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A key bottleneck in the use of Multiview Stereo (MVS) to produce high quality reconstructions is the gaps arising from textureless, shaded areas and lack of fine-scale detail. Shape-from-Shading (SfS) has been used in conjunction with MVS to obtain fine-scale detail and veridical reconstruction in the gap areas. The similarity metric that gauges candidate correspondences is critical to this process, typically a combination of photometric consistency and brightness gradient constancy. Two observations motivate this paper. First, brightness gradient constancy can be erroneous due to foreshortening. Second, the standard ZSSD/NCC patchwise photometric consistency measures when applied to shaded areas is, to a first-order approximation, a calculation of brightness gradient differences, which can be subject to foreshortening. The paper proposes a novel trinocular differential photometric consistency that constrains the brightness gradients in three views so that the image gradient in one view is completely determined by the image gradients at corresponding points in the the other two views. The theoretical developments here advocate the integration of this new measure, whose viability in practice has been demonstrated in a set of illustrative numerical experiments.

Code available at http://github.com/rfabbri/minus; International audience; We present a method for solving two minimal problems for relative camera pose estimation from three views, which are based on three view correspondences of (i) three points and one line and (ii) three points and two lines through two of the points. These problems are too difficult to be efficiently solved by the state of the art Grobner basis methods. Our method is based on a new efficient homotopy continuation (HC) solver, which dramatically speeds up previous HC solving by specializing HC methods to generic cases of our problems. We show in simulated experiments that our solvers are numerically robust and stable under image noise. We show in real experiment that (i) SIFT features provide good enough point-and-line correspondences for three-view reconstruction and (ii) that we can solve difficult cases with too few or too noisy tentative matches where the state of the art structure from motion initialization fails.

This study aimed to detect the differentially expressed genes between oral squamous cell carcinoma (OSCC) tissues and adjacent normal tissues, and perform pathway analysis and protein-protein interaction (PPI) analysis on differentially expressed genes (DEGs).Gene Expression Omnibus (GEO) database related to human tumors was selected from the National Center for Biotechnology Information (NCBI), and GSE31056 and GSE3524, two microarrays containing OSCC gene expression data, were extracted from it. Analysis of differentially expressed genes in the two microarrays was performed using "R" software, and the volcanic map was drawn. Then, Venn diagram was used to integrate the differentially expressed genes screened out by the two microarrays, and PPI [Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG)] analysis of DEGs after integration was performed using Cytoscape, DAVID, STRING and KOBAS. A total of 207 differentially expressed genes were screened out by the two microarrays. 103 proteins encoded by differentially expressed genes screened out by STRING software had interaction. The expression network of differentially expressed genes was constructed, and some proteins, closely related to other proteins such as STAT1, were screened out by Cytoscape software.GO analysis and KEGG analysis found that the differentially expressed genes were mainly enriched in "extracellular region", "extracellular region part" and "membrane-bound vesicle", and mainly involved in biological processes such as "Amoebiasis", "Glycerolipid metabolism" and "Arachidonic acid metabolism". In this study, 207 differentially expressed genes were successfully screened out from the two OSCC microarrays. PPI, GO and KEGG pathways of 103 interacting proteins were successfully constructed. Key genes were screened out, annotation and pathway analysis of which were performed.This study was helpful to further study the relationship between OSCC gene directions.

Mercury is a potent neurotoxin, which causes serious and permanent damage to biota including human beings. Nanomaterials like gold have been used to detect mercury, especially the mercuric ions in recent years, but few have been done on the determination of methylmercury (CH₃Hg⁺). In this study, we present a simple, selective and sensitive method for the determination of CH₃Hg⁺ co-existing with Hg²⁺ based on the fluorescence quenching of bovine serum albumin (BSA) stabilized gold nanoclusters (BSA-Au NCs). It was found that the fluorescence quenching of BSA-Au NCs by Hg²⁺ is stronger than CH₃Hg⁺ at the same concentration. Hg²⁺ can be masked by EDTA while CH₃Hg⁺ is less affected. Therefore, the determination of CH₃Hg⁺ was achieved through EDTA masking. The detection limit for CH₃Hg⁺ is 35 nmol/L after masking Hg²⁺ with EDTA. This method has been successfully applied to quantify CH₃Hg⁺ in rice paddy water from Qingzhen, Guizhou and tap water from Beijing.

