Comparison of corneal flap thickness using a FS200femtosecond laser and a moria SBK microkeratome

AIMTo evaluate differences in flap thickness resulting from use of an Alcon Wavelight FS200 femtosecond laser and a MORIA SBK microkeratome when making a 110-µm-thick corneal flap and to identify the potential factors that affect corneal flap thickness.

Effects of intensive control of blood glucose and blood pressure on microvascular complications in patients with type Ⅱ diabetes mellitus

AIM: To evaluate the effects of intensive control of blood glucose and blood pressure on microvascular complications in patients with type Ⅱ diabetes by comparing the therapeutic effects of intensive and standard treatment in patients with type Ⅱ diabetes. METHODS: A total of 107 patients with type Ⅱ diabetes were randomly assigned into intensive and standard treatment groups. Patients in the intensive treatment group received preterax (perindopril/ indapamide) to control blood pressure, and gliclazide (diamicron) MR to control blood glucose. Patients in the standard treatment group received routine medications or placebo. Urinary microalbumin (UMA), urinary creatinine (UCR), the UMA/ UCR ratio, and visual acuity were monitored according to the study design of the ADVANCE trial. Direct ophthalmoscopy and seven-field stereoscopic retinal photography were used to examine the fundi at baseline,and repeated after 5 years of treatment. RESULTS: The characteristics of patients in both groups were well balanced at baseline. After 5 years of treatment, visual acuity was found to be decreased in the standard group (P=0.04), but remained stable in the intensive group. The severity of diabetic retinopathy had not progressed in patients in the intensive group, but had deteriorated in the standard group (P=0.0006). The UMA/UCR ratio was not obviously changed in patients in the intensive group, whereas it was significantly increased in the standard group (P=0.00). CONCLUSION: Intensive control of blood glucose and blood pressure can decrease the incidence or slow the progression of microvascular complications in patients with type Ⅱ diabetes, and maintain stable vision.

Ocular manifestations of Alport syndrome

AIMTo analyze the clinical manifestation of Alport syndrome, especially the ocular features.

Comparison of visual effects of FS-LASIK for myopia centered on the coaxially sighted corneal light reflex or the line of sight

AIM：To compare visual quality after femtosecond laser in situ keratomileusis（FS-LASIK）,between the coaxially sighted corneal light reflex（CSCLR） group and conventional ablation line of sight（LOS） group.METHODS：In total,243 eyes（122 patients） were treated with centration on the CSCLR（visual axis） and 238 eyes（119 patients） treated with centration on the pupil center（LOS）.Postoperative outcomes [uncorrected visual acuity（UCVA）,best spectacle-corrected visual acuity（BSCVA）],safety index,efficacy index,refractive outcome,ablation center distance from the visual axis,corneal high-order aberrations,subjective discomfort glare and shadowing incidence rate,and contrast sensitivity at 1,3,and 6mo were measured and compared.RESULTS：The mean age was 27.77±7.1y in the CSCLR group and 26.03±7.70 y in the LOS group.Preoperatively,the manifest refraction spherical equivalent（MRSE） was-6.68±2.60 D in the CSCLR group and-6.65±2.68 D in the LOS group.The postoperative UCVA,BSCVA,MRSE（-0.03±0.263 D in the CSCLR group,-0.05±0.265 D in the LOS group）,efficacy index（1.04,1.03）,and safety index（1.09,1.08） were not significantly different between the groups（all P〉0.05）.In total,3% lost one line and more of BSCVA in the CSCLR group,as 9% in the LOS group postoperatively（P〈0.05）.The ablation center deviation was 0.20±0.15 mm from the visual axis（Pentacam system default setting;range,0-0.75 mm） in the CSCLR group,and 0.43±0.22 mm（range,0-1.32 mm） in the LOS group（P〈0.0001）.Statistically significant greater augmentationof total corneal higher-order aberrations（0.15±0.10 μm and 0.20±0.12 μm respectively,P=0.03） and vertical and horizontal coma（P〈0.0001） were noted in the LOS group.Subjective discomfort glare and shadowing incidence rates were 8.59% and 17.5% in the CSCLR and LOS groups,respectively（P〈0.05）.The 1-month postoperative contrast sensitivity visual acuity in the CSCLR group was significantly higher than that in the LOS group on contrast（100%,25%,10%） with a dark background,but there was no significant difference between the groups at 3 or 6m.CONCLUSION：Myopic LASIK centered on the CSCLR achieves significantly lower induction of loss of BSCVA,corneal high-order aberrations,and lower risk of subjective discomfort glare and shadowing,and lower decline in early contrast sensitivity by comparison with centration on the LOS,giving advantages in visual quality postoperatively.

