39 research outputs found
Self-oscillations in rocks,results of laboratory experiments
The method of generation of self-oscillations in rocks is developed here. Self-oscillations arise as a result of direct and inverse mechanoelectric transformations without an external generator. Laboratory experiments were
executed with different samples. A relation between self-oscillation parameters from samples humidity and direct electrical field applied to samples was detected
Parasympathetic cholinergic and neuropeptide mechanisms of migraine
© 2016, Iranian Society of Regional Anesthesia and Pain Medicine (ISRAPM).Context: Migraine mechanisms remain largely uncovered for various reasons including a very high complexity of the neurophysiological mechanisms implicated in this disorder and a plethora of endogenous biologically active compounds involved in the pathological process. The functional role of parasympathetic innervation of meninges and cholinergic mechanisms of migraine are among little explored issues despite multiple evidence indirectly indicating the role of acetylcholine (ACh) and its analogues in migraine and other types of headache. In the current short review, we discuss morphological, functional, and clinical issues related to the role of ACh and its analogues such as carbachol and nicotine in this most common neurological disorder. Evidence Acquisition: In the present work, studies published from 1953 to 2016 were investigated. Literature was searched with following keywords: acetylcholine (ACh), carbachol, nicotine, parasympathetic, mast cells, vasoactive intestinal polypeptide (VIP), and pituitary adenylate cyclase-activating polypeptide (PACAP). Results: Parasympathetic fibers originatedfromSPGandtrigeminal nerves can interact at the level of meninges which is considered to be the origin site of migraine pain. Here, in dura mater, ACh, VIP, and PACAP released by parasympathetic afferents can both affect mast cells provoking its degranulation and additional release of neurotransmitters, or they can directly affect trigeminal nerves inducing nociception. Conclusions: In summary, cholinergic mechanisms in migraine and other types of headache remain little elucidated and future studies should clarify the role of parasympathetic nerves and molecular mechanisms of cholinergic modulation within the nociceptive system
Quantitative measurement of the vibrational amplitude and phase in photorefractive time-average interferometry: A comparison with electronic speckle pattern interferometry
Experimental study of mechanoelectric transformations in low saturated rocks
The results of study of the electrical response of dry and slightly saturated with salted water (NaCl) or kerosene cores of Berea sandstone to acoustic effect in the frequency range of 0.5–10 kHz are presented herein. A strong lateral inhomogeneity by saturation was created during the experiments. The electrical response is sensitive to the addition of all types of fluid in the rock samples. At the same time, the reaction to the addition of highly concentrated salt solution in the samples is weak, while the reaction to the addition of weak concentrated salt solution and kerosene is strong. A high correlation is observed between the shape of the electrical response spectra of dry and damped cores, up to 0.9. For kerosene, the shape of the spectrum varies greatly, the rank correlation coefficient of the shape of the spectra is 0.3. The fact of a significant increase in electrical response on addition of non-polar fluid (kerosene) to the core is beyond the theoretical framework and may be associated with the creation of strong lateral petrophysical heterogeneity by saturation. The strong sensitivity of the amplitude of the electroseismic response of rocks to very weak but non-homogeneous saturation is interesting for the development of remote methods for determination of the type of fluid saturation of rocks, when searching for minerals and for the development of the methods for prediction of geophysical catastrophes
RESEARCH OF MECHANOELECTRIC TRANSFORMATIONS IN ROCK WITH A SMALL DEGREE OF FLUID SATURATION
The paper describes an experimental plant and data processing technique for investigations of acoustoelectric transformations in rock samples with varying degrees of moistening. The results of investigations are presented for dry and moistened with kerosene core of Berea Grey sandstone under acoustic effect produced by linearly frequencymodulated signal in 0,7–10 kHz band. The was discovered a strong effect nonlinearity expressing itself in the second and third harmonics emerging, and an increase in the amplitude of the response of the electric signal. In the lower frequency band the amplitude of the second harmonic of the electric field intensity oscillations is comparable with the amplitude of the first one and can even exceed it. With the dropwise addition of kerosene, the power of the electrical signal varies at many times with a strong change in the shape of the signal spectrum. Therewith the shape of the acoustic signal spectrum is practically unchanged. The strong sensitivity of the coefficient of acoustoelectric transformation of rocks to moistening, which significantly changes the amplitude and phase of the response, is interesting from the point of view of developing remote methods for identifying the type of fluid saturation of rocks and methods for predicting geophysical catastrophes
Parasympathetic cholinergic and neuropeptide mechanisms of migraine
