Negative effects of enlarging internal limiting membrane peeling for idiopathic macular hole surgery

AIM: To observe the effects of the different extents of internal limiting membrane(ILM) peeling on the surgical success and anatomical and functional outcomes of idiopathic macular hole(IMH).METHODS: In this retrospective cohort study, 36 patients were reviewed and divided into two groups according to the extent of ILM peeling: group A(18 patients), with the peeling area within one-half of the optic disc macular distance as the radius;group B(18 patients), with the peeling area larger than that of group A but did not exceed the optic disc macular distance as the radius. The main outcomes included the best corrected visual acuity(BCVA), light-adaptive electroretinography, macular hole(MH) closure rate, central macular thickness(CMT), retinal nerve fiber layer(RNFL) and ganglion cell complex(GCC) thickness [nine regions based on the Early Treatment of Diabetic Retinopathy Study(ETDRS) ring] before and 1, 3, and 6mo after surgery.RESULTS: The closure rate was 94.4%(17/18) both in groups A and B. The BCVA in both groups improved significantly compared with the preoperative values, but there was no difference between the two groups. The b-wave amplitude of the electroretinogram analysis was significantly improved in both groups compared to that of the preoperative period, with a greater increase in group A than in group B at 6mo(P=0.017). The CMT in both groups gradually decreased after surgery, and there was no difference between the two groups. The RNFL thickness of the temporal outer ring region in group B was significantly lower than that in group A at 3 and 6mo after surgery(P=0.010, 0.032). The GCC thickness of the temporal outer ring region in group B was significantly lower than that in group A at 6mo after surgery(P=0.038).CONCLUSION: Enlarging the extent of ILM peeling doesn’t affect the IMH closure rate and visual acuity recovery, but the greater the extent of peeling, the greater the damage to the inner retinal structures.

3D analysis of functionally graded material plates with complex shapes and various holes

In this paper, the basic formulae for the semi-analytical graded FEM on FGM members are derived. Since FGM parameters vary along three space coordinates, the parameters can be integrated in mechanical equations. Therefore with the parameters of a given FGM plate, problems of FGM plate under various conditions can be solved. The approach uses 1D discretization to obtain 3D solutions, which is proven to be an effective numerical method for the mechanical analyses of FGM structures. Examples of FGM plates with complex shapes and various holes are presented.

Complex frequencies of a massless scalar field in loop quantum black hole spacetime

Recently, considerable progress has been made in understanding the early universe by loop quantum cosmology. Modesto et al. investigated the loop quantum black hole （LQBH）using improved semiclassical analysis and they found that the LQBH has two horizons, an event horizon and a Cauchy horizon, just like the Reissner-NordstrSm black hole. This paper focuses on the dynamical evolution of a massless scalar wave in the LQBH background. By investigating the relation between the complex frequencies of the massless scalar field and the LQBH parameters using the numerical method, we find that the polymeric parameter P makes the massless scalar field decay more quickly and makes the ground scalar wave oscillate slowly. However, the polymeric parameter P causes the frequency of the high harmonic massless scalar wave to shift according to its value. We also find that the loop quantum gravity area gap parameter a0 causes the massless scalar field to decay more slowly and makes the period of the massless scalar field wave become longer. In the complex ω plane, the frequency curves move counterclockwise when the polymeric parameter P increases and this spiral effect is more obvious for a higher harmonic scalar wave.

Managing Macular Holes in a Developing Economy

Background: Macular holes are the common cause of visual impairment especially in the elderly and have a variety of etiological factors. The advances in the management of macular holes are encouraging and are now available in developing countries although scarce, where hitherto;patients seek attention outside their country. The need to understand this disease has therefore become pertinent in all retina clinics. Objective: To evaluate the pattern of presentation of macular holes and its management in a retina clinic in South South Nigeria. Methods: A 5 year retrospective, non comparative review of 24 consecutive cases presenting to a retinal clinic was carried out. Relevant information was extracted from the medical records and analyzed. Results: Three hundred and sixty four cases were seen between January 2009 and December 2013. Twenty four cases had macular holes and ten (41.7%) had bilateral presentation with a total of 34 eyes. The incidence of macular holes was 6.6%. The mean age was 46 years (SD ± 13.42) with a female preponderance, 5:1. Idiopathic holes formed the bulk of the cases 14(58.3%);others were trauma 4(16.7%), posterior uveitis 2, (8.3%), chemotherapy 2 (8.3%), Solar retinopathy and retinitis pigmentosa 1 (4.2%). Nineteen (55.9%) of the 34 eyes were visually impaired (BCVA <6/18). Nineteen eyes had full thickness holes (55.9%) requiring surgery, however only 3(12.5%) of these could afford to have surgery with one reoperation. Four patients (16.7%) had complications in form of retinal detachments at presentation. Conclusion: This study has shown that the incidence of macular holes in the developing world is significant and resources to manage these cases are grossly lacking. Specialist training, with government subsidizing costs will alleviate these difficulties and reduce visual loss from macular holes.

