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ABSTRACT: Pseudomonas fluorescens is a psychrophilic bacterium that can cause dairy spoilage by producing heat-stable enzymes. Bacteriophages are proved as one of the alternatives to control spoilage bacteria in today's dairy industry. This study aimed to investigate how a previously identified phage YZU_PF006 prevents dairy spoilage caused by P. fluorescens. Results demonstrated that phage YZU_PF006 effectively controlled P. fluorescens growth and production of protease at 7°C and 28°C in milk in a phage concentration-dependent way. Phage YZU_PF006 at a multiplicity of infection (MOI) of 100 increased the pH values of milk by 1.43 at 28°C and 0.81 at 7°C, increased the particle size of milk by 2.74 μm at 28°C and 1.74 μm at 7°C. Phage YZU_PF006 reduced the free AA content by 15.36% at 28°C and 32.03% at 7°C, and decreased the contents of Glu (206.678 mmol/L at 28°C and 40.481 mmol/L at 7°C), Phe (94.137 mmol/L at 28°C and 144.137 mmol/L at 7°C) and other amino acids in milk. In contrast, high-throughput sequencing analysis revealed that phage YZU_PF006 specifically prevented the growth of Pseudomonas in raw milk at low temperatures. Results demonstrated that phage YZU_PF006 can be used alone or in combination with other control strategies to serve as one of the good antimicrobial candidates to control P. fluorescens contamination in dairy processing environments, and to promote the safety and sensory quality of raw milk and milk products.

Abstract This study aimed to develop a deep learning system for the detection of three-rooted mandibular first molars (MFMs) on panoramic radiographs and to assess its diagnostic performance. Panoramic radiographs, together with cone beam computed tomographic (CBCT) images of the same subjects, were retrospectively collected from 730 patients, encompassing a total of 1444 MFMs (367 teeth were three-rooted and the remaining 1077 teeth were two-rooted). Five convolutional neural network (CNN) models (ResNet-101 and − 50, DenseNet-201, MobileNet-v3 and Inception-v3) were employed to classify three- and two-rooted MFMs on the panoramic radiographs. The diagnostic performance of each model was evaluated using standard metrics, including accuracy, sensitivity, specificity, precision, negative predictive value, and F1 score. Receiver operating characteristic (ROC) curve analyses were performed, with the CBCT examination taken as the gold standard. Among the five CNN models evaluated, ResNet-101 demonstrated superior diagnostic performance, and the AUC value attained was 0.907, significantly higher than that of all other models (all P

To investigate the association between impacted mandibular third molars (IMTMs) and the prevalence of distal caries in adjacent mandibular second molars (MSMs) in a Chinese population, a retrospective analysis was conducted using cone-beam computed tomography (CBCT) images obtained from routine dental practice for various diagnostic purposes. The impaction patterns of the mandibular third molars were recorded using Winter's classification and Pell and Gregory's classification. The occurrence and severity of distal caries in MSMs were also documented. Chi-square tests and logistical regression analyses were used to assess the association between distal caries in the MSM and variables. A total of 552 scans were included, and the frequency of IMTMs was 64.5 % (647/1003). According to Winter's classification, the most common type of impaction was mesioangular impaction (45.5 %), followed by horizontal (31.2 %) and vertical impaction (17.5 %). Based on Pell and Gregory's classification, level B impaction (54.9 %) and class II impaction (57.5 %) were the most frequent. Compared to the non-impaction group, the frequency of distal caries in the MSMs for the impaction group was significantly higher (19.5 % [126/647] vs. 3.5 % [12/346]; p

This study explores the optimal subsidy policy to maximize the benefits associated with the suburbanization of university campuses. A transport accessibility index is introduced, and a model is developed to analyze faculty housing relocation, incorporating factors such as transport accessibility, housing price, relocation subsidy, and the influence of children. The impact of housing relocation is assessed using a regional output model that considers both production and consumption aspects. Subsequently, a decision-making model is established to determine the optimal subsidy level and the number of faculty to relocate, with the overarching goal of maximizing total regional benefits. The findings reveal that an increase in subsidies correlates with a rise in the willingness of faculty to relocate, leading to heightened benefits for the region. However, the rate of benefit increase shows diminishing returns with each increment change in the subsidy. Notably, the study demonstrates that 70% of the additional benefits to the region emanate from the housing market, accurately reflecting the current financial landscape in China. This insight underscores why city governments frequently leverage land markets to actively promote suburbanization.

