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1.
Int Ophthalmol ; 43(11): 4131-4136, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37505289

RESUMO

INTRODUCTION: It is well known that the femtosecond laser lamellar cut induces some degree of surface roughness. Nevertheless, as in femtosecond laser-assisted LASIK (FS-LASIK), an excimer LASIK ablation is performed, and the post-ablation stromal bed should show some degree of smoothening. We decided to compare, using atomic force microscopy (AFM), the roughness of the corneal stromal bed, after a femtosecond lasers device flap was created with or without an excimer myopic ablation. METHODS: Using 6 freshly enucleated porcine eyes, we created in every eye a flap using a femtosecond laser. Additionally, in 3 eyes, an excimer laser ablation to correct-3 diopters (D) was made. AFM imaging of the remaining corneal stroma was performed. Ten different square areas of 20 µm x 20 µm at the central area of the stroma of each corneal sample were studied. The roughness parameters used were the root-mean-square deviation from a perfectly flat surface. RESULTS: The RMS deviation was 360 ± 120 nm in femtosecond laser only, and 110 ± 20 nm in those cases where excimer is also involved (p < 0.0001). CONCLUSIONS: Our results show that the roughness of the surface treated with excimer is clearly lower than in the group with no excimer ablation; thus, the application of laser excimer after a flap created by femtosecond laser seems to soften the nano-irregularities created by this technique.


Assuntos
Córnea , Ceratomileuse Assistida por Excimer Laser In Situ , Animais , Suínos , Microscopia de Força Atômica , Córnea/cirurgia , Substância Própria/cirurgia , Ceratomileuse Assistida por Excimer Laser In Situ/métodos , Lasers de Excimer/uso terapêutico
2.
Int Ophthalmol ; 42(1): 73-80, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34370173

RESUMO

INTRODUCTION: Higher preoperative myopic astigmatism is associated with a higher probability of retreatment due to patient dissatisfaction as a result of residual cylindrical error. Nonetheless, retreatment is safe and the final clinical results are comparable to those of patients with lower preoperative astigmatism who were satisfied with the primary treatment. Our purpose is to compare the efficacy and safety of femtosecond LASIK (FS-LASIK) for the refractive correction of patients with low (< 1.5 Diopters (D) versus high (≥ 1.5 D) myopic astigmatism. METHODS: Retrospective observational study of 841 eyes of 825 eligible patients treated with FSLASIK for the correction of simple or compound myopic astigmatism. Outcome measures included residual error, best corrected and uncorrected distance visual acuity (BCVA and UCVA), efficacy and safety 3 months after the primary procedure or the retreatment. RESULTS: Of 841 eyes in total, 432 (51.37%) had < 1.5 D (Group 1) and 409 (48.63%) had ≥ 1.5 D (Group 2) preoperative myopic astigmatism. The efficacy index of primary treatment was 0.94 ± 0.18 in Group 1 and 0.89 ± 0.22 in Group 2 (P = 0.001). Of 138 eyes (16.41%) that were retreated due to dis-satisfaction related to residual refractive error, 28 belonged to Group 1 (6.5%) and 110 (26.9%) to Group 2 (P < 0.001). Following retreatment, small but statistically significant differences in the residual mean postoperative cylinder (-0.08 ± 0.24 vs -0.27 ± 0.46 D, P = 0.001) and UCVA (1.11 vs 0.96, P = 0.0001) were detected for Groups 1 and 2, respectively. However, there were no statistically significant differences in the safety and efficacy indices. CONCLUSION: Following FS-LASIK, eyes with myopic astigmatism ≥ 1.5 D have approximately four times more chances of undergoing retreatment due to dis-satisfaction caused by residual refractive error compared to eyes with myopic astigmatism < 1.5 D. However, the clinical results after retreatment are highly satisfactory and comparable in both groups.


Assuntos
Astigmatismo , Ceratomileuse Assistida por Excimer Laser In Situ , Miopia , Astigmatismo/cirurgia , Substância Própria , Humanos , Lasers de Excimer/uso terapêutico , Miopia/complicações , Miopia/cirurgia , Refração Ocular , Resultado do Tratamento , Acuidade Visual
3.
J Chem Phys ; 154(4): 044307, 2021 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-33514099

RESUMO

The photodissociation channels of nitrosobenzene (PhNO) induced by a 255 nm photolytic wavelength have been studied using the complete active space self-consistent method and the multistate second-order multiconfigurational perturbation theory. It is found that there exists a triplet route for photodissociation of the molecule. The reaction mechanism consists of a complex cascade of nonadiabatic electronic transitions involving triple and double conical intersections as well as intersystem crossing. Several of the relevant states (S2, S4, and S5 states) correspond to double excitations. It is worth noting that the last step of the photodissociation implies an internal conversion process. The experimentally observed velocity pattern of the NO fragment is a signature of such a conical intersection.

