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1.
Phys Rev Lett ; 131(2): 020601, 2023 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-37505962

RESUMO

We present a new method for coherent control of trapped ion qubits in separate interaction regions of a multizone trap by simultaneously applying an electric field and a spin-dependent gradient. Both the phase and amplitude of the effective single-qubit rotation depend on the electric field, which can be localized to each zone. We demonstrate this interaction on a single ion using both laser-based and magnetic-field gradients in a surface-electrode ion trap, and measure the localization of the electric field.

2.
Phys Rev Lett ; 128(8): 080503, 2022 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-35275689

RESUMO

We propose and implement a novel scheme for dissipatively pumping two qubits into a singlet Bell state. The method relies on a process of collective optical pumping to an excited level, to which all states apart from the singlet are coupled. We apply the method to deterministically entangle two trapped ^{40}Ca^{+} ions. Within 16 pumping cycles, an initially separable state is transformed into one with 83(1)% singlet fidelity, and states with initial fidelity of ⪆70% converge onto a fidelity of 93(1)%. We theoretically analyze the performance and error susceptibility of the scheme and find it to be insensitive to a large class of experimentally relevant noise sources.

3.
Kathmandu Univ Med J (KUMJ) ; 19(75): 399-401, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-36254434

RESUMO

End Stage Renal Disease is a last stage of Chronic Kidney Disease which is characterized by Glomerular Filtration rate of less than 15 ml/min/1.73 m2 . Hemodialysis is the most commonly used modality for treatment of Chronic Kidney disease. Among the access for hemodialysis arteriovenous fistula is the most common modality. However most common problems of fistula are significant stenosis of more than 50% which is characterized by limb swelling, pigmentation, tortuous veins, and difficulty maintaining flow during dialysis from AV fistula. These can be managed either by minimal intervention or with surgical intervention. Very few hospitals in Nepal and other countries have an angiographic suite to perform minimal intervention include angiogram with angioplasty. So in this case we try to address the use of C-Arm to perform angiogram or fistulogram and even angioplasty for the management of significant stenosis or complications of arteriovenous fistula.


Assuntos
Fístula Arteriovenosa , Derivação Arteriovenosa Cirúrgica , Insuficiência Renal Crônica , Angiografia , Angioplastia/métodos , Fístula Arteriovenosa/diagnóstico por imagem , Fístula Arteriovenosa/cirurgia , Derivação Arteriovenosa Cirúrgica/efeitos adversos , Constrição Patológica , Hospitais Universitários , Humanos , Nepal , Diálise Renal , Resultado do Tratamento
4.
Phys Rev Lett ; 120(18): 180401, 2018 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-29775358

RESUMO

We use a single trapped-ion qutrit to demonstrate the quantum-state-independent violation of noncontextuality inequalities using a sequence of randomly chosen quantum nondemolition projective measurements. We concatenate 53×10^{6} sequential measurements of 13 observables, and unambiguously violate an optimal noncontextual bound. We use the same data set to characterize imperfections including signaling and repeatability of the measurements. The experimental sequence was generated in real time with a quantum random number generator integrated into our control system to select the subsequent observable with a latency below 50 µs, which can be used to constrain contextual hidden-variable models that might describe our results. The state-recycling experimental procedure is resilient to noise and independent of the qutrit state, substantiating the fact that the contextual nature of quantum physics is connected to measurements and not necessarily to designated states. The use of extended sequences of quantum nondemolition measurements finds applications in the fields of sensing and quantum information.

