Modeling User Viewing Flow using Large Language Models for Article Recommendation

This paper proposes the User Viewing Flow Modeling (SINGLE) method for the article recommendation task, which models the user constant preference and instant interest from user-clicked articles. Specifically, we employ a user constant viewing flow modeling method to summarize the user's general interest to recommend articles. We utilize Large Language Models (LLMs) to capture constant user preferences from previously clicked articles, such as skills and positions. Then we design the user instant viewing flow modeling method to build interactions between user-clicked article history and candidate articles. It attentively reads the representations of user-clicked articles and aims to learn the user's different interest views to match the candidate article. Our experimental results on the Alibaba Technology Association (ATA) website show the advantage of SINGLE, which achieves 2.4% improvements over previous baseline models in the online A/B test. Our further analyses illustrate that SINGLE has the ability to build a more tailored recommendation system by mimicking different article viewing behaviors of users and recommending more appropriate and diverse articles to match user interests.Comment: 8 pages

Probiotic <i>Bifidobacterium</i> longum BB68S Improves Cognitive Functions in Healthy Older Adults: A Randomized, Double-Blind, Placebo-Controlled Trial

Probiotics could improve cognitive functions in patients with neurological disorders such as Alzheimer’s disease, but the effects on cognitive function in healthy older adults without cognitive impairment need further study. The purpose of this study was to investigate the effect of Bifidobacterium longum BB68S (BB68S) on cognitive functions among healthy older adults without cognitive impairment. A randomized, double-blind, placebo-controlled trial was conducted with 60 healthy older adults without cognitive impairment who were divided into probiotic or placebo groups and required to consume either a sachet of probiotic (BB68S, 5 × 1010 CFU/sachet) or placebo once daily for 8 weeks. The Montreal Cognitive Assessment (MoCA) was used as an inclusion screening tool to screen elderly participants with healthy cognitive function in our study, and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) was used to assess cognitive function in subjects before and after intervention as an assessment tool. BB68S significantly improved subjects’ cognitive functions (total RBANS score increased by 18.89 points after intervention, p Lachnospira, Bifidobacterium, Dorea, and Cellulosilyticum, while decreasing those of bacteria related to cognition impairment, such as Collinsella, Parabacteroides, Tyzzerella, Bilophila, unclassified_c_Negativicutes, Epulopiscium, Porphyromonas, and Granulicatella. In conclusion, BB68S could improve cognitive functions in healthy elderly adults without cognitive impairment, along with having beneficial regulatory effects on their gut microbiota. This study supports probiotics as a strategy to promote healthy aging and advances cognitive aging research

Effect of Pre-Stressing on the Acid-Stress Response in Bifidobacterium Revealed Using Proteomic and Physiological Approaches.

Weak acid resistance limits the application of Bifidobacteria as a probiotic in food. The acid tolerance response (ATR), caused by pre-stressing cells at a sublethal pH, could improve the acid resistance of Bifidobacteria to subsequent acid stress. In this study, we used Bifidobacterium longum sub. longum BBMN68 to investigate the effect of the ATR on the acid stress response (ASR), and compared the difference between the ATR and the ASR by analyzing the two-dimensional-PAGE protein profiles and performing physiological tests. The results revealed that a greater abundance of proteins involved in carbohydrate metabolism and protein protection was present after the ASR than after the ATR in Bifidobacterium. Pre-stressing cells increased the abundance of proteins involved in energy production, amino acid metabolism, and peptidoglycan synthesis during the ASR of Bifidobacterium. Moreover, after the ASR, the content of ATP, NH3, thiols, and peptidoglycan, the activity of H+-ATPase, and the maintenance of the intracellular pH in the pre-stressed Bifidobacterium cells was significantly higher than in the uninduced cells. These results provide the first explanation as to why the resistance of Bifidobacterium to acid stress improved after pre-stressing

Influence of Temperature during Freeze-Drying Process on the Viability of <i>Bifidobacterium longum</i> BB68S

Maintaining optimum temperature during freeze-drying is crucial to ensuring the viability of strains. In this study, we evaluated the effect of pre-freezing, sublimation and desorption temperatures on the viability of Bifidobacterium longum BB68S (BB68S). Moreover, we examined the water content, water activity, enzyme activities, and scanning electron microscope of BB68S to explore mechanisms underpinning the effect of temperature on viability. Our analyses revealed the highest survival rates of BB68S collected after pre-freezing and sublimation drying at −40 °C (94.9 ± 2.2%) and −10 °C (65.4 ± 3.8%), respectively. Additionally, response surface methodology demonstrated that the optimum conditions for freeze-drying of BB68S were pre-freezing temperature at −45.52 °C and sublimation temperature at −6.58 °C, and the verification test showed that survival rates of BB68S could reach 69.2 ± 3.8%. Most of the vitality loss occurred during the sublimation drying phase. Further studies showed that different sublimation temperatures affected water content and activity, β-galactosidase, lactate dehydrogenase, Na+-K+-ATP and Ca2+-Mg2+-ATP activities. In conclusion, the temperature during freeze-drying, especially sublimation temperature, is a key factor affecting the survival rate of BB68S, and the vitality loss during freeze-drying process might be due to compromised cell membrane integrity and permeability

