702 research outputs found
Liquid Crystalline Thermosets from Ester, Ester-imide, and Ester-amide Oligomers
Main chain thermotropic liquid crystal esters, ester-imides, and ester-amides were prepared from AA, BB, and AB type monomeric materials and end-capped with phenylacetylene, phenylmaleimide, or nadimide reactive end-groups. The end-capped liquid crystal oligomers are thermotropic and have, preferably, molecular weights in the range of approximately 1000-15,000 grams per mole. The end-capped liquid crystaloligomers have broad liquid crystalline melting ranges and exhibit high melt stability and very low melt viscosities at accessible temperatures. The end-capped liquid crystal oli-gomers are stable forup to an hour in the melt phase. They are highly processable by a variety of melt process shape forming and blending techniques. Once processed and shaped, the end-capped liquid crystal oigomers were heated to further polymerize and form liquid crystalline thermosets (LCT). The fully cured products are rubbers above their glass transition temperatures
Liquid crystalline thermosets from ester, ester-imide, and ester-amide oligomers
Main chain thermotropic liquid crystal esters, ester-imides, and ester-amides were prepared from AA, BB, and AB type monomeric materials and were end-capped with phenylacetylene, phenylmaleimide, or nadimide reactive end-groups. The resulting reactive end-capped liquid crystal oligomers exhibit a variety of improved and preferred physical properties. The end-capped liquid crystal oligomers are thermotropic and have, preferably, molecular weights in the range of approximately 1000-15,000 grams per mole. The end-capped liquid crystal oligomers have broad liquid crystalline melting ranges and exhibit high melt stability and very low melt viscosities at accessible temperatures. The end-capped liquid crystal oligomers are stable for up to an hour in the melt phase. These properties make the end-capped liquid crystal oligomers highly processable by a variety of melt process shape forming and blending techniques including film extrusion, fiber spinning, reactive injection molding (RIM), resin transfer molding (RTM), resin film injection (RFI), powder molding, pultrusion, injection molding, blow molding, plasma spraying and thermo-forming. Once processed and shaped, the end-capped liquid crystal oligomers were heated to further polymerize and form liquid crystalline thermosets (LCT). The fully cured products are rubbers above their glass transition temperatures. The resulting thermosets display many properties that are superior to their non-end-capped high molecular weight analogs
Wholly aromatic liquid crystalline polyetherimide (LC-PEI) resins
