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1.
Braz. j. oral sci ; 20: e210525, jan.-dez. 2021. ilus
Artigo em Inglês | LILACS, BBO - Odontologia | ID: biblio-1253928

RESUMO

Aim: Recent reports indicate that deproteinization of acid-etched dentin surface can extend penetration depth of adhesive agents. The main goal of the present research was to investigate the deproteinization effect of Nd:YAG and diode 940 lasers on acid-etched dentin and microleakage grade in class V composite restorations. Methods: 36 extracted human premolar teeth were selected to make standard buccal and lingual class V cavities. These samples were randomly split into three sub-groups: 1.Control group, in which composite was applied for restoration after etch and bonding process without deproteinization; 2.Nd:YAG laser group, in which the teeth were deproteinized with Nd:YAG laser after etching and painting internal surfaces of cavities with Van Geison stain and then composite restorations applied just as control group; 3.Diode laser group, in which the process was similar to Nd:YAG laser group, but instead, diode 940 laser was irradiated. The teeth were bisected into two equal longitudinal buccal and lingual halves. Marginal microleakage of samples was scored by using a stereomicroscope. Kruskal- Wallis, Mann-Whitney U and Fisher's statistical tests were employed for analysis of the obtained data. Results: A significant reduction in marginal microleakage was observed for both groups treated with laser (Nd:YAG and diode 940)compared to control (p=0.001 & p=0.047). There was no significant difference in marginal microleakage between Nd:YAG laser and diode 940groups (P = 0.333). Conclusion: Nd:YAG and diode 940 laser deproteinization of acid-etched dentin decreased the marginal microleakage of in-vitro class V resin composite restorations


Assuntos
Humanos , Condicionamento Ácido do Dente , Adesivos Dentinários , Infiltração Dentária , Lasers
2.
Talanta ; 233: 122535, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34215038

RESUMO

Bacterial infection poses a serious threat to human health worldwide. Rapid antimicrobial susceptibility testing (AST) is essential for the clinical treatment of bacterial infection patients. However, the traditional AST relies on bacteria culture, which is time-consuming and limits the analysis to culturable species. Herein, we present a laser desorption ionization (LDI) mass spectrometry-based method for rapid bacterial viability assessment and AST by tracing the redox of resazurin (RS) by viable bacteria. RS as well as its reduction product, fluorescent resorufin (RF), can be directly detected by LDI-MS in the absence of matrix. The intensity ratio between RF and RS can be used to assess the viability of bacteria in specimens. We have demonstrated the high efficiency of the method using different bacterial species, including K. pneumoniae, S. aureus, E. coli, and P. aeruginosa, and various antibiotic drugs, such as ciprofloxacin, ampicillin, tetracycline, oxytetracycline, ciprofloxacin and levofloxacin. Compared to traditional methods based on optical absorption, the current method is faster and more sensitive. Furthermore, we applied the method to bacterial viability detection and AST using human body fluid samples, i.e. serum and urine, demonstrating that it can screen rapidly appropriate antibiotic drugs for timely clinical treatment of infectious diseases. With the advantages of simplicity in methodology as well as sensitivity and speed in analysis, the current method holds the potential of clinical usages.


Assuntos
Escherichia coli , Staphylococcus aureus , Antibacterianos/farmacologia , Humanos , Lasers , Testes de Sensibilidade Microbiana , Viabilidade Microbiana , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
3.
Mater Sci Eng C Mater Biol Appl ; 127: 112247, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34225886

RESUMO

The osteogenic activity of medical metal can be improved by lowering its surface stiffness and elastic modulus. However, it is very difficult to directly reduce the elastic modulus of medical metal surfaces. In this paper, with selected parameters, the titanium surface was treated via femtosecond laser irradiation. Micro indentation revealed that the femtosecond laser ablation can effectively reduce the surface Young's modulus and Vickers hardness of titanium. Besides, In order to explain the mechanical properties of degradation of titanium surface, Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) was used to simulate the process of laser ablation process of titanium surface, and it was found that after the ablation of titanium surface, voids were produced in the subsurface layer. The simulation showed that the voids are formed by the cavitation of metastable liquid induced by high tensile stress and high temperature during femtosecond laser irradiation. Subsurface voids with a thickness of about 40 nm were observed under the oxide layer in the experiment. Cell experiments showed that the surface with low Young's modulus was more conducive to cell proliferation and osteogenic differentiation.