4.
BMC Ophthalmol ; 21(1): 280, 2021 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-34261440

RESUMO

BACKGROUND: To compare the anterior surface roughness of two commercially available posterior chamber phakic intraocular lenses (IOLs) using atomic force microscopy (AFM). METHODS: Four phakic IOLs were used for this prospective, experimental study: two Visian ICL EVO+ V5 lenses and two iPCL 2.0 lenses. All of them were brand new, were not previously implanted in humans, were monofocal and had a dioptric power of - 12 diopters (D). The anterior surface roughness was assessed using a JPK NanoWizard II® atomic force microscope in contact mode immersed in liquid. Olympus OMCL-RC800PSA commercial silicon nitride cantilever tips were used. Anterior surface roughness measurements were made in 7 areas of 10 × 10 µm at 512 × 512 point resolution. The roughness was measured using the root-mean-square (RMS) value within the given regions. RESULTS: The mean of all anterior surface roughness measurements was 6.09 ± 1.33 nm (nm) in the Visian ICL EVO+ V5 and 3.49 ± 0.41 nm in the iPCL 2.0 (p = 0.001). CONCLUSION: In the current study, we found a statistically significant smoother anterior surface in the iPCL 2.0 phakic intraocular lenses compared with the VISIAN ICL EVO+ V5 lenses when studied with atomic force microscopy.


Assuntos
Cristalino , Lentes Intraoculares Fácicas , Humanos , Implante de Lente Intraocular , Cristalino/cirurgia , Microscopia de Força Atômica , Estudos Prospectivos
5.
Optom Vis Sci ; 98(4): 350-354, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33852551

RESUMO

SIGNIFICANCE: The development of confocal microscopy allows one to obtain high-resolution corneal images like its optical density. Some studies have evaluated the optical density with Scheimpflug cameras in the early post-operative period after photorefractive keratectomy, but no studies have evaluated the long-term evolution of optical density after surface ablation when mitomycin C is used. PURPOSE: This work aimed to study the changes in corneal optical density measured with confocal microscopy in eyes treated with laser-assisted subepithelial keratectomy (LASEK) and intraoperative mitomycin C (MMC) to correct myopia. METHODS: A study of 24 consecutive myopic eyes that underwent LASEK with 0.02% MMC and a control group of 24 healthy nontreated eyes was performed. Optical density was measured using the images by the confocal microscopy of the Heidelberg Retina Tomograph II with the Rostock Cornea Module. An analysis of confocal microscopy images was performed using the ImageJ software to obtain the optical density, in gray-scale units (GSU). The optical density of the stromal bed was evaluated 3 months, 15 months, and 3 years after surgery and was compared with the optical density at the equivalent depth of the stroma in controls. RESULTS: The mean values of optical density for the LASEK group were 81.7 ± 9.7, 78.6 ± 11.7, and 73.6 ± 18.7 GSU at 3 months, 15 months, and 3 years, respectively, and it was 61.8 ± 8.2 GSU for the control group. A statistically higher optical density 3 and 15 months after LASEK with MMC was found compared with controls (P < .001). No significant difference was found in optical density at 3 years post-operatively. CONCLUSIONS: Our study suggests that, after LASEK with MMC, the anterior corneal stroma has a higher optical density at 3 and 15 months post-operatively, which gradually returns to normal values 3 years after surgery.


