23 research outputs found
Real-time Short Video Recommendation on Mobile Devices
Short video applications have attracted billions of users in recent years,
fulfilling their various needs with diverse content. Users usually watch short
videos on many topics on mobile devices in a short period of time, and give
explicit or implicit feedback very quickly to the short videos they watch. The
recommender system needs to perceive users' preferences in real-time in order
to satisfy their changing interests. Traditionally, recommender systems
deployed at server side return a ranked list of videos for each request from
client. Thus it cannot adjust the recommendation results according to the
user's real-time feedback before the next request. Due to client-server
transmitting latency, it is also unable to make immediate use of users'
real-time feedback. However, as users continue to watch videos and feedback,
the changing context leads the ranking of the server-side recommendation system
inaccurate. In this paper, we propose to deploy a short video recommendation
framework on mobile devices to solve these problems. Specifically, we design
and deploy a tiny on-device ranking model to enable real-time re-ranking of
server-side recommendation results. We improve its prediction accuracy by
exploiting users' real-time feedback of watched videos and client-specific
real-time features. With more accurate predictions, we further consider
interactions among candidate videos, and propose a context-aware re-ranking
method based on adaptive beam search. The framework has been deployed on
Kuaishou, a billion-user scale short video application, and improved effective
view, like and follow by 1.28%, 8.22% and 13.6% respectively.Comment: Accepted by CIKM 2022, 10 page
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Activated mouse T cells facilitate melanoma metastasis via Qa-1-dependent suppression of NK-cell cytotoxicity
The regulatory activities of mouse T cells on various immune cells, including NK cells, have been well documented. Under some conditions, conventional T cells in the periphery are able to acquire inhibitory function on other T cells, but their roles in controlling innate immune cells are poorly defined. As a potential cellular therapy for cancer, ex vivo activated effector T cells are often infused back in vivo to suppress tumor growth and metastasis. Whether such activated T cells could affect NK-cell control of tumorigenesis is unclear. In the present study, we found that mitogen-activated T cells exhibited potent suppressor function on NK-cell proliferation and cytotoxicity in vitro, and notably facilitated B16 melanoma metastasis in vivo. Suppression of NK cells by activated T cells is cell-cell contact dependent and is mediated by Qa-1:NKG2A interaction, as administration of antibodies blocking either Qa-1 or NKG2A could completely reverse this suppression, and significantly inhibited otherwise facilitated melanoma metastasis. Moreover, activated cells from Qa-1 knockout mice completely lost the suppressor activity on NK cells, and failed to facilitate melanoma metastasis when transferred in vivo. Taken together, our findings indicate that innate anti-tumor response is counter regulated by the activation of adaptive immunity, a phenomenon we term as âactivation-induced inhibitionâ. Thus, the regulatory role of activated T cells in NK-cell activity must be taken into consideration in the future design of cancer therapies
Cu/Fe-Cocatalyzed MeyerâSchuster-like Rearrangement of Propargylic Amines: Direct Access to <i>E</i>âÎČ-Aminoacryaldehydes
A simple
and efficient method for the synthesis of ÎČ-aminoacryaldehydes
via CuÂ(OAc)<sub>2</sub>·H<sub>2</sub>O and FeCl<sub>3</sub> cocatalyzed
MeyerâSchuster-Like rearrangement of propargylic amines was
developed. The reactions proceed selectively as the <i>E</i>-isomers in generally good yields under aerobic conditions, and are
compatible with a broad range of functional groups. This method combines
CâN bond cleavage as well as the <i>N</i>-aryl group
migration and provides a practical and mild synthetic approach to
α,ÎČ-unsaturated carbonyl compounds, which are useful precursors
in a variety of functional group transformations
Enhancement of Immune Response and Anti-Infection of Mice by Porcine Antimicrobial Peptides and Interleukin-4/6 Fusion Gene Encapsulated in Chitosan Nanoparticles
In order to develop a novel and effective immunoregulator to enhance both the immune response and antimicrobial function, a recombinant eukaryotic expression plasmid-pVAX1 co-expressing fusion cathelicidin antimicrobial peptides (CAMPs) and fusion porcine interleukin-4/6 gene (IL-4/6) was constructed and encapsulated in chitosan nanoparticles (CS-VAP4/6), prepared by the ionotropic gelation method. Four-week-old female Kunming mice were divided into three groups and intramuscularly injected, respectively, with CS-VAP, CS-VAP4/6, and CS-pVAX1. On 28 days post-inoculation, the mice were challenged by intraperitoneal injection with Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 25922); IgG, IgG1 and IgG2a, CD4+, and CD8+ T cells increased significantly in the VAP- and VAP4/6- treated mice, detected by ELISA and flow cytometry, correspondingly (p < 0.05). As analyzed by qPCR, expression levels of Toll-like receptor (TLR) 1, TLR4, TLR6, TLR9, IL-1, IL-2, IL-4, IL-6, IL-7, IL-12, IL-15, IL-23, Tumor Necrosis Factor (TNF)-α, and Interferon-gamma (IFN-γ) genes were also significantly up-regulated in comparison with those of the control mice (p < 0.05). Their immunological markers were elevated significantly to different degrees in CS-VAP4/6-treated mice compared with CS-VAP in different days post-inoculation (p < 0.05). After challenge with E. coli and Staphylococcus aureus, most of the VAP- and VAP4/6- treated mice survived, and no symptoms of bacterial infection were observed. In contrast, 80% of control mice died of infection. Among the treated groups, VAP4/6 had a stronger resistance against challenge with E. coli infection. These results demonstrated that the fusion gene of antimicrobial peptide and interleukin-4/6 has the promising potential as a safe and effective immunomodulator for the control of bacterial infections
