Structural and functional investigation of the DHH/DHHA1 family proteins in Deinococcus radiodurans.

DHH/DHHA1 family proteins have been proposed to play critical roles in bacterial resistance to environmental stresses. Members of the most radioresistant bacteria genus, Deinococcus, possess two DHH/DHHA1 family proteins, RecJ and RecJ-like. While the functions of Deinococcus radiodurans RecJ (DrRecJ) in DNA damage resistance have been well characterized, the role and biochemical activities of D. radiodurans RecJ-like (DrRecJ-like) remain unclear. Phenotypic and transcriptomic analyses suggest that, beyond DNA repair, DrRecJ is implicated in cell growth and division. Additionally, DrRecJ-like not only affects stress response, cell growth, and division but also correlates with the folding/stability of intracellular proteins, as well as the formation and stability of cell membranes/walls. DrRecJ-like exhibits a preferred catalytic activity towards short single-stranded RNA/DNA oligos and c-di-AMP. In contrast, DrRecJ shows no activity against RNA and c-di-AMP. Moreover, a crystal structure of DrRecJ-like, with Mg2+ bound in an open conformation at a resolution of 1.97 Å, has been resolved. Subsequent mutational analysis was conducted to pinpoint the crucial residues essential for metal cation and substrate binding, along with the dimerization state, necessary for DrRecJ-like's function. This finding could potentially extend to all NrnA-like proteins, considering their conserved amino acid sequence and comparable dimerization forms.

Study of the emissions and spatial distributions of various power-generation technologies in China.

The power sector is the main contributor to climate change and atmospheric pollution, and reducing the emissions from the power sector is essential for achieving sustainable development. However, few studies have accounted for the emissions from various power-generation technologies. In this paper, a high-resolution inventory of power plants with more than 6 MW accounting for 93% of the national power generation in China is established for the first time. Based on this inventory, the CO2, NOx and SO2 emissions of China's hard coal power, natural gas power, hydropower, wind power, photovoltaic power, biomass power and nuclear power are calculated by using the life cycle assessment method, and their spatial distributions in 2014 are further analyzed. The results show that China's power plants emitted 3.44 E+09 t CO2, 8.56 E+06 t NOx, and 1.19 E+07 t SO2, and the uncertainties were (-18.66%, +19.14%), (-67.10%, +66.41%) and (-88.69%, +87.61%) in 2014, respectively. Renewable-energy power plants accounted for approximately 15% of the national power generation but only contributed less than 1% of the total emissions. Meanwhile, in China's eastern cities, renewable-energy power accounts for the lowest proportion of the total installed capacity. In addition, both the emission amount and intensity were significantly higher in eastern cities than central and western cities. This study will help improve research on the emissions of all power-generation technologies in China and help achieve a comprehensive and systematic emissions reduction strategy.

Staphylococcus aureus SOS response: Activation, impact, and drug targets.

Staphylococcus aureus is a common cause of diverse infections, ranging from superficial to invasive, affecting both humans and animals. The widespread use of antibiotics in clinical treatments has led to the emergence of antibiotic-resistant strains and small colony variants. This surge presents a significant challenge in eliminating infections and undermines the efficacy of available treatments. The bacterial Save Our Souls (SOS) response, triggered by genotoxic stressors, encompasses host immune defenses and antibiotics, playing a crucial role in bacterial survival, invasiveness, virulence, and drug resistance. Accumulating evidence underscores the pivotal role of the SOS response system in the pathogenicity of S. aureus. Inhibiting this system offers a promising approach for effective bactericidal treatments and curbing the evolution of antimicrobial resistance. Here, we provide a comprehensive review of the activation, impact, and key proteins associated with the SOS response in S. aureus. Additionally, perspectives on therapeutic strategies targeting the SOS response for S. aureus, both individually and in combination with traditional antibiotics are proposed.

CAISeg: A Clustering-Aided Interactive Network for Lesion Segmentation in 3D Medical Imaging.

Accurate lesion segmentation in medical imaging is critical for medical diagnosis and treatment. Lesions' diverse and heterogeneous characteristics often present a distinct long-tail distribution, posing difficulties for automatic methods. Currently, interactive segmentation approaches have shown promise in improving accuracy, but still struggle to deal with tail features. This triggers a demand of effective utilizing strategies of user interaction. To this end, we propose a novel point-based interactive segmentation model called Clustering-Aided Interactive Segmentation Network (CAISeg) in 3D medical imaging. A customized Interaction-Guided Module (IGM) adopts the concept of clustering to capture features that are semantically similar to interaction points. These clustered features are then mapped to the head regions of the prompted category to facilitate more precise classification. Meanwhile, we put forward a Focus Guided Loss function to grant the network an inductive bias towards user interaction through assigning higher weights to voxels closer to the prompted points, thereby improving the responsiveness efficiency to user guidance. Evaluation across brain tumor, colon cancer, lung cancer, and pancreas cancer segmentation tasks show CAISeg's superiority over the state-of-the-art methods. It outperforms the fully automated segmentation models in accuracy, and achieves results comparable to or better than those of the leading point-based interactive methods while requiring fewer prompt points. Furthermore, we discover that CAISeg possesses good interpretability at various stages, which endows CAISeg with potential clinical application value.