Assuntos
Alquilantes/administração & dosagem , Córnea/fisiopatologia , Ceratectomia Subepitelial Assistida por Laser/métodos , Lasers de Excimer/uso terapêutico , Mitomicina/administração & dosagem , Miopia/cirurgia , Refração Ocular/fisiologia , Adulto , Biometria , Terapia Combinada , Córnea/diagnóstico por imagem , Córnea/efeitos dos fármacos , Substância Própria/diagnóstico por imagem , Substância Própria/efeitos dos fármacos , Substância Própria/fisiopatologia , Feminino , Humanos , Masculino , Microscopia Confocal , Pessoa de Meia-Idade , Miopia/diagnóstico por imagem , Miopia/fisiopatologia , Estudos Prospectivos , Adulto Jovem
6.
Eye Contact Lens ; 47(4): 213-218, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33323876

RESUMO

OBJECTIVE: The objective of this study was to assess the impact of 0.50 diopter (D) positive or negative defocus on visual function in patients implanted with trifocal and trifocal toric intraocular lenses (IOLs). METHODS: The study included patients implanted with the AcrySof IQ PanOptix IOL or the PanOptix Toric. Visual acuity (VA) at high (100%), medium (50%) and low (10%) contrast, contrast sensitivity function (CSF), and halo perception were assessed three months after surgery. Explorations were performed with corrected distance visual acuity (CDVA), with a positive defocus of +0.50D (myopization) and with a negative defocus of -0.50D (hyperopization). RESULTS: The study included 60 eyes of 60 patients (30 eyes with PanOptix and 30 eyes with PanOptix Toric). For both groups, VA was better for all contrast settings at the CDVA situation (P<0.05 in all cases). For low spatial frequencies, no differences in CSF were found among the three refractive situations in either group. For higher frequencies, the results showed an overall trend for better CSF results for the CDVA situation. The halo effect was lower for the CDVA situation if compared to myopization and hyperopization in both the PanOptix and the PanOptix Toric groups (P<0.05 for all cases). CONCLUSIONS: There is an impact on visual quality and halo perception in patients implanted with trifocal or trifocal toric IOLs even for low residual refractive errors.


Assuntos
Lentes Intraoculares , Facoemulsificação , Erros de Refração , Humanos , Implante de Lente Intraocular , Satisfação do Paciente , Estudos Prospectivos , Desenho de Prótese , Refração Ocular , Erros de Refração/terapia
7.
Int Ophthalmol ; 41(1): 163-172, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32844238

RESUMO

PURPOSE: To report visual outcomes and patient-perceived satisfaction after trifocal or extended depth-of-focus (EDOF) intraocular lens (IOL) implantation in a real-world scenario. METHODS: Three months after bilateral cataract surgery, corrected and uncorrected visual acuity for far, intermediate and near distances and binocular defocus curves and contrast sensitivity were measured. The patients also completed the Catquest SF-9 questionnaire and reported on dysphotopsia and spectacle use. RESULTS: There were 23 patients in the Symfony, 32 patients in the Finevision and 36 patients in the Panoptix group. The percentage of eyes receiving a toric IOL was 41.2%. There were no differences in uncorrected binocular visual acuities, save for near vision, which was lower in the Symfony group. Binocular defocus curves for the trifocal IOLS were almost identical, while vision achieved with the Symfony IOL was significantly lower starting at - 1.5 D defocus. Contrast sensitivity, as well as the perception of halos and glare and the difficulty for night-driving was similar for all groups, except for contrast sensitivity at 6 cycles per degree, which was lower in the Symfony group compared to both Finevision and Panoptix. For near vision, only 47.6% of the Symfony patients reported being completely spectacle-free, compared to 93.3% and 94.4% for the Finevision and Panoptix groups. CONCLUSIONS: Clinically relevant differences were only detected for near vision, with lower values for EDOF IOLs. In order to achieve patient satisfaction, it is imperative to explain the results expected with each IOL; for EDOF IOLs, patients should be advised that they may require near-spectacle correction.


Assuntos
Óculos , Lentes Intraoculares , Humanos , Implante de Lente Intraocular , Satisfação do Paciente , Estudos Prospectivos , Desenho de Prótese , Pseudofacia , Refração Ocular , Visão Binocular
8.
Pediatr Diabetes ; 21(7): 1268-1276, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32737942

