Manipulating and dispensing liquids on the micrometre- and nanoscale is important in biotechnology and combinatorial chemistry, and also for patterning inorganic, organic and biological inks. Several methods for dispensing liquids exist, but many require complicated electrodes and high-voltage circuits. Here, we show a simple way to draw attolitre liquid droplets from one or multiple sessile drops or liquid film reservoirs using a pyroelectrohydrodynamic dispenser. Local pyroelectric forces, which are activated by scanning a hot tip or an infrared laser beam over a lithium niobate substrate, draw liquid droplets from the reservoir below the substrate, and deposit them on the underside of the lithium niobate substrate. The shooting direction is altered by moving the hot tip or laser to form various patterns at different angles and locations. Our system does not require electrodes, nozzles or circuits, and is expected to have many applications in biochemical assays and various transport and mixing processes.
When primary extended surgery limits LR, histologic subtype and grade determine the outcome. At recurrence, a second surgery is of limited benefit.
Aggressive fibromatosis (AF) is a monoclonal proliferative disease but does not metastasize and does not dedifferentiate to a high-grade malignancy in case of recurrence. Biopsy is usually necessary to confirm the diagnosis. A hallmark is its apparent unpredictable clinical course producing a large heterogeneity even with an indistinguishable morphology. Additional studies of the molecular determinants of desmoid behavior are needed to guide selection of the various therapeutic modalities. During the last 10 years, the treatment of AF has evolved and the role of routine, aggressive first-line treatment (radiotherapy and surgery) is now debated. If a wait-and-see policy is used at initial presentation, it is observed that >50% of patients will have relatively indolent disease. Aggressive treatments that take their indications from retrospective studies should be re-evaluated in the light of new data. The objective of this article is to propose an algorithm that commences with more conservative approaches before treatments that have associated long-term morbidity, the more aggressive therapies being reserved only for those who really need it.
La1, but not BB536, adheres to the colonic mucosa, and affects intestinal microbiota by reducing the concentration of pathogens and modulates local immunity.
In liquids realm, surface tension and capillarity are the key forces driving the formation of the shapes pervading the nature. The steady dew drops appearing on plant leaves and spider webs result from the minimization of the overall surface energy [Zheng Y, et al. (2010) Nature 463:640-643]. Thanks to the surface tension, the interfaces of such spontaneous structures exhibit extremely good spherical shape and consequently worthy optical quality. Also nanofluidic instabilities generate a variety of fascinating liquid silhouettes, but they are however intrinsically short-lived. Here we show that such unsteady liquid structures, shaped in polymeric liquids by an electrohydrodynamic pressure, can be rapidly cured by appropriate thermal treatments. The fabrication of many solid microstructures exploitable in photonics is demonstrated, thus leading to a new concept in 3D lithography. The applicability of specific structures as optical tweezers and as novel remotely excitable quantum dots-embedded microresonators is presented.A wide variety of lithographic techniques have been developed for fabricating 3D structures (1-5), such as soft lithography (6) that allows one to develop lab-on-chip devices with applications ranging from organic light emitting diode to biology and biochemistry (7). Among others, "capillary-force lithography" is able to nicely pattern polymers at nano-/microscale, but with a very low aspect ratio, in a single step and avoiding the use of external forces (8). Other approaches generate self-patterned structures by using destabilizing forces produced by electric fields, namely electrohydrodynamic (EHD) lithography (9). In EHD lithography, amazing polymeric patterns have been reported, demonstrating the possibility of controlling the process with high accuracy. This method appears suitable only for a few types of periodic patterns having a relatively low aspect ratio (i.e., pillars, dots, and lines). In fact, the control of liquid film instabilities is a demanding task as very little perturbations could drag the nanofluidic system toward nonfully predictable configurations. Such occurrence, for high aspect-ratio features, would prevent the achievement of the expected final steady state. The EHD lithography is usually performed at temperatures above the glass transition of the polymer film [typically polystyrene or poly (methyl methacrylate)], obtaining permanent microstructures by slow annealing and successive cooling, taking hours (10-13).In general, the hydrodynamic techniques produce steadystate structures resulting from the equilibrium state of a specific fluidic effect. Conversely, the core of our approach consists in "rapid-curing" temporary structures, which evolve continuously under specific fluidic instabilities, by a fast heating procedure. The interesting aspect of this approach is that it gives access to very intriguing fluid shapes, occurring in unsteady fluid physics at nanoscale, which could be very useful in modern science. As investigated recently, breakup of viscoelastic filaments...
Hypodermic needle injection is still the most common method of drug delivery despite its numerous limitations and drawbacks, such as pain, one‐shot administration, and risk of infection. Seeking a viable, safe, and pain‐free alternative to the over 16 billion injections per year has therefore become a top priority for our modern technological society. Here, a system that uses a pyroelectric cartridge in lieu of the syringe piston as a potential solution is discussed. Upon stimulation, the cartridge electro‐draws, at room temperature, an array of drug‐encapsulated, biodegradable polymer microneedles, able to deliver into hypodermic tissue both hydrophobic and hydrophilic bioactive agents, according to a predefined chrono‐programme. This mould‐free and contact‐free method permits the fabrication of biodegradable polymer microneedles into a ready‐to‐use configuration. In fact, they are formed on a flexible substrate/holder by drawing them directly from drop reservoirs, using a controlled electro‐hydrodynamic force. Tests of insertion are performed and discussed in order to demonstrate the possibility to prepare microneedles with suitable geometric and mechanical properties using this method.
We report a novel method for direct printing of viscous polymers based on a pyro-electrohydrodynamic repulsion system capable of overcoming limitations on the material type, geometry and thickness of the receiving substrate. In fact, the results demonstrate that high viscosity polymers can be easily manipulated for optical functionalizing of lab-on-a-chip devices through demonstration of direct printing of polymer microlenses onto microfluidic chips and optical fibre terminations. The present system has great potential for applications from biomolecules to nano-electronics. Moreover, in order to prove the effectiveness of the system, the optical performance of such microlenses has been characterized by testing their imaging capabilities when the fibroblast cells were allowed to flow inside the microfluidic channel, showing one of their possible applications on-board a LoC platform.
Lab-on-a-Chip (LoC) devices are extremely promising in that they enable diagnostic functions at the point-of-care. Within this scope, an important goal is to design imaging schemes that can be used out of the laboratory. In this paper, we introduce and test a pocket holographic slide that allows digital holography microscopy to be performed without an interferometer setup. Instead, a commercial off-the-shelf plastic chip is engineered and functionalized with this aim. The microfluidic chip is endowed with micro-optics, that is, a diffraction grating and polymeric lenses, to build an interferometer directly on the chip, avoiding the need for a reference arm and external bulky optical components. Thanks to the single-beam scheme, the system is completely integrated and robust against vibrations, sharing the useful features of any common path interferometer. Hence, it becomes possible to bring holographic functionalities out of the lab, moving complexity from the external optical apparatus to the chip itself. Label-free imaging and quantitative phase contrast mapping of live samples are demonstrated, along with flexible refocusing capabilities. Thus, a liquid volume can be analyzed in one single shot with no need for mechanical scanning systems.
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