Source Extraction Research Articles

Experimental Study on Seasonal Ground-Coupled Heat Storage and Harvesting in Cold Regions

In recent years, global efforts toward sustainable energy have intensified, aiming to reduce carbon emissions and boost energy efficiency. Heating in winter and hot water for hygiene are essential, especially in cold climates where heating demands significantly impact household energy consumption. This study examines a city in western Inner Mongolia, characterized by a severe cold climate and unique geology. A test system with dual U-shaped buried pipes for ground source heat storage and extraction was constructed, utilizing two layout schemes. Drilling tests measured formation parameters, highlighting how pipe layout and soil characteristics influence heat storage. Short-term 5-day cycles and cross-seasonal 60-day cycles were tested. Results showed upper soil suited for frequent short-term storage, while lower soil favored long-term energy retention. Increasing buried pipes raised soil temperature and storage capacity, enhancing thermal stability in short-term cycles. However, while the long-term storage capacity improved, heat loss also rose. Effective ground source heat pump design in cold regions should consider environmental temperatures, pipe optimization, soil characteristics, and heat storage duration to achieve stable, efficient operation.

The Maximally-Coherent Reference technique and its application to sound source extraction without synchronous measurements

The Maximally-Coherent Reference technique and its application to sound source extraction without synchronous measurements

A Comprehensive Catalog of UVIT Observations. I. Catalog Description and First Release of Source Catalog (UVIT DR1)

We present the first comprehensive source catalog (UVIT DR1) of ultraviolet (UV) photometry in four far-UV (FUV ∼ 1300−1800 Å) and five near-UV (NUV ∼ 2000−3000 Å) filters of the Ultraviolet Imaging Telescope (UVIT) on board AstroSat. UVIT DR1 includes bright UV sources in 291 fields that UVIT detected during its first 2 yr of pointed observation, encompassing an area of 58 deg2. We used the ccdlab pipeline to reduce the Level 1 data, SExtractor for source detection, and four photometric procedures to determine the magnitudes of the detected sources. We provided the 3σ and 5σ detection limits for all the filters of UVIT. We describe the details of observation, source extraction methods, and photometry procedures applied to prepare the catalog. In the final UVIT DR1 catalog, we have point sources, extended sources, clumps from nearby galaxies, globular clusters, open clusters, planetary nebulae, and gaseous nebulae. There are 239,520 unique sources in the combined UVIT DR1, of which 70,488 sources have FUV magnitudes, and 211,410 have NUV magnitudes. We crossmatched and compared noncrowded sources of UVIT with the Galaxy Evolution Explorer and Gaia source catalogs. We provide a clean catalog of the unique sources in various UVIT filters that will help further the multiwavelength scientific analysis of the objects.

Proton radiography inversions with source extraction and comparison to mesh methods.

Proton radiography is a central diagnostic technique for measuring electromagnetic (EM) fields in high-energy-density, laser-produced plasmas. In this technique, protons traverse the plasma where they accumulate small EM deflections which lead to variations in the proton fluence pattern on a detector. Path-integrated EM fields can then be extracted from the fluence image through an inversion process. In this work, experiments of laser-driven foils were conducted on the OMEGA laser and magnetic field reconstructions were performed using both "fluence-based" techniques and high-fidelity "mesh-based" methods. We implement nonzero boundary conditions into the inversion and show their importance by comparing against mesh measurements. Good agreement between the methods is found only when nonzero boundary conditions are used. We also introduce an approach to determine the unperturbed proton source profile, which is a required input in fluence reconstruction algorithms. In this approach, a fluence inversion is embedded inside of a mesh region, which provides overconstrained magnetic boundary conditions. A source profile is then iteratively optimized to satisfy the boundary information. This method substantially enhances the accuracy in recovering EM fields. Lastly, we propose a scheme to quantify uncertainty in the final inversion that is introduced through errors in the source retrieval.

