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1.
J Clin Pediatr Dent ; 44(1): 41-46, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31995416

RESUMO

OBJECTIVE: To evaluate penetration of a flowable resin composite into fissures using three different application methods: (1) conventional, (2) heat, and (3) sonic vibration. STUDY DESIGN: Forty-five sound maxillary third molars were divided randomly into three groups (n=15 per group). The occlusal surfaces of the teeth were etched and flowable resin composites were applied into the fissure using the assigned application method. The crowns were sectioned and examined with an optical microscope to assess penetration. In addition, three-point flexural strength was analyzed. RESULTS: The sonic vibration group exhibited significantly greater penetration into the fissure compared with the other test groups (p<0.001). The heat group exhibited greater penetration into the fissure compared with the conventional group (p=0.003). However, three-point flexural strength was similar among all groups (p>0.05). CONCLUSIONS: Sonic vibration and heat increased penetration into fissures. Notably, sonic vibration exhibited the greatest penetration. We found that the application method did not influence the three-point flexural strength.


Assuntos
Temperatura Alta , Selantes de Fossas e Fissuras , Resinas Compostas , Dente Molar , Vibração
2.
Bioresour Technol ; 300: 122688, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31901780

RESUMO

The optimal operational parameters of a second generation magnetically induced membrane vibration (MMV) system were determined using the response surface methodology (RSM) combined with single-factor experiments. The membrane surfaces were characterized by scanning electron microscopy (SEM) and algae cell states by inverted microscopy. The effect of an intermittent vibration strategy on filtration performance and energy consumption was studied. The results showed that the responses could be fitted by RSM models. High membrane flux, low energy consumption, efficient fouling control and no damage to the microalgae could thus be realized. The filtration strategy tests suggested that an intermittent cycle time of 4 min with 50% vibration rate could be the best vibration strategy for harvesting the microalgae under investigation.


Assuntos
Microalgas , Filtração , Membranas Artificiais , Vibração
3.
Zhongguo Zhen Jiu ; 40(1): 17-20, 2020 Jan 12.
Artigo em Chinês | MEDLINE | ID: mdl-31930893

RESUMO

OBJECTIVE: To compare the therapeutic effect of thunder-fire moxibustion combined with vibration training and simple vibration training on low back pain of primary osteoporosis by Young's modulus of ultrasonic wave, and seek an objective evaluating method. METHODS: A total of 60 patients were randomized into an observation group and a control group, 30 cases in each one. The patients in the two groups were treated with vibration training using whole body vibration treatment bed. In the observation group, thunder-fire moxibustion was applied at Yaoyangguan (GV 3), Mingmen (GV 4), Ganshu (BL 18), Shenshu (BL 23) and Dachangshu (BL 25). The treatment was given once every other day, 3 times a week for 4 weeks. The visual analogue score (VAS), real-time shear wave elastography (RTSWE) and medical outcomes study 36-item short-form hearth survey (SF-36) were used to evaluate pain intensity, multifidus muscle tone (Young's modulus) and quality of life before treatment, after 4-week treatment and 1 month after treatment. RESULTS: Compared before treatment, the VAS scores, Young's modulus of multifidus muscle and 5 dimensions of SF-36 (physical condition, body pain, general health, social function and mental health) after 4-week treatment and 1 month after treatment were significantly improved in the two groups (all P<0.05), the physiological role in the observation group after 4-week treatment and 1 month after treatment were improved (both P<0.05). In the observation group, the VAS scores, Young's modulus of multifidus muscle and 3 dimensions of SF-36 (physiological role, body pain and general health) after 4-week treatment and 1 month after treatment were superior to the control group (all P<0.05). CONCLUSION: The therapeutic effect of thunder-fire moxibustion combined with vibration training is superior to simple vibration training in relieving low back pain intensity and multifidus muscle tone, and improving quality of life for primary osteoporosis. RTSWE technique can be an objective examination method to evaluate pain.