Abstract Background Advanced gastric cancer (GC) is a lethal malignancy, harboring recurrent alterations in cell cycle pathway, especially the CDKN2A-CDK4/CDK6/CCND1 axis. However, monotherapy of CDK4/6 inhibitors has shown limited antitumor effects for GC, and combination treatments were urgently needed for CDK4/6 inhibitors. Methods Here, we performed a comprehensive analysis, including drug screening, pan-cancer genomic dependency analysis, and epigenetic sequencing to identify the candidate combination with CDK4/6 inhibitors. Mechanisms were investigated by bulk RNA-sequencing and experimental validation was conducted on diverse in vitro or in vivo preclinical GC models. Results We found that the BRD4 inhibitor JQ1 augments the antitumor efficacy of the CDK4/6 inhibitor abemaciclib (ABE). Diverse in vitro and in vivo preclinical GC models are examined and synergistic benefits from the combination therapy are obtained consistently. Mechanistically, the combination of ABE and JQ1 enhances the cell cycle arrest of GC cells and induces unique characteristics of cellular senescence through the induction of DNA damage, which is revealed by transcriptomic profiling and further validated by substantial in vitro and in vivo GC models. Conclusion This study thus proposes a candidate combination therapy of ABE and JQ1 to improve the therapeutic efficacy and worth further investigation in clinical trials for GC.

Climate change is altering geographic and phylogeographic distribution of macroalgae, laying great impacts on their conservation and sustainable utilization. The potential distribution of two dominant cultured seaweeds-Neoporphyra haitanensis and Neopyropia yezoensis was predicted under present and three representative concentration pathways (RCP 2.6, 4.5, 8.5) for 2050 s using the maximum entropy model (MaxEnt). The area under the receiver operating characteristic curve (AUC) was 0.998 for N. haitanensis and 0.992 for N. yezoensis, indicating high modelling accuracy. Sea surface temperature contributed mainly to the models. In addition to the predominant distribution in their native habitats in Northwest Pacific, high suitability along the east coast of North America and trans-hemispheric distribution was predicted for both species. In 2050 s, high-latitudinal and offshore expansion was observed, increasing over the present distribution area by 10.75%∼26.13% for N. haitanensis and 18.97%∼26.48% for N. yezoensis. Current geographic distribution centroid of N. yezoensis was located in Seocheon and the centroid shifted northeastward to the Sea of Japan in 2050 s. The most specific haplotypes or high genetic variations (based on chloroplast rbcL sequences) were identified in both regions. Current and future centroids of N. haitanensis were located in East China Sea, where the highest genetic diversity was identified. The overall haplotype and nucleotide diversity of both species was at low levels while the haplotype distribution showed spacial heterogeneity, more diversified at the convergence zones of warm and cold ocean currents. The overlapping between N. yezoensis and N. haitanensis geographic distribution centers and species’ genetic diversity hotspots implied their ability to adapt to future climate change. These findings provided vital information for conservation and sustainable utilization of these important intertidal seaweeds to address the global climate challenges.