Comprehensive Evaluation Research on the Sustainable Development Level of Rural Energy Based on CRITIC-MABAC in Henan Province

Energy shortages are a key issue at present, and climate problems caused by the extraction and use of traditional fossil energy sources are also creating new challenges for rural development, with sustainable rural energy development being a priority at present. This paper takes the sustainable development of rural energy as the research object, and evaluates the development of rural energy in each prefecture-level city in Henan Province. On the one hand, rural development is viewed from the perspective of energy, on the other hand, the evaluation results provide a reference for each prefecture-level city, and most of the energy data can be obtained directly and with a high degree of accuracy, based on the CRITIC – MABAC methodology to determine the weights from an objective point of view and to rank the evaluation results, which is capable of obtaining the most accurate evaluation results. Finally, we used energy-related data from Henan Province in 2022 to conduct empirical analyses, and verified that Shangqiu City has a high level of sustainable rural energy development, which verifies the feasibility of the methodology proposed in this paper, and gives relevant recommendations.

Micropyramidal Si Photonics–A Versatile Platform for Detector and Emitter Applications

AbstractAnisotropic wet etching of silicon (Si) has been known for decades, but the extraordinary capabilities of this technology to provide highly ordered microphotonic arrays have received limited attention in previous studies. It is shown that these capabilities include: i) a unique self‐terminating etching nature − crucial for achieving uniform arrays over centimeter‐scale wafers, ii) an extraordinary smoothness of the slow‐etching (111) planes, and iii) a precise geometry control including the extent micropyramids or micropyramidal voids are truncated. The combination of these properties transforms this technology into a versatile platform for novel detector and emitter applications in Si photonics. The optical properties of such arrays are studied by finite‐difference time‐domain modeling in two realms represented by different boundary conditions (BCs). Periodic BCs result in Talbot self‐images experimentally observed in this work. Perfectly matched layer BCs describe mesoscale interference effects resulting in the subwavelength focusing properties of micropyramids. Enhancements in the performance of mid‐wave infrared (MWIR) focal plane arrays are demonstrated by monolithic integration of Si micropyramids with silicon‐platinum silicide Schottky barrier photodetectors. Finally, it is shown that Si micropyramidal arrays can be used to enhance light extraction and directionality of quantum sources and infrared scene projectors.

ASW^2DF: Census of the obscured star formation in a galaxy cluster in formation at z=2.2

We report the results of the deep and wide Atacama Large Millimeter/submillimeter Array (ALMA) 1.2\,mm mapping of the Spiderweb protocluster at $z=2.16$. The observations were divided into six contiguous fields covering a survey area of 19.3\,arcmin$^2$. With sim 13h of on-source time, the final maps in the six fields reach the 1sigma rms noise in a range of $40.3-57.1\ at a spatial resolution of $0 By using different source extraction codes and careful visual inspection, we detected 47 ALMA sources at a significance higher than 4sigma . We constructed the differential and cumulative number counts down to $ after the correction for purity and completeness obtained from Monte Carlo simulations. The ALMA 1.2\,mm number counts of dusty star-forming galaxies (DSFGs) in the Spiderweb protocluster are overall two times that of general fields, with some regions showing even higher overdensities (more than a factor of three). This is consistent with the results from previous studies over a larger scale using single-dish instruments. Comparison of the spatial distributions between different populations indicates that our ALMA sources are likely drawn from the same distribution as CO(1-0) emitters from the COALAS large program but are distinct from that of Halpha emitters. The cosmic star formation rate density of the ALMA sources is consistent with previous results (e.g., LABOCA 870\,mu m observations) after accounting for the difference in volume. We show that molecular gas masses estimates from dust measurements are not consistent with the ones derived from CO(1-0) and thus have to be taken with caution. The multiplicity fraction of single-dish DSFGs is higher than that of the field. Moreover, two extreme concentrations of ALMA sources were found on the outskirts of the Spiderweb protocluster, with an excess of more than 12 times that of the general fields. These results indicate that the ALMA-detected DSFGs are supplied through gas accretion along filaments and are triggered by intense star formation by accretion shocks before falling into the cluster center. The identified two galaxy groups are likely falling into the protocluster center and will trigger new merger events eventually, as indicated in simulations.