Assuntos
Dor Lombar , Moxibustão , Osteoporose , Pontos de Acupuntura , Humanos , Dor Lombar/etiologia , Dor Lombar/terapia , Osteoporose/complicações , Qualidade de Vida , Resultado do Tratamento , Vibração
4.
Insect Sci ; 27(1): 133-142, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29740981

RESUMO

Over 50 genera of bees release pollen from flower anthers using thoracic vibrations, a phenomenon known as buzz-pollination. The efficiency of this process is directly affected by the mechanical properties of the buzzes, namely the duration, amplitude, and frequency. Nonetheless, although the effects of the former two properties are well described, the role of buzz frequency on pollen release remains unclear. Furthermore, nearly all of the existing studies describing vibrational properties of natural buzz-pollination are limited to bumblebees (Bombus) and carpenter bees (Xylocopa) constraining our current understanding of this behavior and its evolution. Therefore, we attempted to minimize this shortcoming by testing whether flower anthers exhibit optimal frequency for pollen release and whether bees tune their buzzes to match these (optimal) frequencies. If true, certain frequencies will trigger more pollen release and lighter bees will reach buzz frequencies closer to this optimum to compensate their smaller buzz amplitudes. Two strategies were used to test these hypotheses: (i) the use of (artificial) vibrational playbacks in a broad range of buzz frequencies and amplitudes to assess pollen release by tomato plants (Solanum lycopersicum L.) and (ii) the recording of natural buzzes of Neotropical bees visiting tomato plants during pollination. The playback experiment indicates that although buzz frequency does affect pollen release, no optimal frequency exists for that. In addition, the recorded results of natural buzz-pollination reveal that buzz frequencies vary with bee genera and are not correlated with body size. Therefore, neither bees nor plants are tuned to optimal pollen release frequencies. Bee frequency of buzz-pollination is a likely consequence of the insect flight machinery adapted to reach higher accelerations, while flower plant response to buzz-pollination is the likely result of its pollen granular properties.


Assuntos
Abelhas/fisiologia , Lycopersicon esculentum/fisiologia , Polinização , Animais , Brasil , Pólen , Especificidade da Espécie , Vibração
5.
Vestn Otorinolaringol ; 84(5): 38-43, 2019.
Artigo em Russo | MEDLINE | ID: mdl-31793525

RESUMO

AIM: To evaluate the velocity of vocal fold movements by duplex Doppler scanning in adults during breathing, talking and phonation. METHODS: Twenty healthy volunteers (18 women and 2 men) without of voice problems were investigated with scanners Logic-7 or Aloka 1100 by the linear transducer 7-10 MHz. The thyroid cartilage was used as an acoustic window. The dependence between the vocal fold velocity and volume and pitch of the voice were estimated using Spearman correlation. RESULTS: The velocity of movements of the vocal folds during breathing was from 5 to 16 cm/s, during talking and phonation - from 9 to 110 cm/s. Coefficient of Spearman correlation between the voice pitch and the vocal fold velocity was +0.9±0.1 an average, between volume of the voice and the vocal fold velocity was - 0.7±0.1. CONCLUSION: Duplex Doppler ultrasound scanning of the larynx allows measuring the velocity of vocal fold's movements during breathing, conversation and phonation. The fold's velocity increases with increasing of the voice volume and decreases with increasing the voice pitch. Duplex Doppler ultrasound scanning may be useful for early detection of disorders of mobility of the vocal folds.


Assuntos
Prega Vocal , Adulto , Feminino , Humanos , Laringe , Masculino , Fonação , Vibração , Voz
6.
J Phys Chem Lett ; 10(24): 7878-7883, 2019 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-31794222

RESUMO

Local probes are indispensable to study protein structure and dynamics with site-specificity. The isonitrile functional group is a highly sensitive and H-bonding interaction-specific probe. Isonitriles exhibit large spectral shifts and transition dipole moment changes upon H-bonding while being weakly affected by solvent polarity. These unique properties allow a clear separation of distinct subpopulations of interacting species and an elucidation of their ultrafast dynamics with two-dimensional infrared (2D-IR) spectroscopy. Here, we apply 2D-IR to quantify the picosecond chemical exchange dynamics of solute-solvent complexes forming between isonitrile-derivatized alanine and fluorinated ethanol, where the degree of fluorination controls their H-bond-donating ability. We show that the molecules undergo faster exchange in the presence of more acidic H-bond donors, indicating that the exchange process is primarily dependent on the nature of solvent-solvent interactions. We foresee isonitrile as a highly promising probe for studying of H-bonds dynamics in the active site of enzymes.