RESUMO

OBJECTIVE: To develop a multivariable prediction model to identify patients with type 1 diabetes at increased risk of hospitalization for diabetic ketoacidosis or hyperglycemia with ketosis in the 12 months following assessment. METHODS: Retrospective review of clinical data from patients with type 1 diabetes less than 17 years old at a large academic children's hospital (5732 patient years, 652 admissions). Data from the previous 12 months were assessed on October 15, 2015, 2016, 2017, and 2018, and used to predict hospitalization in the following 12 months using generalized estimating equations. Variables that were significant predictors of hospitalization in univariate analyses were entered into a multivariable model. 2014 to 2016 data were used as a training dataset, and 2017 to 2019 data for validation. Discrimination of the model was assessed with receiver operator characteristic curves. RESULTS: Admission in the preceding year, hemoglobin (Hb)A1c, non-commercial insurance, female sex, and non-White race were all individual predictors of hospitalization, but age, duration of diabetes and number of office visits in the preceding year were not. In multivariable analysis with threshold P < .0033, admissions in the previous 12 months, HbA1c, and non-commercial insurance remained as significant predictors. The model identified a subset of ~8% of the patients with a collective 42% risk of hospitalization, thus increased 5-fold compared with the 8% risk of hospitalization in the remaining 93% of patients. Similar results were obtained with the validation dataset. CONCLUSION: Our multivariable prediction model identified patients at increased risk of admission in the 12 months following assessment.


Assuntos
Diabetes Mellitus Tipo 1/complicações , Cetoacidose Diabética/etiologia , Hospitalização , Hiperglicemia/etiologia , Adolescente , Criança , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/terapia , Cetoacidose Diabética/diagnóstico , Cetoacidose Diabética/terapia , Feminino , Hemoglobinas Glicadas/metabolismo , Humanos , Hiperglicemia/diagnóstico , Hiperglicemia/terapia , Seguro Saúde , Masculino , Valor Preditivo dos Testes , Curva ROC , Estudos Retrospectivos , Fatores de Risco
9.
Pediatr Dermatol ; 37(3): 582-584, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32212183

RESUMO

We present a case of iatrogenic Cushing syndrome and adrenal insufficiency in a newborn secondary to an overuse of triamcinolone cream 0.1% prescrived for the treatment of diaper dermatitis.This case highlignts the risks of systemic absorption when prescribing topical medications in the diaper area of an infant, and the importance of caution and proper follow up when prescribing even mid potency steroids to pediatric patients. .


Assuntos
Síndrome de Cushing , Dermatite das Fraldas , Administração Tópica , Síndrome de Cushing/induzido quimicamente , Dermatite das Fraldas/tratamento farmacológico , Glucocorticoides/efeitos adversos , Humanos , Lactente , Recém-Nascido , Triancinolona/efeitos adversos
10.
Phys Chem Chem Phys ; 21(5): 2389-2396, 2019 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-30649110

RESUMO

Photochemistry of 3- and 4-methoxyphenyl azide at 266 nm has been studied by means of the complete active space self-consistent field (CASSCF) and multi-configurational second-order perturbation (MS-CASPT2) methods. Minima and interstate crossing points have been optimized using the CASSCF method. The calculations predict that the key step of the photolysis of both azides is a non-radiative process. However, an important difference is found when we compare the reactivity of both isomers of azide, deactivation of 3-methoxyphenyl azide (1) can occur via two reaction channels (internal conversion or intersystem crossing), which lead to formation of the dimer of 2H-azepine derivative (2a) and 3,3'-dimethoxyazobenzene (2b). In contrast, deactivation of 4-methoxyphenyl azide (3) takes place via a singlet to triplet intersystem crossing, which leads to formation of 4,4'-dimethoxyazobenzene (4). After initial deactivation, both isomers follow a cascade of surface crossings until they reach the final nitrenes, respectively. The reference active space for the two azides is 14 electrons in 13 orbitals and comprises the six π-type orbitals of the aromatic ring plus four σ-(N-N2) and five π-type orbitals of the -N3 moiety.

11.
J Phys Chem A ; 123(42): 9053-9060, 2019 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-31573200

RESUMO

In the present work, we demonstrate that the formation of triplet and singlet phenylnitrene, when arises from the photodissociation of phenyl azide, fulfills El-Sayed's rules or the electronic angular momentum conservation law. It is shown that the singlet-triplet inversion of phenylnitrene via the vibronic coupling mechanism is not an effective process. In contrast, it is found that there exist two independent dissociation channels that yield alternatively singlet and triplet phenylnitrene. Therefore, a proposed mechanism that violates the angular momentum low is avoided. The clue of the photoreaction lies in the conjunction (energetic and spatial) of two crossing points in a very narrow region of the multidimensional space: (i) an intersystem crossing (ISC1) and (ii) a conical intersection (CI1). The geometrical separation between these two crossing geometries is only 0.016 Å measured in Cartesian coordinates, and the respective energy difference is 2 kcal/mol. This work has been performed by application of the complete active space self-consistent field and multiconfigurational second-order perturbation method.

