Research on User Interest Expression and Recommendation Service based on Three-dimensional Relationship of Users and Items

The existing recommendation algorithms often rely heavily on the original score information in the user rating matrix. However, the user's rating of items does not fully reflect the user's real interest. Therefore, the key to improve the existing recommendation system algorithm effectively is to eliminate the influence of these unfavorable factors and the accuracy of the recommendation algorithm can be improved by correcting the original user rating information reasonably. This paper makes a comprehensive theoretical analysis and method design from three aspects: the quality of the item, the memory function of the user and the influence of the social friends trusted by the user on the user's rating. Based on these methods, this paper finally proposes a collaborative filtering recommendation algorithm (FixCF) based on user rating modification. Using data sets such as Movielens, Epinions and Flixster, the data sets are divided into five representative subsets, and the experimental demonstration is carried out. FixCF and classical collaborative filtering algorithms, existing matrix decomposition-based algorithms and trust network-based inference are compared. The experimental results show that the accuracy and coverage of FixCF have been improved under many experimental conditions

VIRULENCE GENOTYPE AND PHYLOGENETIC GROUPS IN RELATION TO CHINESE HERB RESISTANCE AMONG ESCHERICHIA COLI FROM PATIENTS WITH ACUTE PYELONEPHRITIS

Background: Clinical isolates of herb-resistant uropathogenic E. coli were isolated. It was possible that the virulence genotypes and phylogenetic background of E. coli differed between Chinese herb-resistant E. coli and -susceptible isolates. For this purpose, the prevalence of virulence factors (VFs) and phylogenetic background, with regard to Chinese herb resistance, among E. coli strains causing acute pyelonephritis from China were investigated. Materials and Methods: E. coli isolates from patients with acute pyelonephritis were used in this study. Standard disc diffusion methodology was used to test the susceptibility of Chinese herbal concoction against E. coli strains. Multiplex PCR amplifications employed three markers (chuA, yjaA, and TSPE4.C2) to classify E. coli isolates into one of four phylogenetic groups (group A, B1, B2, or D). The isolates were also tested for 14 virulence-associated traits (VFs) of uropathogenic E. coli. Results: A total of 115 E. coli strains were isolated. 79 (68.7%) were susceptible and 36 (31.3%) were resistant to the herbal concoction. 20.9% of the isolates encoded three or more of VFs for which they were screened, with 13.9% in susceptible isolates and 36.1% in resistant isolates. The key VFs (fyuA and/or iutA siderophores) present in >80% of isolates. The papA and papC adhesins were detected in the majority of resistant isolates (72.2% and 63.9% respectively). 78.5% of susceptible isolates belong to phylogenetic groups A, while 83.3% of resistant isolates belong to group B2. Conclusion: PapA and papC are significant VFs with an essential role in contributing to Chinese herb-resistance. Chinese herb-resistance is associated with a shift towards more virulent strains and B2 phylogenetic group

Hidden Addressing Encoding for DNA Storage

DNA is a natural storage medium with the advantages of high storage density and long service life compared with traditional media. DNA storage can meet the current storage requirements for massive data. Owing to the limitations of the DNA storage technology, the data need to be converted into short DNA sequences for storage. However, in the process, a large amount of physical redundancy will be generated to index short DNA sequences. To reduce redundancy, this study proposes a DNA storage encoding scheme with hidden addressing. Using the improved fountain encoding scheme, the index replaces part of the data to realize hidden addresses, and then, a 10.1 MB file is encoded with the hidden addressing. First, the Dottup dot plot generator and the Jaccard similarity coefficient analyze the overall self-similarity of the encoding sequence index, and then the sequence fragments of GC content are used to verify the performance of this scheme. The final results show that the encoding scheme indexes with overall lower self-similarity, and the local thermodynamic properties of the sequence are better. The hidden addressing encoding scheme proposed can not only improve the utilization of bases but also ensure the correct rate of DNA storage during the sequencing and decoding processes

Soil N-oxide emissions decrease from intensive greenhouse vegetable fields by substituting synthetic N fertilizer with organic and bio-organic fertilizers