Assuntos
Alanina/química , Técnicas Biossensoriais/métodos , Espectrofotometria Infravermelho/métodos , Simulação por Computador , Ligações de Hidrogênio , Cinética , Modelos Moleculares , Conformação Molecular , Transição de Fase , Solventes/química , Vibração
7.
Indian J Dent Res ; 30(5): 678-686, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31854356

RESUMO

Introduction: Osseointegration as formulated by Alberktson is crucial for implant survival and success. Osseointegration is a measure of implant stability. Measuring implant stability helps to arrive at decisions as to loading of an implant, allows protocol choice on a patient to patient basis and provides enhanced case documentation. The RFA technique provides with clinically relevant information about the state of the implant-bone interface at any stage after implant placement. Aim: Evaluation of primary and secondary stability between implants of two different systems by resonance frequency analysis device. Methodology: This study was conducted among 17 patients divided into two groups. Group 1 (n = 10) receiving 20 MIS seven implants and Group 2 (n = 7) received 20 Alphadent active implants. The primary implant stability was measured at the time of implant placement and secondary stability is measured at 3-4 months interval using RFA device OSSTELL ISQ. Statistical analysis was performed using paired t test for intra group and independent sample test for intergroup comparisons. Results: No statistically significant differences in primary and secondary stabilities were found between the implant systems at either time intervals (P > 0.05). A positive correlation was noticed between mesiodistal stability and implant diameter in MIS seven group (P < 0.05). A positive correlation was noticed between mesiodistal, labiolingual stabilities and implant diameter in Alphadent group (P = 0.03). A positive correlation was noticed between mesiodistal, labiolingual stabilities and implant length in Alphadent group (P = 0.03). Conclusion: From the present data, it can be concluded that within the limitations of study, implant systems used and their design features showed no significant correlation to implant stability between the groups. More studies are required to assess the effect of implant designs and surface conditions on implant stability on a long-term basis.


Assuntos
Implantes Dentários , Retenção em Prótese Dentária , Implantação Dentária Endo-Óssea , Planejamento de Prótese Dentária , Humanos , Osseointegração , Vibração
8.
J Environ Pathol Toxicol Oncol ; 38(3): 271-283, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31679313

RESUMO

Certain mechanical stimuli-particularly low-magnitude, high-frequency vibration-could induce bone marrow stem cell osteogenic differentiation and promote bone formation via Wnt signaling pathway, although the molecular mechanism is still unclear. In this study, we found that miR-335-5p is significantly upregulated after low-magnitude, high-frequency vibration, which suppresses the expression of the Wnt signaling inhibitor Dickkopf-related protein 1. Inhibition of miR-335-5p greatly reduced the osteogenic differentiation. Furthermore, the increase of miR-335-5p level was also confirmed in vivo after LMHF vibration in rabbit. Our study elucidates the prominent role of miRNAs that links the LMHF vibration and osteogenic differentiation.


Assuntos
Expressão Gênica , Células-Tronco Mesenquimais/metabolismo , MicroRNAs/genética , Osteogênese/fisiologia , Vibração/efeitos adversos , Animais , Diferenciação Celular/fisiologia , Masculino , MicroRNAs/metabolismo , Coelhos
9.
J Phys Chem Lett ; 10(24): 7817-7822, 2019 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-31682445

RESUMO

We present the spectrum of the S1 ← S0 transition of an anionic model for the chromophore of the green fluorescent protein in vacuo at cryogenic temperatures, showing previously unresolved vibrational features, and resolving the band origin at 20 930 cm-1 (477.8 nm) with unprecedented accuracy. The vibrational spectrum establishes that the molecule is in the Z isomer at low temperature. At increased temperature, the S1 ← S0 band shifts to the red, which we tentatively attribute to emergent population of the E isomer.


Assuntos
Compostos de Benzilideno/química , Corantes Fluorescentes/química , Proteínas de Fluorescência Verde/química , Imidazóis/química , Modelos Moleculares , Temperatura Baixa , Íons/química , Isomerismo , Nitrogênio/química , Processos Fotoquímicos , Conformação Proteica , Solventes/química , Espectrometria de Fluorescência/métodos , Termodinâmica , Vibração
10.
Chem Commun (Camb) ; 56(1): 58-61, 2019 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-31690925

RESUMO

Herein, as a proof of concept, we developed the first enzymatic VIE fluorogenic probe for protein tyrosine phosphatase 1B (PTP1B). The detection and imaging of PTP1B using VIE in living cells were both realized. Particularly importantly, the designed probe herein provides a guideline and platform for the development of new VIE-based enzymatic probes.


