DPIF-Net: a dual path network for rural road extraction based on the fusion of global and local information.

Background: Automatic extraction of roads from remote sensing images can facilitate many practical applications. However, thus far, thousands of kilometers or more of roads worldwide have not been recorded, especially low-grade roads in rural areas. Moreover, rural roads have different shapes and are influenced by complex environments and other interference factors, which has led to a scarcity of dedicated low level category road datasets.

Distinguishing G-Quadruplexes Stabilizer and Chaperone for c- Promoter G-Quadruplexes through Single-Molecule Manipulation.

G-quadruplex (G4) selective stabilizing ligands can regulate c- gene expression, but the kinetic basis remains unclear. Determining the effects of ligands on c- promoter G4s' folding/unfolding kinetics is challenging due to the polymorphic nature of G4s and the high energy barrier to unfold c- promoter G4s. Here, we used single-molecule magnetic tweezers to manipulate a duplex hairpin containing a c- promoter sequence to mimic the transiently denatured duplex during transcription.

Naringenin prevents non-alcoholic steatohepatitis by modulating the host metabolome and intestinal microbiome in MCD diet-fed mice.

Non-alcoholic steatohepatitis (NASH) is a severe inflammatory phase of the non-alcoholic fatty liver disease (NAFLD) spectrum and can progress to advanced stages of NAFLD if left untreated. This study uses multi-omics data to elucidate the underlying mechanism of naringenin's reported benefit in alleviating (NASH). Male mice were fed a NASH-inducing (methionine-choline-deficient) MCD diet with or without naringenin supplementation for 6 weeks.

Nonselective Intercalation of G-Quadruplex-Targeting Ligands into Double-Stranded DNA Quantified by Single-Molecule Stretching.

Most G-quadruplex (G4)-targeting ligands reported so far contain planar heteroaromatic groups and can intercalate into adjacent base pairs of double-stranded DNA (dsDNA). However, quantitative data on the binding number γ (ligands/bp) of G4 ligands that intercalate into long dsDNA remain lacking, which are essential for understanding the selectivity of G4 ligands. Here, using a single-molecule stretching assay based on the lengthening of dsDNA, we analyzed the dissociation constants and the binding number of eight most commonly used G4 ligands that intercalate into dsDNA.

Force-Dependent Intercalative Bulky DNA Adduct Formation Detected by Single-Molecule Stretching.

Quantitatively analyzing the binding topology and reactivity is essential for understanding the cytotoxic or tumorigenic activities of bulky DNA adducts formed by chemotherapeutic drugs or carcinogens. Biochemical methods require purification of DNA and discontinuous steps to digest or label the adducts and thus have difficulties in identifying the binding topology and are not suitable for detecting unstable adducts. Herein, we used a single-molecule stretching assay to characterize the number of intercalative adducts, the formation kinetics, and the mechanical properties of intercalative DNA adducts based on measuring adduct-induced DNA elongation.

Characterization of G-Quadruplexes Folding/Unfolding Dynamics and Interactions with Proteins from Single-Molecule Force Spectroscopy.

G-quadruplexes (G4s) are stable secondary nucleic acid structures that play crucial roles in many fundamental biological processes. The folding/unfolding dynamics of G4 structures are associated with the replication and transcription regulation functions of G4s. However, many DNA G4 sequences can adopt a variety of topologies and have complex folding/unfolding dynamics.

Mechanical diversity and folding intermediates of parallel-stranded G-quadruplexes with a bulge.

A significant number of sequences in the human genome form noncanonical G-quadruplexes (G4s) with bulges or a guanine vacancy. Here, we systematically characterized the mechanical stability of parallel-stranded G4s with a one to seven nucleotides bulge at various positions. Our results show that G4-forming sequences with a bulge form multiple conformations, including fully-folded G4 with high mechanical stability (unfolding forces > 40 pN), partially-folded intermediates (unfolding forces < 40 pN).

High Mechanical Stability and Slow Unfolding Rates Are Prevalent in Parallel-Stranded DNA G-Quadruplexes.

Guanine-rich repeat sequences are known to adopt diverse G-quadruplex (G4) topologies. Determining the unfolding rates of individual G4 species is challenging due to the coexistence of multiple G4 conformations in a solution. Here, using single-molecule magnetic tweezers, we systematically measured the unfolding force distributions of 4 oncogene promoter G4s, 12 model sequences with two 1-nucleotide (nt) thymine loops that predominantly adopt parallel-stranded G4 structures, and 6 sequences forming multiple G4 structures.

Folding/unfolding kinetics of G-quadruplexes upstream of the P1 promoter of the human oncogene.

The G-rich Pu39 region of the P1 promoter of the oncogene , an apoptosis regulator, can fold into multiple G-quadruplex (G4) structures. Bcl2-2345 and Bcl2-1245 are two major G4 species forming with high thermal stability and distinct topologies in the Pu39 region, but their folding/unfolding kinetics have not yet been investigated. Here, we used magnetic tweezers to measure the mechanical stability and the folding/unfolding kinetics of the Bcl2-2345 and Bcl2-1245 G4 structures.