Highly stable perovskite solar cells with a novel Ni-based metal organic complex as dopant-free hole-transporting material

Hole-transporting material(HTM)plays a paramount role in enhancing the photovltaic performance of perovskite solar cells(PSCs).Currently,the vast majority of these HTMs employed in PSCs are organic small molecules and polymers,yet the use of organic metal complexes in PSCs applications remains less explored.To date,most of reported HTMs require additional chemical additives(e.g.Li-TFSI,t-TBP)towards high performance,however,the introduction of additives decrease the PSCs device stability.Herein,an organic metal complex(Ni-TPA)is first developed as a dopant-free HTM applied in PSCs for its facile synthesis and efficient hole extract/transfer ability.Consequently,the dopant-free Ni-TPAbased device achieves a champion efficiency of 17.89%,which is superior to that of pristine Spiro-OMeTAD(14.25%).Furthermore,we introduce a double HTM layer with a graded energy bandgap containing a Ni-TPA layer and a CuSCN layer into PSCs,the non-encapsulated PSCs based on the Ni-TPA/CuSCN layers affords impressive efficiency up to 20.39%and maintains 96%of the initial PCE after 1000 h at a relative humidity around 40%.The results have demonstrated that metal organic complexes represent a great promise for designing new dopant-free HTMs towards highly stable PSCs.

Einstein Energy-Momentum Complex for a Phantom Black Hole Metric

We calculate the energy distribution associated with a static spherically symmetric non-singular phantom black hole metric in Einstein＇s prescription in general relativity. As required for the Einstein energy-momentum complex, we perform the calculations in quasi-Cartesian coordinates. We also calculate the momentum components and obtain a zero value, as expected from the geometry of the metric.

Measurement of Nodes Importance for Complex Networks Structural-Holes-Oriented

Mining important nodes in the complex network should not only consider the core nodes, but also consider the locations of the nodes in the network. Despite many researches on discovering important nodes, the importance of nodes in the structural holes is still ignored easily. Therefore, this paper proposes a method of local centrality measurement based on structural holes, which evaluates the nodes importance both by direct and indirect constraints caused by the lack of structural holes around the nodes. In this method, the attributes and locations of the nodes and their first-order and second-order neighbors are taken into account simultaneously. Deliberate attack simulation is carried out through selective deletion in a certain proportion of network nodes. Calculating the decreased ratio of network efficiency is to quantitatively describe the importance of nodes in before-and-after attacks. Experiments indicate that this method has more advantages to mine important nodes compared to clustering coefficient and k-shell decomposition method. And it is suitable for the quantitative analysis of the nodes importance in large scale networks.

Computational Complex Method for Finite Elastic Plane Problem with Multiple Elliptical Holes

把多复变量应力函数和边界配点最小二乘法相结合，计算含有任意多个椭圆孔有限大小弹性板的应力场．每个孔的大小、位置为任意．板的边界由下列四种边界条件以及它们的组合所组成：１）已知Ｐｘ和Ｐｙ的应力边界，２）已知Ｖｘ和Ｖｙ的位移边界，３）已知法向位移ＶＮ和切向力ＰＴ的混合边界，４）已知法向力ＰＮ和切向位移ＶＴ的混合边界．编制了相应的ＦＯＲＴＲＡＮ程序，进行考题和算例分析，结果表明本方法行之有效．

INTEGRAL EQUATION METHOD'S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.

Thermoelectric field for a coated hole of arbitrary shape in a nonlinearly coupled thermoelectric material

We study the thermoelectric field for an electrically and thermally insulated coated hole of arbitrary shape embedded in an infinite nonlinearly coupled thermoelectric material subject to uniform remote electric current density and uniform remote energy flux.A conformal mapping function for the coating and matrix is introduced,which simultaneously maps the hole boundary and the coating-matrix interface onto two concentric circles in the image plane.Using analytic continuation,we derive a general solution in terms of two auxiliary functions.The general solution satisfies the insulating conditions along the hole boundary and all of the continuity conditions across the perfect coating-matrix interface.Once the two auxiliary functions have been obtained in the elementary-form,the four original analytic functions in the coating and matrix characterizing the thermoelectric fields are completely and explicitly determined.The design of a neutral coated circular hole that does not disturb the prescribed thermoelectric field in the thermoelectric matrix is achieved when the relative thickness parameter and the two mismatch parameters satisfy a simple condition.Finally,the neutrality of a coated circular thermoelectric inhomogeneity is also accomplished.

