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991.
Inside Back Cover: Development of a 3‐dimensional tissue lung phantom of a preterm infant for optical measurements of oxygen—Laser‐detector position considerations (J. Biophotonics 3/2018) 下载免费PDF全文
Jim Larsson Peilang Liao Patrik Lundin Emilie Krite Svanberg Johannes Swartling Märta Lewander Xu Joakim Bood Stefan Andersson‐Engels 《Journal of biophotonics》2018,11(3)
The picture depicts the different 3d‐printed organs, thorax, lungs, heart and bone. Assembled it is used as an optical phantom of a preterm infant for performing percutaneous optical measurements of the gas content in the lungs. In order to simulate the optical properties of the tissue, the heart and thorax can be filled with liquid phantoms, a mixture of Intralipid and Indian Ink. Further details can be found in the article by Jim Larsson et al. ( e201700097 ).
992.
Stable nitrogen isotope analysis of dentine serial sections elucidate sex differences in weaning patterns of wild chimpanzees (Pan troglodytes) 下载免费PDF全文
Geraldine E. Fahy Michael P. Richards Benjamin T. Fuller Tobias Deschner Jean‐Jacques Hublin Christophe Boesch 《American journal of physical anthropology》2014,153(4):635-642
Offspring provisioning is one of the most energetically demanding aspects of reproduction for female mammals. Variation in lactation length and weaning strategies between chimpanzees (Pan troglodytes), our closest living relative, and modern human societies have been reported. When and why these changes occurred is frequently debated. Our study used stable nitrogen isotope data of tooth root dentine from wild Western chimpanzees (Pan troglodytes verus) in Taï National Park, Côte d'Ivoire, to quantify weaning in these chimpanzees and explore if infant sex plays a role in maternal investment. We analyzed serial sections of deciduous lateral incisor root dentine from four Taï chimpanzees to establish the δ15N signal of nursing infants; we then analyzed serial sections of first permanent mandibular molar root dentine from 12 Taï chimpanzees to provide quantitative δ15N data on weaning in this population. Up to 2 years of age both sexes exhibited dentine δ15N values ≈2–3‰ higher than adult female Taï chimpanzees, consistent with a nursing signal. Thereafter a steady decrease in δ15N values consistent with the onset, and progression, of weaning, was visible. Sex differences were also evident, where male δ15N values decreased at a significantly slower rate compared to females. Confirmation of sex differences in maternal investment among Taï chimpanzees, demonstrates the viability of using isotope analysis to investigate weaning in non‐human primates. Additionally, assuming that behaviors observed in the Taï chimpanzees are illustrative of the ancestral pattern, our results provide a platform to enable the trajectory of weaning in human evolution to be further explored. Am J Phys Anthropol 153:635–642, 2014. © 2013 Wiley Periodicals, Inc. 相似文献
993.