Prophages as a part of Staphylococcus aureus genome contribute to the genetic diversity as well as survival strategies of their host. Some S. aureus prophages also have an imminent risk of host cell lysis and become a lytic phage. Nonetheless, interactions among S. aureus prophages, lytic phages, and their hosts, as well as the genetic diversity of S. aureus prophages, remain unclear. We identified 579 intact and 1,389 incomplete prophages in the genomes of 493 S. aureus isolates obtained from the NCBI database. The structural diversity and gene content of intact and incomplete prophages were investigated and compared with 188 lytic phages. Mosaic structure comparison, ortholog group clustering, phylogenetic analysis, and recombination network analysis were performed to estimate genetic relatedness among S. aureus intact prophages, incomplete prophages, and lytic phages. The intact and incomplete prophages harbored 148 and 522 distinct mosaic structures, respectively. The major difference between lytic phages and prophages was the lack of functional modules and genes. Compared to the lytic phages, both the S. aureus intact and incomplete prophages harbored multiple antimicrobial resistance (AMR) and virulence factor (VF) genes. Several functional modules of lytic phages 3_AJ_2017 and 23MRA shared more than 99% nucleotide sequence identity with S. aureus intact (ST20130943_p1 and UTSW_ MRSA_55_ip3) and incomplete prophages (SA3_LAU_ip3 and MRSA_FKTN_ip4); other modules showed little nucleotide sequence similarity. Ortholog and phylogenetic analyses revealed a common gene pool shared between the prophages and lytic Siphoviridae phages. Moreover, most shared sequences existed within intact (43428/137294, 31.6%) and incomplete prophages (41248/137294, 30.0%). Therefore, the maintenance or loss of functional modules in intact and incomplete prophages is key to balance the costs and benefits of large prophages harboring various AMR and VF genes in the bacterial host. The shared identical functional modules between S. aureus lytic phages and prophages are likely to result in the exchange, acquisition, and loss of functional modules, and therefore contribute to their genetic diversity. Moreover, constant recombination events within prophages globally were responsible for the coevolution of lytic phages and their bacterial hosts.

To better understand the characteristics of coupled heat transfer in liquid rocket engines, a calculation scheme is proposed in this paper. This scheme can simulate the coupled heat transfer processes, including combustion and flow in the thrust chamber, radiation heat transfer, heat conduction in the wall, heat transfer of coolant flow in the cooling channel, and gas film cooling in the thrust chamber wall. The numerical method used in each physical area, the data transfer method between each computing module, the strategy of data transfer on the coupling interface, the calculation process, and the convergence criterion are all introduced in detail. The calculation scheme was verified by analyzing a water-cooled nozzle. Then, the coupled heat transfer calculation was carried out for a liquid rocket engine using a propellant composed of unsymmetrical dimethylhydrazine and dinitrogen tetroxide. Two working conditions were analyzed: whether the gas film cooling was performed or not. The results showed that the algorithm successfully indicated the protective effect of the gas film on the wall surface, and the calculation results were reasonable. It played a guiding role for the coupled heat transfer of the liquid rocket engine using a composite cooling method.

Thermophilic endoglucanases have become of significant interest for effectively catalyzing the hydrolysis of cellulose. Myceliophthora thermophila is an ideal source of thermophilic enzymes. Interestingly, different hosts differently express the same enzymes. In this study, we successfully overexpressed endoglucanase (MtEG5-1) from M. thermophila in the methylotrophic yeast, Pichia pastoris GS115, via electroporation. We found that purified MtEG5-1 exhibited optimum activity levels at pH 5 and 70 °C, with 88% thermal stability after being incubated at 70 °C for 2 h. However, we observed that purified MtEG5-1 had a molecular weight of 55 kDa. The Km and Vmax values of purified MtEG5-1 were approximately 6.11 mg/mL and 91.74 μmol/min/mg at 70 °C (pH 5.0), respectively. Additionally, the optimum NaCl concentration of purified MtEG5-1 was found to be 6 g/L. Furthermore, we observed that the activity of purified MtEG5-1 was significantly enhanced by Mn2+ and was inhibited by K+. These results indicated that MtEG5-1 expressed by P. pastoris GS115 is more heat-tolerant than that expressed by A. niger and P. pastoris X33. These properties of MtEG5-1 make it highly suitable for future academic research and industrial applications.

