The frequency of dental implant related surgeries that involve soft tissue and bone augmentation procedures has increased significantly. Bovine-derived substitutes have been by far the most commonly ...used xenografts in dentistry. Albeit literature is replete with clinical studies in favor of bovine-derived graft materials, bibliographical data reporting on risks and clinical complications is scarce. Clinical impression and concern for patient safety led to the report we have provided. The aim of the present case series was to raise awareness on the long-term risks and late clinical complications of bovine-derived graft materials. Patients were referred to a private practice due to bone augmentation complications. Demographics, significant medical and dental findings are reported. Complications included sinus and maxillary bone pathoses, displacement of the graft materials, oroantral communications, implant failure, foreign body reactions, encapsulation, chronic inflammation, soft tissue fenestrations and associated cysts. Bovine-derived graft materials were not biodegradable. Resolution of the associated lesions and symptoms was achieved after the removal of the bone graft materials. The surgical removal of the xenograft materials may require advanced clinical skills because of the different configurations clinicians might encounter of the non-resorbed and migrated particles. The authors' concern is that patient morbidity may not be reduced with xenografts, due to the inherent risks and associated complications. Clinicians seeking to provide functional and esthetic outcomes should be aware of the complications of the bovine-derived graft materials. The long-term safety of xenografts and their potential association with disease are valid concerns.
Triple-negative breast cancer (TNBC) is an aggressive form of breast cancer with no effective targeted therapy. Inducible nitric oxide synthase (iNOS) is associated with poor survival in patients ...with breast cancer by increasing tumor aggressiveness. This work aimed to investigate the potential of iNOS inhibitors as a targeted therapy for TNBC. We hypothesized that inhibition of endogenous iNOS would decrease TNBC aggressiveness by reducing tumor initiation and metastasis through modulation of epithelial-mesenchymal transition (EMT)-inducing factors.
iNOS protein levels were determined in 83 human TNBC tissues and correlated with clinical outcome. Proliferation, mammosphere-forming efficiency, migration, and EMT transcription factors were assessed in vitro after iNOS inhibition. Endogenous iNOS targeting was evaluated as a potential therapy in TNBC mouse models.
High endogenous iNOS expression was associated with worse prognosis in patients with TNBC by gene expression as well as immunohistochemical analysis. Selective iNOS (1400 W) and pan-NOS (L-NMMA and L-NAME) inhibitors diminished cell proliferation, cancer stem cell self-renewal, and cell migration in vitro, together with inhibition of EMT transcription factors (Snail, Slug, Twist1, and Zeb1). Impairment of hypoxia-inducible factor 1α, endoplasmic reticulum stress (IRE1α/XBP1), and the crosstalk between activating transcription factor 3/activating transcription factor 4 and transforming growth factor β was observed. iNOS inhibition significantly reduced tumor growth, the number of lung metastases, tumor initiation, and self-renewal.
Considering the effectiveness of L-NMMA in decreasing tumor growth and enhancing survival rate in TNBC, we propose a targeted therapeutic clinical trial by re-purposing the pan-NOS inhibitor L-NMMA, which has been extensively investigated for cardiogenic shock as an anti-cancer therapeutic.
The interfacial activity of 3.5 nm homogeneous (HPs) and amphiphilic Janus gold nanoparticles (JPs) was characterized by pendant drop tensiometry for water/air and water/decane interfaces. This ...technique requires a smaller quantity of nanoparticles than the traditional Langmuir balance technique. The direct deposition at the interface of the nanoparticles dispersed in a spreading solvent also requires smaller quantities of sample than does adsorption from the bulk. From the growing and shrinking of the pendant drops, the interfacial activity of the nanoparticles can be evaluated and compared within a wide range of area per particle. In this work, the JPs exhibited a higher interfacial activity than did the HPs in all cases. A hard disk model fits the piecewise compression isotherm of the HPs, yet this model underestimates the interactions between the JPs adsorbed at the interface.
Surface heterogeneity affects the behavior of nanoparticles at liquid interfaces. To gain a deeper understanding on the details of these phenomena, we have measured the interfacial activity and ...contact angle at water/decane interfaces for three different types of nanoparticles: homogeneous poly(methyl methacrylate) (PMMA), silica functionalized with a capping ligand containing a methacrylate terminal group, and Ag-based Janus colloids with two capping ligands of different hydrophobicity. The interfacial activity was analyzed by pendant drop tensiometry, and the contact angle was measured directly by freeze-fracture shadow-casting cryo-scanning electron microscopy. The silver Janus nanoparticles presented the highest interfacial activity, compared to the silica nanoparticles and the homogeneous PMMA nanoparticles. Additionally, increasing the bulk concentration of the PMMA and silica nanoparticles up to 100-fold compared to the Janus nanoparticles led to silica particles forming fractal-like structures at the interface, contrary to the PMMA particles that did not show any spontaneous adsorption.