Assuntos
Corantes Fluorescentes/química , Organofosfatos/química , Fenazinas/química , Proteína Tirosina Fosfatase não Receptora Tipo 1/análise , Linhagem Celular Tumoral , Ensaios Enzimáticos/métodos , Corantes Fluorescentes/síntese química , Humanos , Microscopia Confocal/métodos , Microscopia de Fluorescência/métodos , Organofosfatos/síntese química , Fenazinas/síntese química , Estudo de Prova de Conceito , Vibração
11.
Clin Implant Dent Relat Res ; 21(6): 1124-1131, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31715656

RESUMO

Adequate implant stability is an essential requirement. The introduction of the Penguin resonance frequency analysis raises some questions regarding its reliability, reproducibility, and repeatability as well as how it compares to the older Osstell device. PURPOSE: To assess the newer Penguin implant stability coefficient (ISQ) device (vs the Osstell device). MATERIALS AND METHODS: A total of 120 implants were used, divided into four groups (A, B, C, and D) (according to design) and placed in fresh bovine bone. Consecutive measurements were made with both devices (Penguin/Osstell) with their respective transducers. Then, the ISQ values were measured with the Penguin device using the Osstell transducer, and vice-versa. RESULTS: The mean insertion torque (N/cm) values for the implants were as follows: Group A = 24.7 ± 9.4; Group B = 25.6 ± 9.7; Group C = 28.7 ± 7.9; Group D = 19.1 ± 5.5. The mean ISQ values for the entire sample were as follows: Penguin 67.7 ± 6.1 and Osstell 68.5 ± 9.6. The ISQ value measured with the Penguin device using a SmartPeg transducer was 67.0 ± 8.0, and that for the Osstell device using a MultiPeg transducer was 68.3 ± 7.5. The intraclass correlation coefficient (ICC) was calculated for the ISQ values obtained from both devices and was >0.90 for all transducers. When the ICC transducers were interchanged, the values were <0.77. CONCLUSIONS: Both ISQ devices allow for reliable and repeatable measurement of implant stability; however, the use of each device-specific transducer is recommended.


Assuntos
Implantes Dentários , Retenção em Prótese Dentária , Animais , Transplante Ósseo , Bovinos , Reprodutibilidade dos Testes , Análise de Frequência de Ressonância , Vibração
12.
Klin Padiatr ; 231(6): 304-312, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31724139

RESUMO

BACKGROUND: Physiotherapy, including vibration-assisted therapy, has been proven to be effective for patients with ataxic cerebral palsy. Herewith, we studied the effect of a functional, goal-oriented interval rehabilitation program, including vibration-assisted home-training on the motor function of children with congenital ataxias. PATIENTS: 45 children (mean age 7.7 years, SD 4.70) with ataxia, having received a 6-month home-based side-alternating vibration-assisted therapy combined with intensive, goal-oriented, functional rehabilitation intervals, were included in the study, classified according to the progressive or non-progressive ataxia character. METHOD: Retrospective analysis of the prospectively collected data of the registry of the Cologne rehabilitation program "Auf die Beine". Motor abilities have been assessed prior to the intervention (M0), after 6 months of home-training (M6) as well as in a follow-up 6 months later (M12). We performed a gait analysis, a 1-minute walking test (1-MWT), and the Gross Motor Function Measure (GMFM-66). RESULTS: The GMFM-66 improvement (M6-M0 vs. M12-M6) was statistically significant with median improvement of 2.4 points (non-progressive) and 2.9 points (progressive) respectively, and clinically relevant. The 1-MWT improvement was statistically significant and clinically relevant for non-progressive ataxia. CONCLUSION: The intensive training, including vibration-assisted therapy significantly improved the motor function of children with ataxia. Six months later the skills were preserved in children with progressive ataxia and could be further developed in non-progressive forms.