Assuntos
Nanoporos , Osteogênese , Lasers , Próteses e Implantes , Propriedades de Superfície , Titânio
4.
Mater Sci Eng C Mater Biol Appl ; 127: 112250, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34225889

RESUMO

Customized spinal implants fabricated by additive manufacturing have been increasingly used clinically to restore the physiological functions. However, the mechanisms and methods about the design for the spinal implants are not clear, especially for the reconstruction of multi-segment vertebral. This study aims to develop a novel multi-objective optimization methodology based on various normal spinal activities, to design the artificial vertebral implant (AVI) with lightweight, high-strength and high-stability. The biomechanical performance for two types of AVI was analyzed and compared under different loading conditions by finite element method. These implants were manufactured via selective laser melting technology and evaluated via compressive testing. Results showed the maximum Mises stress of the optimized implant under various load cases were about 41.5% of that of the trussed implant, and below fatigue strength of 3D printed titanium materials. The optimized implant was about 2 times to trussed implant in term of the maximum compression load and compression stiffness to per unit mass, which indicated the optimized implant can meet the safety requirement. Finally, the optimized implant has been used in clinical practice and good short-term clinical outcomes were achieved. Therefore, the novel developed method provides a favorable guarantee for the design of 3D printed multi-segment artificial vertebral implants.


Assuntos
Próteses e Implantes , Titânio , Fenômenos Biomecânicos , Análise de Elementos Finitos , Lasers , Impressão Tridimensional , Estresse Mecânico
5.
Mymensingh Med J ; 30(3): 780-788, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34226468

RESUMO

LASER Haemorrhoidoplasty (LH) is a novel procedure in modern medical science. It is a no cut, painless and bloodless clinical procedure with comparatively fewer complications in comparison to Stapler Haemorrhoidopexy (SH) for the treatment of grade III-IV haemorrhoids. It is very applicable surgical procedure at shrinking the terminal branches of haemorrhiodal arteries with fewer complications than Stapler Haemorrhoidopexy (SH). The aim of the study was to compare LASER Haemorrhoidoplasty (LH) with Stapler Haemorrhoidopexy (SH). The comparative study was performed in Bangabandhu Sheikh Mujib Medical University (BSMMU), Anower Khan Modern Medical College and Hospital and Care Medical College and Hospital, Dhaka, Bangladesh from August 2019 to July 2020. A total of 84 patients with grade III-IV haemorrhoids were allocated into two groups: LASER Haemorrhoidoplasty (LH) and Stapler Haemorrhoidopexy (SH) with 42 patients in each group prospectively. Comparative results and post-operative follow up periods were 4 months. The mean operative time was 28.6min (LH) and 36.2min (SH) (p=0.0006). The average blood loss was 6.42ml (LH) and 12.6ml (SH) (p<0.05). The mean hospital stay 18.36 hours (LH) and 28.40 hours (SH) (p<0.05). Mean postoperative pain score (VAS) at 12 hours was 3.8 (LH) and 6.81 (SH) (p<0.05), at 24 hours was 2.6 (LH) and 4.6 (SH) (p<0.05), at 1 week was 0.46 (LH) and 0.88 (SH) (p=0.05) and at 3 months 0.04 (LH) and 0.10 (SH) (p=0.401). Complications were found in (2.4%) patients ≤1 week in the (LH) group 7(16.7%) in the (SH) group which was statistically significant (p<0.05) between the two groups. Patients with haemorrhoids treated with LASER Haemorrhoidoplasty had a better outcome than stapler haemorrhoidopexy in terms of early postoperative pain as well as complications and was associated with a shorter hospital stay and early return to work. LASER Haemorrhoidoplasty was most effective and alternative to the popular stapler Haemorrhoidopexy for grade III-IV haemorrhoids.


