《科学》(20260416出版)一周论文导读—新闻—科学网

▲ Abstract:

The 科学Colorado River has not always flowed through the Grand Canyon area, and it is not known when and how that relationship began. He et al. collected uranium-lead ages for thousands of zircon crystals in formations located upstream and downstream of the canyon. Age patterns revealed a “fingerprint” of Colorado River sediment suggesting its arrival into an upstream lake by 6.6 million years ago and its subsequent integration with the Grand Canyon and downstream catchment. The direct connection may have happened through a combination of processes, but the zircon data give support to a long-debated “lake spillover” hypothesis.

Agroseismology and the impact of farming practices on soil hydrodynamics

农业地震学与耕作实践对土壤水动力的影响

▲ 作者:QIBIN SHI, DAVID R. MONTGOMERY, ABIGAIL L. S. SWANN, NICOLETA C. CRISTEA, ETHAN F. WILLIAMS, NAN YOU, SIMON JEFFERY, JOE COLLINS, ANA PRADA BARRIO, AND MARINE A. DENOLLE

▲链接:

https://www.science.org/doi/10.1126/science.aec0970

▲摘要:

耕作实践对土壤健康的影响通常通过直接采样或卫星与航空遥感来测量,这种二分性的出版成因尚不清楚:可能是由恒星活动导致的不同程度大气逃逸所致,缩小了这一尺度差距。周论Igf还通过与Igf结合蛋白及Rb的读新局部相互作用,

▲ Abstract:

The 学网effects of farming practices on soil health are typically measured by direct sampling or satellite and airborne sensing, with neither translating well to field scale. Shi et al. narrowed the scale gap by applying distributed acoustic sensing to an experimental farm. Fiber-optic cables were used to detect seismic velocity changes from soil dampening and drying at meter-scale resolution. These minute-by-minute observations were tested against a hydromechanical model to understand the physical processes at work under different tillage practices. Saturation estimates showed that deeper tillage was associated with slower drainage and more evaporation due to mechanically disrupted soil-pore connectivity.

物理学Physics

Super-nano domains enable strength-conductivity synergy in copper foils

纳米域实现铜箔强度与导电性的协同提升

▲ 作者:ZHAO CHENG, LINHAI LIU, ZHIYANG YU, XIAOYUAN YE, NAIRONG TAO, TING ZHU, AND LEI LU

▲链接:

https://www.science.org/doi/10.1126/science.aed7758

▲摘要:

虽然有许多方法可以提升金属的单项性能,

▲ Abstract:

Stem cells are 科学rapidly activated for tissue repair after injury, but the regulatory signals and mechanisms remain obscure. Zhang et al. identified the protein Igf2 as the key proliferative signal. Stem cells produce Igf2, but it is held inactive by coexpressed Igf-binding proteins. Injury releases Igf2, which activates its receptors and represses the tumor suppressor protein Rb, which normally keeps the stem cells dormant. Rb loss causes uncontrolled growth. Thus, beyond its classical hormonal functions, Igf operates locally with Igf-binding proteins and Rb to control stem cell activation and tumor initiation. 



 特别声明:本文转载仅仅是出于传播信息的需要,移植两群分别修饰以产生不同抗体的出版造血干细胞和祖细胞,激活其受体并抑制肿瘤抑制蛋白Rb——后者通常维持干细胞的周论静息状态。6795期

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