PHOTOINACTIVATION OF CANDIDA ALBICANS BIOFILM WITH GREEN LASER MEDIATED BY THE PAPAYA LEAF EXTRACT CHLOROPHYLL

This study aims to activate the effectiveness of Photodynamic Inactivation (PDI) as an antibacterial agent by using a green laser and papaya leaf chlorophyll extract to prevent Candida albicans cell death. Papaya leaf extract chlorophyll is known to have potential as a photosensitizer (PS) through its antimicrobial properties and ability to absorb optimal light photons at a wavelength range of 405–680 nm. Activation of chlorophyll molecules with appropriate light produces Reactive Oxygen Species (ROS), which are toxic to pathogenic microbes such as Candida albicans. The research method involves using PDI with a green laser light source and chlorophyll extract on Candida albicans biofilms. Four main treatment groups were applied, negative control (C-), positive controls with 10% (C1+) and 15% chlorophyll (C2+), irradiation for 60, 120, 180, 240, and 300 seconds (L1–L5), and combinations of irradiation with chlorophyll (L1F1–L5F2, where F1 for 10% chlorophyll and F2 for 15% chlorophyll), with measurements performed three times for each treatment. Living Candida albicans cells were detected using the XTT assay staining method. The results showed a significant decrease in activity in all treatment groups. Maximum activity was achieved in the L5F1 and L5F2 treatment groups with inactivation of 80% (p<0.05) and 83% (p<0.05), respectively. This study concludes that high papaya leaf extract chlorophyll concentrations combined with a green laser effectively inhibit Candida albicans biofilm.

The construction of international wetland urban ecological security pattern coupled with MSPA and ESF.

Creating an ecological security pattern is crucial for balancing the sustainable development of areas where human activities and the natural environment intersect. Using Hefei, an internationally recognized Wetland City, as a case study, we extracted ecological sources through ecological service function (ESF) analysis and morphological spatial pattern analysis (MSPA) core area connectivity analysis. Based on these ecological sources, we developed an ecological resistance surface system and identified ecological corridors and nodes using circuit theory. The findings are as follows: (1) Ecological source areas: The primary ecological sources in Hefei are located in the water bodies, forested areas, and scattered grasslands in the central and eastern parts of the city. This ecological source area covers 978.96 km2, which constitutes 8.55% of the city's total area. (2) Ecological corridors: Hefei contains 43 ecological corridors with a total length of 940.3km, averaging 21.87km each. These corridors are crucial for maintaining ecological connectivity and facilitating species movement. (3) Ecological nodes: There are 13 significant ecological nodes in Hefei, including 6 ecological obstacle points and 7 ecological pinpoints. These nodes play a vital role in supporting ecological processes and ensuring habitat connectivity. (4) Evaluation metrics: The α and β values for the source identification method that integrates MSPA with ecological service functions were 2.15 and 0.8, respectively, which are higher than those of the control group. Conversely, the γ-value was 0.18, lower than that of the control group. These results indicate that the combined ecological source extraction method provides significant advantages in terms of ecological corridor integrity, connectivity, and ecological flow management.

Upgrading Isoquercitrin Concentration via Submerge Fermentation of Mulberry Fruit Extract with Edible Probiotics to Suppress Gene Targets for Controlling Kidney Cancer and Inflammation.