Assuntos
Hemorroidas , Bangladesh , Hemorroidas/cirurgia , Humanos , Lasers , Dor Pós-Operatória/etiologia , Dor Pós-Operatória/prevenção & controle , Complicações Pós-Operatórias , Estudos Prospectivos , Grampeamento Cirúrgico , Resultado do Tratamento
6.
Sensors (Basel) ; 21(11)2021 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-34198916

RESUMO

Environmental monitoring of aquatic systems is the key requirement for sustainable environmental protection and future drinking water supply. The quality of water resources depends on the effectiveness of water treatment plants to reduce chemical pollutants, such as nitrates, pharmaceuticals, or microplastics. Changes in water quality can vary rapidly and must be monitored in real-time, enabling immediate action. In this study, we test the feasibility of a deep UV Raman spectrometer for the detection of nitrate/nitrite, selected pharmaceuticals and the most widespread microplastic polymers. Software utilizing artificial intelligence, such as a convolutional neural network, is trained for recognizing typical spectral patterns of individual pollutants, once processed by mathematical filters and machine learning algorithms. The results of an initial experimental study show that nitrates and nitrites can be detected and quantified. The detection of nitrates poses some challenges due to the noise-to-signal ratio and background and related noise due to water or other materials. Selected pharmaceutical substances could be detected via Raman spectroscopy, but not at concentrations in the µg/l or ng/l range. Microplastic particles are non-soluble substances and can be detected and identified, but the measurements suffer from the heterogeneous distribution of the microparticles in flow experiments.


Assuntos
Plásticos , Poluentes Químicos da Água , Inteligência Artificial , Monitoramento Ambiental , Lasers , Análise Espectral Raman , Poluentes Químicos da Água/análise
7.
J Contemp Dent Pract ; 22(3): 237-241, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-34210921

RESUMO

AIM AND OBJECTIVE: The present study aimed at evaluating the effectiveness of diverse remineralizing agents on artificial enamel lesion using confocal laser scanning microscope (CLSM). MATERIALS AND METHODS: Totally 80 mandibular premolars which were single rooted were included. All teeth were suspended in a demineralizing solution to create artificial enamel lesions on the exposed enamel. The samples were separated randomly into four groups (20 each) depending on the application of the remineralizing agents as follows: group 1: control; group 2: calcium sucrose phosphate (CaSP); group 3: fluoride varnish; and group 4: casein phosphopeptides-amorphous calcium phosphate (CPP-ACP). The samples in individual group were treated with the corresponding remineralizing agent (except for the control group) two times a day for 14 days. The experimental and control groups were exposed to CLSM assessment to analyze the data of remineralization and demineralization. RESULTS: The mean depth of remineralization of fluoride varnish group was slightly more compared to other groups. The highest mean depth of remineralization was found in the fluoride varnish group (122.26 ± 0.28) followed by CaSP (110.58 ± 1.34), CPP-ACP (107.08 ± 0.48), and control (157.78 ± 0.46) groups. The different comparisons among the remineralization material groups showed a statistically significant difference (p < 0.05) in almost all groups except group 2 vs group 4. CONCLUSION: This study concluded that improved remineralization of artificial enamel lesion could be achieved with the fluoride varnish group when compared to the CaSP and CPP-ACP groups. CLINICAL SIGNIFICANCE: Remineralization as a treatment technique has received a lot of consideration from clinicians. The process of remineralization and demineralization is considered an active process categorized by the movement of calcium and phosphate in and out of the enamel. Presently, the attention has changed toward increasing the resistance of the tooth by applying remineralizing agents topically, which has led to the notable fall in dental caries.


