LightFR: Lightweight Federated Recommendation with Privacy-preserving Matrix Factorization

Federated recommender system (FRS), which enables many local devices to train a shared model jointly without transmitting local raw data, has become a prevalent recommendation paradigm with privacy-preserving advantages. However, previous work on FRS performs similarity search via inner product in continuous embedding space, which causes an efficiency bottleneck when the scale of items is extremely large. We argue that such a scheme in federated settings ignores the limited capacities in resource-constrained user devices (i.e., storage space, computational overhead, and communication bandwidth), and makes it harder to be deployed in large-scale recommender systems. Besides, it has been shown that transmitting local gradients in real-valued form between server and clients may leak users' private information. To this end, we propose a lightweight federated recommendation framework with privacy-preserving matrix factorization, LightFR, that is able to generate high-quality binary codes by exploiting learning to hash technique under federated settings, and thus enjoys both fast online inference and economic memory consumption. Moreover, we devise an efficient federated discrete optimization algorithm to collaboratively train model parameters between the server and clients, which can effectively prevent real-valued gradient attacks from malicious parties. Through extensive experiments on four real-world datasets, we show that our LightFR model outperforms several state-of-the-art FRS methods in terms of recommendation accuracy, inference efficiency and data privacy.Comment: Accepted by ACM Transactions on Information Systems (TOIS

Progress in Research on the Structure and Activity of Polysaccharides from Chlorella

Chlorella contains a variety of polysaccharides with complex composition and structure, which are composed of various monosaccharides such as galactose, rhamnose, glucose, arabinose, mannose, xylose and glucuronic acid. The glycosidic linkages of polysaccharides are diverse, including α-1,6-glucose, β-1,3-galactose, α-1,6-galactose, α-1,3-rhamnose, α-1,2-rhamnose, α-1,5-arabinose, α-1,6-mannose and β-1,4-xylose. Some polysaccharides are modified by methylation, sulfation and acetylation. Meanwhile, many studies have shown that polysaccharides have multiple functions such as immunoregulatory, anti-inflammatory, antioxidant, anti-tumor, antibacterial and intestinal flora-regulatory effects. At present, monosaccharide composition analysis, methylation combined with gas chromatography-mass spectrometry (GC-MS) and two-dimensional nuclear magnetic resonance (2D-NMR) spectroscopy are mainly used for research on the structure of chlorella polysaccharides such as analysis of monosaccharide composition, glycosidic bond types, branch chain substitution positions and branch chain types. This review hopes to provide valuable information for the fine structural analysis and structure-activity relationship study of polysaccharides from Chlorella

A real-world study of anlotinib as third-line or above therapy in patients with her-2 negative metastatic breast cancer

BackgroundAntiangiogenic agents provides an optional treatment strategy for patients with metastatic breast cancer. The present study was conducted to evaluate the efficacy and safety of anlotinib as third-line or above therapy for patients with HER-2 negative metastatic breast cancer.MethodsPatients with HER-2 negative metastatic breast cancer who have failed from prior therapy and treated with anlotinib monotherapy or combined with chemotherapy or immunotherapy from June 2018 to December 2020 were retrospectively analyzed based on real-world clinical practice. The primary end point was progression free survival (PFS). Secondary end points included objective response rate (ORR), disease control rate (DCR), overall survival (OS) and safety.Results47 patients with HER-2 negative metastatic breast cancer received anlotinib monotherapy or combination therapy as third-line or above therapy. In the general population, 10 patients achieved PR, 25 patients had SD and 12 patients had PD. The overall ORR and DCR were 21.3% and 74.5%, respectively. Subgroup analysis suggested that there were no statistically significant differences in ORR and DCR with respect to HR status (positive vs. negative), treatment programs (monotherapy vs. combination) and treatment type in combination group (chemotherapy vs. immunotherapy). The patients who did not received previously anti-angiogenesis therapy had superior DCR (84.8% vs. 50.0%, P=0.012). Median PFS and OS were 5.0 months (95% CI=4.3-5.7) and 21.0 (95% CI=14.9-27.1) months, respectively. The PFS (6.5m vs. 3.5m, P=0.042)and OS (28.2m vs. 12.6m, P=0.040) were better in HR positive patients than HR negative patients. And simultaneously, patients who received anlotinib combination therapy obtained better PFS (5.5m vs. 3.0m, P=0.045). The incidence of Grade 3-4 adverse events(AEs) was 31.9%.ConclusionsAnlotinib monotherapy or combination therapy provide a viable third-line or above therapeutic strategy in patients with HER-2 negative metastatic breast cancer, a median PFS of 5.0 months was obtained with well tolerated toxicity

