41 research outputs found
Spontaneous and driven growth of multicellular lipid compartments to millimeter size from porous polymer structures**
This report describes a method to obtain multicellular shaped compartments made by lipids growing from a sponge-like porous structure. Each compartment is several tens of micrometers in diameter and separated by membranes comprised of phospholipid and amphipathic molecules. The multi-compartment structure spontaneously grew to a millimeter scale, driven by an ionic concentration difference between the interior and exterior environments of the sponge. These compartments can also easily incorporate hydrophilic species as a well as smaller materials such as liposomes. Additionally, we showed that mechanical squeezing of the sponge was also effective in producing multicellular bodies. These simple methods to obtain large-scale multicellular compartment of lipid membrane will help future designs and trials of chemical communications on artificial cells
Characterization of stability of benchmark organic photovoltaic films after proton and electron bombardments
Organic solar cells have attractive potential for space applications as they have very high specific power (power generated per weight) and ultra-high flexibility (to reduce stowed volume). However, one critical issue is whether they are stable under the harsh space environment, particularly their stability under high energy, high flux, electron and proton bombardment. In this paper, the stability of benchmark organic photovoltaic layers under proton bombardment (150 keV with a fluence of 1 × 1012/cm2) and electron bombardment (1 MeV with a fluence of 1 × 1013/cm2) under vacuum is investigated. Raman spectroscopy, photoluminescence spectroscopy, and optical reflectance spectroscopy are applied to study their chemical/structural, photo-chemical/morphological, and optical stability after the bombardments. The results show that all the benchmark organic photovoltaic films are stable under the radiation, implying that organic solar cells could be feasible for space applications
Cガタカンエン ウイルス ジゾク カンセン カンジャ ノ カンセンイカ ニオケル ジョセイ ホルモン ノ ヤクワリ
The most common cause of hepatic fibrosis is chronic hepatitis C virus infection, the characteristic feature of which is hepatic steatosis. Hepatic steatosis leads to an increase in lipid peroxidation in hepatocytes, which in turn activates hepatic stellate cells (HSCs). HSCs are also thought to be the primary target cells for inflammatory stimuli, and produce extracellular matrix components. Clinical observations and death statistics support the view that chronic hepatitis C appears to progress more rapidly in men than in women, and cirrhosis is predominately a disease of men and postmenopausal women. It should be noted in this respect that estradiol (E2) is a potent endogenous antioxidant. Our studies showed that E2 suppressed hepatic fibrosis in hepatic fibrosis models, and attenuated HSC activation in primary culture. Recently, variant estrogen receptors (ERs) were found to be expressed to a greater extent in male patients with chronic liver disease than in female subjects. We also demonstrated decreased levels of ERs in postmenopausal women and cirrhotic patients of both genders. The present review summarizes our current knowledge of the biological functions of E2 and ER status as it relates to fibrogenesis in the liver
Clinical value of the determination of serum guanase activity in patients with chronic hepatitis type C
The study examines the clinical significance of guanase (GU) measurement inpatients with hepatitis C. 688 patients in whom either ALT was abnormal, or in whom HBsAg or HCVAb was detected in the serum, were enrolled into this study. The percentage of cases in which normal ALT while elevated GU was compared among the different disease groups. Then, the percentage of cases with normal ALT but elevated GU was compared between HBV and HCV groups. For the entire population, a significant correlation was observed between ALT and GU (r=0.872). The overall percentage of cases with normal ALT but elevated GU activity was 11.4%. In HCV group, 449 cases had normal ALT. Of these cases, 20.3% had elevated GU, while ALT was normal. Before 1989, no test to check donated blood for HCV antibody was available. However, screening of donated blood for high GU was associated with a reduced incidence of post-transfusion hepatitis. This is probably because following the screening, blood donated by patients with hepatitis C who had normal ALT but elevated GU was rejected. After the introduction of HCV antibody measurement, GU measurement is still useful to reveal the pathophysiological condition in-patients with chronic hepatitis type C
<Preliminary>Molecular Cloning of cDNAs of the Genes Expressed in Differentiating Xylem of Tension Wood Formation in Eucalyptus camaidulensis L.
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Initiation and Development of Spikelets and Florets in Wheat as Influenced by Shading and Nitrogen Supply at the Spikelet Phase
The spike of the main culm in winter wheat was examined by scanning electron microscopy from the double ridge to 6 days after the terminal spikelet stage to quantitatively evaluate the effects of shading and nitrogen supply at the spikelet phase on the numbers of spikelets and floret primordia, and the development of florets. Positional differences on a spike in grain setting at maturity were also investigated. Nitrogen supply affected neither the rate nor duration of spikelet initiation, the number of spikelets remaining unchanged. Although nitrogen supply positively affected the initiation and development of florets, it slightly reduced the grain weight per spike at maturity due to a decrease in the number of grains per spike and the reduced grain weight. These results suggested that under the field condition, nitrogen supply at the double ridge stage is too late to have a significant effect on the spikelet number, and might induce competition for nitrogen between the main culm and tillers, or induce mutual shading between plants, resulting in lighter grain weight per spike. Shading decreased the rate of spikelet initiation, resulting in a significant decrease in spikelet number. The initiation and the development of florets were also decreased by shading. Lower non -structural carbohydrate content at the terminal spikelet stage suggested that the limited assimilate supply by shading was likely responsible for the decreases in the initiation and development of spikelets and florets
Initiation and Development of Spikelets and Florets in Wheat as Influenced by Shading and Nitrogen Supply at the Spikelet Phase
Does restriction of mandibular movements during sleep influence jaw-muscle activity?