Assuntos
Cárie Dentária , Remineralização Dentária , Cariostáticos/farmacologia , Caseínas , Cárie Dentária/tratamento farmacológico , Esmalte Dentário , Fluoretos/farmacologia , Humanos , Lasers
8.
Int J Nanomedicine ; 16: 4351-4369, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34234430

RESUMO

Purpose: Multifunctional nanoparticles with targeted therapeutic function and diagnostic-imaging are of great interest in the domain of precision therapy. NIR laser responsive nanoparticles (PLGA-PEG-FA encapsulating Bi2S3, PFP, and Dox (designed as FBPD NPs)) are synthesized for ovarian cancer targeted combination therapy with CT/PA dual-modal imaging guidance (PA: photoacoustic; CT: X-ray computed tomography). Methods and Results: The FBPD NPS prepared by the double emulsification method revealed excellent dispersity, great stability, outstanding optical properties. The temperature of FBPD NPs increased rapidly after laser irradiation, inducing liquid-to-gas conversion of perfluoropentane (PFP), and promoting the release of Dox up to 86.7%. These FBPD NPs demonstrated their outstanding imaging capability for both PA and CT imaging both in vitro and in vivo, providing the potential for therapeutic guidance and monitoring. Assisted by folic acid, these nanoparticles could highly enrich in ovarian tumor tissue and the accumulation peaked at 3 h after intravenous administration. The desirable photothermal-conversion efficiency of the nanoparticles combined with chemotherapy achieved highly efficient therapy, which was demonstrated both in vitro and in vivo. Conclusion: We successfully constructed multifunctional theranostic FBPD NPs for highly efficient PTT/chemotherapy combined therapy with dual CT/PA imaging guidance/monitoring. The unique nanoparticles with multiple abilities pave an emerging way toward precise treatment of ovarian cancer.


Assuntos
Raios Infravermelhos , Lasers , Nanopartículas/uso terapêutico , Neoplasias Ovarianas/diagnóstico por imagem , Neoplasias Ovarianas/terapia , Técnicas Fotoacústicas , Tomografia Computadorizada por Raios X , Animais , Terapia Combinada , Feminino , Ácido Fólico/química , Humanos , Nanopartículas/química , Poliésteres/química , Polietilenoglicóis/química
9.
Vaccine ; 39(32): 4399-4403, 2021 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-34226102

RESUMO

The skin represents an attractive target tissue for vaccination against respiratory viruses such as SARS-CoV-2. Laser-facilitated epicutaneous immunization (EPI) has been established as a novel technology to overcome the skin barrier, which combines efficient delivery via micropores with an inherent adjuvant effect due to the release of danger-associated molecular patterns. Here we delivered the S1 subunit of the Spike protein of SARS-CoV-2 to the skin of BALB/c mice via laser-generated micropores with or without CpG-ODN1826 or the B subunit of heat-labile enterotoxin of E.coli (LT-B). EPI induced serum IgG titers of 1:3200 that could be boosted 5 to 10-fold by co-administration of LT-B and CpG, respectively. Sera were able to inhibit binding of the spike protein to its receptor ACE2. Our data indicate that delivery of recombinant spike protein via the skin may represent an alternative route for vaccines against Covid-19.


Assuntos
COVID-19 , Glicoproteína da Espícula de Coronavírus , Animais , Anticorpos Antivirais , Vacinas contra COVID-19 , Humanos , Imunização , Lasers , Camundongos , Camundongos Endogâmicos BALB C , Peptidil Dipeptidase A , Ligação Proteica , SARS-CoV-2 , Vacinação
10.
Molecules ; 26(12)2021 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-34198596

RESUMO

Staphylococcus aureus (Gram-positive) and Pseudomonas aeruginosa (Gram-negative) bacteria represent major infectious threats in the hospital environment due to their wide distribution, opportunistic behavior, and increasing antibiotic resistance. This study reports on the deposition of polyvinylpyrrolidone/antibiotic/isoflavonoid thin films by the matrix-assisted pulsed laser evaporation (MAPLE) method as anti-adhesion barrier coatings, on biomedical surfaces for improved resistance to microbial colonization. The thin films were characterized by Fourier transform infrared spectroscopy, infrared microscopy, and scanning electron microscopy. In vitro biological assay tests were performed to evaluate the influence of the thin films on the development of biofilms formed by Gram-positive and Gram-negative bacterial strains. In vitro biocompatibility tests were assessed on human endothelial cells examined for up to five days of incubation, via qualitative and quantitative methods. The results of this study revealed that the laser-fabricated coatings are biocompatible and resistant to microbial colonization and biofilm formation, making them successful candidates for biomedical devices and contact surfaces that would otherwise be amenable to contact transmission.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Materiais Revestidos Biocompatíveis/farmacologia , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Flavonoides/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Antibacterianos/química , Biofilmes/crescimento & desenvolvimento , Materiais Revestidos Biocompatíveis/química , Flavonoides/química , Lasers/normas , Testes de Sensibilidade Microbiana/métodos , Pseudomonas aeruginosa/crescimento & desenvolvimento , Staphylococcus aureus/crescimento & desenvolvimento , Propriedades de Superfície
11.
Int J Mol Sci ; 22(13)2021 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-34206936