12.
Graefes Arch Clin Exp Ophthalmol ; 257(12): 2665-2670, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31650272

RESUMO

PURPOSE: To describe and compare the stromal bed roughness obtained after laser in situ keratomileusis (LASIK) flap creation using a corneal femtosecond laser platform (iFS 150) and a "dual" femtosecond (FS) laser platform (LenSx). METHODS: This ex vivo experimental study was conducted in an animal model using 12 freshly enucleated porcine eyes, six with each femtosecond laser. The standard laser treatment parameters were used for the experiment. After LASIK flap creation, the corneal stromal roughness was assessed using atomic force microscopy (AFM) in contact mode immersed in liquid. In each sample, surface measurements were obtained in 60 regions of six eyes per FS laser in 10 20 × 20-micron areas of the central corneal stroma at 512 × 512-point resolution. The surface roughness was measured and the root-mean-square (RMS) values of the roughness were obtained. RESULTS: The mean RMS ± standard deviation values were 430 ± 150 nm for the corneal femtosecond laser platform and 370 ± 100 nm for the dual FS laser platform (P < 0.011). CONCLUSIONS: In this experimental study with AFM, we found smoother stromal beds after LASIK flap creation with LenSx compared to iFS 150 kHz. Further studies are needed to understand visual implications of the differences found.


Assuntos
Substância Própria/patologia , Ceratomileuse Assistida por Excimer Laser In Situ/métodos , Lasers de Excimer/uso terapêutico , Miopia/cirurgia , Retalhos Cirúrgicos , Acuidade Visual , Animais , Substância Própria/cirurgia , Modelos Animais de Doenças , Microscopia de Força Atômica , Miopia/patologia , Período Pós-Operatório , Suínos
13.
BMC Ophthalmol ; 19(1): 205, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31615462

RESUMO

BACKGROUND: To compare the visual and refractive outcomes after myopic LASEK using three different excimer lasers and standardized surgical and mitomycin C (MMC) application protocols. METHODS: In this retrospective, observational cohort study, we examined 122 eyes treated with Allegretto, 135 eyes treated with Esiris and 137 eyes treated with Technolas excimer lasers. All eyes were treated under the same surgical protocol, and a standardized MMC dosage was used. The three groups were refraction-matched, and both visual and refractive outcomes were evaluated at 1 and 7 days and 1 and 3 months after surgery. RESULTS: At 3 months postsurgery, Allegretto provided significantly better outcomes than Esiris and Technolas in terms of postoperative uncorrected distance visual acuity (UDVA) (1.11 ± 0.2 vs 1.01 ± 0.2 vs 0.98 ± 0.2) (P = 0.0001), corrected distance visual acuity (CDVA) (1.13 ± 0.2 vs 1.10 ± 0.1 vs 1.04 ± 0.2) (P = 0.0001), residual sphere (- 0.01 ± 0.2 vs + 0.29 ± 0.7 vs + 0.27 ± 0.6) (P = 0.0001), and efficacy index (0.99 ± 0.2 vs 0.90 ± 0.2 vs 0.91 ± 0.2) (P = 0.0004). CONCLUSIONS: We found slightly better visual and refractive outcomes in the Allegretto group at 3 months post-op after LASEK with MMC to correct myopia.


Assuntos
Ceratectomia Subepitelial Assistida por Laser/métodos , Lasers de Excimer/uso terapêutico , Miopia/cirurgia , Refração Ocular/fisiologia , Acuidade Visual , Adulto , Feminino , Seguimentos , Humanos , Masculino , Miopia/fisiopatologia , Período Pós-Operatório , Estudos Retrospectivos , Fatores de Tempo
14.
Molecules ; 24(24)2019 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-31861152

RESUMO

Electrochemical surface-enhanced Raman scattering (SERS) of the cruciform system 1,4-bis((E)-2-(pyridin-4-yl)vinyl)naphthalene (bpyvn) was recorded on nanostructured silver surfaces at different electrode potentials by using excitation laser lines of 785 and 514.5 nm. SERS relative intensities were analyzed on the basis of the resonance Raman vibronic theory with the help of DFT calculations. The comparison between the experimental and the computed resonance Raman spectra calculated for the first five electronic states of the Ag2-bpyvn surface complex model points out that the selective enhancement of the SERS band recorded at about 1600 cm-1, under 785 nm excitation, is due to a resonant Raman process involving a photoexcited metal-to-molecule charge transfer state of the complex, while the enhancement of the 1570 cm-1 band using 514.5 nm excitation is due to an intramolecular π→π* electronic transition localized in the naphthalenyl framework, resulting in a case of surface-enhanced resonance Raman spectrum (SERRS). Thus, the enhancement of the SERS bands of bpyvn is controlled by a general chemical enhancement mechanism in which different resonance processes of the overall electronic structure of the metal-molecule system are involved.