Degradation of Host Proteins and Apoptosis Induced by Foot-and-Mouth Disease Virus 3C Protease
Foot-and-mouth disease (FMD), induced by the foot-and-mouth disease virus (FMDV), is a highly contagious disease of cloven-hoofed animals. Previous studies have reported that FMDV 3C protease could degrade multiple host proteins; however, the degradation mechanism mediated by FMDV 3C is still unclear. Here, we found that transient expression of FMDV 3C degraded various molecules in NF-κB signaling in a dose-dependent manner, and the proteolytic activity of FMDV 3C is important for inducing degradation. Additionally, 3C-overexpression was associated with the induction of apoptosis. In this study, we showed that an apoptosis inhibitor CrmA abolished the ability of 3C to degrade molecules in NF-κB signaling. Further experiments using specific caspase inhibitors confirmed the irrelevance of caspase3, caspase8, and caspase9 activity for degradation induced by 3C. Altogether, these results suggest that FMDV 3C induces the widespread degradation of host proteins through its proteolytic activity and that the apoptosis pathway might be an important strategy to mediate this process. Further exploration of the relationship between apoptosis and degradation induced by 3C could provide novel insights into the pathogenic mechanisms of FMDV
Copper-Catalyzed C(sp<sup>2</sup>)âH Amidation with Azides as Amino Sources
A copper-catalyzed CâH amidation
process, with azides as amino sources under oxidant-free conditions,
has been developed. When <i>N</i>-heterocycles were employed
as directing groups, sulfonylazide and benzoylazide could be used
as amidating reagents to provide corresponding <i>N</i>-arylamides.
When amidines or imine were used, tandem CâN/NâN bond
formation occurred to afford indazole derivatives in one pot
Preparation and Optimization of Triptolide-Loaded Solid Lipid Nanoparticles for Oral Delivery with Reduced Gastric Irritation
Triptolide (TP) often causes adverse reactions in the gastrointestinal tract when it is administered orally. This study aimed to prepare and optimize triptolide-loaded solid lipid nanoparticles (TP-SLN) with reduced gastric irritation. The microemulsion technique was used to formulate TP-SLN employing a five-level central composite design (CCD) that was developed for exploring the optimum levels of three independent variables on particle size, encapsulation efficiency (EE) and drug loading (DL). Quadratic polynomial models were generated to predict and evaluate the three independent variables with respect to the three responses. The optimized TP-SLN was predicted to comprise fraction of lipid of 49.73%, surfactant to co-surfactant ratio of 3.25, and lipid to drug ratio of 55.27, which showed particle size of 179.8 ± 5.7 nm, EE of 56.5 ± 0.18% and DL of 1.02 ± 0.003% that were in good agreement with predicted values. In addition, the optimized nanoparticles manifested a sustained-release pattern in vitro and were stable during 3 h of incubation in simulated gastric fluids without significant size change and the majority (91%) of the drug was protected. Furthermore, the nanoparticles did not show obvious gastric irritation caused by oral administration of TP in rats
Preparation and Optimization of Triptolide-Loaded Solid Lipid Nanoparticles for Oral Delivery with Reduced Gastric Irritation
Triptolide (TP) often causes adverse reactions in the gastrointestinal tract when it is administered orally. This study aimed to prepare and optimize triptolide-loaded solid lipid nanoparticles (TP-SLN) with reduced gastric irritation. The microemulsion technique was used to formulate TP-SLN employing a five-level central composite design (CCD) that was developed for exploring the optimum levels of three independent variables on particle size, encapsulation efficiency (EE) and drug loading (DL). Quadratic polynomial models were generated to predict and evaluate the three independent variables with respect to the three responses. The optimized TP-SLN was predicted to comprise fraction of lipid of 49.73%, surfactant to co-surfactant ratio of 3.25, and lipid to drug ratio of 55.27, which showed particle size of 179.8 ± 5.7 nm, EE of 56.5 ± 0.18% and DL of 1.02 ± 0.003% that were in good agreement with predicted values. In addition, the optimized nanoparticles manifested a sustained-release pattern in vitro and were stable during 3 h of incubation in simulated gastric fluids without significant size change and the majority (91%) of the drug was protected. Furthermore, the nanoparticles did not show obvious gastric irritation caused by oral administration of TP in rats