RESUMO

The cascaded dual-chirped optical parametric amplification (DC-OPA) is presented for efficient generation of few-cycle infrared (IR) laser pulses. The input pulses are strategically chirped to optimize the phase-matching bandwidth in each nonlinear crystal, and four regions of the signal spectrum are amplified in cascaded crystals with different cutting angles, enabling flexible manipulation of the output spectrum. Broadband gain and high conversion efficiency are simultaneously achieved owing to the cascaded-crystal arrangement, the signal pulse duration of 4.2 cycles is obtained with 11.7-mJ pulse energy, corresponding to a conversion efficiency of 39.0%. The proposed scheme offers a robust and simple approach to pushing the phase-matching bandwidth limits introduced by the nonlinear crystal, which manifests great prospect in various researches involving ultrafast optics and strong-field physics.


Assuntos
Raios Infravermelhos , Lasers , Cristalização , Óptica e Fotônica/métodos
12.
Molecules ; 26(12)2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-34200763

RESUMO

The development of new antimicrobial strategies that act more efficiently than traditional antibiotics is becoming a necessity to combat multidrug-resistant pathogens. Here we report the efficacy of laser-light-irradiated 5,10,15,20-tetrakis(m-hydroxyphenyl)porphyrin (mTHPP) loaded onto an ethylcellulose (EC)/chitosan (Chs) nanocomposite in eradicating multi-drug resistant Pseudomonas aeruginosa, Staphylococcus aureus, and Candida albicans. Surface loading of the ethylcelllose/chitosan composite with mTHPP was carried out and the resulting nanocomposite was fully characterized. The results indicate that the prepared nanocomposite incorporates mTHPP inside, and that the composite acquired an overall positive charge. The incorporation of mTHPP into the nanocomposite enhanced the photo- and thermal stability. Different laser wavelengths (458; 476; 488; 515; 635 nm), powers (5-70 mW), and exposure times (15-45 min) were investigated in the antimicrobial photodynamic therapy (aPDT) experiments, with the best inhibition observed using 635 nm with the mTHPP EC/Chs nanocomposite for C. albicans (59 ± 0.21%), P. aeruginosa (71.7 ± 1.72%), and S. aureus (74.2 ± 1.26%) with illumination of only 15 min. Utilization of higher doses (70 mW) for longer periods achieved more eradication of microbial growth.


Assuntos
Antibacterianos/química , Celulose/análogos & derivados , Quitosana/química , Nanocompostos/química , Porfirinas/química , Piridonas/química , Pirróis/química , Animais , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Linhagem Celular , Celulose/química , Chlorocebus aethiops , Lasers , Luz , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/química , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Células Vero
13.
Georgian Med News ; (314): 134-139, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-34248043

RESUMO

High-resolution ultrasound (US) was used to examine 25 patients before the procedure and at the 2nd, 7th, 21st days and in 1.5 months after combined exposure to the skin of the face and neck with the Er:YAG laser in cold ablation mode and with the neodymium (Nd:YAG) laser in long pulse mode. The maximum dermis thickness was noted in the middle third (the standard measurement point along the mid-pupillary line in the projection of the infraorbital foramen) and composed 1,75±0,29 mm, the minimum on the neck and in infraorbital area - 1,2 (1,15; 1,3) mm and 1,15±0,15 mm, respectively. On the second day after the procedure, there was a significant increase up to 2,63±0,33 mm in the dermal thickness in the middle third in the projection of the infraobital foramen and up to 1,57±0,23 mm in the submental area of the neck due to all its layers in comparison with the values given ​​before the procedure (p=0.005, p<0.0001). Visualization of the dermis layers was difficult in B-mode during ultrasound, the toughness of the tissues decreased at compression elastography, pronounced vascularization was detected in the CDI mode in comparison with the initial one before the procedure and persisted up to 6 weeks. The ultrasound image in B-mode corresponded to the initial parameters starting from the 7th day.