Association between antibiotic use during early life and early-onset colorectal cancer risk overall and according to polygenic risk and FUT2 genotypes

Early-onset colorectal cancer (EOCRC) has been increasing worldwide. Potential risk factors may have occurred in childhood or adolescence. We investigated the associations between early-life factors and EOCRC risk, with a particular focus on long-term or recurrent antibiotic use (LRAU) and its interaction with genetic factors. Data on the UK Biobank participants recruited between 2006 and 2010 and followed up to February 2022 were used. We used logistic regression to estimate adjusted odds ratios (ORs) and 95% confidence intervals (95% CIs) of the associations between LRAU during early life and EOCRC risk overall and by polygenic risk score (constructed by 127 CRC-related genetic variants) and Fucosyltransferase 2 (FUT2), a gut microbiota regulatory gene. We also assessed the associations for early-onset colorectal adenomas, as precursor lesion of CRC, to examine the effect of LRAU during early-life and genetic factors on colorectal carcinogenesis. A total of 113 256 participants were included in the analysis, with 165 EOCRC cases and 719 EOCRA cases. LRAU was nominally associated with increased risk of early-onset CRC (OR = 1.48, 95% CI = 1.01-2.17, P = .046) and adenomas (OR = 1.40, 95% CI = 1.17-1.68, P < .001). When stratified by genetic polymorphisms of FUT2, LRAU appeared to confer a comparatively greater risk for early-onset adenomas among participants with rs281377 TT genotype (OR = 1.10, 95% CI = 0.79-1.52, P = .587, for CC genotype; OR = 1.75, 95% CI = 1.16-2.64, P = .008, for TT genotype; Pinteraction  = .089). Our study suggested that LRAU during early life is associated with increased risk of early-onset CRC and adenomas, and the association for adenomas is predominant among individuals with rs281377 TT/CT genotype. Further studies investigating how LRAU contributes together with genetic factors to modify EOCRC risk, particularly concerning the microbiome-related pathway underlying colorectal carcinogenesis, are warranted

Molecular Characterization of the 1-Deoxy-D-Xylulose 5-Phosphate Synthase Gene Family in Artemisia annua

Artemisia annua produces artemisinin, an effective antimalarial drug. In recent decades, the later steps of artemisinin biosynthesis have been thoroughly investigated; however, little is known about the early steps of artemisinin biosynthesis. Comparative transcriptomics of glandular and filamentous trichomes and 13CO2 radioisotope study have shown that the 2-C-methyl-D-erythritol-4-phosphate (MEP) pathway, rather than the mevalonate pathway, plays an important role in artemisinin biosynthesis. In this study, we have cloned three 1-deoxy-D-xylulose 5-phosphate synthase (DXS) genes from A. annua (AaDXS1, AaDXS2, and AaDXS3); the DXS enzyme catalyzes the first and rate-limiting enzyme of the MEP pathway. We analyzed the expression of these three genes in different tissues in response to multiple treatments. Phylogenetic analysis revealed that each of the three DXS genes belonged to a distinct clade. Subcellular localization analysis indicated that all three AaDXS proteins are targeted to chloroplasts, which is consistent with the presence of plastid transit peptides in their N-terminal regions. Expression analyses revealed that the expression pattern of AaDXS2 in specific tissues and in response to different treatments, including methyl jasmonate, light, and low temperature, was similar to that of artemisinin biosynthesis genes. To further investigate the tissue-specific expression pattern of AaDXS2, the promoter of AaDXS2 was cloned upstream of the β-glucuronidase gene and was introduced in arabidopsis. Histochemical staining assays demonstrated that AaDXS2 was mainly expressed in the trichomes of Arabidopsis leaves. Together, these results suggest that AaDXS2 might be the only member of the DXS family in A. annua that is involved in artemisinin biosynthesis