Evaluation of peripapillary retinal nerve fiber layer, macula and ganglion cell thickness in amblyopia using spectral optical coherence tomography

AIM:To investigate peripapillary retinal nerve fiber layer (RNFL), macula and ganglion cell layer thicknesses (GCC) in amblyopic eyes with spectral domain optical coherence tomography (SD-OCT). METHODS:Thirty six patients with a history of unilateral amblyopia and thirty two children who had emmetropia without amblyopia were included in this study. In this institutional study, 36 eyes of 36 patients with amblyopia (AE), 36 fellow eyes without amblyopia (FE), and 32 eyes of 32 normal subjects (NE) were included. RNFL, GCC and macular thickness measurements were performed with RS-3000 OCT Retina Scan (Nidek Inc CA. USA). RESULTS:The mean global thicknesses of the RNFL were 113.22 ±21.47, 111.57 ±18.25, 109.96 ±11.31μm in the AE, FE, and NE, respectively. There was no statistically significant difference for mean global RNFL thickness among the eyes (P =0.13). The mean thicknesses of the macula were 258.25±18.31, 258.75±19.54, 248.62±10.57μm in the AE, FE and NE, respectively. There was no statistically significant difference for thickness of macula among the eyes (P =0.06). The GCC was investigated into two parts:superior and inferior. The mean thicknesses of superior GCC were 102.57 ±13.32, 103.32 ±10.64, 100.52 ± 5.88μm in the AE, FE, and NE, respectively. The mean thicknesses of inferior GCC were 103.82 ±12.60, 107.82 ± 12.33, 105.86±10.79μm in the AE, FE and NE, respectively. There was no statistically significant difference for thickness of superior and inferior GCC between the eyes (P =0.63, P =0.46). ·CONCLUSION:The macular thicknesses of AE and FE were greater than the NE, although it was not statistically significant. Amblyopia does not seem to have a profound effect on the RNFL, macula and GCC.

Exact analytic solutions for an elliptic hole with asymmetric collinear cracks in a one-dimensional hexagonal quasi-crystal

Using the complex variable function method and the technique of conformal mapping, the anti-plane shear problem of an elliptic hole with asymmetric colfinear cracks in a one-dimensional hexagonal quasi-crystal is solved, and the exact analytic solutions of the stress intensity factors （SIFs） for mode Ⅲ problem are obtained. Under the limiting conditions, the present results reduce to the Griffith crack and many new results obtained as well, such as the circular hole with asymmetric collinear cracks, the elliptic hole with a straight crack, the mode T crack, the cross crack and so on. As far as the phonon field is concerned, these results, which play an important role in many practical and theoretical applications, are shown to be in good agreement with the classical results.

Relative Degree Structural Hole Centrality, CRD-SH: A New Centrality Measure in Complex Networks

In order to assess influential nodes in complex networks, the authors propose a novel ranking method based on structural hole in combination with the degree ratio of a node and its neighbors. The proposed method is a response to the limitations of other proposed measures in this field. The structural hole gives a comprehensive attention of the information about the node topology in relation to its neighbors, whereas the degree ratio of nodes reflects its significance against the neighbors.Combination of the two aforementioned measures summarized in the structural hole leverage matrix demonstrates the importance of a node according to its position in the network structure. So a more accurate method for ranking influential nodes is established. The simulation results over different-scale networks(small networks with less than 30 nodes, medium networks with less than 150 nodes and large networks with more than 1000 nodes) suggest that the proposed method can rank important nodes more effectively and precisely in complex networks specifically in larger ones.

Anti-plane Analysis of a Circular Hole withThree Unequal Cracks in One-dimensionalHexagonal Piezoelectric Quasicrystals

This paper employes variable function method and the technique of conformal mappingto discuss the anti-plane problem of a circular hole with three unequal cracksin a one-dimensional （1D） hexagonal piezoelectric quasicrystal. Based on the piezoelectricityfundamental equations of quasicrystal materials and the symmetry of1D hexagonal quasicrystal and its linear piezoelectricity effect, 1D hexagonal quasicrystalcontrol equations of anti-plane problem are derived. Applying Cauchyintegral formula, the analytical expressions for the crack tip filed intensity factorsare presented with the assumption that the crack are electrical impermeable andelectrical permeable. With the variation of the hole-size and the crack length, someof the new model of crack are obtained. In the absence of the electric load, theresults match with the classical ones. The numerical results indicate the effects ofgeometric parameters on the field intensity factors. It is verified that the horizontalcrack length and the circle radius can easily promote crack growth. Researchon such issues will provide reliable theoretical value for the engineering materialspreparation and application.