Assuntos
Terapia a Laser , Envelhecimento da Pele , Face/diagnóstico por imagem , Face/cirurgia , Humanos , Lasers , Pescoço/diagnóstico por imagem , Pescoço/cirurgia , Pele
14.
Rev Bras Enferm ; 74(3): e20201117, 2021.
Artigo em Inglês, Português | MEDLINE | ID: mdl-34287493

RESUMO

OBJECTIVES: to evaluate the effects of venous ulcer healing in patients after six months of conventional treatment and adjuvant low-power laser therapy. METHODS: prospective cohort study nested in a randomized clinical trial with 38 patients, allocated into an intervention group (conventional treatment and adjuvant laser therapy) and a control group (conventional treatment). Patients were followed up as outpatients, sociodemographic and clinical variables were collected, and indicators of the outcomes Wound healing: secondary intention (1103) and Tissue integrity: skin and mucous membranes(1101) of the Nursing Outcomes Classification. Generalized estimating equations, Kaplan-Meier tests, and robust Poisson regression were used in the analysis. RESULTS: the clinical indicators Decreased wound size and Scar formation showed a statistically significant difference in the intervention group, higher number of healed wounds, lower rate, longer time to relapse. CONCLUSIONS: laser therapy adjuvant to conventional treatment returned better results in healing and lower recurrence rates after six months of intervention.


Assuntos
Úlcera Varicosa , Doença Crônica , Humanos , Lasers , Estudos Prospectivos , Úlcera Varicosa/terapia , Cicatrização
15.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 56(7): 646-651, 2021 Jul 09.
Artigo em Chinês | MEDLINE | ID: mdl-34275219

RESUMO

Objective: To investigate the accuracy of pure titanium and cobalt-chromium alloy frameworks fabricated using the additive manufacturing (AM) of selective laser melting technology (SLM) for the mandibular implant-supported fixed prostheses and the maxillary removable partial denture (RPD), and to provide a reference for clinical application of SLM pure titanium frameworks. Methods: One edentulous mandibular model with implants and screw fixed abutments at bilateral canines and the first molars was selected and used as the mandibular full arch implant-supported model. At the same time, a Kennedy class Ⅰ maxillary dentition defect model was selected. The digital models were obtained by scanning the dental models, and the metal frameworks of the mandibular full arch implant-supported denture and the maxillary RPD (design model) were designed using the 3 Shape software. Meanwhile, 12 mandibular frameworks in the cobalt-chromium alloy and the pure titanium (6 in each group were treated with heat treatment, while the other 6 were not treated), and 7 maxillary frameworks in the cobalt-chromium alloy and the pure titanium were respectively made by SLM with the improved dual-laser metal printer. The axial direction of the printing powder accumulation was taken as the Z-axis. During the design process, the software (3Shape Dental System 2018) automatically generated the X-axis and Y-axis, X axis was the sagittal axis of the dental model and Y axis was the coronal axis of the dental model. The deviation of the interface center of the abutment of the digital model of the mandibular frameworks from the design model in the X, Y and Z axes was analyzed. As for the trueness of the mandibular framework, the larger the deviation data was, the worse the trueness was. The deviation of the whole maxillary framework and 7 measuring points (palatal plate center point and bilateral occlusal rests, I bars, proximal plates) were analyzed. The fitness of the whole maxillary framework to the design model was expressed by root mean square (RMS) of the deviation data, and the fitness of measuring points was expressed by the mean±standard deviation of the data. The trueness differences of each group before and after heat treatment of the mandibular framework and the fitness of the maxillary framework were compared. Results: The cobalt-chromium alloy frameworks showed lower trueness on the X, Y, Z-axes [(96.3±12.1), (86.3±11.4), (61.2±13.2) µm] than did the pure Ti frameworks [(82.3±11.2), (72.2±10.2), (51.2±11.6) µm] by SLM, and the heat treatment could reduce the discrepancy between the SLM frameworks and STL models, for pure titanium frameworks [(62.4±11.3), (55.2±13.2), (41.3±10.8) µm] and for cobalt-chromium alloy [(84.5±10.5), (72.3±11.2), (54.2±11.6) µm]. For the thin RPD major frameworks, pure titanium had better fitness [(121.3±17.0) µm] than cobalt-chromium alloy [(174.0±18.3) µm] by SLM, and the difference was statistically significant (P<0.05). Conclusions: Pure titanium frameworks fabricated by SLM additive manufacturing technology exhibited better fitness and trueness than did the Co-Cr frameworks after heat treatment respectively, and this satisfied the requirements of implant-supported fixed prostheses and RPD major metal frameworks.