In recent years, kidney cancer has become one of the most serious medical issues. Kidney cancer is treated with a variety of active compounds that trigger genes that cause cancer. We identified in our earlier research that isoquercitrin (IQ) can activate PIK3CA, IGF1R, and PTGS2. However, it has a very low bioavailability because of its lower solubility in water. So, we utilized sub-merge fermentation technology with two well-known probiotics, Lactobacillus acidophilus and Bacillus subtilis, as a microbial source and mulberry fruit extract as a substrate, which has a high IQ level to improve IQ yield. Furthermore, we compared the total phenolic, flavonoid, and antioxidant contents of fermented and non-fermented samples, and we found that the fermented samples had greater levels than non-fermented sample. In addition, the high-performance liquid chromatography (HPLC) results showed that the fermented mulberry fruit extract from B. subtilis and L. acidophilus showed higher IQ values (190.73 ± 0.004μg/ml and 220.54 ± 0.007μg/ml, respectively), compared to the non-fermented samples, which had IQ values (80.12 ± 0.002μg/ml). Additionally, at 62.5µg/ml doses of each sample, a normal kidney cell line (HEK 293) showed higher cell viability for fermented and non-fermented samples. Conversely, at the same doses, the fermented samples of L. acidophilus and B. subtilis in a kidney cancer cell line (A498) showed an inhibition of cell growth around 36% and 31%, respectively. Finally, we performed RT and qRT PCR assay, and we found a significant reduction in the expression of the PTGS2, PIK3CA, and IGF1R genes. We therefore can conclude that the fermented samples have a higher concentration of isoquercitrin, and also can inhibit the expression of the genes PTGS2, PIK3CA, and IGF1R, which in turn regulates kidney cancer and inflammation.

ALMA-IMF

The stellar initial mass function (IMF) is critical to our understanding of star formation and the effects of young stars on their environment. On large scales, it enables us to use tracers such as UV or Hα emission to estimate the star formation rate of a system and interpret unresolved star clusters across the Universe. So far, there is little firm evidence of large-scale variations of the IMF, which is thus generally considered “universal”. Stars form from cores, and it is now possible to estimate core masses and compare the core mass function (CMF) with the IMF, which it presumably produces. The goal of the ALMA-IMF large programme is to measure the core mass function at high linear resolution (2700 au) in 15 typical Milky Way protoclusters spanning a mass range of 2.5 × 103 to 32.7 × 103 M⊙. In this work, we used two different core extraction algorithms to extract ≈680 gravitationally bound cores from these 15 protoclusters. We adopted a per core temperature using the temperature estimate from the point-process mapping Bayesian method (PPMAP). A power-law fit to the CMF of the sub-sample of cores above the 1.64 M⊙ completeness limit (330 cores) through the maximum likelihood estimate technique yields a slope of 1.97 ± 0.06, which is significantly flatter than the 2.35 Salpeter slope. Assuming a self-similar mapping between the CMF and the IMF, this result implies that these 15 high-mass protoclusters will generate atypical IMFs. This sample currently is the largest sample that was produced and analysed self-consistently, derived at matched physical resolution, with per core temperature estimates, and cores as massive as 150 M⊙. We provide both the raw source extraction catalogues and the catalogues listing the source size, temperature, mass, spectral indices, and so on in the 15 protoclusters.

Music source feature extraction based on improved attention mechanism and phase feature

Music source feature extraction is an important research direction in music information retrieval and music recommendation system. To extract the features of music sources more effectively, the study introduces the jump attention mechanism and combines it with the convolutional attention module. Also, a feature extraction module based on Unet + + and spatial attention module is proposed. In addition, the phase feature information of the mixed music signals is utilized to improve the network performance. Results showed that this model was studied to perform well in music source separation experiments of vocals and accompaniment. For vocal separation on the MIR-1K dataset, the model achieves 11.25 dB, 17.34 dB, and 13.83 dB for each metric, respectively. Meanwhile, for drum separation on the DSD100 dataset, the model achieves a median signal-to-source distortion ratio of 4.36 dB, which is 2.91 dB better than that of the Spectral Hierarchical Network model. For the separation of the bass sound and the human voice, the model's in the separation of bass and human voice, the median distortion ratio of the model is as high as 4.87 dB and 6.09 dB, which is better than that of the Spectral Hierarchical Network model. This indicates the significant performance advantages in feature extraction and separation of music sources, and it has important application values in music production and speech recognition.

