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631.
The pyramidal system of the slow loris was investigated physiologically and histologically. The cerebral response to medullary
pyramid stimulation was mapped and found to distribute in two separate foci, rostral to the hand and foot somatosensory foci.
The tract was found to contain about 204,000 fibers at the midolivary level on one side, with about 85% of the fibers less
than 2 Μm and 1% greater than 4 Μm. Calculation of the amplitude and configuration of the true antidromic response, based
on the histological findings, disagreed with the observed response. The latter was found to be analogous to the rwave of the American opossum, which appears to result from intracortical pyramidal tract collateral activation of the cerebral
neurons. This response is not present in the macaque monkey. 相似文献
632.
Maxim Zhadobov Robin Augustine Ronan Sauleau Stanislav Alekseev Alessandra Di Paola Catherine Le Quément Yonis Soubere Mahamoud Yves Le Dréan 《Bioelectromagnetics》2012,33(4):346-355
The main purpose of this study is to provide experimental data on the complex permittivity of some biological solutions in the 2–67 GHz range at room and human body temperatures. The permittivity measurements are performed using an open‐ended coaxial probe. Permittivity spectra of several representative monomolecular solutions of proteins, amino acids, nucleic acids, and carbohydrates are analyzed and compared. Furthermore, measurements have also been performed for complex biomolecular solutions, including bovine serum albumin (BSA)–DNA–glucose mixture, culture medium, and yeast extract solution. The results demonstrate that for concentrations below 1%, the permittivity spectra of the solutions do not substantially differ from that of distilled water. Measurements carried out for 4% and 20% BSA solutions show that the presence of proteins results in a decrease in permittivity. For highly concentrated RNA solutions (3%), a slight increase in the imaginary part of the permittivity is observed below 10 GHz. Experimental data show that free water permittivity can be used for modeling of the culture medium above 10 GHz. However, at lower frequencies a substantial increase in the imaginary part of the permittivity due to ionic conductivity should be carefully taken into account. A similar increase has also been observed for the yeast extract solution in the lower frequency region of the considered spectrum. Above 10 GHz, the high concentration of proteins and other low‐permittivity components of the yeast extract solution results in a decrease in the complex permittivity compared to that of water. Obtained data are of utmost importance for millimeter‐wave dosimetry studies. Bioelectromagnetics 33:346–355, 2012. © 2011 Wiley Periodicals, Inc. 相似文献
633.
Effects of continuous and pulsed 2450-MHz radiation on spontaneous lymphoblastoid transformation of human lymphocytes in vitro. 总被引:3,自引:0,他引:3
Normal human lymphocytes were isolated from the peripheral blood of healthy donors. One-ml samples containing (10(6)) cells in chromosome medium 1A were exposed for 5 days to conventional heating or to continuous wave (CW) or pulsed wave (PW) 2450-MHz radiation at non-heating (37 degrees C) and various heating levels (temperature increases of 0.5, 1.0, 1.5, and 2 degrees C). The pulsed exposures involved 1-microsecond pulses at pulse repetition frequencies from 100 to 1,000 pulses per second at the same average SAR levels as the CW exposures. Actual average SARs ranged to 12.3 W/kg. Following termination of the incubation period, spontaneous lymphoblastoid transformation was determined with an image analysis system. The results were compared among each of the experimental conditions and with sham-exposed cultures. At non-heating levels, CW exposure did not affect transformation. At heating levels both conventional and CW heating enhanced transformation to the same extent and correlate with the increases in incubation temperature. PW exposure enhanced transformation at non-heating levels. This finding is significant (P less than .002). At heating levels PW exposure enhanced transformation to a greater extent than did conventional or CW heating. This finding is significant at the .02 level. We conclude that PW 2450-MHz radiation acts differently on the process of lymphoblastoid transformation in vitro compared with CW 2450-MHz radiation at the same average SARs. 相似文献
634.