NanoMAX is the first hard X‐ray nanoprobe beamline at the MAX IV laboratory. It utilizes the unique properties of the world's first operational multi‐bend achromat storage ring to provide an intense ...and coherent focused beam for experiments with several methods. In this paper we present the beamline optics design in detail, show the performance figures, and give an overview of the surrounding infrastructure and the operational diffraction endstation.
This work is an overview of the multi‐modal hard X‐ray nanoprobe beamline at the MAX IV Laboratory. The beamline provides an intense and coherent beam, focused to 40–200 nm in the energy range 5–28 eV.
Low-density nanocellular polymers are required to take advantage of the full potential of these materials as high efficient thermal insulators. However, their production is still a challenging task. ...One promising approach is the use of nanostructured polymer blends of poly(methyl methacrylate) (PMMA) and a block copolymer poly(methyl methacrylate)-poly(butyl acrylate)-poly(methyl methacrylate) (MAM), which are useful for promoting nucleation but seem to present a severe drawback, as apparently avoid low relative densities. In this work, new strategies to overcome this limitation and produce low-density nanocellular materials based on these blends are investigated. First, the effect of very low amounts of the MAM copolymer is analysed. It is detected that nanostructuration can be prevented using low copolymer contents, but nucleation is still enhanced as a result of the copolymer molecules with high CO2 affinity dispersed in the matrix, so nanocellular polymers are obtained using very low percentages of the copolymer. Second, the influence of the foaming temperature is studied. Results show that for systems in which there is not a clear nanostructuration, cells can grow more freely and smaller relative densities can be achieved.
For these studies, blends of PMMA with MAM with copolymer contents from 10 wt% and as low as 0.1 wt% are used. For the first time, the production strategies proposed in this work have allowed obtaining low density (relative density 0.23) nanocellular polymers based on PMMA/MAM blends.
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•Low-density nanocellular polymers based on PMMA/MAM blends are produced.•Low MAM copolymer contents, as low as 0.1 wt%, are used to produce such materials.•The physical mechanisms that allow this reduction of the density are discussed.
Let
D
3
be the three-dimensional Siegel domain and
A
λ
2
(
D
3
)
the weight-ed Bergman space with weight parameter
λ
>
-
1
. In the present paper, we analyse the commutative (not
C
∗
) Banach algebra
...T
(
λ
)
generated by Toeplitz operators with parabolic quasi-radial quasi-homogeneous symbols acting on
A
λ
2
(
D
3
)
. We remark that
T
(
λ
)
is not semi-simple, describe its maximal ideal space and the Gelfand map, and show that this algebra is inverse-closed.
•Aerial manipulation allows physical contact tasks while flying.•Design and development of lightweight (1.8 kg), human size dual arm manipulator.•Dual arm manipulator integrated in multirotor ...platform.•Derivation of the dynamics and controller of the dual arm aerial manipulator.•Aerial manipulator design evaluated through experiments and outdoor flight tests.
This paper presents the development and experimental validation of a low weight and inertia, human-size and highly dexterous dual arm system designed for aerial manipulation with multirotor platform. The arms, weighting 1.8 kg in total and with a maximum lift load per arm around 0.75 kg, provide five degrees of freedom (DOF) for end-effector positioning and wrist orientation. A customized aluminum frame structure supports the servo actuators, placing most part of the mass close to the shoulder structure in order to reduce the inertia. A double flange bearing mechanism in side-by-side configuration isolates the servos from impacts and radial/axial overloads, increasing robustness. This is important to prevent that the arms are damaged during physical interactions with the environment, as they should support the kinetic energy of the whole platform. The motivation in the development of a dual arm aerial manipulator is extending the range of applications and tasks that can be performed with respect to the single arm case, like grasping large objects or assembling. The paper covers the kinematic and dynamic modeling of the aerial robot, proposing a control scheme that deals with the technological limitations of the smart servo actuators. The performance of the arms and the interactions with the aerial platform are evaluated in test bench experiments. The proposed dual arm design is validated through outdoor flight tests with two commercial hexarotor platforms equipped with standard industrial autopilots.
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In this work, the optical properties of transparent nanocellular polymethylmethacrylate (PMMA) have been studied, experimental and theoretically. Transmittance measurements of samples presenting ...different cell sizes (14, 24, 39 and 225 nm) and a constant relative density of around 0.45 have been carried out obtaining values as high as 0.94 for the sample with the smaller cell size and a thickness of 0.05 mm. In addition, the light absorption coefficient has been measured as a function of cell size and wavelength. It has been found that the transmittance has a strong dependence with the wavelength, presenting these transparent materials Rayleigh scattering. On the other hand, the transmission of visible light through these nanocellular materials has been modelled for the first time. The developed model reproduces with good accuracy the trends observed in the experimental results and provides remarkable insights into the physics mechanisms controlling the optical behavior of these materials.
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•Transmittance to visible light of transparent nanocellular polymethylmethacrylate was measured.•Samples with a cell size 14 nm and a relative density of 0.46 can present transmittances as high as 0.94.•A theoretical model predicting the transmittance to visible light of nanocellular polymers has been developed.•Rayleigh scattering is main mechanisms of light transmission in transparent nanocellular polymethylmethacrylate.
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