AIM: To investigate the effect of restriction of mandibular movements during sleep on jaw-muscle activity. MATERIALS AND METHODS: Eleven healthy subjects (four men, seven women; mean age 25.9 ± 3.1 years) with self-reports and clinical indications of sleep-bruxism participated in three randomized sessions with three different types of oral appliances: 1) a full-arch maxillary and mandibular appliances which did not allow any mandibular movement, i.e., restrictive oral appliance (ROA), 2) full-arch maxillary and mandibular oral appliances (MMOA) with no restrictions of mandibular movements, and 3) a conventional full-arch flat stabilization appliance, i.e., maxillary oral appliance (MOA). Baseline recordings of jaw-muscle activity during sleep without any oral appliance were performed and followed by one week of nightly use of the oral appliances. After the baseline recording, subjects did three sessions with oral appliance during sleep. During the last night in each session, jaw-muscle activity was recorded and compared to baseline values. A detection threshold of 10 % of maximal voluntary clenching was used to analyze the electromyographic (EMG) activity from both sides of the masseter muscles and in accordance with published criteria (Lavigne et al. 1996). RESULTS: All subjects completed the experimental protocol. Regarding to the average of left and right sides, jaw-muscle activity expressed as number of EMG episodes per hour sleep was significantly lower during MOA (5.2 ± 1.1 episodes/h) compared to baseline values (6.7 ± 1.2, P < 0.01). Furthermore, the number of EMG bursts per hour sleep was significantly lower for ROA (28.3 ± 5.0 bursts/h) and MOA (25.0 ± 6.8) compared to baseline values (40.9 ± 7.7, P < 0.05). The number of phasic EMG episodes and bursts (ROA: 1.5 ± 0.4 episodes/h and 14.8 ± 2.8 bursts/h, MMOA: 1.9 ± 0.3 and 17.7 ± 4.0, MOA: 1.5 ± 0.5 and 15.1 ± 4.7) especially decreased for all three types of appliances compared to baseline (3.0± 0.5 and 29.2 ± 5.8, P < 0.05). CONCLUSION: The results indicated that restriction of mandibular movements with oral appliances may not have major influence on jaw-muscle activity during sleep but rather that the immediate effect of any combination of oral appliances lead to a suppression of EMG bursts per hour of sleep
On Multicellular Lipid Compartments and Their Electrical Activity
In this manuscript, we report our ground-breaking result on development of artificial multicellular structures capable for neuron like spiking activity. These structures are self-growing ensembles of vesicles whose membranes are combinations of phospholipid and viscous amphipathic molecules. The vesicles grow from a porous gel, and an osmotic pressure difference between the interior of the gel and its surrounding drives the growth. The vesicles’ membranes have also incorporated pore forming proteins. The growing ensembles exhibit spike-like dynamics in electrical potential recorded on the electrodes inserted in the ensembles. We speculate that the spike-like electrical activity is due to the breaking and leaking of the compartments, fusion, and fission of the vesicles during the growth. We demonstrate the spontaneous growth of multi-cellular lipid compartments, which can also incorporate liposomes with membrane proteins, and their generation of an electrical spike-like signal. The bottom-up development of a multicellular artificial molecular system like this report would lead the transition of material\u27s complexity toward information transfer emulating that of a nervous system. The evidence of neuromorphic electrical activity in multicellular systems of lipid vesicles is a promising indication of feasibility of future designs of self-growing artificial proto-brains. We, therefore, think that this manuscript should attract outstanding interest from the wide community of scientists, engineers and laymen, especially those interested in in artificial life, molecular computing, origins of life, artificial cell, molecular robotics, and synthetic biology.</p
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Effects of Vegetation Switch and Subsequent Change in Soil Invertebrate Composition on Soil Carbon Accumulation Patterns, Revealed by Radiocarbon Concentrations
From the 20th International Radiocarbon Conference held in Kona, Hawaii, USA, May 31-June 3, 2009.Vegetation types strongly affect soil organic carbon (SOC) accumulation in the terrestrial ecosystem through multiple factors such as litter quality and soil biodiversity. However, the roles of soil fauna in SOC accumulation remain unclear. The objectives of this study were to (1) examine how changes in litter types and soil animal communities affect SOC accumulation in continuously forested or vegetation-switched forest areas; and (2) discuss the role of soil animals in SOC accumulation in forest ecosystems. We focused on soils that have accumulated on top of a volcanic ash layer in the 268 yr since a volcanic eruption in 1739. The radiocarbon "bomb spike" in the late 1950s and early 1960s provides a unique isotopic signature of soil carbon age. We investigated the combined effects of litter quality and soil invertebrate function on soil 14C accumulation patterns. To determine the effects of vegetation types on SOC accumulation, we selected 4 types of cool temperate forests, 2 of which had undergone a vegetation switch in about 1960 (conifer to broadleaved forest, CB; broadleaved forest to conifer, BC), and 2 that had continuous forests (conifer forest, CC; broadleaved forest, BB). The ∆14C values at depth intervals in CC were consistent with the expected bomb-14C profile. In contrast, ∆14C patterns in BB, BC, and CB differed from that of CC. Compared to CC, ∆14C values of the other sites showed relatively high 14C concentrations even in deeper soil layers, which suggests the bomb-induced 14C has been transported to a greater depth by soil animals. Current broadleaved forests (BB and CB) had higher biomass of litter-feeding invertebrates than in current coniferous forests (CC and BC). These results suggest that carbon from leaf litter was vertically translocated to deeper soil layers by the abundant soil invertebrates in broad-leaved forests. Disagreement with the expected soil profile in BC suggests that past vegetation (broadleaved forest) has affected the present SOC accumulation pattern.The Radiocarbon archives are made available by Radiocarbon and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform February 202