Giant Monopole Resonance and Nuclear Incompressibility of Hypernuclei

The isoscalar giant monopole resonances（ISGMRs）of hypernucleiAA42Ca,AA（122）Sn,andAA（210）Pb are investigated using a fully self-consistent Skyrme-Hartree-Fock plus random phase approximation method.The Skyrme-type forces,SGII,No.5 and SAAl,are adopted to describe the nucleon-nucleon,A hyperon-nucleon and A hyperon-A hyperon（AA）interactions,respectively.For a given hyperon fraction,we find that effects of AA interaction on the properties of infinite symmetric nuclear matter and finite hypernuclei are very small.The ISGMR strengths are shifted to the high energy region when two A are added into normal nuclei.The changes are from two parts,one is due to the mean field calculations,and the other is from the residual interaction associated with A hyperons.The constrained energies are increased by about 0.5-0.7MeV,which consequently enhances the effective incompressibility modulus of hypernuclei.

Study of the deformed halo nucleus^(31)Ne with Glauber model based on microscopic self-consistent structures

The exotic deformed nucleus^(31)Ne is studied with an approach that combines self-consistent structure and reaction theories.The deformed relativistic Hartree-Bogoliubov theory in continuum(DRHBc)is utilized to demonstrate that deformation and pairing correlations give rise to a halo structure with a large-amplitude p-wave configuration in^(31)Ne.Then the valence nucleon wave functions and angle-averaged density distributions of ^(30)Ne from this theory are used as input for the Glauber reaction model to study the observables of neutron-rich neon isotopes to search halo signatures.With NL1 effective interaction,our predictions of the reaction cross sections for these exotic neon isotopes on a carbon target can better reproduce the experimental data than those from the relativistic mean field model for a spherical shape with resonances and pairing correlation contributions,and are roughly 3.3%(∼50 mb)larger than those with Gaussian function-fitted densities of the core nuclei.The calculated one-neutron removal cross section at 240 MeV/nucleon,and the inclusive longitudinal momentum distribution of the 30Ne residues from the^(31)Ne breakup reaction are largely improved over previous theoretical predictions and agree well with data.These reaction evalu-ations indicate a dilute density distribution in coordinate space and are a canonical signature of a halo structure.Moreover,our predictions with the NL3 and PK1 effective interactions give slightly better descriptions of reaction observables for exotic neon isotopes.

Charge radii of potassium isotopes in the RMF(BCS)^(*) approach

We apply the recently proposed RMF(BCS)*ansatz to study the charge radii of the potassium isotopic chain up to^(52)K.It is shown that the experimental data can be reproduced rather well,qualitatively similar to the Fayans nuclear density functional theory,but with a slightly better description of the odd-even staggerings(OES).Nonetheless,both methods fail for ^(50)K and to a lesser extent for ^(48,52)K.It is shown that if these nuclei are deformed with aβ_(20)≈−0.2,then one can obtain results consistent with experiments for both charge radii and spin-parities.We argue that beyond-mean-field studies are needed to properly describe the charge radii of these three nuclei,particularly for ^(50)K.

Effect of pairing correlation on low-lying quadrupole states in Sn isotopes

We examined the low-lying quadrupole states in Sn isotopes in the framework of fully self-consistent Hartree-Fock+BCS plus QRPA.We focus on the effect of the density-dependence of pairing interaction on the properties of the low-lying quadrupole state.The SLy5 Skyrme interaction with surface,mixed,and volume pairings is employed in the calculations,respectively.We find that the excitation energies and the corresponding reduced electric transition probabilities of the first 2^(+) state are different,given by the three pairing interactions.The properties of the quasiparticle state,two-quasiparticle excitation energy,reduced transition amplitude,and transition densities in ^(112)Sn are analyzed in detail.Two different mechanisms,the static and dynamical effects,of the pairing correlation are also discussed.The results show that the surface,mixed,and volume pairings indeed affect the properties of the first 2^(+) state in the Sn isotopes.