An analytical solution for the stress field and stress intensity factor in an infinite plane containing an elliptical hole with two unequal aligned cracks

The existing analytical solutions are extended to obtain the stress fields and the stress intensity factors(SIFs) of two unequal aligned cracks emanating from an elliptical hole in an infinite isotropic plane. A conformal mapping is proposed and combined with the complex variable method. Due to some difficulties in the calculation of the stress function, the mapping function is approximated and simplified via the applications of the series expansion. To validate the obtained solution, several examples are analyzed with the proposed method, the finite element method, etc. In addition, the effects of the lengths of the cracks and the ratio of the semi-axes of the elliptical hole(a/b) on the SIFs are studied. The results show that the present analytical solution is applicable to the SIFs for small cracks.

Line field analysis and complex variable method for solving elastic-plastic fields around an anti-plane elliptic hole

A new approach is proposed to solve the elastic-plastic fields near the major-axis line of an elliptical hole. The complex variable method is used to determine the elastic fields near the major-axis line of the elliptical hole. Then, by using the line field analysis method, the exact and new solutions of the stresses, strains in the plastic zone, the size of the plastic region and the unit normal vector of the elastic-plastic boundary near the major-axis line of the elliptical hole are obtained for an anti-plane elliptical hole in a perfectly elastic-plastic solid. The usual small scale yielding assumptions are not adopted in the analysis. The present method is simple, easy and efficient. The influences of applied mechanical loading on the size of plastic zone are discussed.

Rapid iterative incremental model of the intermittent chaos of deep hole developing in coal-gas outburst

In view of the occurrence of the coal and gas, outburst coal body separates in series of layer form, and tosses in a series of coal shell, and the morphological characteristics of the holes that formed in the coal layers are very similar to some iterative morphological characteristics of the system state under highly nonlinear condition in chaos theory. Two kinds of morphology as well as their starting and end states are comparatively studied in this paper. The research results indicate that the outburst coal and rock system is in a chaotic state of lower nested hierarchy before outburst, and the process that lots of holes form owing to continuous outburst of a series of coal shells in a short time is in a rhythmical fast iterative stage of intermittent chaos state. And the state of the coal-gas system is in a stable equilibrium state after outburst. The behaviors of outburst occurrence, development and termination, based on the universal properties of various nonlinear mappings in describing complex problems, can be described by iterative operation in mathematics which uses the Logistic function f (x,μ)=μx(1-x) and the composite function F(3, x) = f(3)(x, μ) as kernel function. The primary equation of relative hole depth x and outburst parameter l in kernel function are given in this paper. The given results can deepen and enrich the understanding of physical essence of outburst.

SOLUTION OF DIFFERENT HOLES SHAPE BORDERS OF FIBRE REINFORCED COMPOSITE PLATES BY INTEGRAL EQUATIONS

Accurate boundary conditions of composite material plates with different holes are founded to settle boundary condition problems of complex holes by conformal mapping method upon the nonhomogeneous anisotropic elastic and complex function theory. And then the two stress functions required were founded on Cauchy integral by boundary conditions. The final stress distributions of opening structure and the analytical solution on composite material plate with rectangle hole and wing manholes were achieved. The influences on hole-edge stress concentration factors are discussed under different loads and fiber direction cases, and then contrast calculates are carried through FEM.

Dynamic stress concentrations in thick plates with two holes based on refined theory

Based on complex variables and conformal mapping, the elastic wave scat- tering and dynamic stress concentrations in the plates with two holes are studied by the refined dynamic equation of plate bending. The problem to be solved is changed to a set of infinite algebraic equations by an orthogonM function expansion method. As examples, under free boundary conditions, the numerical results of the dynamic moment concen- tration factors in the plates with two circular holes are computed. The results indicate that the parameters such as the incident wave number, the thickness of plates, and the spacing between holes have great effects on the dynamic stress distributions. The results are accurate because the refined equation is derived without any engineering hypothese.

Surface Effects on the Scatter of SH-Wave by a Shallow Buried the Elliptical Hole

The methods of complex function, multi-polar coordinate system, and conformal mapping are used to solve dynamic stress concentration factor. The surface elasticity theory is applied to obtain the stress boundary conditions on the surface. The effects of frequency and the ration of the major and minor axis of the ellipse on the dynamic stress concentration factor around the elliptical nano-hole are discussed in detail. When the size of elliptical hole shrinks to nanometers, the numerical results show that the surface effect has a significant effect on the scattering of SH-wave.