Direct observation of spin polarization in epitaxial Fe3O4(001)/MgO thin films grown by magnetron sputtering

We obtained epitaxial single-crystal Fe3O4(001)/MgO(001) thin films by magnetron sputtering. The high quality of the grown Fe3O4 films was confirmed by reflection high-energy electron diffraction and x-ray photoelectron spectroscopy. Atomic magnetic properties of Fe3O4(001)/MgO(001) were investigated using vibrating sample magnetometry and x-ray magnetic circular dichroism. The values of saturation magnetization and magnetic moment are 407 ± 5 emu/cm3 (3.26 ± 0.04 μ B / (f. u.)) and 3.31 ± 0.15 μ B / (f. u.), respectively, in the Fe3O4 film as thin as 5 nm, which are close to the bulk values. The spin polarization was directly measured using spin-resolved photoemission spectroscopy. The measured spin polarization has a maximum value of -42% ± 3%, which is comparable to the theoretical value for the (2 × 2)R45° reconstructed Fe3O4(001) surface. Furthermore, the film thickness-dependent measurements indicate that the anti-phase boundaries significantly decrease the spin polarization rather than the lattice mismatch. Our results demonstrate that epitaxial Fe3O4(001)/MgO thin films grown by magnetron sputtering have desired magnetic properties, facilitating the potential application of Fe3O4-based spintronic devices

MoIVD-Mediated Leucine Catabolism Is Required for Vegetative Growth, Conidiation and Full Virulence of the Rice Blast Fungus Magnaporthe oryzae

Isovaleryl-CoA dehydrogenase (IVD), a member of the acyl-CoA dehydrogenase (ACAD) family, is a key enzyme catalyzing the conversion of isovaleryl-CoA to β-methylcrotonyl-CoA in the third reaction of the leucine catabolism pathway and simultaneously transfers electrons to the electron-transferring flavoprotein (ETF) for ATP synthesis. We previously identified the ETF ortholog in rice blast fungus Magnaporthe oryzae (MoETF) and showed that MoETF was essential for fungal growth, conidiation and pathogenicity. To further investigate the biological function of electron-transferring proteins and clarify the role of leucine catabolism in growth and pathogenesis, we characterized MoIVD (M. oryzaeisovaleryl-CoA dehydrogenase). MoIvd is highly conserved in fungi and its expression was highly induced by leucine. The Δmoivd mutants showed reduced growth, decreased conidiation and compromised pathogenicity, while the conidial germination and appressorial formation appeared normal. Consistent with a block in leucine degradation, the Δmoivd mutants accumulated isovaleric acid, grew more slowly, fully lacked pigmentation and completely failed to produce conidia on leucine-rich medium. These defects were largely rescued by raising the extracellular pH, suggesting that the accumulation of isovaleric acid contributes to the growth and conidiation defects. However, the reduced virulence of the mutants was probably due to their inability to overcome oxidative stress, since a large amount of ROS (reactive oxygen species) accumulated in infected host cell. In addition, MoIvd is localized to mitochondria and interacted with its electron receptor MoEtfb, the β subunit of MoEtf. Taken together, our results suggest that MoIVD functions in leucine catabolism and is required for the vegetative growth, conidiation and full virulence of M. oryzae, providing the first evidence for IVD-mediated leucine catabolism in the development and pathogenesis of plant fungal pathogens