Assuntos
Desenho Assistido por Computador , Titânio , Ligas de Cromo , Prótese Dentária Fixada por Implante , Prótese Total , Lasers
16.
Transl Vis Sci Technol ; 10(8): 8, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-34251423

RESUMO

Purpose: To create a mouse traumatic optic neuropathy (TON) model that is reproducible, reliable, and easy to manipulate with high specificity to retinal ganglion cell (RGC) layer and no mortality. The model will be useful for understanding the pathophysiology of retinal ganglion cell death and for testing neuroprotective therapeutics. Methods: An Nd:YAG laser was used to generate focal photodisruptive retinal damage. Noninvasive in vivo ophthalmologic imaging technologies such as optical coherence tomography (OCT) and confocal laser scanning ophthalmoscopy (CSLO) were used to longitudinally track the retinal nerve fiber layer (RNFL) thickness and RGC number change, respectively. Immunostaining and pattern electroretinography (PERG) were also used to evaluate structure and functional change after laser injury. Results: Our ND:YAG laser generates a concussive photodisruptive laser shockwave force which induces focal RGC death in the targeted area. We observed a correlative decrease in RGCs number, RNFL, and PERG function of RGC in the laser zone. The pattern of RNFL thinning and RGC soma loss correlates with the pattern and amount of fluorescence loss on OCT and CSLO images, respectively. The ND:YAG laser does not cause any damage to other layers in the retina nor any side effects including changes in intraocular pressure, corneal edema, and calcification or mortality (which has been observed in other TON models). Conclusions: We have created a new and novel RGC TON death model that confers no mortality and produces a quantifiable decrease in RGC number and function. The laser targeted regions of the retina correlate with both in vivo imaging by OCT and CSLO and histologically with regions of RGC loss without ophthalmic side effects. Translational Relevance: This laser-based TON injury model is simple to implement, is reproducible, and is useful for determining the molecular and cellular pathophysiology of TON and RGC death and for testing neuroprotective therapeutics.


Assuntos
Traumatismos do Nervo Óptico , Células Ganglionares da Retina , Animais , Lasers , Camundongos , Tomografia de Coerência Óptica , Tonometria Ocular
18.
J Cataract Refract Surg ; 47(8): 1011-1018, 2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-34290197

RESUMO

PURPOSE: To compare the accuracy of the methods for calculation of intraocular lens (IOL) power in eyes with previous myopic laser refractive surgery. SETTING: EENT Hospital of Fudan University, Shanghai, China. DESIGN: Network meta-analysis. METHODS: A literature search of MEDLINE and Cochrane Library from January 2000 to July 2019 was conducted for studies that evaluated methods of calculating IOL power in eyes with previous myopic laser refractive surgery. Outcomes measurements were the percentages of prediction error within ±0.50 diopters (D) and ±1.00 D of the target refraction (% ±0.50 D and % ±1.00 D). Traditional and network meta-analysis were conducted. RESULTS: Nineteen prospective or retrospective clinical studies, including 1217 eyes and 13 calculation methods, were identified. A traditional meta-analysis showed that compared with the widely used Haigis-L method, the Barrett True-K formula, optical coherence tomography (OCT), and Masket methods showed significantly higher % ±0.50 D, whereas no difference was found in the % ±1.00 D. A network meta-analysis revealed that compared with the Haigis-L method, the OCT, Barrett True-K formula, and optiwave refractive analysis (ORA) methods performed better on the % ±0.50 D, whereas the Barrett True-K formula and ORA methods performed better on the % ±1.00 D. Based on the performances of both outcomes, the Barrett True-K formula, OCT, and ORA methods showed highest probability to rank the top 3 among the 13 methods. CONCLUSIONS: The Barrett True-K formula, OCT, and ORA methods seemed to offer greater accuracy than others in calculating the IOL power for postrefractive surgery eyes.


