2,295 research outputs found
First R and I Lights and Their Photometric Analyses of GSC 02393-00680
We obtained complete and light curves of GSC 02393-00680 in 2008 and
analyzed them with the 2003 version of the W-D code. It is shown that GSC
02393-00680 is a W-type shallow contact binary system with a high mass ratio
and a degree of contact factor . It will be a good
example to check up on the TRO theory. A period investigation based on all
available data suggests that the system has a small-amplitude period
oscillation (; years). This may indicate it has a
moderate mass close third body, which is similar to XY Leo
Room temperature gas sensing with a hybrid poly-Si/ZnO TFT cell
In this work, we study the capability of a novel poly-Si/Zno hybrid TFT cell in sensing NO2 gas. Fabrication and structural features of this cell are identical to that reported in one of our previous works [1] except that the IGZO TFT is replaced by a ZnO one. The equivalent circuit of the hybrid cell is shown in Fig. 1, in which the poly-Si TFT and ZnO TFT are employed as the amplifier and sensor, respectively. In the configuration, the top gate of the poly-Si TFT is electrically connected to the drain of the bottom-gated ZnO TFT, while the top surface of the ZnO channel is exposed to the environment for sensing purposes. For the electrical measurements conducted at room temperature, the current source (IIN) was set at 100 pA with a compliance VG of 2 V. Concentration of the NO2 gas in the ambient was varied from 0 ~100 ppm. Transfer characteristics of the cell are expressed by showing the drain current of the poly-Si TFT as a function of the back-gate bias (VBG) of the ZnO TFT. In the figure, we can see the I-V curves show a parallel and positive shift as the concentration of the NO2 gas is increased. Meanwhile, the transitions in the figure are steep with a slope of around -60 mV/dec whose absolute value is much smaller than the subthreshold slopes of the individual ZnO TFT (\u3e300 mV/dec). The finding provides good evidence showing the potential of this scheme in promoting measurement sensitivity compared with conventional oxide-semiconductor TFTs. The experimental results also show that UV irradiation can recover the characteristics.
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Modulation of Gene Expression in Liver of Hibernating Asiatic Toads (Bufo gargarizans)
Hibernation is an effective energy conservation strategy that has been widely adopted by animals to cope with unpredictable environmental conditions. The liver, in particular, plays an important role in adaptive metabolic adjustment during hibernation. Mammalian studies have revealed that many genes involved in metabolism are differentially expressed during the hibernation period. However, the differentiation in global gene expression between active and torpid states in amphibians remains largely unknown. We analyzed gene expression in the liver of active and torpid Asiatic toads (Bufo gargarizans) using RNA-sequencing. In addition, we evaluated the differential expression of genes between females and males. A total of 1399 genes were identified as differentially expressed between active and torpid females. Of these, the expressions of 395 genes were significantly elevated in torpid females and involved genes responding to stresses, as well as contractile proteins. The expression of 1004 genes were significantly down-regulated in torpid females, most which were involved in metabolic depression and shifts in the energy utilization. Of the 715 differentially expressed genes between active and torpid males, 337 were up-regulated and 378 down-regulated. A total of 695 genes were differentially expressed between active females and males, of which 655 genes were significantly down-regulated in males. Similarly, 374 differentially expressed genes were identified between torpid females and males, with the expression of 252 genes (mostly contractile proteins) being significantly down-regulated in males. Our findings suggest that expression of many genes in the liver of B. gargarizans are down-regulated during hibernation. Furthermore, there are marked sex differences in the levels of gene expression, with females showing elevated levels of gene expression as compared to males, as well as more marked down-regulation of gene-expression in torpid males than females.Peer reviewe
The crystal structure of the DNase domain of colicin E7 in complex with its inhibitor Im7 protein
AbstractBackground: Colicin E7 (ColE7) is one of the bacterial toxins classified as a DNase-type E-group colicin. The cytotoxic activity of a colicin in a colicin-producing cell can be counteracted by binding of the colicin to a highly specific immunity protein. This biological event is a good model system for the investigation of protein recognition.Results: The crystal structure of a one-to-one complex between the DNase domain of colicin E7 and its cognate immunity protein Im7 has been determined at 2.3 Å resolution. Im7 in the complex is a varied four-helix bundle that is identical to the structure previously determined for uncomplexed Im7. The structure of the DNase domain of ColE7 displays a novel α/β fold and contains a Zn2+ ion bound to three histidine residues and one water molecule in a distorted tetrahedron geometry. Im7 has a V-shaped structure, extending two arms to clamp the DNase domain of ColE7. One arm (α1∗–loop12–α2∗; where ∗ represents helices in Im7) is located in the region that displays the greatest sequence variation among members of the immunity proteins in the same subfamily. This arm mainly uses acidic sidechains to interact with the basic sidechains in the DNase domain of ColE7. The other arm (loop 23–α3∗–loop 34) is more conserved and it interacts not only with the sidechain but also with the mainchain atoms of the DNase domain of ColE7.Conclusions: The protein interfaces between the DNase domain of ColE7 and Im7 are charge-complementary and charge interactions contribute significantly to the tight and specific binding between the two proteins. The more variable arm in Im7 dominates the binding specificity of the immunity protein to its cognate colicin. Biological and structural data suggest that the DNase active site for ColE7 is probably near the metal-binding site
A comparison about the inhibitory effect of curcunmin and Avastin on the rat corneal neovascularization
AIM: To compare the inhibitory effect of curcunmin and Avastin on the rat corneal neovascularization(CNV), and approach the mechanism of the curcunmin's inhibition. METHODS: CNV was established in thirty SD rats by alkaline burning. Rats were divided equally to group A and group B at random. In group A, right eyes were experimental group A1, treated by 40μmol/L curcunmin solution, and left eyes were control group A2, treated by 0.09% sodium chloride. In group B, right eyes were experimental group group B1, treated by 5g/L avastin, and left eyes were control group B2, treated by 0.09% sodium chloride. Cornea and aqueous humor were collected by time spot. The capillary vessels were study, and the expressions of VEGF were detected by Enzyme-Linked immunosorbnent Assay(ELISA). RESULTS: No toxic effects of the drugs were found. The capillary vessels in experimental group were less than those of control group(P<0.01). No statistical different of the capillary vessels between two drugs were found. The expressions of VEGF in experimental group were less than those in control group(P<0.01). The expressions of VEGF in B1 group were less than in group A1. CONCLUSION: The inhibitory effect to CNV of curcunmin and avastin have no statistical different in the experiment, but curcunmin has the less inhibitory effect to the expressions of VEGF than avastin. Curcunmin may have other mechanism in the inhibitory action on CNV
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