5.
Caries Res ; 46(6): 555-60, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22922508

RESUMO

The aim of this in vitro single blind study was to investigate the dose response of fluoride in milk on enamel demineralisation and remineralisation under pH cycling using transverse microradiography (TMR). Enamel slabs (n = 11) with caries-like lesions were exposed to milk containing 6 different fluoride concentrations (0, 0.25, 0.5, 1.0, 5.0 and 10.0 ppm F). On each of the 14 days of the cycling period the lesions were exposed to five 2-minute periods of cariogenic challenge (1.5 mM CaCl2, 0.9 mM KH2PO4 and 50 mM acetic acid at pH 5.0) and two 5-min periods in milk plus 10 min in a milk/saliva (1:3) slurry. The slabs were stored at 37°C in artificial saliva throughout the cycling period and demineralisation and remineralisation was assessed by TMR using dedicated image software. Remineralisation (ΔZ) was observed in all fluoride groups in contrast to demineralisation in the non-fluoride control. Remineralisation was significant (p < 0.05) for all concentrations above 1.0 ppm F. The results showed that fluoride concentration in milk exhibited a clear dose dependency and that the presence of fluoride even at low concentrations promoted remineralisation in this pH-cycling model.


Assuntos
Cariostáticos/administração & dosagem , Fluoretos/administração & dosagem , Leite/química , Desmineralização do Dente/tratamento farmacológico , Remineralização Dentária/métodos , Animais , Bovinos , Esmalte Dentário , Relação Dose-Resposta a Droga , Humanos , Microrradiografia/métodos , Método Simples-Cego
6.
Eur J Med Res ; 15(8): 345-50, 2010 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-20947471

RESUMO

PURPOSE: Volumetric assessment of the liver regularly yields discrepant results between pre- and intraoperatively determined volumes. Nevertheless, the main factor responsible for this discrepancy remains still unclear. The aim of this study was to systematically determine the difference between in vivo CT-volumetry and ex vivo volumetry in a pig animal model. MATERIAL AND METHODS: Eleven pigs were studied. Liver density assessment, CT-volumetry and water displacement volumetry was performed after surgical removal of the complete liver. Known possible errors of volume determination like resection or segmentation borders were eliminated in this model. Regression analysis was performed and differences between CT-volumetry and water displacement determined. RESULTS: Median liver density was 1.07g/ml. Regression analysis showed a high correlation of r(2) = 0.985 between CT-volumetry and water displacement. CT-volumetry was found to be 13% higher than water displacement volumetry (p<0.0001). CONCLUSION: In this study the only relevant factor leading to the difference between in vivo CT-volumetry and ex vivo water displacement volumetry seems to be blood perfusion of the liver. The systematic difference of 13 percent has to be taken in account when dealing with those measures.


Assuntos
Fígado/anatomia & histologia , Fígado/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Animais , Tamanho do Órgão , Análise de Regressão , Suínos , Porco Miniatura
7.
Postgrad Med ; 132(3): 288-295, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32027205

RESUMO

OBJECTIVES: This study aimed to assess various types of safety lancets in terms of blood volume and pain perception during capillary blood sampling, a routine finger-puncture procedure for obtaining a small amount of human blood for running various screening and diagnostic tests. METHODS: Data were collected from 100 adult healthy volunteers following finger-puncture procedure. Four different types of safety lancets were tested (Acti-Lance, Prolance, Medlance Plus, and MediSafe Solo). Each type has its own versions, giving 16 different safety lancets in total. RESULTS: A significant difference in the mean capillary blood volume was found between blade and needle equipped safety lancets. MediSafe Solo type lancet had no blade version, and hence its use was associated with the lowest mean collected capillary blood volume (42.4 µL). Acti-Lance and Medlance Plus type lancets had one blade version and the mean collected capillary blood volume was 82.2 and 99.0 µL, respectively. Prolance type lancet had two blade versions, and its use was associated with the highest mean capillary blood volume (118.3 µL). The level of pain intensity was evaluated as low by the majority of patients for all lancets. Medlance Plus was the least painful and Acti-Lance was the most painful type of safety lancet. On a 0-to-10 scale of pain, 75% of punctures were assessed by the participants at a level not exceeding 3 points. CONCLUSIONS: This study suggests that although all investigated safety lancets achieve adequate performance regarding the necessary capillary blood volume to run a diagnostic of test, lancets equipped with blades differ significantly from those equipped with needles in terms of the mean obtained capillary blood volume. Further, although all devices produced relatively low levels of pain, the amount of pain caused by blade versions of safety lancets has been found to be higher than that of needle versions. CLINICALTRIALS.GOV ID: NCT04001348. (https://clinicaltrials.gov/ct2/show/NCT04001348?term=NCT04001348&draw=2&rank=1).