Xiao-hong Cao Si-si Zhao Dong-yue Liu Zhuo Wang Li-li Niu Li-hua Hou Chun-ling Wang 《Chemico-biological interactions》2011,(1):16
The surfactin can inhibit proliferation and induce apoptosis in cancer cells. Moreover, surfactin can induce cell death in human breast cancer MCF-7 cells through mitochondrial pathway. However, the molecular mechanism involved in this pathway remains to be elucidated. Here, the reactive oxygen species (ROS) and Ca2+ on mitochondria permeability transition pore (MPTP) activity, and MCF-7 cell apoptosis which induced by surfactin were investigated. It is found that surfactin evoked mitochondrial ROS generation, and the surfactin-induced cell death was prevented by N-acetylcysteine (NAC, an inhibitor of ROS). An increasing cytoplasmic Ca2+ concentration was detected in surfactin-induced MCF-7 apoptosis, which was inhibited by 1,2-bis (2-aminophenoxy) ethane-N,N,N′,N′-tetraacetic acid (BAPTA-AM, a chelator of calcium). In addition, the relationship between ROS generation and the increase of cytoplasm Ca2+ was determined. The results showed that surfactin initially induced the ROS formation, leading to the MPTP opening accompanied with the collapse of mitochondrial membrane potential (ΔΨm). Then the cytoplasmic Ca2+ concentration increased in virtue of the changes of mitochondrial permeability, which was prevented by BAPTA-AM. Besides, cytochrome c (cyt c) was released from mitochondria to cytoplasm through the MPTP and activated caspase-9, eventually induced apoptosis. In summary, surfactin has notable anti-tumor effect on MCF-7 cells, however, there was no obvious cytotoxicity on normal cells. 相似文献
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The biological effects of rare-earth ions on the organism have been studied using Pr3+ as a probe ion and Escherichia coli cell as a target. Atomic force microscopy (AFM) observation of the surface of E. coli cells shows that the presence of Pr3+ substantially changes the structure of the outer membrane. By induced coupled plasma-mass spectrometry (ICP-MS), more Cu2+ was found in the cells grown in the presence of Pr3+, indicating changes of cell permeability. Using energy dispersive X-ray spectroscopy (EDX), Ca2+ is found on the outer surface of the original cell. It is proposed that Pr3+ can replace Ca2+ from the binding sites because of their close ionic radii and similar ligand speciality. 相似文献
997.
Trapa maximowiczii is a floating-leaved macrophyte common in China. The plant population in East Bay, Lake Taihu, has been expanding rapidly
in recent years. In order to better understand the mechanisms controlling the population dynamics in this species, two outdoor
experiments were conducted from 9 May to 8 July 2007, evaluating the effect on the growth of T. maximowiczii of different nutrient levels in water column and sediment. Results showed that high concentration of nutrients (nitrogen
and phosphorous) in water led to significant increases in rosette diameter and plant dry weight, dry weight of aquatic roots
and anchoring roots, but had no effect on plant height or main stem node count. Phosphorus enrichment resulted in increases
in plant dry weight and seed number. However, no such difference was observed between the nitrogen enrichment treatment and
the control. Sediment fertility had significant effects on plant growth. Plant height, plant dry weight, dry weight of aquatic
and anchoring roots, and maximum rosette diameter were significantly greater in high-nutrient sediment than those in low-nutrient
sediment. This study suggests that eutrophication of water (especially increasing phosphorus loading) and accumulated nutrients
in sediment may be among the causes leading to increasing biomass of the floating-leaved macrophyte T. maximowiczii in East Bay of Lake Taihu. 相似文献
998.
Alterations of plasma lipids in mice via adenoviral-mediated hepatic overexpression of human ABCA1 总被引:3,自引:0,他引:3
Wellington CL Brunham LR Zhou S Singaraja RR Visscher H Gelfer A Ross C James E Liu G Huber MT Yang YZ Parks RJ Groen A Fruchart-Najib J Hayden MR 《Journal of lipid research》2003,44(8):1470-1480
ATP binding cassette transporter A1 (ABCA1) is a widely expressed lipid transporter essential for the generation of HDL. ABCA1 is particularly abundant in the liver, suggesting that the liver may play a major role in HDL homeostasis. To determine how hepatic ABCA1 affects plasma HDL cholesterol levels, we treated mice with an adenovirus (Ad)-expressing human ABCA1 under the control of the cytomegalovirus promoter. Treated mice showed a dose-dependent increase in hepatic ABCA1 protein, ranging from 1.2-fold to 8.3-fold using doses from 5 x 108 to 1.5 x 109 pfu, with maximal expression observed on Day 3 posttreatment. A selective increase in HDL cholesterol occurred at Day 3 in mice treated with 5 x 108 pfu Ad-ABCA1, but higher doses did not further elevate HDL cholesterol levels. In contrast, total cholesterol, triglycerides, phospholipids, non-HDL cholesterol, and apolipoprotein B levels all increased in a dose-dependent manner, suggesting that excessive overexpression of hepatic ABCA1 in the absence of its normal regulatory sequences altered total lipid homeostasis. At comparable expression levels, bacterial artificial chromosome transgenic mice, which express ABCA1 under the control of its endogenous regulatory sequences, showed a greater and more specific increase in HDL cholesterol than Ad-ABCA1-treated mice. Our results suggest that appropriate regulation of ABCA1 is critical for a selective increase in HDL cholesterol levels. 相似文献
999.