Assuntos
Metais/análise , Metais/química , Naftalenos/análise , Naftalenos/química , Análise Espectral Raman , Complexos de Coordenação/análise , Complexos de Coordenação/química , Teoria da Densidade Funcional , Eletroquímica , Modelos Químicos , Modelos Moleculares , Estrutura Molecular
15.
Phys Chem Chem Phys ; 20(46): 29430-29439, 2018 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-30452048

RESUMO

Surface-enhanced Raman scattering (SERS) spectroscopy of pyridazine shows the selective enhancement of the bands recorded at about 1570, 1450 and 380 cm-1, which are assigned to two different types of vibrations. The first two correspond to in-plane 8a;νring and 19b;δ(CH) totally symmetric A1 modes, respectively, while the last band is assigned to the out-of-plane 16b;τring,B1 vibration. The selective enhancement has been analyzed on the basis of a resonant Raman process involving photoexcited metal (M)-to-molecule (A) charge transfer (CT: M-A + hν → M+-A-) states of the metal-adsorbate surface complex, which have also been related to the doublet electronic states of the corresponding radical anion of the adsorbate (A-). According to the selection rules of the electromagnetic/plasmonic SERS enhancement mechanism, the simultaneous enhancement of in-plane and out-of-plane modes could be attributed to different orientations of the adsorbate (perpendicular and parallel, respectively, or tilted) with respect to the metallic surface. The calculated resonance Raman-CT spectra (SERS-CT) and the vibrational wavenumbers of isolated pyridazine and of the pyridazine-Ag2 complex obtained from electronic structure calculations suggest a single type of molecule adsorbed with perpendicular orientation. The relative SERS enhancements of both in-plane and out-of-plane modes are due to Franck-Condon factors related to differences between the equilibrium geometries (A1 vibrations, ΔQ ≠ 0) and gradients (B1 vibrations, Δν ≠ 0 and ΔQ ≠ 0), respectively, of the potential energy surfaces of the involved ground and photoinduced CT electronic states. Therefore, the selective enhancement of the SERS bands of pyridazine is controlled by a general metal-to-molecule resonant CT mechanism. This conclusion supports the usefulness of SERS in studying the subtle electronic structure of charged interfaces as well as key processes such as electron transfer at the nanoscale.

16.
Phys Chem Chem Phys ; 20(11): 7764-7771, 2018 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-29504003

RESUMO

The photochemical decomposition of 4-methoxyphenyl azide (CH3O-Ph-N3) is investigated using multiconfigurational second-order perturbation theory (MS-CASPT2). In addition, the multi-state resonance Raman spectra of the reactant, intermediates, and product are computed with a multi-state version of the vibronic theory of Albrecht. The results support that the key step of the photolysis of the parent azide is a 21A'/23A'' intersystem crossing which in a second step decays through a 23A''/13A'' conical intersection to give directly the formation of triplet 4-methoxyphenyl nitrene (CH3O-Ph-N) in its lowest electronic state, 13A''. It is found that the efficiency of the cited intersystem crossing is enhanced by the close presence of a 21A'/21A'' conical intersection. On the other hand, the calculated spectra suggest that the only two species which would be observed in the gas phase experiments are the triplet nitrene plus 4,4'-dimethoxyazobenzene.