Assuntos
Coleta de Amostras Sanguíneas/efeitos adversos , Coleta de Amostras Sanguíneas/instrumentação , Hemorragia/patologia , Percepção da Dor , Adolescente , Adulto , Idoso , Dedos , Humanos , Pessoa de Meia-Idade , Agulhas , Estudos Prospectivos , Método Simples-Cego , Adulto Jovem
8.
Sci Rep ; 10(1): 17165, 2020 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-33051504

RESUMO

The community composition of betaproteobacterial ammonia-oxidizing bacteria (ß-AOB) in the River Elbe Estuary was investigated by high throughput sequencing of ammonia monooxygenase subunit A gene (amoA) amplicons. In the course of the seasons surface sediment samples from seven sites along the longitudinal profile of the upper Estuary of the Elbe were investigated. We observed striking shifts of the ß-AOB community composition according to space and time. Members of the Nitrosomonas oligotropha-lineage and the genus Nitrosospira were found to be the dominant ß-AOB within the river transect, investigated. However, continuous shifts of balance between members of both lineages along the longitudinal profile were determined. A noticeable feature was a substantial increase of proportion of Nitrosospira-like sequences in autumn and of sequences affiliated with the Nitrosomonas marina-lineage at downstream sites in spring and summer. Slightly raised relative abundances of sequences affiliated with the Nitrosomonas europaea/Nitrosomonas mobilis-lineage and the Nitrosomonas communis-lineage were found at sampling sites located in the port of Hamburg. Comparisons between environmental parameters and AOB-lineage (ecotype) composition revealed promising clues that processes happening in the fluvial to marine transition zone of the Elbe estuary are reflected by shifts in the relative proportion of ammonia monooxygenase sequence abundance, and hence, we propose ß-AOB as appropriate indicators for environmental dynamics and the ecological condition of the Elbe Estuary.


Assuntos
Amônia/metabolismo , Nitrosomonas/genética , Nitrosomonas/metabolismo , Rios/microbiologia , Betaproteobacteria/genética , Betaproteobacteria/metabolismo , DNA Bacteriano/genética , Genes Bacterianos/genética , Sedimentos Geológicos/microbiologia , Oxirredução , Filogenia
9.
Langenbecks Arch Surg ; 394(6): 1047-56, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19533168

RESUMO

PURPOSE: Postoperative liver failure (PLF) is a relatively frequent and life-threatening complication after extended liver resection. This study describes the economic burden of PLF from the hospitals' perspective and explores the role of liver function capacity. MATERIALS AND METHODS: Economic data of total costs and cost distribution were analyzed for 48 patients who had participated in a prospective study with the LiMAx test, a novel test for liver function capacity. For this population, detailed individual data were available. The economic data were analyzed and adjusted for relevant covariates. In addition, economic data of 916 patients who had undergone liver resection during 2005-2007 were retrieved from the hospitals' medical controlling office for comparison. RESULTS: A significant difference between the costs of patients with regular recovery (25,980 Euro [95% confidence interval (95%CI) = 9,559 to 42,401]) versus patients developing PLF (82,199 Euro [95%CI = 42,812 to 121,586]; p = 0.013) was observed. The mean additional costs of PLF were 56,219 Euro. An equivalent cost difference of mortality was obtained from the analysis of 916 patients. Patients developing PLF had a decreased LiMAx of 61 microg/kg/h compared to the regular group 122 microg/kg/h (p < 0.001) after surgery. Initial postoperative LiMAx and total costs revealed a linear correlation coefficient of r = -0.340 (p = 0.018). CONCLUSIONS: PLF is a very relevant medical and economic problem. Liver function capacity does not only predict PLF but also correlates with total costs in general.