Possible shape coexistence in odd-A Ne isotopes and the impurity effects ofΛhyperons

In this study, shape evolution and possible shape coexistence are explored in odd-A Ne isotopes in the framework of the multidimensionally constrained relativistic-mean-field(MDC-RMF)model. By introducing ~sΛ and phyperons, the impurity effects on the nuclear shape, energy, size, and density distribution are investigated.For the NN interaction, the PK1 parameter set is adopted, and for the ΛN interaction, the PK1-Y1 parameter set is used. The nuclear ground state and low-lying excited states are determined by blocking the unpaired odd neutron in different orbitals around the Fermi surface. Moreover, the potential energy curves(PECs), quadrupole deformations,nuclear r.m.s. radii, binding energies, and density distributions for the core nuclei as well as the corresponding hy pernuclei are analyzed. By examining the PECs, possibilities for shape coexistence inNe and a triple shape coexistence inNe are found. In terms of the impurity effects ofΛhyperons, as noted for even-even Ne hypernuclear isotopes, the shyperon exhibits a clear shrinkage effect, which reduces the nuclear size and results in a more spherical nuclear shape. The phyperon occupying the 1/2~-[110]orbital is prolate, which causes the nuclear shape to be more prolate, and the phyperon occupying the 3/2~-[101] orbital displays an oblate shape, which drives the nuclei to be more oblate.

Isovector giant dipole resonances in proton-rich Ar and Ca isotopes

The isovector giant dipole resonances(IVGDR)in proton-rich Ar and Ca isotopes have been systematic-ally investigated using the resonant continuum Hartree-F ock+BCS(HF+BCS)and quasiparticle random phase ap-proximation(QRPA)methods.The Skyrme SLy5 and density-dependent contact pairing interactions are employed in the calculations.In addition to the giant dipole resonances at energy around 18 MeV,pygmy dipole resonances(PDR)are found to be located in the energy region below 12 MeV.The calculated energy-weighted moments of PDR in nuclei close to the proton drip-line exhaust about 4%of the TRK sum rule.The strengths decrease with in-creasing mass number in each isotopic chain.The transition densities of the PDR states show that motions of pro-tons and neutrons are in phase in the interiors of nuclei,while the protons give the main contribution at the surface.By analyzing the QRPA amplitudes of proton and neutron 2-quasiparticle configurations for a given low-lying state,we find that only a few proton configurations give significant contributions.They contribute about 95%to the total QRPA amplitudes,which indicates that the collectivity of PDR states is not strong in proton-rich nuclei in the present study.

Fully self-consistent calculation ofβ-decay half-lives within Skyrme energy density functional

β-decay half-lives of some magic and semi-magic nuclei have been studied in a fully self-consistent Skyrme Hartree-Fock(HF) plus charge-exchange random phase approximation(RPA).The self-consistency is addressed,in that the same Skyrme energy density functional is adopted in the calculation of ground states and Gamow-Teller excited states.First,the impact of J2 terms on the β-decay half-lives is investigated by using the SGII interaction,revealing a large influence.Subsequently,numerical calculations are performed for the selected nuclei with Skyrme energy density functionals SGII,LNS,SKX,and SAMi.Finally,comparisons to available experimental data and predictions of different theoretical models are discussed.

Neutron drip line of Z=9–11 isotopic chains

A recent experimental breakthrough identified the last bound neutron-rich nuclei in fluorine and neon isotopes.Based on this finding,we perform a theoretical study of Z=9,10,11,12 isotopes in the relativistic mean field(RMF)model.The mean field parameters are assumed from the PK1 parameterization,and the pairing correlation is described by the particle number conservation BCS(FBCS)method recently formulated in the RMF model.We show that the FBCS approach plays an essential role in reproducing experimental results of fluorine and neon isotopes.Furthermore,we predict 39Na and 40Mg to be the last bound neutron-rich nuclei in sodium and magnesium isotopes.