1,685 research outputs found
The Shadow of Supertranslated Schwarzschild Black Hole
The supertranslated black hole proposed by Hawking, Perry, and Strominger
might provide a resolution to the information paradox, which is usually defined
by a complicated space-time metric with even less space-time symmetries
compared to Kerr black hole. In this paper, we figure out the shadow for the
supertranslated Schwarzschild black hole by making use of supertranslated
4-velocities and the trajectories of the light rays. Based on this approach, we
find that the photon sphere gets distorted due to the supertranslation hairs
and the position of the shadow on the projection plane is shifted by the
supertranslation vector, but the size and shape of the shadow remain the same
as those of Schwarzschild black hole.Comment: 7 pages, 5 figure
Constructing minimal telescopers for rational functions in three discrete variables
We present a new algorithm for constructing minimal telescopers for rational
functions in three discrete variables. This is the first discrete
reduction-based algorithm that goes beyond the bivariate case. The termination
of the algorithm is guaranteed by a known existence criterion of telescopers.
Our approach has the important feature that it avoids the potentially costly
computation of certificates. Computational experiments are also provided so as
to illustrate the efficiency of our approach
Mapping of the methylation pattern of the hMSH2 promoter in colon cancer, using bisulfite genomic sequencing
The detailed methylation status of CpG sites in the promoter region of hMSH2 gene has yet not to be reported. We have mapped the complete methylation status of the hMSH2 promoter, a region that contains 75 CpG sites, using bisulfite genomic sequencing in 60 primary colorectal cancers. And the expression of hMSH2 was detected by immunohistochemistry. The hypermethylation of hMSH2 was detected in 18.33% (11/60) of tumor tissues. The protein of hMSH2 was detected in 41.67% (25/60) of tumor tissues. No hypermethylation of hMSH2 was detected in normal tissues. The protein of hMSH2 was detected in all normal tissues. Our study demonstrated that hMSH2 hypermethylation and protein expression were associated with the development of colorectal cancer
Poly[[diaquaÂbis(ÎŒ2-isonicotinato-Îș2 N:O)bisÂ(ÎŒ3-isonicotinato-Îș3 N:O:OâČ)neodymium(III)disilver(I)] nitrate monohydrate]
In the title complex, {[Ag2Nd(C6H4NO2)4(H2O)2]NO3·H2O}n, the NdIII ion is coordinated by eight O atoms from six isonicotinate ligands and two water molÂecules in a distorted square antiÂprismatic geometry. Each AgI ion is coordinated by two N atoms from two different isonicotinate ligands. The crystal structure exhibits a two-dimensional heterometallic polymeric layer. OâHâŻO hydrogen bonds involving the coordinated and uncoordinated water molÂecules and intraÂlayer ÏâÏ interÂactions between the pyridine rings [centroidâcentroid distances = 3.571â
(2) and 3.569â
(2)â
Ă
] are observed. Each layer interÂacts with two neighboring ones via AgâŻO(H2O) contacts and interÂlayer ÏâÏ interÂactions [centroidâcentroid distances = 3.479â
(3) to 3.530â
(3)â
Ă
], leading to a three-dimensional supraÂmolecular network
A Sensitive and Rapid Assay for Investigating Vertical Transmission of Hepatitis B Virus via Male Germ Line Using EGFP Vector as Reporter
Hepatitis B virus (HBV) constitutes a serious menace to man. DNA recombination and sequencing, interspecific in vitro fertilization, single-embryo PCR and RT-PCR were employed to establish a sensitive and rapid assay for exploring the vertical transmission of viruses via male germ line. Plasmid pIRES2-EGFP-HBs which expressed enhanced green fluorescent protein as reporter for the expression of hepatitis B virus S gene was successfully constructed and confirmed by PCR, EcoR I and Sal I digestion, and DNA sequencing. After exposure to the plasmid, human spermatozoa were used to fertilize with zona-free hamster ova. Two-cell embryos were collected and classified into group A with green fluorescence and group B without green fluorescence under fluorescence microscope. The results showed that HBs DNA positive bands were detected in the embryos with green fluorescence (PCR and RT-PCR) and positive control (PCR) indicating expression of pIRES2-EGFP-HBs, and not observed in the embryos without green fluorescence and negative controls (PCR and RT-PCR) indicating no pIRES2-EGFP-HBs in the cells. The advantages and application foreground of this assay for study on vertical transmission of viruses such as HCV, HIV, HPV, and SARS via germ line were discussed