Assuntos
Custos de Cuidados de Saúde , Hepatectomia/efeitos adversos , Falência Hepática/economia , Falência Hepática/etiologia , Adulto , Idoso , Estudos de Coortes , Feminino , Humanos , Falência Hepática/diagnóstico , Testes de Função Hepática , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Recuperação de Função Fisiológica , Estudos Retrospectivos , Resultado do Tratamento
10.
J Phys Condens Matter ; 21(3): 035113, 2009 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-21817271

RESUMO

A competition between two anti-Stokes emissions has been observed and interpreted in ZBLAN glass activated by Ho(3+) ions. The first anti-Stokes emission intensity was seen to increase with temperature, whereas another, upconverted emission, was seen to decrease under the same conditions. Both observed tendencies are believed to be caused by the same effect: the multiphonon anti-Stokes excitation of the state responsible for the first emission. Analysis of the kinetics and fits of the theoretical model to experimental data are presented.

11.
Biomech Model Mechanobiol ; 18(5): 1351-1361, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30980211

RESUMO

The tricuspid leaflets coapt during systole to facilitate proper valve function and, thus, ensure efficient transport of deoxygenated blood to the lungs. Between their open state and closed state, the leaflets undergo large deformations. Quantification of these deformations is important for our basic scientific understanding of tricuspid valve function and for diagnostic or prognostic purposes. To date, tricuspid valve leaflet strains have never been directly quantified in vivo. To fill this gap in our knowledge, we implanted four sonomicrometry crystals per tricuspid leaflet and six crystals along the tricuspid annulus in a total of five sheep. In the beating ovine hearts, we recorded crystal coordinates alongside hemodynamic data. Once recorded, we used a finite strain kinematic framework to compute the temporal evolutions of area strain, radial strain, and circumferential strain for each leaflet. We found that leaflet strains were larger in the anterior leaflet than the posterior and septal leaflets. Additionally, we found that radial strains were larger than circumferential strains. Area strains were as large as 97% in the anterior leaflet, 31% in the posterior leaflet, and 31% in the septal leaflet. These data suggest that tricuspid valve leaflet strains are significantly larger than those in the mitral valve. Should our findings be confirmed they could suggest either that the mechanobiological equilibrium of tricuspid valve resident cells is different than that of mitral valve resident cells or that the mechanotransductive apparatus between the two varies. Either phenomenon may have important implications for the development of tricuspid valve-specific surgical techniques and medical devices.


Assuntos
Coração/fisiopatologia , Contração Miocárdica/fisiologia , Valva Tricúspide/fisiopatologia , Animais , Fenômenos Biomecânicos , Hemodinâmica , Ovinos , Estresse Mecânico , Sístole/fisiologia , Fatores de Tempo
12.
Pol J Vet Sci ; 11(2): 97-104, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18683537

RESUMO

UNLABELLED: The genus Rhodiola (Crassulaceae) consists of more than 100 species. They grow mainly in Tibet, China and Mongolia and are traditionally used as tonic, adaptogen, antidepressant and anti-inflammatory drugs. The best known is Rhodiola rosea (R. rosea) now cultivated also in Europe and North America, and present on the market as dietary supplement. Some authors reported anti-tumor activity of R. rosea extracts. Recently, we have published some data on immunomodulatory and antiangiogenic properties of R. rosea. Rhodiola quadrifida (R. quadrifida) belongs to the same family, but is almost not known in Europe, and there is no information about its possible anti-tumor as well as immunotropic and angiotropic activity. The aim of this study was to determine the influence of 50% hydro-alcoholic extract from rhizomes of R. quadrifida (Mongolian origin) and its main biologically active compound salidroside on tumor-induced angiogenesis. Angiogenesis was induced in the skin of Balb/c mice by grafting of syngeneic L-1 sarcoma cells. Mice were fed R. quadrifida extract or salidroside in daily doses 40, 200 and 400 microg, or 0.5, 1, 2, and 4 microg, respectively. After 72 hours, mice were sacrificed with lethal dose of Morbital. All newly formed blood vessels were identified and counted in dissection microscope. RESULTS: It was found that R. quadrifida extract and salidroside highly significantly decreased neovascular reaction in all doses applied.