The aim of this study was to evaluate the effects of various acidic solutions on the surface mechanical properties of commercial resin composites with different microstructures (Filtek Z350 XT, TPH3, Durafill, and Superlux). Specimens were immersed in orange juice, cola, and distilled water for 5 days and the nanohardness, elastic modulus, and wear behavior of the samples were determined via the nanoindentation test and a reciprocating nanoscratch test. The nanoscratch morphology was observed using scanning electron microscopy (SEM) and the wear depth was recorded by scanning probe microscopy (SPM). The results indicate that the nanofilled resin composites had the greatest hardest and highest elastic modulus, whereas the microfilled composites exhibited the lowest nanohardness and elastic modulus values. SEM observations showed that all resin composites underwent erosion and surface degradation after immersion in acidic solutions. Furthermore, the wear resistance was influenced by the composition of the acidic solution and was correlated with the nanohardness and elastic modulus. The dominant wear mechanism changed from plastic deformation to delamination after immersion in acidic solutions.

We develop quantum mechanical Dirac ket-bra operator’s integration theory in \(\mathfrak{Q}\)-ordering or \(\mathfrak{P}\)-ordering to multimode case, where \(\mathfrak{Q}\)-ordering means all Qs are to the left of all Ps and \(\mathfrak{P}\)-ordering means all Ps are to the left of all Qs. As their applications, we derive \(\mathfrak{Q}\)-ordered and \(\mathfrak{P}\)-ordered expansion formulas of multimode exponential operator \(e^{ - iP_l \Lambda _{lk} Q_k } \). Application of the new formula in finding new general squeezing operators is demonstrated. The general exponential operator for coordinate representation transformation \(\left| {\left. {\left( {_{q_2 }^{q_1 } } \right)} \right\rangle \to } \right|\left. {\left( {_{CD}^{AB} } \right)\left( {_{q_2 }^{q_1 } } \right)} \right\rangle \) is also derived. In this way, much more correpondence relations between classical coordinate transformations and their quantum mechanical images can be revealed.

Biomechanical factors play a key role in the success of dental implants. Fracture and loosening of abutment screws are major issues. This study investigated the effect of lubricants on the stability of dental implant-abutment connection. As lubricants, graphite and vaseline were coated on the abutment screw surface, respectively, and a blank without lubricant served as the control. The total friction coefficient (μtot), clamping force, fatigue behavior and detorque of the joint combined with dynamic cyclic loading were measured under different lubricating conditions. Further, a three-dimensional finite element analysis was used to investigate stress distribution, in conjunction with experimental images. The results showed that the lubricant reduced μtot, which in turn led to an increase in clamping force. Decrease in loading increased the fatigue life of the screw. However, use of lubricant at high load reduced the fatigue life. Ductile fracture at the first thread of the screw was the chief failure mode, which was due to maximum von Mises stress. Higher stress levels occurred in the lubricant groups. Lubricated screws resulted in lower detorque which made the joint easier to loosen. In conclusion, the lubricant cannot effectively improve the reliability of dental implant-abutment connection. Keeping the interfaces of implant-screw uncontaminated and strengthening the surface of the screw may be recommend for clinical operation and future design.

We theoretically investigate the hybrid absorptive–dispersive optical bistability and multistability in a four-level inverted-Y quantum well system inside a unidirectional ring cavity. We find that the coupling field, the pumping field as well as the cycling field can affect the optical bistability and multistability dramatically, which can be used to manipulate efficiently the threshold intensity and the hysteresis loop. The effects of the relative phase and the electronic cooperation parameter on the OB and OM are also studied. Our study is much more practical than its atomic counterpart due to its flexible design and the wide adjustable parameters. Thus, it may provide some new possibilities for technological applications in optoelectronics and solid-state quantum information science.

Mesenchymal stem cells (MSCs) have been broadly used for tissue regeneration and repair due to their broad differentiation potential and potent paracrine properties such as angiogenic capacity. Strategies to increase their survival rate after transplantation and the angiogenic ability are of priority for the utility of MSCs. In this study, we found that mechanical stretch (10% extension, 30 cycles/min cyclic stretch) preconditioning increase the angiogenic capacity via VEGFA induction. In addition, mechanical stretch also increases the survival rate of mesenchymal stem cells under nutrients deprivation. Consistent with the increase VEGFA expression and resistance to apoptosis, nuclear localization of NFκB activity p65 increased upon mechanical stretch. Inhibition of NFκB activity by BAY 11-708 blocks the pro-angiogenesis and anti-apoptosis function of mechanical stretch. Taken together, our findings here raise the possibility that mechanical stretch preconditioning might enhance the therapeutic efficacy of mesenchymal stem cells.