Diversity Temporal–Spatial Dynamics of Potato Rhizosphere Ciliates and Contribution to Nitrogen- and Carbon-Derived Nutrition in North-East China

Ciliates are an important component of the rhizosphere microorganism community, but their nutritional contribution to plants has not been fully revealed. In this paper, we investigated the rhizosphere ciliate community of potatoes during six growth stages, illustrated the spatial–temporal dynamics of composition and diversity, and analyzed the correlation between soil physicochemical properties. The contributions of ciliates to the carbon- and nitrogen-derived nutrition of potatoes were calculated. Fifteen species of ciliates were identified, with higher diversity in the top soil, which increased as the potatoes grew, while they were more abundant in the deep soil, and the number decreased as the potatoes grew. The highest number of species of ciliates appeared in July (seedling stage). Among the five core species of ciliates, Colpoda sp. was the dominant species in all six growth stages. Multiple physicochemical properties affected the rhizosphere ciliate community, with ammonium nitrogen (NH4+-N) and the soil water content (SWC) greatly influencing ciliate abundance. The key correlation factors of ciliates diversity were NH4+-N, available phosphorus (AP), and soil organic matter (SOM). The annual average contribution rates of carbon and nitrogen by rhizosphere ciliates to potatoes were 30.57% and 23.31%, respectively, with the highest C/N contribution rates reaching 94.36% and 72.29% in the seedling stage. This study established a method for estimating the contributions of carbon and nitrogen by ciliates to crops and found that ciliates could be potential organic fertilizer organisms. These results might be used to improve water and nitrogen management in potato cultivation and promote ecological agriculture

Comparison of the physiological characteristics of <i>Bifidobacterium</i> in the different treatment groups.

<p>The same letters indicate no significant difference among the detected values (<i>p</i> > 0.05).Biological repeats, n = 6.</p

Schematic of the experimental design.

<p>Cultures in the mid-exponential phase (OD₆₀₀ = 0.6) were harvested and divided into two. Half of the cells were cultured for 2 h in the original medium, serving as the control group, and the other half of the cells wereculturedat pH 4.5 for 2 h, serving as the pre-stressed group. Then, the cells from both groups were harvested and challengedat a lethal pH 3.5 for 2 h. The resulting cells served as the control-pH 3.5 group and the pre-stressed-pH 3.5 group. ATR, response to pH 4.5; ASR, response to pH 3.5 of the cells in the control group; ASR, response to pH 3.5 of the cells in the pre-stressed group.</p

Protein-profiles of Bifidobacteriumlongum subsp. longum BBMN68 cells belonging to the different groups.

<p>A, control group; B, pre-stressed group; C, control-pH 3.5 group; D, pre-stressed-pH 3.5 group. Numbers indicate the protein spots of interest, for which information is listed in Table A in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0117702#pone.0117702.s001" target="_blank">S1 File</a>.</p

Effect of environmental pH on the intracellular pH in <i>Bifidobacterium</i>.

<p>White bars, the control cells; black bars, the pre-stressed cells. The same letters indicate no significant difference among the pH_in values in <i>B</i>. <i>longum</i>BBMN68 cells under different environmental conditions (<i>p</i>> 0.05). Biological repeats, n = 6.</p

Controlled fragmentation of single-atom-thick polycrystalline graphene

Controlling the fragmentation of atomically thin and brittle materials is of critical importance for both fundamental interest and technical purposes in fracture mechanics. However, the fragmentation of graphene is often random and uncontrollable because of the presence of grain boundaries and numerous defects. Here, by harnessing the strong localized strain during the necking process of thermoplastic polymers, we introduce a simple yet controllable method to tear apart a monolayer polycrystalline graphene (MPG) sheet into ordered graphene ribbons. More importantly, we show that the presence of active edges helps the graphene ribbons in exhibiting a field-effect characteristic pH response and improves the introduction of dopants. Furthermore, we demonstrate an optically transparent (∼98%), ultrathin (∼70 ± 15 nm), and skin-conformal pressure sensor for real-time tactile sensing. We believe that our results lead to further understanding of the fracture mechanics of graphene and offer unique advantages for practical applications, such as flexible electronics, chemical sensing, and biosensing.Ministry of Education (MOE)National Research Foundation (NRF)This work was supported in part by the Singapore Ministry of Education Academic Research Fund Tier 2 (MOE2015-T2-2-010) and the Singapore Ministry of Education Academic Research Fund Tier 1 (MOE 2019-T1-001-103 and MOE2019-T1-001- 111). This work was supported in part by the EEE Ignition Research Grant. This work was supported in part by the National Nature Science Foundation of China: 11804354. M.T. and K.F. acknowledge the Air Force Office of Scientific Research (AFOSR) grant 17RT0244. T.Z. acknowledges the Bureau of International Cooperation of Chinese Academy of Sciences, International Partnership Program grant 182211KYSB20170029. This work was supported in part by the Singapore National Research Foundation under NRF award numbers NRF-NRFF2013-08 and NRFCRP13-2014-05