Report

Paper

인쇄

All 3,239,317 Page 93/323,932

2024
The longwave feedback λ characterizes how Earth’s outgoing longwave radiation changes with surface temperature Ts, making it an important quantity to estimate Earth’s climate sensitivity. Compared to the traditionally studied λ, its spectrally resolved counterpart λν offers deeper insights into the underlying physical processes. Both λ and λν are known to vary with Ts, but this Ts dependence has so far only been investigated using models. Here, we derive the clear-sky spectral longwave feedback λν for surface temperatures Ts between 210K and 310K based on observations of the AIRS instrument onboard the Aqua satellite. We disentangle the radiative signatures of the atmospheric general circulation by simulating λν based on a single-column model with different degrees of idealization. We find that at low Ts, the observed λν is dominated by the surface response and sensitive to biases in Earth’s skin temperature. At higher Ts, changes in atmospheric temperature and humidity, as well as their vertical distribution, play an important role in shaping λν . These changes impact both the absorption of surface emission in the atmospheric window and the atmospheric emission in the water vapor and CO2 absorption bands. Our results demonstrate that we can fully understand the observed λν at a wide range of Ts using a simple conceptual model of Earth’s atmosphere. This understanding can be used to better constrain changes in R and T with warming in Earth’s climate using satellite observations, as well as for paleoclimate and exoplanet studies.
- Book : ()
- Pub. Date : 2024
- Page :
- Keyword :
2024
Abstract
This study utilizes the calculated mass attenuation coefficient (MAC) in conjunction with probability theory to evaluate the suitability of various energy regions for medical applications by analyzing the energy of transmitted radiation beams through samples. The findings reveal a strong correlation between the shielding properties of carbonated hydroxyapatite (CHA) compounds, the unit cell crystalline parameters, and preparation temperature. Notably, an introduction of a probabilistic methodology for transmission energy assessment, identifying the photoelectric process as the most probable scattering process with an average energy of equal 8.7 MeV. Specifically, the outcomes show that CHA compounds with a 4 mol% molar ratio exhibit the most promising characteristics for radiation shielding. An establishment of a connection between their shielding properties and atomic molar volume, preparation temperature, and structural configurations within bioactive networks, providing valuable insights for applications compared to standard glasses like RS-520.
- Book : ()
- Pub. Date : 2024
- Page :
- Keyword :
2024
Glycans, consisting of covalently linked sugar units, are a major class of biopolymers essential to all known living organisms. To better understand their biological functions and further applications in fields from biomedicine to materials science, detailed knowledge of their structure is essential. However, due to the extraordinary complexity and conformational flexibility of glycans, state-of-the-art glycan analysis methods often fail to provide structural information with atomic precision. Here, we combine electrospray deposition in ultra-high vacuum with noncontact atomic force microscopy and theoretical calculations to unravel the structure of β-cyclodextrin, a cyclic glucose oligomer, with atomic-scale detail. Our results, established on the single-molecule level, reveal the different adsorption geometries and conformations of β-cyclodextrin. The cyclic arrangement of hydroxy groups on both faces of the molecule and the stabilizing H-bonds are imaged with atomic resolution, enabling the unambiguous assignment of the molecular structure and demonstrating the potential of the method for glycan analysis.
- Book : ()
- Pub. Date : 2024
- Page :
- Keyword :
2024
SummaryThe highly conserved Dbf4-Dependent Kinase (DDK) plays a pivotal role in the nucleus during S phase, where it directly phosphorylates the replicative helicase, the minichromosome maintenance (MCM) complex. This leads to the initiation of chromosome replication. However, aside from the MCM complex, few other targets have been identified to date, leaving DDK an understudied kinase.Here, we describe a two-pronged mass spectrometry-based approach and define the nuclear DDK-dependent phosphoproteome, which consists of approximately 400 phosphorylation events. Within this network, we found that DDK directly phosphorylates the Arp8 subunit of the multi-subunit chromatin remodeler complex INO80. Arp8 phosphorylation stabilises INO80’s intramolecular complex integrity, which finetunes its nucleosome spacing activity at replication origins. This adjustment of origin chromatin architecture stimulates replication and is important for the response to replication stress. Our results represent a significant advance in our understanding of the molecular mechanisms underlying the regulation of replication origins.
- Book : ()
- Pub. Date : 2024
- Page :
- Keyword :
2024
AbstractIn this paper, the EC-5 water sensor and the MPS-6 water potential sensor were used to measure water content and suction, respectively, to investigate the evolution of soil–water retention properties of compacted loess samples prepared at different dry densities and subjected to different numbers of wetting–drying cycles. The water retention data were integrated with a detailed microstructural investigation, including morphological analysis (by scanning electron microscopy) and pore size distribution determination (by nuclear magnetic resonance). The microstructural information obtained shed light on the double porosity nature of compacted loess, allowing the identification of the effects of compaction dry density and wetting–drying cycles at both intra- and inter-aggregate levels. The information obtained at the microstructural scale was used to provide a solid physical basis for the development of a simplified version of the water retention model presented in Della Vecchia et al. (Int J Numer Anal Meth Geomech 39: 702–723, 2015). The model, adapted for engineering application to compacted loess, requires only five parameters to capture the water retention properties of samples characterized by different compaction dry densities and subjected to different numbers of wetting–drying cycles. The comparison between numerical simulations and experimental results, both original and from the literature, shows that only one set of parameters is needed to reproduce the effects of dry density variation, while the variation of only one parameter allows the reproduction of the effects of wetting and drying cycles. With respect to the approaches presented in the literature, where ad hoc calibrations are often used to fit density and wetting–drying cycle effects, the model presented here shows a good compromise between simplicity and predictive capabilities, making it suitable for practical engineering applications.