Assuntos
Glucosídeos/uso terapêutico , Neovascularização Patológica/veterinária , Fenóis/uso terapêutico , Fitoterapia/veterinária , Extratos Vegetais/uso terapêutico , Rhodiola/química , Neoplasias Cutâneas/veterinária , Animais , Relação Dose-Resposta a Droga , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Neovascularização Patológica/tratamento farmacológico , Neovascularização Patológica/patologia , Fitoterapia/métodos , Distribuição Aleatória , Neoplasias Cutâneas/tratamento farmacológico , Neoplasias Cutâneas/patologia
13.
Pol J Vet Sci ; 11(2): 105-11, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18683538

RESUMO

Rhodiola quadrifida (Rq) roots and rhizomes are traditionally used in Asia as a tonic, adaptogen, antidepressant and anti-inflammatory drug. The aim of this work was to study the in vivo effect of aqueous and 50% hydro-alcoholic extracts of Rq rhizomes on some parameters of cellular immunity in mice and rats. The metabolic activity of blood phagocyting cells was determined based on the measurement of intracellular respiratory burst after stimulation by PMA in RBA test. Potential bactericidal activity of phagocyting cells was determined in isolated blood leukocytes stimulated with killed microorganisms, according to the PKA test. Proliferative response of lymphocytes stimulated by mitogen concanavaline A (ConA) or lipopolysaccharide (LPS) were determined by MTT assay. Both extracts stimulated granulocytes activity in vitro and increased lymphocyte response to mitogens. The ability of parental strain mice lymphocytes to induce local cutaneous graft-versus-host reaction (GVH) in F1 hybrids was stimulated by 50% hydro-alcoholic extract only.


Assuntos
Doença Enxerto-Hospedeiro/imunologia , Imunidade Celular/efeitos dos fármacos , Fagocitose/efeitos dos fármacos , Extratos Vegetais/farmacologia , Rhodiola/química , Animais , Concanavalina A/toxicidade , Citotoxicidade Imunológica , Relação Dose-Resposta a Droga , Feminino , Reação Enxerto-Hospedeiro , Lipopolissacarídeos , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos DBA , Raízes de Plantas/química , Distribuição Aleatória , Ratos , Ratos Endogâmicos Lew , Explosão Respiratória
14.
J Dent ; 70: 87-91, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29292066

RESUMO

OBJECTIVES: To evaluate the effect on enamel of varying the frequency of consumption of 1.0 mg F in milk once per day, twice per day or once every other day under cariogenic challenge in situ. MATERIALS AND METHODS: In a controlled, randomised, cross-over, single-blind study, 25 subjects wore an intra-oral lower removable appliance with enamel slabs for 21 days during each study arm. Subjects used F-free toothpaste, the cariogenic challenge comprising of five 2 min dippings per day in a 12% sucrose solution. Subjects dipped the appliances in 50 ml of 5.0 ppm fluoridated milk for five minutes during the test period once per day, twice per day, and once every other day and drank 200 ml of the same milk, once per day, twice per day (100 ml each time), or once every other day (200 ml) immediately on re-inserting their appliance in order to replicate topical and systemic effects. Slabs were analysed with surface microhardness (SMH) for protection against further demineralisation and transverse microradiography (TMR) to assess changes in mineralisation. RESULTS: Using SMH, 200 ml of 5.0 ppm F milk once per day was significantly better than 100 ml of 5.0 ppm F twice/day (p < 0.05) and 200 ml once every other day, but not significantly. Using TMR there was a statistically significant difference in mineral loss of enamel between baseline and treatment for all groups, but not between groups. CONCLUSIONS: Drinking 200 ml of 5.0 ppm milk once per day every day protected enamel against further demineralisation whereas all three frequencies were effective in promoting remineralisation.