The mixing process and distribution characteristics of a supercritical endothermic hydrocarbon fuel (EHF) jet injected into a supersonic crossflow were investigated by experimental and numerical methods, respectively. The schlieren system and acetone planar laser-induced fluorescence (PLIF) optical system were used to capture the flow-field structural characteristics and instantaneous plume. The mixture and real gas models were employed to calculate the interaction of a transverse jet and supersonic crossflow and reveal a good accuracy with the experimental results. The mixing efficiency and total pressure loss were analyzed based on the numerical results. The results indicate that the supercritical-state EHF directly changes to a gaseous state as it enters the supersonic crossflow from the injector. The EHF jet plume boundary increases with the increasing momentum flux ratio (q). As the streamwise and spanwise distance increases, the traverse heights and expand width increase, and the EHF jet plume presents a semicircle shape in the cross-sectional plane. With the increase in the traverse direction, the concentration distribution shows a fast and then slow power exponential decreasing law; the highest concentration point starts from the near-wall region and rises in the transverse direction with the flow distance increasing. For the same injection condition, the higher the inflow Mach number, the higher the mixing efficiency. For the same Ma, the mixing efficiency is better for the case with low injection pressure and high injection temperature. The total pressure loss is greater in the higher Ma, and high injection pressure conditions cause greater total pressure loss.

The study of bacteriophages is experiencing a resurgence owing to their antibacterial efficacy, lack of side effects, and low production cost. Nonetheless, the interactions between Staphylococcus aureus bacteriophages and their hosts remain unexplored. In this study, whole-genome sequences of 188 S. aureus bacteriophages—20 Podoviridae, 56 Herelleviridae, and 112 Siphoviridae—were obtained from the National Center for Biotechnology Information (NCBI, USA) genome database. A phylogenetic tree was constructed to estimate their genetic relatedness using single-nucleotide polymorphism analysis. Comparative analysis was performed to investigate the structural diversity and ortholog groups in the subdividing clusters. Mosaic structures and gene content were compared in relation to phylogeny. Phylogenetic analysis revealed that the bacteriophages could be distinguished into three lineages (I–III), including nine subdividing clusters and seven singletons. The subdividing clusters shared similar mosaic structures and core ortholog clusters, including the genes involved in bacteriophage morphogenesis and DNA packaging. Notably, several functional modules of bacteriophages 187 and 2368A shared more than 95% nucleotide sequence identity with prophages in the S. aureus strain RJ1267 and the Staphylococcus pseudintermedius strain SP_11306_4, whereas other modules exhibited little nucleotide sequence similarity. Moreover, the cluster phages shared similar types of holins, lysins, and DNA packaging genes and harbored diverse genes associated with DNA replication and virulence. The data suggested that the genetic diversity of S. aureus bacteriophages was likely due to gene replacement, acquisition, and loss among staphylococcal phages, which may have crossed species barriers. Moreover, frequent module exchanges likely occurred exclusively among the subdividing cluster phages. We hypothesize that during evolution, the S. aureus phages enhanced their DNA replication in host cells and the adaptive environment of their host.

Genetic engineering is one of the most effective methods to obtain fungus strains with desirable traits. However, in some filamentous fungi, targeted gene deletion transformant screening on primary transformation plates is time-consuming and laborious due to a relatively low rate of homologous recombination. A strategy that compensates for the low recombination rate by improving screening efficiency was performed in F. venenatum TB01. In this study, the visualized gene deletion system that could easily distinguish the fluorescent randomly inserted and nonfluorescent putative deletion transformants using green fluorescence protein (GFP) as the marker and a hand-held lamp as the tool was developed. Compared to direct polymerase chain reaction (PCR) screening, the screening efficiency of gene deletion transformants in this system was increased approximately fourfold. The visualized gene deletion system developed here provides a viable method with convenience, high efficiency, and low cost for reaping gene deletion transformants from species with low recombination rates.