For multifocus image fusion in spatial domain, sharper blocks from different source images are selected to fuse a new image. Block size significantly affects the fusion results and a fixed block size is not applicable in various multifocus images. In this paper, a novel multifocus image fusion algorithm using biogeography-based optimization is proposed to obtain the optimal block size. The sharper blocks of each source image are first selected by sum modified Laplacian and morphological filter to contain an initial fused image. Then, the proposed algorithm uses the migration and mutation operation of biogeography-based optimization to search the optimal block size according to the fitness function in respect of spatial frequency. The chaotic search is adopted during iteration to improve optimization precision. The final fused image is constructed based on the optimal block size. Experimental results demonstrate that the proposed algorithm has good quantitative and visual evaluations.

After a penetrating analysis of the known number–phase commutative relations we find that the common eigenvector |η of two particles' relative coordinate and total momentum also embodies the entanglement with respect to the correlative amplitude–operational phase. Based on the fact that the number-difference operator is the canonical conjugate to the Noh–Fougeres–Mandel operational phase operator, the corresponding entanglement is also briefly discussed.

The generalized Wigner operator and Wigner distribution function in phase space corresponding to the field-intensity-dependent operators is constructed in the nonlinear coherent state representation. The generalized Wigner theorem is also derived. The whole discussion is based on the technique of integration within an ordered product of the field-intensity-dependent operators.

We find that the resolution of unity for the EPR (Einstein, Podolsky and Rosen) entangled state representation can be in differential form. Its application in studying normally ordered expansion of some complicated exponential operators is demonstrated.

We introduce the dual vector | z,f (n)* of a single-mode nonlinear coherent state (NCS) by using the contour integral form of δ-function, and the explicit form of | z,f (n)* is obtained in enlarged Hilbert space. The nonlinear Fock states and their contour representation are deduced. A new completeness relation composed of | z,f (n)* and NCS in contour integral form is derived and its application in constructing a complex P-representation of density operators is shown.

We introduce the nonlinear SU(3) charged and hypercharged bosonic coherent state in three-mode Fock space. It can be further recast into a compact exponential form. The fermionic case is also discussed.

We introduce a generalized entangled state |η,λ1,λ2>, which spans a complete and orthonormal representation. Using the technique of integration within an ordered product of operators we prove that the projection operator |η,λ1,λ2>1,λ2| is just the Radon transformation of the entangled Wigner operator. The inverse Radon transformation is also derived and the tomography theory for two-mode correlated system is established.

We derive the entangled eigenstate ‖ξ> of complex scalar fields ϕ and ϕ† in the Fock space. The ‖ξ> state is found to embed the entanglement possessed by the Einstein–Podolsky–Rosen states in quantum mechanics. The ‖ξ> set spans a complete and orthonormal representation. The advantage of the new

The explicit common eigenvectors for complex scalar fields ϕ(x) and ϕ+ (x) are derived. They span an orthonormal and complete space. Based on this, the charge conjugate unitary operator and the operator which generates Bogolyubov pseudo-particles transformation can be neatly derived. It is emphasized that ¦ξ〉 is different from the direct product of two independent eigenvectors respectively belonging to two real scalar fields, and ¦ξ〉 is named the correlated eigenstates of ϕ(x) and ϕ+ (x).

By using the technique of integration within an ordered product (IWOP) of operators, we derive the normal-product form of the gauge-invariant Wigner operator of an electron in a uniform magnetic field and its expression in the newly constructed |λ> representation. The virtue of working in the |λ> representation lies in the fact that it is expressed in terms of the ladder operators Π±, K±(see Eq. (10)), thus the magnetic vector potential can naturally be included. On these bases we can easily obtain Wigner functions of some important electron states.

We give common eigenkets of three compatible observables {${P}_{1}{+P}_{2}{+P}_{3},$ $({\ensuremath{\mu}}_{2}{Q}_{2}+{\ensuremath{\mu}}_{3}{Q}_{3})/({\ensuremath{\mu}}_{2}+{\ensuremath{\mu}}_{3})\ensuremath{-}{Q}_{1},$ ${Q}_{3}\ensuremath{-}{Q}_{2}$}, which are composed of three particles' coordinate ${Q}_{i}$ and momentum ${P}_{i},$ where ${\ensuremath{\mu}}_{i}{=m}_{i}{/(m}_{1}{+m}_{2}{+m}_{3}).$ This set of operators are so-called Jacobi coordinates and momenta. By compatible we mean such observables can be simultaneously determined. Using the technique of integration within an ordered product of operators, we prove that the common eigenkets are complete and orthonormal, and hereby qualified for making up a representation. Applying this representation to solving some new three-body problems is also shown.