Blockade of L-type voltage-gated Ca channel inhibits ischemia-induced neurogenesis by down-regulating iNOS expression in adult mouse 总被引:3,自引:0,他引:3
Luo CX Zhu XJ Zhang AX Wang W Yang XM Liu SH Han X Sun J Zhang SG Lu Y Zhu DY 《Journal of neurochemistry》2005,94(4):1077-1086
Neurogenesis in the adult mammalian hippocampus may contribute to repairing the brain after injury. The signals that regulate neurogenesis in the dentate gyrus following ischemic stroke insult are not well known. We have previously reported that inducible nitric oxide synthase (iNOS) expression is necessary for ischemia-stimulated neurogenesis in the adult dentate gyrus. Here, we show that mice subjected to 90 min of middle cerebral artery occlusion (MCAO) significantly increased the number of new neurons and up-regulated iNOS expression in the dentate gyrus. Blockade of the L-type voltage-gated Ca(2+) channel (L-VGCC) prevented neurogenesis in the dentate gyrus and subventricular zone (SVZ), and down-regulated iNOS expression in the dentate gyrus after cerebral ischemia. This study suggests that Ca(2+) influx through L-VGCC is involved in ischemia-induced neurogenesis by up-regulating iNOS expression. 相似文献
1000.
Novel Partial Reductive Pathway for 4-Chloronitrobenzene and Nitrobenzene Degradation in Comamonas sp. Strain CNB-1 总被引:3,自引:0,他引:3 下载免费PDF全文
Jian-feng Wu Cheng-ying Jiang Bao-jun Wang Ying-fei Ma Zhi-pei Liu Shuang-jiang Liu 《Applied microbiology》2006,72(3):1759-1765
Comamonas sp. strain CNB-1 grows on 4-chloronitrobenzene (4-CNB) and nitrobenzene as sole carbon and nitrogen sources. In this study, two genetic segments, cnbB-orf2-cnbA and cnbR-orf1-cnbCaCbDEFGHI, located on a newly isolated plasmid, pCNB1 (ca. 89 kb), and involved in 4-CNB/nitrobenzene degradation, were characterized. Seven genes (cnbA, cnbB, cnbCa, cnbCb, cnbD, cnbG, and cnbH) were cloned and functionally expressed in recombinant Escherichia coli, and they were identified as encoding 4-CNB nitroreductase (CnbA), 1-hydroxylaminobenzene mutase (CnbB), 2-aminophenol 1,6-dioxygenase (CnbCab), 2-amino-5-chloromuconic semialdehyde dehydrogenase (CnbD), 2-hydroxy-5-chloromuconic acid (2H5CM) tautomerase, and 2-amino-5-chloromuconic acid (2A5CM) deaminase (CnbH). In particular, the 2A5CM deaminase showed significant identities (31 to 38%) to subunit A of Asp-tRNAAsn/Glu-tRNAGln amidotransferase and not to the previously identified deaminases for nitroaromatic compound degradation. Genetic cloning and expression of cnbH in Escherichia coli revealed that CnbH catalyzed the conversion of 2A5CM into 2H5CM and ammonium. Four other genes (cnbR, cnbE, cnbF, and cnbI) were tentatively identified according to their high sequence identities to other functionally identified genes. It was proposed that CnbH might represent a novel type of deaminase and be involved in a novel partial reductive pathway for chloronitrobenzene or nitrobenzene degradation. 相似文献