The benefits of liquid crystal polymers and polyetherimides are combined in an all-aromatic thermoplastic liquid crystalline polyetherimide. Because of the unique molecular structure, all-aromatic thermotropic liquid crystal polymers exhibit outstanding processing properties, excellent barrier properties, low solubilities and low coefficients of thermal expansion in the processing direction. These characteristics are combined with the strength, thermal, and radiation stability of polyetherimides
Modeling the interactions of biomatter and biofluid
The internal motions of biomatter immersed in biofluid are investigated. The
interactions between the fragments of biomatter and its surrounding biofluid
are modeled using field theory. In the model, the biomatter is coupled to the
gauge field representing the biofluid. It is shown that at non-relativistic
limit various equation of motions, from the well-known Sine-Gordon equation to
the simultaneous nonlinear equations, can be reproduced within a single
framework.Comment: 10 pages, 3 figure
ΠΠ½ΡΠ΅Π»Π»ΠΈΠ³Π΅Π½ΡΠΈΡ ΠΊΠ°ΠΊ ΡΡΠ±ΡΠ΅ΠΊΡ ΠΈ ΠΎΠ±ΡΠ΅ΠΊΡ ΠΌΠ°Π½ΠΈΠΏΡΠ»ΡΡΠΈΠΈ
Humans are exposed to distinct structural classes of insecticides with different neurotoxic modes of action. Because calcium homeostasis is essential for proper neuronal function and development, we investigated the effects of insecticides from different classes (pyrethroid: (Ξ±-)cypermethrin; organophosphate: chlorpyrifos; organochlorine: endosulfan; neonicotinoid: imidacloprid) and mixtures thereof on the intracellular calcium concentration ([Ca(2+)]i). Effects of acute (20 min) exposure to (mixtures of) insecticides on basal and depolarization-evoked [Ca(2+)]i were studied in vitro with Fura-2-loaded PC12 cells and high resolution single-cell fluorescence microscopy. The data demonstrate that cypermethrin, Ξ±-cypermethrin, endosulfan, and chlorpyrifos concentration-dependently decreased depolarization-evoked [Ca(2+)]i, with 50% (IC50) at 78nM, 239nM, 250nM, and 899nM, respectively. Additionally, acute exposure to chlorpyrifos or endosulfan (10ΞΌM) induced a modest increase in basal [Ca(2+)]i, amounting to 68 Β± 8nM and 53 Β± 8nM, respectively. Imidacloprid did not disturb basal or depolarization-evoked [Ca(2+)]i at 10ΞΌM. Following exposure to binary mixtures, effects on depolarization-evoked [Ca(2+)]i were within the expected effect additivity range, whereas the effect of the tertiary mixture was less than this expected additivity effect range. These results demonstrate that different types of insecticides inhibit depolarization-evoked [Ca(2+)]i in PC12 cells by inhibiting voltage-gated calcium channels (VGCCs) in vitro at concentrations comparable with human occupational exposure levels. Moreover, the effective concentrations in this study are below those for earlier described modes of action. Because inhibition of VGCCs appears to be a common and potentially additive mode of action of several classes of insecticides, this target should be considered in neurotoxicity risk assessment studies
ΠΠ±ΡΠ°Π±ΠΎΡΠΊΠ° ΠΎΠΏΡΠΈΡΠ΅ΡΠΊΠΈΡ ΠΈΠ·ΠΌΠ΅ΡΠ΅Π½ΠΈΠΉ ΡΡΠ°Π΅ΠΊΡΠΎΡΠΈΠΈ Π»Π΅ΡΠ°ΡΠ΅Π»ΡΠ½ΡΡ ΠΎΠ±ΡΠ΅ΠΊΡΠΎΠ²
Π Π°ΡΡΠΌΠΎΡΡΠ΅Π½Ρ ΠΌΠ΅ΡΠΎΠ΄Ρ ΡΡΠ°Π²Π½ΠΈΠ²Π°Π½ΠΈΡ ΡΠ³Π»ΠΎΠ²ΡΡ