The Weyl correspondence and Wigner operator theory for two-mode correlated system is developed on the common eigenstate basis

Objective The aim of this study was to explore the mutual communication of the parathyroid hormone-related peptide (PTHrP) and phosphatidylinositol 3-kinase/threonine protein kinase (PI3K/Akt) pathway on the proliferation and differentiation of condylar chondrocytes from Sprague-Dawley (SD) rats. Methods Condylar chondrocytes from the condylar cartilage were cultured and an organ culture system of mandibular condyles was employed. The distribution of PI3K, phospho-Akt (p-Akt), and PTHrP in condylar cartilage was detected by either immunohistochemistry or immunofluorescence. The second passage chondrocytes and condyle specimens in the organ culture system were treated with PTHrP, LY294002, PTHrP and LY294002 in combination, or dimethyl sulfoxide (DMSO), separately. The mRNA and protein levels of type II (Col II) and type X collagen (Col X) were investigated by real-time polymerase chain reaction (PCR) and Western blot analysis. The condyle growth in organ culture system was analysed by haematoxylin–eosin staining. Results PTHrP, PI3K, and p-Akt were mainly located in the proliferative and hypertrophic zones. PTHrP promoted the proliferation of condylar chondrocytes, while LY294002 limited this effect. The mRNA and protein levels of Col II and Col X in these cells were reduced by PTHrP and enhanced by LY294002. Organ culture showed a significant enhancement of condyle elongation with PTHrP treatment or a combination of PTHrP and LY294002 treatment. After treatment with LY294002, the length of condyles was reduced compared with the samples treated with DMSO. Conclusions We conclude that the PI3K/Akt pathway plays an essential role in the proliferation and differentiation of condylar chondrocytes and is a potential target for PTHrP in regulating chondrocyte differentiation at condylar cartilage.

This paper derives explicit expressions of the infinitesimal gauge operators for pseudoscalalr fields in a gauge theory coupling vector and axial-vector fields with the aid of the method of operator algebra. The gauge operators of the coset pure gauge fields theory under the chiral group SU(N) × SU(N) are also obtainede.

We study even- and odd-displaced squeezed states, which were proposed by us as 1/Ne(D(z)+D(-z))S(r) mod 0) and 1/N0(D(z)-D(-z))S(r) mod 0). We find: (i) when z is real, the 2Nth moments in both states are larger than in the ordinary squeezed state; (ii) for the same z= mod z mod , the two states can not exhibit stronger squeezing than the squeezed state in the same order; (iii) under the condition mod z mod e-r square root 2>>1, the even (odd)-displaced squeezed state can respectively exhibit stronger (4k-2) (4k)-order (k=1,2,3,...) squeezing than the squeezed state.

We examine some properties of the states a+mS(ξ)| 0 > (ξ = reiθ), which are engendered by excitations on a squeezed vacuum state. Using the IWOP (integration within an ordered product of operators) technique, we find that such states are normalized in the form of Legendre polynomials of the squeezing parameter r. Based on this remarkable property, the squeezing and the statistical properties of the fields in such states are discussed.

We show that the operator $U=\mathrm{exp}[\ensuremath{-}{ir(Q}_{1}{P}_{2}{+Q}_{2}{P}_{3}{+Q}_{3}{P}_{1})]$ is a three-mode squeezing operator for the three-mode quadratures exhibiting the standard squeezing, the corresponding squeezed vacuum state in three-mode Fock space is derived by virtue of the technique of integration within ordered product of operators. The entanglement involved in such a state is explained. The optical network for producing the three-mode squeezed state is proposed.

The relationships between the basic mechanical and wear properties of mottled enamel, especially during the mastication process, are important factors and must be explored. This study evaluated mottled enamel's micro-tribological behavior under artificial saliva conditions in vitro. The basic mechanical properties were determined by nanoindentiation testing. A conical diamond nanoindenter tip was used to scratch mottled enamel and normal enamel. The scratches were sliding with a constant normal load of 2 mN, with different cycles during the tests. The hardness, elastic modulus and friction coefficient were obtained to analyze the mechanical properties. The results showed that the hardness and elastic modulus of mottled enamel were 10% and 14.6% less, respectively, than those of normal enamel. Mottled enamel showed a lower friction coefficient and a higher wear rate, compared to normal enamel. The friction coefficient did not appear to be related to the wear rate for either type of enamel. The wear mechanism for normal enamel was plastic deformation for early wear, while the combination of plastic deformation and delamination was the main damage feature of mottled enamel.