Assuntos
Cariostáticos/uso terapêutico , Esmalte Dentário/efeitos dos fármacos , Fluoretos/uso terapêutico , Leite/química , Desmineralização do Dente/prevenção & controle , Administração Tópica , Animais , Cariogênicos/administração & dosagem , Cariogênicos/efeitos adversos , Cariostáticos/administração & dosagem , Estudos Cross-Over , Cárie Dentária , Esmalte Dentário/patologia , Relação Dose-Resposta a Droga , Feminino , Fluoretos/administração & dosagem , Dureza , Humanos , Masculino , Microrradiografia , Método Simples-Cego , Fluoreto de Sódio/administração & dosagem , Fluoreto de Sódio/uso terapêutico , Sacarose , Remineralização Dentária , Cremes Dentais
15.
BJS Open ; 2(5): 301-309, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30263981

RESUMO

BACKGROUND: Liver function tests may help to predict outcomes after liver surgery. The aim of this study was to evaluate the clinical impact on postoperative outcome and patient management of perioperative liver function testing using the LiMAx® test. METHODS: A multicentre RCT was conducted in six academic liver centres. Patients with intrahepatic tumours scheduled for open liver resection of at least one segment were eligible. Patients were randomized to undergo additional perioperative liver function tests (LiMAx® group) or standard care (control group). Patients in the intervention arm received two perioperative LiMAx® tests, one before the operation for surgical planning and another after surgery for postoperative management. The primary endpoint was the proportion of patients transferred directly to a general ward. Secondary endpoints were severe complications, length of hospital stay (LOS) and length of intermediate care/ICU (LOI) stay. RESULTS: Some 148 patients were randomized. Thirty-six of 58 patients (62 per cent) in the LiMAx® group were transferred directly to a general ward, compared with one of 60 (2 per cent) in the control group (P < 0·001). The rate of severe complications was significantly lower in the LiMAx® group (14 per cent versus 28 per cent in the control group; P = 0·022). LOS and LOI were significantly shorter in the LiMAx® group (LOS: 10·6 versus 13·3 days respectively, P = 0·012; LOI: 0·8 versus 3·0 days, P < 0·001). CONCLUSION: Perioperative use of the LiMAx® test improves postoperative management and reduces the incidence of severe complications after liver surgery. Registration number: NCT01785082 ( https://clinicaltrials.gov).

16.
Acta Biomater ; 71: 86-95, 2018 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-29462711

RESUMO

A radical new methodology for the exogenous mineralization of hard tissues is demonstrated in the context of laser-biomaterials interaction. The proposed approach is based on the use of femtosecond pulsed lasers (fs) and Fe3+-doped calcium phosphate minerals (specifically in this work fluorapatite powder containing Fe2O3 nanoparticles (NP)). A layer of the synthetic powder is applied to the surface of eroded bovine enamel and is irradiated with a fs laser (1040 nm wavelength, 1 GHz repetition rate, 150 fs pulse duration and 0.4 W average power). The Fe2O3 NPs absorb the light and may act as thermal antennae, dissipating energy to the vicinal mineral phase. Such a photothermal process triggers the sintering and densification of the surrounding calcium phosphate crystals thereby forming a new, dense layer of typically ∼20 µm in thickness, which is bonded to the underlying surface of the natural enamel. The dispersed iron oxide NPs, ensure the localization of temperature excursion, minimizing collateral thermal damage to the surrounding natural tissue during laser irradiation. Simulated brushing trials (pH cycle and mechanical force) on the synthetic layer show that the sintered material is more acid resistant than the natural mineral of enamel. Furthermore, nano-indentation confirms that the hardness and Young's modulus of the new layers are significantly more closely matched to enamel than current restorative materials used in clinical dentistry. Although the results presented herein are exemplified in the context of bovine enamel restoration, the methodology may be more widely applicable to human enamel and other hard-tissue regenerative engineering. STATEMENT OF SIGNIFICANCE: In this work we provide a new methodology for the mineralisation of dental hard tissues using femtosecond lasers and iron doped biomaterials. In particular, we demonstrate selective laser sintering of an iron doped fluorapatite on the surface of eroded enamel under low average power and mid-IR wavelength and the formation of a new layer to substitute the removed material. The new layer is evaluated through simulated brushing trials and nano-indentation. From the results we can conclude that is more acid resistant than natural enamel while, its mechanical properties are superior to that of current restorative materials. To the best of our knowledge this is the first time that someone demonstrated, laser sintering and bonding of calcium phosphate biomaterials on hard tissues. Although we here we discuss the case of dental enamel, similar approach can be adopted for other hard tissues, leading to new strategies for the fixation of bone/tooth defects.