ΠΈΠ·ΠΌΠ΅ΡΠ΅Π½ΠΈΠΉ ΠΏΠΎ ΡΠΏΠΎΡΠΎΠ±Ρ Π½Π°ΠΈΠΌΠ΅Π½ΡΡΠΈΡ
ΠΊΠ²Π°Π΄ΡΠ°ΡΠΎΠ²: ΠΌΠ΅ΡΠΎΠ΄ ΡΡΠ°Π²Π½ΠΈΠ²Π°Π½ΠΈΡ ΠΈΠ·ΠΌΠ΅ΡΠ΅Π½ΠΈΠΉ ΠΎΡΠ΄Π΅Π»ΡΠ½ΠΎ Π² ΠΊΠ°ΠΆΠ΄ΠΎΠΌ Π²ΡΠ΅ΠΌΠ΅Π½Π½ΠΎΠΌ ΡΠ΅ΡΠ΅Π½ΠΈΠΈ, ΠΏΡΠ΅Π΄ΠΏΠΎΠ»Π°Π³Π°ΡΡΠΈΠΉ Π½ΡΠ»Π΅Π²ΠΎΠ΅ ΠΌΠ°ΡΠ΅ΠΌΠ°ΡΠΈΡΠ΅ΡΠΊΠΎΠ΅ ΠΎΠΆΠΈΠ΄Π°Π½ΠΈΠ΅ ΡΠ»ΡΡΠ°ΠΉΠ½ΡΡ
ΠΎΡΠΈΠ±ΠΎΠΊ ΠΈΠ·ΠΌΠ΅ΡΠ΅Π½ΠΈΠΉ, ΠΈ ΠΌΠ΅ΡΠΎΠ΄ ΡΡΠ°Π²Π½ΠΈΠ²Π°Π½ΠΈΡ ΠΈΠ·Π±ΡΡΠΎΡΠ½ΡΡ
ΠΎΠΏΡΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΈΠ·ΠΌΠ΅ΡΠ΅Π½ΠΈΠΉ Ρ ΠΏΠΎΠ΄Π°Π²Π»Π΅Π½ΠΈΠ΅ΠΌ ΠΈΡ
ΠΏΠΎΡΡΠΎΡΠ½Π½ΡΡ
ΡΠΈΡΡΠ΅ΠΌΠ°ΡΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΎΡΠΈΠ±ΠΎΠΊ Π² ΠΏΡΠ΅Π΄ΠΏΠΎΠ»ΠΎΠΆΠ΅Π½ΠΈΠΈ Π·Π°ΡΠΎΡΠ΅Π½Π½ΠΎΡΡΠΈ ΠΈΠ·ΠΌΠ΅ΡΠ΅Π½ΠΈΠΉ ΠΊΠ°ΠΊ ΡΠ»ΡΡΠ°ΠΉΠ½ΡΠΌΠΈ, ΡΠ°ΠΊ ΠΈ Π½Π΅ΠΈΠ·Π²Π΅ΡΡΠ½ΡΠΌΠΈ ΠΏΠΎ Π²Π΅Π»ΠΈΡΠΈΠ½Π΅ ΠΈ Π·Π½Π°ΠΊΡ ΡΠΈΡΡΠ΅ΠΌΠ°ΡΠΈΡΠ΅ΡΠΊΠΈΠΌΠΈ ΠΏΠΎΠ³ΡΠ΅ΡΠ½ΠΎΡΡΡΠΌΠΈ.Π ΠΎΠ·Π³Π»ΡΠ½ΡΡΠΎ ΠΌΠ΅ΡΠΎΠ΄ΠΈ Π·ΡΡΠ²Π½ΡΠ²Π°Π½Π½Ρ ΠΊΡΡΠΎΠ²ΠΈΡ
Π²ΠΈΠΌΡΡΡΠ²Π°Π½Ρ Π·Π° ΡΠΏΠΎΡΠΎΠ±ΠΎΠΌ Π½Π°ΠΉΠΌΠ΅Π½ΡΠΈΡ
ΠΊΠ²Π°Π΄ΡΠ°ΡΡΠ²: ΠΌΠ΅ΡΠΎΠ΄ Π·ΡΡΠ²Π½ΡΠ²Π°Π½Π½Ρ Π²ΠΈΠΌΡΡΡΠ²Π°Π½Ρ ΠΎΠΊΡΠ΅ΠΌΠΎ Π² ΠΊΠΎΠΆΠ½ΠΎΠΌΡ ΡΠ°ΡΠΎΠ²ΠΎΠΌΡ ΡΠΎΠ·ΡΡΠ·Ρ, ΡΠΎ ΠΏΠ΅ΡΠ΅Π΄Π±Π°ΡΠ°Ρ Π½ΡΠ»ΡΠΎΠ²Π΅ ΠΌΠ°ΡΠ΅ΠΌΠ°ΡΠΈΡΠ½Π΅ ΠΎΡΡΠΊΡΠ²Π°Π½Π½Ρ Π²ΠΈΠΏΠ°Π΄ΠΊΠΎΠ²ΠΈΡ
ΠΏΠΎΡ
ΠΈΠ±ΠΎΠΊ Π²ΠΈΠΌΡΡΡΠ²Π°Π½Ρ, Ρ ΠΌΠ΅ΡΠΎΠ΄ Π·ΡΡΠ²Π½ΡΠ²Π°Π½Π½Ρ Π½Π°Π΄Π»ΠΈΡΠΊΠΎΠ²ΠΈΡ
ΠΎΠΏΡΠΈΡΠ½ΠΈΡ
Π²ΠΈΠΌΡΡΡΠ²Π°Π½Ρ ΡΠ· Π·Π°Π³Π»ΡΡΠ΅Π½Π½ΡΠΌ ΡΡ
ΠΏΠΎΡΡΡΠΉΠ½ΠΈΡ
ΡΠΈΡΡΠ΅ΠΌΠ°ΡΠΈΡΠ½ΠΈΡ
ΠΏΠΎΡ
ΠΈΠ±ΠΎΠΊ Ρ ΠΏΡΠΈΠΏΡΡΠ΅Π½Π½Ρ Π·Π°ΡΠΌΡΡΠ΅Π½ΠΎΡΡΡ Π²ΠΈΠΌΡΡΡΠ²Π°Π½Ρ ΡΠΊ Π²ΠΈΠΏΠ°Π΄ΠΊΠΎΠ²ΠΈΠΌΠΈ, ΡΠ°ΠΊ Ρ Π½Π΅Π²ΡΠ΄ΠΎΠΌΠΈΠΌΠΈ Π·Π° Π²Π΅Π»ΠΈΡΠΈΠ½ΠΎΡ ΡΠ° Π·Π½Π°ΠΊΠΎΠΌ ΡΠΈΡΡΠ΅ΠΌΠ°ΡΠΈΡΠ½ΠΈΠΌΠΈ ΠΏΠΎΡ
ΠΈΠ±ΠΊΠ°ΠΌΠΈ.The methods of equalizing angular measurements according to the method of least squares are examined: the method of equalizing measurements separately in each temporary section, that assumes the zero mathematical expectation of the random errors of measurements, and the method of equalizing excessive optical measurements with suppression of their constant systematic errors under the assumption of the obstruction of measurements by systematic errors both random and unknowns by value and sign
A fabrication guide for planar silicon quantum dot heterostructures
We describe important considerations to create top-down fabricated planar
quantum dots in silicon, often not discussed in detail in literature. The
subtle interplay between intrinsic material properties, interfaces and
fabrication processes plays a crucial role in the formation of
electrostatically defined quantum dots. Processes such as oxidation, physical
vapor deposition and atomic-layer deposition must be tailored in order to
prevent unwanted side effects such as defects, disorder and dewetting. In two
directly related manuscripts written in parallel we use techniques described in
this work to create depletion-mode quantum dots in intrinsic silicon, and
low-disorder silicon quantum dots defined with palladium gates. While we
discuss three different planar gate structures, the general principles also
apply to 0D and 1D systems, such as self-assembled islands and nanowires.Comment: Accepted for publication in Nanotechnology. 31 pages, 12 figure