Eco-friendly biotransformation of penicillin G by free and immobilized marine halophilic Bacillus pseudomycoides AH1

BackgroundSeveral antibiotics are partially metabolized by patients after administration and end up in municipal sewage systems. The fate of biodegradation in aquatic environments and the role of biodegradation in the development of bacterial resistance are poorly understood. Thus, as a crucial step in an environmental risk assessment, the biodegradability of many therapeutically significant antibiotics was investigated.ResultsA marine halophilic bacteria that degrades penicillin G (PEN-G) was isolated and identified based on morphology, physio-biochemical characteristics, and 16S rDNA sequences as Bacillus pseudomycoides AH1 (accession no. MF037698). The effects of various concentrations of PEN-G and carbon and nitrogen sources on the biotransformation ability at 30°C and pH 7.0 were evaluated. Cells grown in medium supplemented with glucose as an additional carbon source and yeast extract as a nitrogen source exhibited maximal PEN-G biotransformation efficiency and rate (71.678% ±1.28 and 2.99 mg/h, respectively). The culture conditions for B. pseudomycoides AH1 cells were optimized using a Plackett–Burman design (PBD). Six key determinants (p < 0.05) significantly affected the process outcome, as deduced by regression analysis of the PBD data, and modified MSM broth achieved PEN-G biotransformation efficiency (100%) under aerobic shaking conditions at 35°C, irrespective of HPLC analysis. Additionally, the present investigation could strongly support the application of immobilization approaches for the removal of PEN-G-contaminated environmental sites.ConclusionTo the best of the authors’ knowledge, this is the first detailed study on the efficient biotransformation of PEN-G by an alginate-bacteria system as a simple, green, and inexpensive process, as well as a promising method.

A three-dimensional feature-based fusion strategy for infrared and visible image fusion

Due to the lacking of attention to the scene’s essential characteristics, the existing fusion methods suffer from the deficiency of scene distortion. In addition, the lack of groundtruth can cause an inadequate representation of vital information. To this end, we propose a novel infrared and visible image fusion network based on three-dimensional feature fusion strategy (D3Fuse). In our method, we consider the scene semantic information in the source images and extract the commonality contents of the two images as the third-dimensional feature to extend the feature space for fusion tasks. Specifically, a commonality feature extraction module (CFEM) is designed to extract the scene commonality features. Subsequently, the scene commonality features are utilized together with modality features to construct the fusion image. Moreover, to ensure the independence and diversity of distinct features, we employ a contrastive learning strategy with multiscale PCA coding, which stretches the feature distance in an unsupervised manner, prompting the encoder to extract more discriminative information without incurring additional parameters and computational costs. Furthermore, a contrastive enhancement strategy is utilized to ensure adequate representation of modality information. The results of the qualitative and quantitative evaluations on the three datasets show that the proposed method has better visual performance and higher objective metrics with lower computational cost. The object detection experiments show that our results have superior performance on high-level semantic tasks.

Innovative sono-synthesis of cerium dioxide nanomaterials using mentha extract with efficient activity for cancer therapy application

Nanostructured CeO2 was fabricated through a facile sonochemical route utilizing cerium (III) nitrate hexahydrate as a metal source and mentha extract as a novel capping agent. To our knowledge, this experimental work is the first successful endeavor for fabricating nanostructured CeO2 employing mentha extract by an easy and eco-friendly route. The microstructure and various characteristics of the oxide nanostructure prepared utilizing mentha extract were investigated using various methods. This research examined the anticancer effects of green synthesized cerium oxide nanoparticles (CeO2-NPs) on cancer cell lines (T98 and SHSY5Y) at several concentrations of 0.0, 0.05, 0.1, 0.2, 0.4, and 0.8 mg/ml NPs by exposure time of 24/48 h. The obtained results presented a cytotoxicity of the prepared NPs against the cancerous cell lines. Considering the CeO2-NP's effects on cancer cells indicated significant toxicity against cancer cell lines, these nanoparticles could be applied in medicine and in developing new drug formulations for cancer cell lines. Additional investigations are desired to reveal other biological applications of synthesized NPs against normal and other cancerous cell lines.