Assuntos
Lentes Intraoculares , Facoemulsificação , Procedimentos Cirúrgicos Refrativos , Teorema de Bayes , Biometria , China , Humanos , Lasers , Implante de Lente Intraocular , Metanálise em Rede , Óptica e Fotônica , Estudos Prospectivos , Refração Ocular , Estudos Retrospectivos
19.
Anal Chem ; 93(27): 9356-9363, 2021 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-34192871

RESUMO

As key characteristic molecules, several H2S-activated probes have been explored for colon cancer studies. However, a few ratiometric fluorescence (FL) probes with NIR-II emissions have been reported for the quantitative detection of H2S in colon cancer in vivo. Here, we developed an in situ H2S-activatable ratiometric nanoprobe with two NIR-II emission signals for the detection of H2S and intelligently lighting up colon cancer. The nanoprobe comprised a down conversion nanoparticle (DCNP), which emitted NIR-II FL at 1550 nm on irradiation with a 980 nm laser (F1550Em, 980Ex). Further, human serum albumin (HSA) was combined with Ag+ on the surface of DCNP to form a DCNP@HSA-Ag+ nanoprobe. In the presence of H2S, Ag2S quantum dots (QDs) were formed in coated HSA, which emitted FL at approximately 1050 nm on irradiation with an 808 nm laser (F1050Em, 808Ex) through an H2S-induced chemical reaction between H2S and Ag+; however, the FL signal of DCNP was stable at 1550 nm (F1550Em, 980Ex), generating a H2S concentration-dependent ratiometric F1050Em, 808Ex/F1550Em, 980Ex signal. The NIR-II ratiometric nanoprobe was successfully used for the accurate quantitative detection of H2S and the detection of the precise location of colon cancer through an endogenous H2S-induced in situ reduction reaction to form Ag2S QDs. Thus, these findings provide a new strategy for the specific detection of targeted molecules and diagnosis of disease based on the in situ-activatable NIR-II ratiometric FL nanoprobe.


Assuntos
Neoplasias do Colo , Nanopartículas , Pontos Quânticos , Fluorescência , Humanos , Lasers
20.
Int J Nanomedicine ; 16: 4289-4319, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34211272

RESUMO

Recent developments in three-dimensional (3D) printing technology offer immense potential in fabricating scaffolds and implants for various biomedical applications, especially for bone repair and regeneration. As the availability of autologous bone sources and commercial products is limited and surgical methods do not help in complete regeneration, it is necessary to develop alternative approaches for repairing large segmental bone defects. The 3D printing technology can effectively integrate different types of living cells within a 3D construct made up of conventional micro- or nanoscale biomaterials to create an artificial bone graft capable of regenerating the damaged tissues. This article reviews the developments and applications of 3D printing in bone tissue engineering and highlights the numerous conventional biomaterials and nanomaterials that have been used in the production of 3D-printed scaffolds. A comprehensive overview of the 3D printing methods such as stereolithography (SLA), selective laser sintering (SLS), fused deposition modeling (FDM), and ink-jet 3D printing, and their technical and clinical applications in bone repair and regeneration has been provided. The review is expected to be useful for readers to gain an insight into the state-of-the-art of 3D printing of bone substitutes and their translational perspectives.


Assuntos
Materiais Biocompatíveis/química , Substitutos Ósseos , Nanoestruturas/química , Impressão Tridimensional , Engenharia Tecidual/métodos , Ligas/química , Animais , Substitutos Ósseos/química , Osso e Ossos/fisiologia , Humanos , Lasers , Impressão Tridimensional/instrumentação , Regeneração , Estereolitografia , Titânio/química
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