In order to reduce soil and environmental quality degradation associated with the use of synthetic nitrogen (N), substituting chemical fertilizer with organic or bio-organic fertilizer has become an increasingly popular option. However, components of this fertilizer strategy related to mitigation of soil N-oxide emissions and maintenance of crop yield remain uncertain. Here, we evaluated the effects of three different fertilizer strategies, with equal amounts of N, on nitrous oxide (N2O) and nitric oxide (NO) emissions, vegetable yield, and yield-scaled N2O and NO emissions under three consecutive cucumber growing seasons. The three treatments were chemical fertilizer (NPK, urea), organic fertilizer (O, composted cattle manure), and bio-organic fertilizer (O + T, O combined with Trichoderma.spp). Results showed that the NPK plot had the highest area-scaled emissions of N2O (13.1 ± 0.48 kg N ha−1 yr−1) and NO (5.01 ± 0.34 kg N ha−1 yr−1), which were 1.3–1.4 and 3.1–3.7 times greater than the O and O + T plots, respectively. The annual direct emission factors for N2O and NO were 2.08% and 0.92% for the NPK plot, which declined to 1.34% and 0.09% in the O plot, and 1.12% and 0.03% in the O + T plot, respectively. The annual vegetable yield was 117 ± 2.9 t ha−1 for NPK plot and 122 ± 2.0 t ha−1 for O + T plot, which was higher than 111 ± 1.7 t ha−1 for O plot. The yield-scaled N2O + NO emissions differed significantly with fertilization treatment, with the lowest value observed in the O + T plot. We attributed the lower soil N-oxide emissions following organic fertilizer application to the slow release of available N and enhanced denitrification caused by the increase of soil dissolved organic carbon and pH. Compared with the use of organic fertilizer alone, the addition of Trichoderma.spp significantly increased the potential denitrification rate but decreased N2O emissions, which may have promoted the reduction of N2O to N2. Therefore, our results suggest that adopting composted organic fertilizer mixtures with microbial inoculants could be a win-win practice to mitigate gaseous N losses and simultaneously improve crop yield in intensively managed vegetable cropping systems

Neurological Manifestation of Incretin-Based Therapies in Patients with Type 2 Diabetes: A Systematic Review and Network Meta-Analysis.

As a new class of antidiabetic drug, incretin-based therapies, which include dipeptidyl peptidase-4 inhibitors (DPP-4Is) and glucagon-like peptide-1 receptor agonists (GLP-1 RAs), have raised concerns about symptoms of withdrawal in patients with type 2 diabetes mellitus (T2DM), such as dizziness and headache. To systematically evaluate whether incretin-based therapies may lead to dizziness and headache in patients with T2DM compared to other traditional antidiabetic drugs or placebo. We searched Medline, Embase, the Cochrane library, and clinicaltrials.gov from inception through June 23, 2017, to identify randomized controlled trials of the safety of DPP-4Is or GLP-1 RAs versus placebo or other antidiabetic drugs in T2DM patients. We used the network meta-analysis under the frequentist framework to compare the association between multiple antidiabetic drugs and dizziness and headache. A total of 233 clinical trials with nine treatments and 147,710 patients were included: two incretin-based therapies, one placebo, and six traditional antidiabetic drugs (metformin, insulin, sulfonylurea, thiazolidinediones, alpha-glucosidase inhibitor, and sodium-glucose co-transporter 2). Compared to insulin, thiazolidinediones, or placebo, GLP-1 RAs statistically significantly increased the risk of dizziness (odds ratios [ORs]: 1.92, 1.57, and 1.40, respectively) and headache (ORs: 1.34, 1.41, and 1.18, respectively). DPP-4Is increased the risk of headache (OR: 1.22, 95% confidence interval [CI]: 1.02 to 1.46; moderate quality) and dizziness (OR: 1.46, 95% CI: 1.05 to 2.03; moderate quality) compared to insulin. Of the incretin-based therapies, DPP-4Is had a lower risk of dizziness than GLP-1 RAs (OR: 0.76, 95% CI: 0.67 to 0.87; high quality). Ranking probability analysis indicated that GLP-1 RAs may have the greatest risk of both dizziness and headache among the nine treatments (22.5% and 23.4%, respectively), whereas DPP-4Is were in the middle (46.2% and 45.0%, respectively). Incretin-based therapies increase the risk of dizziness and headache compared to insulin, thiazolidinediones, and placebo