Assuntos
Esmalte Dentário/química , Lasers , Nanopartículas de Magnetita/química , Animais , Bovinos
17.
Pharmazie ; 62(4): 308-11, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17484290

RESUMO

Column chromatography of hydrophilic extracts from Rhodiola rosea and Rodiola quadrifida led to the isolation of cinnamic alcohol, chlorogenic acid, rhodiooctanoside, rosiridin, rosavin and the phenolic compounds salidroside, rhodiolin and a novel compound consisting of viridoside with an attached arabinose unit (mongrhoside). HPLC analysis of plant material from different sources and from different collection periods showed a great variability in the composition and in the amount of pharmacologically active compounds contained.


Assuntos
Rhodiola/química , Sequência de Carboidratos , Cromatografia Líquida de Alta Pressão , Dimetil Sulfóxido , Espectroscopia de Ressonância Magnética , Dados de Sequência Molecular , Mongólia , Extratos Vegetais/análise , Solventes , Tibet
18.
J Dent ; 66: 37-44, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28859965

RESUMO

OBJECTIVES: To investigate in vitro the effect of MI Paste, MI Paste Plus and 2800ppm fluoride (F) toothpaste (TP) on the remineralisation of enamel subsurface lesions and to compare these to the effect of 1450ppm and 0ppm F toothpastes. METHODS: Enamel subsurface lesions were created in bovine enamel slabs (n=120) which were assigned randomly to five groups; (1) 0ppm F TP, (2) 1450ppm F TP, (3) 2800ppm F TP, (4) 1450ppm F TP+MI Paste (Tooth Mousse-TM,10% w/v CPP-ACP) and (5) 1450ppm F TP+MI Paste Plus (Tooth Mousse Plus,10% w/v CPP-ACP, 900ppm F as 0.2% w/w sodium fluoride). The enamel slabs were subjected to a pH cycling regimen for 21days. Quantitative Light-induced Fluorescence (QLF) images were taken and analysed. Data analysis was carried out using one way ANOVA. RESULTS: In all groups, both ΔF (percentage fluorescence loss) and ΔQ (ΔF times the area) values improved significantly within the same group after the treatment. In addition, the mean difference in ΔF of the non-fluoride control group was significantly lower than all other groups but not for the 2800ppm F- group. Whereas the mean difference in ΔQ of the non-fluoride control of group was significantly lower when compared with all other groups (p<0.05). CONCLUSIONS: Both MI Paste and MI Paste Plus when used in conjunction with 1450ppm F did not show a significant increase in efficacy for the remineralisation of bovine enamel subsurface lesions in the model used in this study. CLINICAL SIGNIFICANCE: Newer preventive agents such as MI paste and MI paste plus are advocated as promoting remineralisation when used in addition to routine oral care. This in vitro study shows that they may have a limited value in promoting remineralisation over and above that of 1450ppm F toothpaste used twice a day.