- Book : ()
- Pub. Date : 2024
- Page :
- Keyword :
2024
AbstractIn recent years, silicon‐based room temperature Terahertz (THz) detectors have become the most optimistic research area because of their high speed, low cost, and unimpeded compatibility with mainstream complementary metal‐oxide‐semiconductor (CMOS) device technologies. However, Silicon (Si) suffers from low responsivity and high noise at THz frequencies. In this review, the recent advances in Si‐based THz detectors using silicon‐on‐insulator (SOI) substrates are presented. These offer several advantages over bulk counterparts, such as reduced parasitic capacitance, enhanced electric field confinement, and improved thermal isolation. The different types of THz detectors exploiting SOI substrate, such as conventional metal‐oxide‐semiconductor field effect transistors (MOSFETs), junction‐less MOSFETs, junction‐less nanowires field effect transistors (JLNWFETs), micro‐electromechanical system (MEMS), metal‐semiconductor‐metal (MSM) structures, and single electron transistor (SET), are discussed, and their key performances in terms of responsivity, noise equivalent power (NEP), bandwidth, and dynamic range are compared. The challenges and opportunities for further improvement of SOI THz detectors, such as device scaling, integration, and modulation, are also highlighted. This review may offer compelling evidence supporting the idea that SOI THz detectors have the potential to facilitate high performance, low power consumption, and scalability—qualities essential for advancing next‐level technologies.
- Book : ()
- Pub. Date : 2024
- Page :
- Keyword :
2024
Genome and epigenome integrity in eukaryotes depends on the proper coupling of histone deposition with DNA synthesis. This process relies on the evolutionary conserved histone chaperone CAF-1, for which the links between structure and function are still a puzzle. While studies of the S. cerevisiae CAF-1 complex enabled to propose a model for the histone deposition mechanism, we still lack a framework to demonstrate its generality and in particular, how its interaction with the polymerase accessory factor PCNA is operating. Here, we reconstituted a complete SpCAF-1 from fission yeast. We characterized its dynamic structure using NMR, SAXS and molecular modeling together with in vitro and in vivo functional studies on rationally designed interaction mutants. Importantly, we identify the unfolded nature of the acidic domain which folds up when binding to histones. We also show how the long KER helix mediates DNA binding and stimulates SpCAF-1 association with PCNA. Our study highlights how the organization of CAF-1 comprising both disordered regions and folded modules enables the dynamics of multiple interactions to promote histone deposition coupled to DNA synthesis, and is essential for CAF-1 functions in DNA replication, heterochromatin maintenance, and genome stability.
- Book : ()
- Pub. Date : 2024
- Page :
- Keyword :
2024
- Book : ()
- Pub. Date : 2024
- Page :
- Keyword :
2024
Abstract
Background We compared the dosimetric and clinical outcomes of VMAT and 3D-CRT in breast cancer patients undergoing regional nodal irradiation (RNI) to determine the effectiveness of VMAT. Methods This retrospective cohort study included breast cancer patients who underwent adjuvant radiotherapy with RNI between July 2016 and September 2022. Patients were assigned to receive either 3D-CRT or VMAT based on the laterality of their cancer. Right-sided breast cancer received 3D-CRT, while left-sided breast cancer received VMAT. Radiotherapy consisted of a dose of 50 Gy/25 fr to the chest wall or breast and the regional nodes. Dosimetric parameters, adverse events, and survival were compared between 3D-CRT and VMAT. Results A total of 126 patients were included in the analysis, with 64 in the 3D-CRT group and 62 in the VMAT group. VMAT showed better coverage of the clinical target volume (P < 0.01). Among patients who received internal mammary node irradiation, VMAT resulted in a lower total lung V20 Gy compared to 3D-CRT (17% vs. 11%, P < 0.01), whereas total lung V5 Gy was higher for VMAT (27% vs. 34%, P < 0.01). The incidence of grade 2 acute dermatitis was lower in the VMAT group (27%) than in the 3D-CRT group (47%) (P= 0.02). The 5-year overall survival and breast cancer-specific survival rates were 87% and 90% in the 3D-CRT group and 100% and 100% in the VMAT group, respectively (P = 0.06 and 0.09). Conclusions VMAT showed better target coverage and less acute radiation dermatitis compared to 3D-CRT.
- Book : ()
- Pub. Date : 2024
- Page :
- Keyword :
2024
Multilocular cystic renal cell carcinoma is a rare cystic tumour of kidney with excellent outcome. It is usually included in the group of tumours of undetermined malignant potential with low nuclear grade. We are presenting a case of 61 year. old female came with history of giddiness for 1 week and weight loss of 20 kg in 2 years. Imaging was suggestive of cortical based tumour arising from upper pole of right kidney. Right side partial nephrectomy was done. On histopathologic examination it was found to be MCRCC, stage 1 with Fuhrman nuclear grade 1. Immunohistochemistry with epithelial membrane antigen and cytokeratin-7 confirmed the diagnosis.
- Book : 11(8)
- Pub. Date : 2024
- Page : pp.1358-1361
- Keyword :

First Prev 88 89 90 91 92 93 94 95 96 97 Next Last

Paper

RCA

DATA-HUB

E-CAMPUS

ROEM