Characterisation and classification of oligometastatic disease : a European Society for Radiotherapy and Oncology and European Organisation for Research and Treatment of Cancer consensus recommendation
Oligometastatic disease has been proposed as an intermediate state between localised and systemically metastasised disease. In the absence of randomised phase 3 trials, early clinical studies show improved survival when radical local therapy is added to standard systemic therapy for oligometastatic disease. However, since no biomarker for the identification of patients with true oligometastatic disease is clinically available, the diagnosis of oligometastatic disease is based solely on imaging findings. A small number of metastases on imaging could represent different clinical scenarios, which are associated with different prognoses and might require different treatment strategies. 20 international experts including 19 members of the European Society for Radiotherapy and Oncology and European Organisation for Research and Treatment of Cancer OligoCare project developed a comprehensive system for characterisation and classification of oligometastatic disease. We first did a systematic review of the literature to identify inclusion and exclusion criteria of prospective interventional oligometastatic disease clinical trials. Next, we used a Delphi consensus process to select a total of 17 oligometastatic disease characterisation factors that should be assessed in all patients treated with radical local therapy for oligometastatic disease, both within and outside of clinical trials. Using a second round of the Delphi method, we established a decision tree for oligometastatic disease classification together with a nomenclature. We agreed oligometastatic disease as the overall umbrella term. A history of polymetastatic disease before diagnosis of oligometastatic disease was used as the criterion to differentiate between induced oligometastatic disease (previous history of polymetastatic disease) and genuine oligometastatic disease (no history of polymetastatic disease). We further subclassified genuine oligometastatic disease into repeat oligometastatic disease (previous history of oligometastatic disease) and de-novo oligometastatic disease (first time diagnosis of oligometastatic disease). In de-novo oligometastatic disease, we differentiated between synchronous and metachronous oligometastatic disease. We did a final subclassification into oligorecurrence, oligoprogression, and oligopersistence, considering whether oligometastatic disease is diagnosed during a treatment-free interval or during active systemic therapy and whether or not an oligometastatic lesion is progressing on current imaging. This oligometastatic disease classification and nomenclature needs to be prospectively evaluated by the OligoCare study
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