17.
Phys Chem Chem Phys ; 20(28): 19071-19081, 2018 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-29972160

RESUMO

Despite the growing interest in the potential electrochemical applications of both aluminium and ionic liquids in batteries, the microstructure of mixtures of trivalent salts and these dense ionic environments is completely unknown. In this work, the solvation of Al3+ cations in highly dense ionic solvents is investigated. For this purpose, molecular dynamics simulations of mixtures of a protic ionic liquid, ethylammonium nitrate (EAN), with aluminium nitrate (Al(NO3)3), both in bulk and confined between graphene walls, are performed. Several structural quantities of the system are calculated for different salt concentrations, such as densities, radial distribution functions, structure factors, coordination numbers and hydrogen bonds for the bulk mixture and ionic density profiles for the confined ones. Moreover, vibrational density of states is calculated for the salt cations, both in bulk and when close to the walls. The results obtained are analyzed and compared to those for mixtures of EAN with monovalent and divalent salts, in order to probe the influence of the salt cation charge on the system's properties. Finally, ab initio density functional theory calculations were performed in order to analyze the structure of the Al3+-ligand complexes, and their predictions for the Raman spectrum are compared both to the corresponding experimental one and the one coming from molecular dynamics simulations. According to our calculations, [Al(NO3)6]3- octahedral complexes do not significantly change the microstructure of the mixtures relative to those of Mg2+-based ones.

18.
BMC Ophthalmol ; 17(1): 72, 2017 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-28514944

RESUMO

BACKGROUND: Today, patients often expect to achieve spectacle independance after cataract surgery. New trifocal intraocular lenses have been developed to try and fullfill this demand. The purpose of this study is to report the short-term visual outcomes of a new trifocal intraocular lens (AcrySof PanOptix™). METHODS: Consecutive adult patients undergoing cataract surgery with bilateral implantation of the study intraocular lens in a private practice clinic were considered for inclusion. Exclusion criteria were the presence of other ocular pathologies or preoperative astigmatism >1.5 diopters (D). Patients with intraoperative complications were excluded from analysis. One month after surgery patients underwent: monocular defocus curve; monocular and binocular uncorrected visual acuity in photopic and mesopic conditions, for far (4 m), intermediate (60 cm) and near (33 cm) distances and binocular contrast sensitivity. Patients completed a visual satisfaction questionnaire between 9 and 12 months after surgery. RESULTS: One hundred and sixteen eyes of fifty-eight patients receiving bilateral implantation of the study intraocular lens were analysed. Mean binocular uncorrected visual acuity in photopic conditions was 0.03 LogMAR for far, 0.12 for intermediate and 0.02 for near distances. All patients achieved a binocular uncorrected visual acuity better than 0.3 LogMAR (20/40 Snellen equivalent) for distance and near vision and 94.8% of patients for intermediate vision. Mesopic binocular uncorrected visual acuity values were similar to photopic values. The monocular defocus curves showed that the best visual acuity was reached at a vergence of 0.00D. Visual acuity dropped slightly at -1.00D and peaked again at -2.00D. Visual acuities better than 0.2 LogMAR were maintained between -2.50D and +0.50D. Contrast sensitivity was high and similar in photopic and mesopic conditions. As regards patient-evaluated outcomes, only 2 patients (3.4%) were fairly dissatisfied with their sight after surgery. Three patients (5.1%) reported the need for spectacle correction for certain activities. All other patients (94.8%) reported never using spectacle correction. CONCLUSIONS: The PanOptix trifocal IOL provides good short-term visual outcomes, with good intermediate performance and excellent patient-reported satisfaction. The similar values achieved in mesopic and photopic conditions in binocular uncorrected visual acuity and contrast sensitivity suggest low pupillary dependence for light distribution. TRIAL REGISTRATION NUMBER: ISRCTN60143265 , retrospectively registered on the 24th of April 2017.


Assuntos
Lentes Intraoculares , Pseudofacia/terapia , Refração Ocular/fisiologia , Visão Binocular/fisiologia , Acuidade Visual/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Córnea/patologia , Topografia da Córnea/métodos , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Estudos Prospectivos , Desenho de Prótese , Pseudofacia/diagnóstico , Pseudofacia/fisiopatologia , Qualidade de Vida , Inquéritos e Questionários , Fatores de Tempo
19.
Eur J Health Law ; 24(2): 175-97, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29210260

RESUMO

The rapid advance of genetics increases the availability in the market of different genetic tests, which can be acquired directly by consumers without the intermediation of a healthcare professional. Both the European and the Spanish legal framework have restricted the access to these direct-to-consumer (DTC) genetic tests on the grounds of different reasons, such as the protection of consumers or the preservation of public health. The present article discusses these legal restrictions under the light of the right to information.


Assuntos
Acesso à Informação/legislação & jurisprudência , Triagem e Testes Direto ao Consumidor/legislação & jurisprudência , Testes Genéticos/legislação & jurisprudência , Europa (Continente) , Humanos
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