Assuntos
Ataxia/reabilitação , Paralisia Cerebral/reabilitação , Modalidades de Fisioterapia , Vibração/uso terapêutico , Criança , Feminino , Humanos , Masculino , Destreza Motora , Estudos Retrospectivos , Resultado do Tratamento
13.
J Chem Phys ; 151(14): 144101, 2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31615220

RESUMO

Phycobiliprotein is a light-harvesting complex containing linear tetrapyrrole bilin pigments that are responsible for absorption and funneling the sun's energy in cryptophytes algae. In particular, the protein structure determines relative positions and orientations of the pigments and thus controls energy transfer pathways. The present research reveals the impact of molecular vibrations (in the 850-2700 cm-1 region) on excitation energy transfer in phycobiliprotein. The analysis of the excitation energy transfer pathways indicates a possibility of the coherent mechanism of energy transfer (delocalization) in central dihydrobiliverdin pigments and incoherent vibration-assisted energy transfer to peripheral phycocyanobilin pigments at a sub-picosecond time scale. A computational approach that enables modeling the dynamics of the excitation energy transfer with the quantum master equation formalism employing Huang-Rhys factors to describe electronic-vibrational coupling has been developed. The computational methodology has been implemented in PyFREC software.


Assuntos
Transferência de Energia , Ficocianina/química , Biliverdina/análogos & derivados , Biliverdina/química , Criptófitas/química , Modelos Químicos , Ficobilinas/química , Teoria Quântica , Software , Vibração
14.
Nature ; 574(7779): 491-492, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31645716
15.
Pharm Res ; 36(12): 173, 2019 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-31659476

RESUMO

PURPOSE: In the present study the influence and application of a newly developed external lower punch vibration system for an improved die filling on a running rotary tablet press was investigated. METHODS: Tablets were manufactured at different conditions (with and without vibration) and characterized regarding their direct compressibility and mechanical stability. Thus, two typical pharmaceutical binders for direct compression (Parmcel 102 and Tablettose® 80) were compared with two binders unsuitable for direct compression (Ceolus® KG1000 and GranuLac® 200). The powders were characterized by helium pycnometry, laser diffraction, scanning electron microscopy, and by determination of the powder flow. Furthermore, a novel technique to determine the occurrences of segregation within a tablet after manufacturing was introduced. For this purpose, a powder blend containing one spray-colored type of microcrystalline cellulose (Vivapur® 200) were prepared. RESULTS: It was shown that under application of externally applied lower punch vibration, the powder flow into the die increased and thus the die filling process was significantly improved. Hence, it was possible to manufacture tablets from powders, which are actually unsuitable for direct compression. In addition, the mechanical stability of the produced tablets was distinctly improved by application of lower punch vibration, whereby the occurrence of segregation was comparatively low. CONCLUSION: In summary, lower punch vibration allows a more efficient die filling, whereby the powder flow as well as mechanical stability of the tablets are improved.


Assuntos
Celulose/química , Excipientes/química , Comprimidos/química , Composição de Medicamentos/métodos , Estabilidade de Medicamentos , Fenômenos Mecânicos , Pós/química , Vibração
16.
Nat Commun ; 10(1): 4764, 2019 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-31628307

RESUMO

Water is arguably the most common and yet least understood material on Earth. Indeed, the biophysical behavior of water in crowded intracellular milieu is a long-debated issue. Understanding of the spatial and compositional heterogeneity of water inside cells remains elusive, largely due to a lack of proper water-sensing tools with high sensitivity and spatial resolution. Recently, stimulated Raman excited fluorescence (SREF) microscopy was reported as the most sensitive vibrational imaging in the optical far field. Herein we develop SREF into a water-sensing tool by coupling it with vibrational solvatochromism. This technique allows us to directly visualize spatially-resolved distribution of water states inside single mammalian cells. Qualitatively, our result supports the concept of biological water and reveals intracellular water heterogeneity between nucleus and cytoplasm. Quantitatively, we unveil a compositional map of the water pool inside living cells. Hence we hope SREF will be a promising tool to study intracellular water and its relationship with cellular activities.