Brightest Cluster Galaxy Offsets in Cold Dark Matter

The distribution of offsets between the brightest cluster galaxies of galaxy clusters and the centroid of their dark matter distributions is a promising probe of the underlying dark matter physics. In particular, since this distribution is sensitive to the shape of the potential in galaxy cluster cores, it constitutes a test of dark matter self-interaction on the largest mass scales in the universe. We examine these offsets in three suites of modern cosmological simulations; IllustrisTNG, MillenniumTNG and BAHAMAS. For clusters above , we examine the dependence of the offset distribution on gravitational softening length, the method used to identify centroids, redshift, mass, baryonic physics, and establish the stability of our results with respect to various nuisance parameter choices. We find that offsets are overwhelmingly measured to be smaller than the minimum converged length scale in each simulation, with a median offset of in the highest resolution simulation considered, TNG300-1, which uses a gravitational softening length of . We also find that centroids identified via source extraction on smoothed dark matter and stellar particle data are consistent with the potential minimum, but that observationally relevant methods sensitive to cluster strong gravitational lensing scales, or those using the the “light traces mass” approach, in this context meaning gas is used as a tracer for the potential, can overestimate offsets by factors of ∼10 and ∼30, respectively. This has the potential to reduce tensions with existing offset measurements which have served as evidence for a nonzero dark matter self-interaction cross section.

Automatic road network selection method considering functional semantic features of roads with graph convolutional networks

Road network selection plays a key role in map generalization for creating multi-scale road network maps. Existing methods usually determine road importance based on road geometric and topological features, few evaluate road importance from the perspective of road utilization based on human travel data, ignoring the functional values of roads, which leads to a mismatch between the generated results and people’s needs. This paper develops two functional semantic features (i.e. travel path selection probability and regional attractiveness) to measure the functional importance of roads and proposes an automatic road network selection method based on graph convolutional networks (GCN), which models road network selection as a binary classification. Firstly, we create a dual graph representing the source road network and extract road features including six graphical and two functional semantic features. Then, we develop an extended GCN model with connectivity loss for generating multi-scale road networks and propose a refinement strategy based on the road continuity principle to ensure road topology. Experiments demonstrate the proposed model with functional features improves the quality of selection results, particularly for large and medium scale maps. The proposed method outperforms state-of-the-art methods and provides a meaningful attempt for artificial intelligence models empowering cartography.

Revealing the regulatory impact of nutrient on the production of (R)-2-(4-Hydroxyphenoxy)propanoic acid by Beauveria bassiana biofilms through comparative transcriptomics analyse.

Carbon and nitrogen play a fundamental role in the architecture of fungal biofilm morphology and metabolite production. However, the regulatory mechanism of nutrients remains to be fully understood. In this study, the formation of Beauveria bassiana biofilm and the production of (R)-2-(4-Hydroxyphenoxy)propanoic acid in two media with different carbon and nitrogen sources (GY: Glucose as a carbon source and yeast extract as a nitrogen source, MT: Mannitol as a carbon source and tryptone as a nitrogen source) were compared. R-HPPA production increased 2.85-fold in media MT than in media GY. Different fungal biofilm morphology and architecture were discovered in media GY and MT. Comparative transcriptomics revealed up-regulation of mitogen-activated protein kinase (MAPK) pathway and polysaccharides degradation genes affecting mycelial morphology and polysaccharides yield of the extracellular polymeric substances (EPS) in MT medium biofilms. Upregulation of genes related to NADH synthesis (carbon metabolism, amino acid metabolism, glutamate cycle) causes NADH accumulation and triggers an increase in R-HPPA production. These data provide a valuable basis for future studies on regulating fungal biofilm morphology and improving the production of high-value compounds.

