants were placed in 30 phantoms. The mean preparation times for the AR, PR and SR groups were 3.85 ± 0.17 min, 2.14 ± 0.06 mins and 1.65 ± 0.19 mins, respectively. The mean operation time of the PR group (3.76 ± 0.59 min) was shorter that of than the AR (4.89 ± 0.70 mins) and SR (4.59 ± 0.56 min) groups (all P < 0.001). The operation time of the AR group in the anterior region (4.47 ± 0.31 min) was longer than that of the SR group (4.07 ± 0.10 min) (P = 0.007). The mean coronal, apical and axial deviations of the PR group (0.40 ± 0.12 mm, 0.49 ± 0.13 mm, 0.96 ± 0.22°) were higher than those of the AR (0.23 ± 0.11 mm, 0.24 ± 0.11 mm, 0.54 ± 0.20 °) (all P < 0.001) and SR (0.31 ± 0.10 mm, 0.36 ± 0.12 mm, 0.43 ± 0.14 °) groups (P = 0.044, P = 0.002, and P < 0.001, respectively). CONCLUSIONS: Human-robot interactions affect the efficiency of implant surgery. Active and semi-active robots show comparable implant accuracy. However, the implants placed by the passive robot show higher deviations. CLINICAL SIGNIFICANCE: This in vitro study preliminarily demonstrates that implant placement is accurate when using implant robots with different human-robot interactions. However, different human-robot interactions have variable surgical efficiencies.


Assuntos
Implantes Dentários , Procedimentos Cirúrgicos Robóticos , Robótica , Cirurgia Assistida por Computador , Humanos , Implantação Dentária Endóssea , Tomografia Computadorizada de Feixe Cônico , Imageamento Tridimensional , Desenho Assistido por Computador
19.
J Hazard Mater ; 441: 129829, 2023 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-36058186

RESUMO

Low-cost and sustainable superwetting materials are urgently required for oily wastewater treatment. Many poly(vinylidene fluoride) (PVDF)-based materials have been designed for oil-water separation. However, their fabrication processes frequently require toxic organic solvents and high-cost materials (e.g., carbon tubes and graphene). In this study, a highly porous and superhydrophobic bamboo powders (BP)-enhanced PVDF foam (SBPF) was fabricated via an organic solvent-free process. The SBPF exhibits efficient adsorption and recovery for various oils and organic solvents. Moreover, the SBPF shows high adsorption and separation performance under ultraviolet exposure and turbulent environments. It can also be used for water-in-oil emulsions separation, with a high separation efficiency more than 99.3 % under gravity. Interestingly, the amphiphilic PVDF-BP foam (ABPF) shows underwater superoleophobicity and underoil superhydrophobicity after delignification of SBPF. Owing to the conversion of wettability, it presents a high performance in treatment of both surfactant-stabilied water-in-oil and oil-in-water emulsions with the high separation efficiency achieving more than 99.6 % and 99.5 % respectively under gravity. In addition, the ABPF shows a high separation performance even after ten cycles. Hence, this fabricated organic solvent-free foams are promising candidates for sustainable on-demand separation of oils or organic solvents and water in complex environments.


Assuntos
Grafite , Polímeros de Fluorcarboneto , Óleos/química , Polivinil , Pós , Solventes , Tensoativos , Água/química
20.
Chemosphere ; 313: 137582, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36529175

RESUMO

Microplastics (MPs) have emerged as a global concern, with a recent study being the first to detect them in the bloodstream of healthy people. However, precise information regarding the toxic effects of MPs on the human vascular system is currently lacking. In this study, we used human vascular endothelial EA. hy926 cells to examine the toxic potential of polystyrene MPs (PSMPs) under realistic blood concentrations. Our findings indicated that PSMPs can cause oxidative stress by reducing the expression of antioxidants, thereby leading to apoptotic cytotoxicity in EA. hy926 cells. Furthermore, the protective potential of heat shock proteins can be reduced by PSMPs. PSMP-induced apoptosis might also lower the expression of rho-associated protein kinase-1 and nuclear factor-κB expression, thus dampening LRR- and pyrin domain-containing protein 3 in EA. hy926 cells. Moreover, we observed that PSMPs induce vascular barrier dysfunction via the depletion of zonula occludens-1 protein. However, although protein expression of the nuclear hormone receptor 77 was inhibited, no significant increase in ectin-like oxidized low-density lipoprotein receptor-1 was noted in PSMP-treated EA. hy926 cells. These results demonstrate that exposure to PSMPs may not sufficiently increase the risk of developing atherosclerosis. Overall, our research signifies that exposure to realistic blood concentrations of PSMPs is associated with low atherosclerotic cardiovascular risk in humans.


Assuntos
Microplásticos , Poliestirenos , Humanos , Microplásticos/toxicidade , Microplásticos/metabolismo , Poliestirenos/metabolismo , Plásticos/metabolismo , Células Endoteliais/metabolismo , Estresse Oxidativo
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