Assuntos
Microscopia de Fluorescência/métodos , Microscopia Óptica não Linear/métodos , Análise de Célula Única/métodos , Água/metabolismo , Núcleo Celular/química , Núcleo Celular/metabolismo , Fenômenos Fisiológicos Celulares , Cor , Citoplasma/química , Citoplasma/metabolismo , Células HeLa , Humanos , Espaço Intracelular/química , Espaço Intracelular/metabolismo , Reprodutibilidade dos Testes , Solventes/química , Vibração , Água/química
17.
Int J Occup Environ Med ; 10(4): 174-184, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31586382

RESUMO

BACKGROUND: Whole-body vibration (WBV) and mental workload (MWL) are common stressors among drivers who attempt to control numerous variables while driving a car, bus, or train. OBJECTIVE: To examine the individual and combined effects of the WBV and MWL on the autonomic nervous system. METHODS: ECG of 24 healthy male students was recorded using NeXus-4 while performing two difficulty levels of a computerized dual task and when they were exposing to WBV (intensity 0.5 m/s2; frequency 3-20 Hz). Each condition was examined for 5 min individually and combined. Inter-beat intervals were extracted from ECG records. The time-domain and frequency-domain heart rate variability parameters were then extracted from the inter-beat intervals data. RESULTS: A significant (p=0.008) increase was observed in the mean RR interval while the participants were exposed to WBV; there was a significant (p=0.02) reduction in the mean RR interval while the participants were performing the MWL. WBV (p=0.02) and MWL significantly (p<0.001) increased the standard deviation of normal-to-normal intervals with a moderate-to-large effect size. All active periods increased the low-frequency component and low-frequency/high-frequency ratio. However, only the WBV significantly increased the highfrequency component. A significant (p=0.01) interaction was observed between the WBV and MWL on low-frequency component and low-frequency/high-frequency ratio. CONCLUSION: Exposure to WBV and MWL can dysregulate the autonomic nervous system. WBV stimulates both sympathetic and parasympathetic nervous system; MWL largely affects sympathetic nervous system. Both variables imbalance the sympatho-vagal control as well.


Assuntos
Condução de Veículo , Sistema Nervoso Autônomo/fisiologia , Processos Mentais/fisiologia , Vibração , Carga de Trabalho , Adulto , Condução de Veículo/psicologia , Condução de Veículo/estatística & dados numéricos , Frequência Cardíaca/fisiologia , Humanos , Masculino , Ruído Ocupacional/efeitos adversos , Ruído Ocupacional/estatística & dados numéricos , Ruído dos Transportes/efeitos adversos , Ruído dos Transportes/estatística & dados numéricos , Exposição Ocupacional/estatística & dados numéricos , Projetos Piloto , Estudantes , Carga de Trabalho/psicologia , Carga de Trabalho/estatística & dados numéricos , Adulto Jovem
18.
Inorg Chem ; 58(20): 13933-13944, 2019 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-31566371

RESUMO

Density functional vibrational frequency calculations have been performed on eight geometry optimized cytochrome c oxidase (CcO) dinuclear center (DNC) reaction cycle intermediates and on the oxymyoglobin (oxyMb) active site. The calculated Fe-O and O-O stretching modes and their frequency shifts along the reaction cycle have been compared with the available resonance Raman (rR) measurements. The calculations support the proposal that in state A[Fea33+-O2-•···CuB+] of CcO, O2 binds with Fea32+ in a similar bent end-on geometry to that in oxyMb. The calculations show that the observed 20 cm-1 shift of the Fea3-O stretching mode from the PR to F state is caused by the protonation of the OH- ligand on CuB2+ (PR[Fea34+═O2-···HO--CuB2+] → F[Fea34+═O2-···H2O-CuB2+]), and that the H2O ligand is still on the CuB2+ site in the rR identified F[Fea34+═O2-···H2O-CuB2+] state. Further, the observed rR band at 356 cm-1 between states PR and F is likely an O-Fea3-porphyrin bending mode. The observed 450 cm-1 low Fea3-O frequency mode for the OH active oxidized state has been reproduced by our calculations on a nearly symmetrically bridged Fea33+-OH-CuB2+ structure with a relatively long Fea3-O distance near 2 Å. Based on Badger's rule, the calculated Fea3-O distances correlate well with the calculated νFe-O-2/3 (νFe-O is the Fea3-O stretching frequency) with correlation coefficient R = 0.973.