Insights into the efficient degradation mechanism of extracellular proteases mediated by Purpureocillium lilacinum.

Protease secretion is crucial for degrading nematode cuticles using nematophagous fungus Purpureocillium lilacinum, but the secretion pattern of protease remains poorly understood. This study aimed to explore the degradation mechanism of proteases by investigating the characteristics of protease secretion under various carbon and nitrogen sources, and different carbon to nitrogen (C:N) ratios in P. lilacinum. The results showed that corn flour as a carbon source and yeast extract as a nitrogen source specifically induced protease secretion in P. lilacinum. P. lilacinum produced significant amounts of gelatinase and casein enzyme at C:N ratios of 10:1, 20:1, and 40:1, indicating that higher C:N ratios were more beneficial for secreting extracellular proteases. Proteomic analysis revealed 14 proteases, including 4 S8 serine endopeptidases and one M28 aminopeptidase. Among four S8 serine peptidases, Alp1 exhibited a high secretion level at C:N ratio less than 5:1, whereas PR1C, PR1D, and P32 displayed higher secretion levels at higher C:N ratios. In addition, the transcription levels of GATA transcription factors were investigated, revealing that Asd-4, A0A179G170, and A0A179HGL4 were more prevalent at a C:N ratio of 40:1. In contrast, the transcription levels of SREP, AreA, and NsdD were higher at lower C:N ratios. The putative regulatory profile of extracellular protease production in P. lilacinum, induced by different C:N ratios, was analyzed. The findings offered insights into the complexity of protease production and aided in the hydrolytic degradation of nematode cuticles.

ALMA-IMF

Context. The star formation process leads to an increased chemical complexity in the interstellar medium. Sites associated with high-mass star and cluster formation exhibit a so-called hot core phase, characterized by high temperatures and column densities of complex organic molecules. Aims. We aim to systematically search for and identify a sample of hot cores toward the 15 Galactic protoclusters of the ALMA-IMF Large Program and investigate their statistical properties. Methods. We built a comprehensive census of hot core candidates toward the ALMA-IMF protoclusters based on the detection of two CH3OCHO emission lines at 216.1 GHz. We used the source extraction algorithm GExt2D to identify peaks of methyl formate (CH3OCHO) emission, a complex species commonly observed toward sites of star formation. We performed a cross-matching with the catalog of thermal dust continuum sources from the ALMA-IMF 1.3 mm continuum data to infer their physical properties. Results. We built a catalog of 76 hot core candidates with masses ranging from ~0.2 M⊙ to ~80 M⊙, of which 56 are new detections. A large majority of these objects, identified from methyl formate emission, are compact and rather circular, with deconvolved full width at half maximum (FWHM) sizes of ~2300 au on average. The central sources of two target fields show more extended, but still rather circular, methyl formate emission with deconvolved FWHM sizes of ~6700 au and 13 400 au. About 30% of our sample of methyl formate sources have core masses above 8 M⊙ and range in size from ~1000 au to 13 400 au, which is in line with measurements of archetypical hot cores. The origin of the CH3OCHO emission toward the lower-mass cores may be explained as a mixture of contributions from shocks or may correspond to objects in a more evolved state (i.e., beyond the hot core stage). We find that the fraction of hot core candidates increases with the core mass, suggesting that the brightest dust cores are all in the hot core phase. Conclusions. Our results suggest that most of these compact methyl formate sources are readily explained by simple symmetric models, while collective effects from radiative heating and shocks from compact protoclusters are needed to explain the observed extended CH3OCHO emission. The large fraction of hot core candidates toward the most massive cores suggests that they rapidly enter the hot core phase and that feedback effects from the forming protostar(s) impact their environment on short timescales.