Results 41 to 50 of about 33,036 (248)

Inhibition of SIRT7 Overcomes Radioresistance in Pancreatic Neuroendocrine Tumors by Reactivating MEN1 Expression

Advanced Science, EarlyView.
Pancreatic neuroendocrine tumors frequently silence MEN1 through epigenetic mechanisms. Here, SIRT7 recruits DNMT1 to the MEN1 promoter, drives hypermethylation, and enhances DNA repair. Inhibiting SIRT7 restores MEN1, reduces MRN complex abundance, impairs double‐strand break repair, and sensitizes PanNET models to radiation, supporting SIRT7 as a ...
Jianyun Jiang, Yan Wang, Yi Qin, Luohai Chen, Xiaowu Xu, Guixiong Fan, Desheng Jing, Miaoyan Wei, Xianjun Yu, Junfeng Xu, Shunrong Ji, Jie Chen   +11 more
wiley   +1 more source

The Extreme Activity in Comet Hale–Bopp (C/1995 O1): Investigations of Extensive Narrowband Photoelectric Photometry

The Planetary Science Journal
Conventional narrowband photoelectric photometry of Comet Hale–Bopp (1995 O1) was obtained on 99 nights from mid-1995 to early-2000, yielding gas and dust production rates over an unprecedented range of time and distance. The appearance of Hale–Bopp (H-B)
David G. Schleicher, Peter V. Birch, Tony L. Farnham, Allison N. Bair   +3 more
doaj   +1 more source

Thirty Years of Cometary Spectroscopy from McDonald Observatory

, 2011
We report on the results of a spectroscopic survey of 130 comets that was conducted at McDonald observatory from 1980 through 2008. Some of the comets were observed on only one night, while others were observed repeatedly.
A.L. Cochran, Arvesen, A’Hearn, A’Hearn, A’Hearn, C.L. Gray, Clegg, Cochran, Cochran, Cochran, Cochran, Cochran, Cochran, Cochran, Cochran, Cochran, Cochran, Cochran, Cochran, Cochran, Combi, E.S. Barker, Fink, Fink, Fink, Ihalawela, Jehin, Jørgensen, Kim, Kobayashi, Langland-Shula, Newburn, Oliversen, Randall, Roueff, Schleicher, Schleicher, Schleicher, Stone, Tatum, Tegler, Weaver, Ádámkovics   +42 more
core   +1 more source

Glutamine Deprivation Triggers Tribbles Homolog 3 Dependent G‐Quadruplex Resolution to Maintain DNA Repair and Tumor Survival

Advanced Science, EarlyView.
Glutamine deprivation triggers transient DNA damage yet activates adaptive repair in hepatocellular carcinoma cells. We identify TRIB3 as a stress‐induced nuclear scaffold that associates with DDX5 and G‐quadruplex DNA atBRCA1 andRAD51AP1 promoters. TRIB3 loss increases G4 accumulation, suppresses HR gene transcription, elevates γ‐H2A.X, and sensitizes
Qiang Ji, Xuedan Sun, Zhangran Sun, Mengfan Li, Xinyu Cheng, Shuai Tian, Rick F. Thorne, Jinming Li, Guangzhi Liu, Mian Wu, Xiaoying Liu   +10 more
wiley   +1 more source

Demise of Kreutz Sungrazing Comet C/2024 S1 (ATLAS)

The Astronomical Journal
Most Kreutz family sungrazing comets are discovered only days before perihelion, severely limiting observational opportunities to study their physical nature and decay.
David Jewitt, Jane Luu, Jing Li
doaj   +1 more source

Nongravitational perturbations of long-period comets

The Astronomical Journal, 1979
The model of Marsden et al. (1973) is used to investigate the effect of nongravitational forces resulting from water ice sublimation on the orbits of long-period comets. The orbits of hypothetical comets with perihelion distances of 0.005 to 4 AU are integrated numerically along initially parabolic trajectories through one perihelion passage for ...
openaire   +1 more source

Light‐Switched Mesenchymal Stem Cells for In Situ Exosome Amplification in Craniofacial Bone Defect Reconstruction

Advanced Science, EarlyView.
Light‐switchable MSCs (MSC‐UCNPs) were constructed by intracellular incorporation of UCNPs. Upon 980 nm irradiation, UCNPs emitted localized ultraviolet light (365 nm), activating the ROS/HEXB/LAMP1 signaling pathway to suppress lysosome–multivesicular body fusion and thereby enhance exosome biogenesis. Embedded within an injectable hydrogel, MSC‐UCNPs
Tingting Wu, Yajing Liu, Shuman Wang, Xiaoming Bai, Luyun Zhang, Yuwei Liu, Zhiwen Fu, Chen Shi   +7 more
wiley   +1 more source

Dust and Volatiles in the Disintegrating Comet C/2019 Y4 (ATLAS)

The Astrophysical Journal
C/2019 Y4 (ATLAS) is an Oort cloud comet with an orbital period of ∼5895 yr. Starting in 2020 March, its nucleus underwent disintegration. In order to investigate the gas and dust properties of C/2019 Y4 (ATLAS) during its disintegration, we obtained ...
Ruining Zhao, Aigen Li, Bin Yang, Liang Wang, Huijuan Wang, Yu-Juan Liu, Jifeng Liu   +6 more
doaj   +1 more source

Magnitude and size distribution of long-period comets in Earth-crossing or approaching orbits

, 2012
We analyse the population of near-Earth Long-Period Comets (LPCs) (perihelion distances q 10^3 yr). We have considered the sample of LPCs discovered during the period 1900-2009 and their estimated absolute total visual magnitudes H.
Andrea Sosa, Asphaug, Ceplecha, Chen, Di, Dohnanyi, Donnison, Dybczyński, Dybczyński, Everhart, Everhart, Farinella, Fernández, Fernández, Fernández, Francis, Hasegawa, Hughes, Hughes, Jenniskens, Julio A. Fernández, Kaib, Kenyon, Kresák, Kresák, Kronk, Kronk, Królikowska, Lamy, Marsden, Meisel, Meisel, Neslušan, Oort, Prialnik, Rickman, Samarasinha, Sekanina, Sekanina, Sekanina, Snodgrass, Sosa, Sosa, Stern, Szabó, Tancredi, Trigo-Rodríguez, Vsekhsvyatskii, Vsekhsvyatskii, Vsekhsvyatskii, Vsekhsvyatskii, Vsekhsvyatskii, Weissman, Wetherill, Whipple, Wiegert   +55 more
core   +1 more source

Alternative Policy Designs to Help Farmers Select Profitable Conservation Practices

Agribusiness, EarlyView.
ABSTRACT Voluntary private carbon initiatives (VPCIs) promote the implementation of agricultural conservation practices that mitigate emissions of greenhouse gases (GHGs) via financial incentives to participating farmers. Simultaneously, an array of public policies supports the adoption of conservation practices through technical and financial ...
Oranuch Wongpiyabovorn, Alejandro Plastina   +1 more
wiley   +1 more source