Portable Intelligent Oscilloscope Based on Innovative Education
Based on the innovative education idea that students in various universities can do experiments anytime and anywhere without being limited by the course time, a portable oscilloscope suitable for students' experiment and teaching practice is designed by using Arduino, Android and Bluetooth Technology. This oscilloscope not only realizes the basic functions of an oscilloscope, but also makes the measurement images of low-frequency signals more clear and impressive. In addition, the design based on the mobile App is more user-friendly, which enhances the user's sense of use and facilitates the sorting and query of experimental data. The application test shows that the oscilloscope has stable performance, clear waveform, satisfies students' learning and teaching practice to a large extent, and has a good development prospect
Poly[diaquaÂbis(ÎŒ3-1H-benzimidazole-5,6-dicarboxylÂato-Îș4 N 3:O 5,O 5âČ:O 6)bisÂ(ÎŒ2-1H,3H-benzimidazolium-5,6-dicarboxylÂato-Îș3 O 5,O 5âČ:O 6)digadolinium(III)]
In the title complex, [Gd2(C9H4N2O4)2(C9H5N2O4)2(H2O)2]n, two of the benzimidazole-5,6-dicarboxylÂate ligands are proÂtonÂated at the imidazole groups. Each GdIII ion is coordinated by six O atoms and one N atom from five ligands and one water molÂecule, displaying a distorted bicapped trigonal-prismatic geometry. The GdIII ions are linked by the carboxylÂate groups and imidazole N atoms, forming a layer parallel to (001). These layers are further connected by OâHâŻO and NâHâŻO hydrogen bonds into a three-dimensional supraÂmolecular network
Expression of hypoxia inducible factor-1α and vascular endothelial growth factor-C in human chronic periodontitis
AbstractBackground/purposeEvidence shows that there is a relationship between hypoxia and inflammatory response in periodontitis. Hypoxia-inducible factor (HIF)-1α is a major regulator of energy homeostasis and cellular adaptation to low oxygen stress. Although experimental results demonstrate an association between HIF-1α and vascular endothelial growth factor (VEGF)-C in tumor angiogenesis, the role of HIF-1α and VEGF-C in the pathogenesis of periodontitis is still ambiguous. So far, limited attention has been given to the role of hypoxia and VEGF-C in periodontitis. The present study aimed to investigate the expression and distribution of HIF-1α and VEGF-C in gingival tissue samples from patients with different stages of chronic periodontitis and healthy individuals.Materials and methodsA total of 56 samples were involved in this study, including moderate chronic periodontitis (n = 20), advanced chronic periodontitis (n = 20), and healthy control tissues (n = 16). The gingival specimens were stained with hematoxylin and eosin for histopathology. The expression of HIF-1α and VEGF-C in gingival tissues was detected by immunohistochemical staining.ResultsHIF-1α and VEGF-C were found in gingival tissues from patients with different stages of chronic periodontitis as well as healthy control tissues. HIF-1α protein was expressed mainly in the epithelial layer of gingival tissues, and VEGF-C protein was mostly located in the connective tissue papilla of gingival tissues. Compared with healthy controls, the expression of HIF-1α and VEGF-C in chronic periodontitis groups was significantly higher (P < 0.01), and the density of HIF-1α and VEGF-C in advanced chronic periodontitis group was even significantly higher than that in the moderate chronic periodontitis group (P < 0.01).ConclusionOur results suggest that the expression of HIF-1α and VEGF-C increased with severity of periodontitis. So, we conclude that HIF-1α may play an important role in the pathophysiology of human periodontitis and may be related to the function of VEGF-C during periodontitis
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