Assuntos
Cárie Dentária/tratamento farmacológico , Esmalte Dentário/efeitos dos fármacos , Fluoretos/uso terapêutico , Remineralização Dentária/métodos , Cremes Dentais/uso terapêutico , Animais , Cariostáticos/uso terapêutico , Bovinos , Cárie Dentária/patologia , Esmalte Dentário/patologia , Dentifrícios/uso terapêutico , Combinação de Medicamentos , Fluoretos/administração & dosagem , Concentração de Íons de Hidrogênio , Teste de Materiais , Fosfatos , Distribuição Aleatória , Fluoreto de Sódio/administração & dosagem , Fluoreto de Sódio/uso terapêutico
19.
J Vet Cardiol ; 19(6): 502-513, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29097107

RESUMO

OBJECTIVES: To determine the feasibility of acquiring quality transesophageal (TEE), epicardial (EE), and intracardiac (ICE) echocardiographic images in ovine subjects and to discuss the merits of each technique with a focus on ICE image acquisition. ANIMALS: Eleven male castrated Dorset adult sheep. METHODS: Transesophageal echocardiography was performed under general anesthesia. Epicardial echocardiography was performed as part of an open chest (thoracotomy or sternotomy) experiment. Subjects were recovered with permanent jugular vein indwelling catheter and ICE from this approach was described. Feasibility of each technique was qualitatively assessed based on subjective image quality from three images for each image plane in each sheep. RESULTS: Transesophageal echocardiography was technically challenging and did not provide adequate image quality for consistent interpretation. Epicardial echocardiography and ICE had more favorable results with ICE demonstrating unique benefits for post-operative serial monitoring. CONCLUSIONS: Epicardial echocardiography and ICE were effective imaging techniques. Epicardial echocardiography required the least specialized training but was considered to have limited feasibility due to its requirement for an open chest procedure. Even with the necessity for permanent indwelling jugular cannulation, ICE was the least invasive of the three imaging techniques and potentially the most practical approach for chronic studies by minimizing post-operative stress. Transesophageal echocardiography was not a feasible technique in this study.


Assuntos
Ecocardiografia Transesofagiana/veterinária , Ecocardiografia/veterinária , Coração/diagnóstico por imagem , Modelos Animais , Ovinos/fisiologia , Animais , Coração/fisiologia , Masculino , Sujeitos da Pesquisa , Ultrassonografia de Intervenção/veterinária
20.
Mater Sci Eng C Mater Biol Appl ; 75: 885-894, 2017 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-28415544

RESUMO

Tooth hypersensitivity is a growing problem affecting both the young and ageing population worldwide. Since an effective and permanent solution is not yet available, we propose a new methodology for the restoration of dental enamel using femtosecond lasers and novel calcium phosphate biomaterials. During this procedure the irradiated mineral transforms into a densified layer of acid resistant iron doped ß-pyrophosphate, bonded with the surface of eroded enamel. Our aim therefore is to evaluate this densified mineral as a potential replacement material for dental hard tissue. To this end, we have tested the hardness of ß-pyrophosphate pellets (sintered at 1000°C) and its mineral precursor (brushite), the wear rate during simulated tooth-brushing trials and the cytocompatibility of these minerals in powder form. It was found that the hardness of the ß-pyrophosphate pellets is comparable with that of dental enamel and significantly higher than dentine while, the brushing trials prove that the wear rate of ß-pyrophosphate is much slower than that of natural enamel. Finally, cytotoxicity and genotoxicity tests suggest that iron doped ß-pyrophosphate is cytocompatible and therefore could be used in dental applications. Taken together and with the previously reported results on laser irradiation of these materials we conclude that iron doped ß-pyrophosphate may be a promising material for restoring acid eroded and worn enamel.


Assuntos
Materiais Biocompatíveis/química , Fosfatos de Cálcio/química , Esmalte Dentário/química , Animais , Bovinos , Difosfatos/química , Microscopia Eletrônica de Varredura , Difração de Raios X
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