S. S. Mayakaduwa Anurudda Karunarathna Dinesh Mohan 《Chemical Speciation and Bioavailability》2016,28(1-4):110-118
Biochars showed a potential as adsorbents for organic contaminants, however, have not been tested for carbofuran, which has been detected frequently in water. This study provides evidences for the use of infused tea residue derived biochar for carbofuran removal. Biochars were produced at 300, 500 and 700 °C by slow pyrolysis and were characterized by proximate and ultimate analysis, FT-IR, SEM, BET and pore size distribution. Pyrolysis temperature showed a pronounced effect on biochar properties. The maximum carbofuran removal was achieved at pH 5. Freundlich and Temkin models best fit the equilibrium data. Biochars produced at 700 °C showed the highest sorption intensity. The adsorption process was likely to be a favorable chemisorption process with electrostatic interactions between carbofuran molecules and biochar surface. Acid-base interactions, electrophilic addition reactions and amide bond formations are the possible mechanisms of carbofuran adsorption. Overall, biochars prepared from tea waste can be utilized as effective adsorbents for removal of aqueous carbofuran. 相似文献
635.
Telmisartan ameliorates vascular endothelial dysfunction in coronary slow flow phenomenon (CSFP)
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Coronary slow flow phenomenon (CSFP) is a coronary microvascular disorder with an increasing morbidity, and currently, available therapies are of limited clinical value for its cure. Hence, it is urgent to find a novel approach to CSFP treatment. Several studies show that endothelial dysfunction plays a critical role in the aetiology of CSFP. Telmisartan (TMST) is a clinically available anti‐hypertensive medicine and has shown its potential properties for improving vascular endothelial function. Thus, we aimed to investigate the effect of TMST on endothelial dysfunction in CSFP, Endothelial‐dependent flow‐mediated vasodilation, serum levels of nitric oxide, adiponectin, and endothelin‐1 were surveyed before and after 3 months of TMST treatment. And the percentages of vasodilator response to acetylcholine (Ach) were detected after 12 weeks of TMST treatment. Compare with pretreatment, flow‐mediated vasodilation, nitric oxide, and adiponectin were substantially improved after TMST treatment; meanwhile, endothelin‐1 was decreased in the TMST group (all P < .01). Compared with the model group, the vasodilator response to Ach was enormously increased after TMST intervention. Additionally, administration of SU11274 or GW9662 would partially reverse the protective effects of TMST on accumulative concentration‐vasodilator responses to Ach (P < .01). We demonstrated that administration of TMST could remarkably increase the mRNA and/or protein levels of hepatocyte growth factor, mesenchymal‐epithelial transition factor, peroxisome proliferation‐activated receptor γ, whereas dramatically diminish mRNA and/or protein levels of p‐JNK1/2, mitogen‐activated protein kinase, and nuclear factor kappa B (P < .05). Our results thus implicate that TMST ameliorates endothelial dysfunction in CSFP. It is suggested that TSMF may play an important role in the medication of CSFP. 相似文献
636.
637.
Carolyn M. Crockett 《American journal of primatology》1984,6(2):121-122
This study examines the positional and activity behavior of a captive slow loris, Nycticebus coucang. The male individual was housed in a primate facility providing a seminatural environment and was subjected to a series of videotape recordings from which 1,878 point observations were taken. The enclosure was designed to allow maximum flexibility of substrate use. Quantitative information detailing activity, positional mode, and substrate geometry was collected using a checklist of 15 variables. Data were tabulated and compared as frequency distributions to describe activity budgets, the use of locomotor and postural modes, and the relation of posture to activity behavior and substrate geometry. The results indicated that almost 90% of the active day may be devoted to behaviors directly or indirectly related to dietary functions. For locomotor behavior, both climbing and walking were associated with the use of diagonal couplets. The loris devoted 52% of its positional behavior to postural modes, favoring the quadrupedal stand, triplets, and sitting. Suspension was found to be used more often in posture than locomotion. Overall, the loris's repertory of positional modes accommodated a wide range of substrate geometries. 相似文献
638.
Vacuoles play various roles in many physiologically relevant processes in plants. Some of the more prominent are turgor provision, the storage of minerals and nutrients, and cellular signalling. To fulfil these functions a complement of membrane transporters is present at the tonoplast. Prolific patch clamp studies have shown that amongst these, both selective and non-selective ion channels participate in turgor regulation, nutrient storage and signalling. This article reviews the physiological roles, expression patterns and structure function properties of plant vacuolar anion and cation channels that are gated by voltage and ligands. 相似文献
639.
640.
《Cell reports》2023,42(2):112022
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