© 2016, Iranian Society of Regional Anesthesia and Pain Medicine (ISRAPM).Context: Migraine mechanisms remain largely uncovered for various reasons including a very high complexity of the neurophysiological mechanisms implicated in this disorder and a plethora of endogenous biologically active compounds involved in the pathological process. The functional role of parasympathetic innervation of meninges and cholinergic mechanisms of migraine are among little explored issues despite multiple evidence indirectly indicating the role of acetylcholine (ACh) and its analogues in migraine and other types of headache. In the current short review, we discuss morphological, functional, and clinical issues related to the role of ACh and its analogues such as carbachol and nicotine in this most common neurological disorder. Evidence Acquisition: In the present work, studies published from 1953 to 2016 were investigated. Literature was searched with following keywords: acetylcholine (ACh), carbachol, nicotine, parasympathetic, mast cells, vasoactive intestinal polypeptide (VIP), and pituitary adenylate cyclase-activating polypeptide (PACAP). Results: Parasympathetic fibers originatedfromSPGandtrigeminal nerves can interact at the level of meninges which is considered to be the origin site of migraine pain. Here, in dura mater, ACh, VIP, and PACAP released by parasympathetic afferents can both affect mast cells provoking its degranulation and additional release of neurotransmitters, or they can directly affect trigeminal nerves inducing nociception. Conclusions: In summary, cholinergic mechanisms in migraine and other types of headache remain little elucidated and future studies should clarify the role of parasympathetic nerves and molecular mechanisms of cholinergic modulation within the nociceptive system
Parasympathetic cholinergic and neuropeptide mechanisms of migraine
© 2016, Iranian Society of Regional Anesthesia and Pain Medicine (ISRAPM).Context: Migraine mechanisms remain largely uncovered for various reasons including a very high complexity of the neurophysiological mechanisms implicated in this disorder and a plethora of endogenous biologically active compounds involved in the pathological process. The functional role of parasympathetic innervation of meninges and cholinergic mechanisms of migraine are among little explored issues despite multiple evidence indirectly indicating the role of acetylcholine (ACh) and its analogues in migraine and other types of headache. In the current short review, we discuss morphological, functional, and clinical issues related to the role of ACh and its analogues such as carbachol and nicotine in this most common neurological disorder. Evidence Acquisition: In the present work, studies published from 1953 to 2016 were investigated. Literature was searched with following keywords: acetylcholine (ACh), carbachol, nicotine, parasympathetic, mast cells, vasoactive intestinal polypeptide (VIP), and pituitary adenylate cyclase-activating polypeptide (PACAP). Results: Parasympathetic fibers originatedfromSPGandtrigeminal nerves can interact at the level of meninges which is considered to be the origin site of migraine pain. Here, in dura mater, ACh, VIP, and PACAP released by parasympathetic afferents can both affect mast cells provoking its degranulation and additional release of neurotransmitters, or they can directly affect trigeminal nerves inducing nociception. Conclusions: In summary, cholinergic mechanisms in migraine and other types of headache remain little elucidated and future studies should clarify the role of parasympathetic nerves and molecular mechanisms of cholinergic modulation within the nociceptive system
Self-oscillations in rocks,results of laboratory experiments
The method of generation of self-oscillations in rocks is developed here. Self-oscillations arise as a result of direct and inverse mechanoelectric transformations without an external generator. Laboratory experiments were
executed with different samples. A relation between self-oscillation parameters from samples humidity and direct electrical field applied to samples was detected.PublishedJCR Journalope
Parasympathetic cholinergic and neuropeptide mechanisms of migraine
© 2016, Iranian Society of Regional Anesthesia and Pain Medicine (ISRAPM).Context: Migraine mechanisms remain largely uncovered for various reasons including a very high complexity of the neurophysiological mechanisms implicated in this disorder and a plethora of endogenous biologically active compounds involved in the pathological process. The functional role of parasympathetic innervation of meninges and cholinergic mechanisms of migraine are among little explored issues despite multiple evidence indirectly indicating the role of acetylcholine (ACh) and its analogues in migraine and other types of headache. In the current short review, we discuss morphological, functional, and clinical issues related to the role of ACh and its analogues such as carbachol and nicotine in this most common neurological disorder. Evidence Acquisition: In the present work, studies published from 1953 to 2016 were investigated. Literature was searched with following keywords: acetylcholine (ACh), carbachol, nicotine, parasympathetic, mast cells, vasoactive intestinal polypeptide (VIP), and pituitary adenylate cyclase-activating polypeptide (PACAP). Results: Parasympathetic fibers originatedfromSPGandtrigeminal nerves can interact at the level of meninges which is considered to be the origin site of migraine pain. Here, in dura mater, ACh, VIP, and PACAP released by parasympathetic afferents can both affect mast cells provoking its degranulation and additional release of neurotransmitters, or they can directly affect trigeminal nerves inducing nociception. Conclusions: In summary, cholinergic mechanisms in migraine and other types of headache remain little elucidated and future studies should clarify the role of parasympathetic nerves and molecular mechanisms of cholinergic modulation within the nociceptive system