Assuntos
Teoria da Densidade Funcional , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Ferro/química , Oxigênio/química , Biocatálise , Domínio Catalítico , Cristalografia por Raios X , Complexo IV da Cadeia de Transporte de Elétrons/química , Ferro/metabolismo , Ligantes , Modelos Moleculares , Oxigênio/metabolismo , Vibração
19.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 36(5): 769-776, 2019 Oct 25.
Artigo em Chinês | MEDLINE | ID: mdl-31631625

RESUMO

The purpose of this study is to reveal the protective effect of rib cage on scoliotic spine by comparing the different effect of rib cage on the stability of normal spine and Lenke1 scoliotic spine. Firstly, according to X-ray computed tomography (CT) image data, four spinal finite element models (SFEMs), including normal spine without rib cage (N1), normal spine with normal rib cage (N2), scoliotic spine without rib cage (S1) and scoliotic spine with deformed rib cage (S2), from the first thoracic vertebrae to the sacral vertebrae (T1~S) were established. Secondly, the natural vibration characteristics of the four SFEMs were obtained by modal analysis. Finally, the maximum vibration amplitudes of the four SFEMs under external excitation were obtained by steady-state analysis. As shown in results, compared with N1, the maximum deformation of N2 segment T4~T6 in the X -axis (coronal axis), Y -axis (sagittal axis) and Z -axis (vertical axis) directions decreases by 38.44%, 53.80% and 33.72%, respectively. Compared with S1, the maximum deformation of S2 segment T4~T6 in the X -axis direction, Y -axis direction and Z -axis directions decreases by 44.26%, increases by 32.80% and decreases by 49.23%, respectively. As it can be seen, for normal spine, the rib cage can improve the stability of the whole spine in three directions; for the Lenke1 scoliotic spine, the rib cage can reduce the vibration of the scoliotic spine in the X -axis and Z -axis directions and improves the stability of the whole spine in the two directions, while in the Y -axis direction, for the serious severe anteversion of scoliotic spine, the deformed rib cage exacerbates the vibration of the scoliotic spine in this direction and destroys the stability of the scoliotic spine in the Y -axis direction. This study reveals the biomechanical characteristics of rib caged influence on the stability of the scoliotic spine and it has guiding significance for the study of daily protection methods and protective tools for scoliotic patients.


Assuntos
Caixa Torácica , Escoliose/fisiopatologia , Coluna Vertebral , Fenômenos Biomecânicos , Análise de Elementos Finitos , Humanos , Vértebras Torácicas , Tomografia Computadorizada por Raios X , Vibração
20.
Acta Cir Bras ; 34(7): e201900702, 2019 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-31531537

RESUMO

PURPOSE: To investigate the effect of intermittent vibration at different intervals on bone fracture healing and optimize the vibration interval. METHODS: Ninety sheep were randomized to receive no treatment (the control group), incision only (the sham control group), internal fixation with or without metatarsal fracture (the internal fixation group), and continuous vibration in addition to internal fixation of metatarsal fracture, or intermittent vibration at 1, 2, 3, 5, 7 and 17-day interval in addition to internal fixation of metatarsal fracture (the vibration group). Vibration was done at frequency F=35 Hz, acceleration a=0.25g, 15 min each time 2 weeks after bone fracture. Bone healing was evaluated by micro-CT scan, bone microstructure and mechanical compression of finite element simulation. RESULTS: Intermittent vibration at 7-day interval significantly improved bone fracture healing grade. However, no significant changes on microstructure parameters and mechanical properties were observed among sheep receiving vibration at different intervals. CONCLUSIONS: Clinical healing effects should be the top concern. Quantitative analyses of bone microstructure and of finite element mechanics on the process of fracture healing need to be further investigated.


Assuntos
Consolidação da Fratura/fisiologia , Fraturas Ósseas/diagnóstico por imagem , Ossos do Metatarso/lesões , Vibração/uso terapêutico , Animais , Análise de Elementos Finitos , Fixação Interna de Fraturas/instrumentação , Fixação Interna de Fraturas/normas , Fraturas Ósseas/cirurgia , Fraturas Ósseas/terapia , Ossos do Metatarso/diagnóstico por imagem , Ossos do Metatarso/cirurgia , Distribuição Aleatória , Ovinos , Microtomografia por Raio-X
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