7,479 research outputs found
Degree correlation effect of bipartite network on personalized recommendation
In this paper, by introducing a new user similarity index base on the
diffusion process, we propose a modified collaborative filtering (MCF)
algorithm, which has remarkably higher accuracy than the standard collaborative
filtering. In the proposed algorithm, the degree correlation between users and
objects is taken into account and embedded into the similarity index by a
tunable parameter. The numerical simulation on a benchmark data set shows that
the algorithmic accuracy of the MCF, measured by the average ranking score, is
further improved by 18.19% in the optimal case. In addition, two significant
criteria of algorithmic performance, diversity and popularity, are also taken
into account. Numerical results show that the presented algorithm can provide
more diverse and less popular recommendations, for example, when the
recommendation list contains 10 objects, the diversity, measured by the hamming
distance, is improved by 21.90%.Comment: 9 pages, 3 figure
The content and ratio of type I and III collagen in skin differ with age and injury
The aim of this study is to examine type I and III collagen content and distribution in skin within the contexts of patient age and injury, as well as to elucidate possible mechanisms of hypertrophic scar formation. Normal human skin and hypertrophic scar specimens were obtained from spontaneously aborted fetuses and burn patients of different ages (adolescent group, ≤18 years; adult group, >19 and ≤50 years; elderly group, >50 years). Total collagen content was indirectly determined by quantification of hydroxyproline. Levels of type I and III collagen as well as the ratio of type I/III were determined by immunohistochemistry and image analysis. Results obtained showed that the mean content of type I and III and type I/III ratio in normal skin differed significantly among age groups (P0.05), with the lowest levels of type I, III, and the highest ratio of type I/III observed in the elderly age group. Differences between normal uninjured skin and hypertrophic scar tissue were significant for all investigated parameters within any of the three age groups examined (adolescent, adult, elderly; P<0.05). Content of type I, III collagen and type I/III ratio also exhibited age-dependent differences during recovery in hypertrophic scar specimens. Thus, type III collagen synthesis decreases with age resulting in a skewed type I/III ratio and changes in skin tension, elasticity, and healing. Also, the content of type I, III collagen and type I/III ratio are significantly altered in hypertrophic scar tissue compared to uninjured age-matched controls, resulting in a different structural organization that is also influenced by patient age.Key words: Age group, hypertrophic scar, collagen type I, collagen type III, immunohistochemistry, hydroxyproline
On the Robustness of Generative Retrieval Models: An Out-of-Distribution Perspective
Recently, we have witnessed generative retrieval increasingly gaining
attention in the information retrieval (IR) field, which retrieves documents by
directly generating their identifiers. So far, much effort has been devoted to
developing effective generative retrieval models. There has been less attention
paid to the robustness perspective. When a new retrieval paradigm enters into
the real-world application, it is also critical to measure the
out-of-distribution (OOD) generalization, i.e., how would generative retrieval
models generalize to new distributions. To answer this question, firstly, we
define OOD robustness from three perspectives in retrieval problems: 1) The
query variations; 2) The unforeseen query types; and 3) The unforeseen tasks.
Based on this taxonomy, we conduct empirical studies to analyze the OOD
robustness of several representative generative retrieval models against dense
retrieval models. The empirical results indicate that the OOD robustness of
generative retrieval models requires enhancement. We hope studying the OOD
robustness of generative retrieval models would be advantageous to the IR
community.Comment: 4 pages, submit to GenIR2
An increase in the cerebral infarction area during fatigue is mediated by il-6 through an induction of fibrinogen synthesis
OBJECTIVES: Our study aimed to investigate the impact of fatigue on the severity of stroke and to explore the underlying mechanisms. METHODS: Fatigued male rats underwent middle cerebral artery occlusion and the infarcted brain area was determined. Then, coagulation parameters were assessed in the fatigued group and a control group. In addition, the level of fibrinogen was determined in rats deprived of sleep for various numbers of days. To study whether interleukin-6 was involved in fibrinogen synthesis during fatigue, we also measured levels of interleukin-6 in rats deprived of sleep for various numbers of days. Furthermore, brain injury by middle cerebral artery occlusion was measured in wild-type mice, interleukin-6-/- mice and wild-type mice treated with bezafibrate. RESULTS: More severe cerebral infarction was observed in the fatigued rats, resulting in an infarct ratio of 23.4%. The infarct ratio was significantly increased in the fatigued rats compared with that in the control group (8%,
5,6,7-Trichloro-2-methoxy-8-hydroxyquinoline
In the title compound, C10H6Cl3NO2, a mean plane fitted through all non-H atoms has an r.m.s. deviation of 0.035 Å. In the crystal, adjacent molecules are connected by O—H⋯O hydrogen bonds and π–π stacking interactions [centroid–centroid distance = 3.650 (1) Å], resulting in an infinite chain which propagates in the b-axis direction
Field emission enhancement of Au-Si nano-particle-decorated silicon nanowires
Au-Si nano-particle-decorated silicon nanowire arrays have been fabricated by Au film deposition on silicon nanowire array substrates and then post-thermal annealing under hydrogen atmosphere. Field emission measurements illustrated that the turn-on fields of the non-annealed Au-coated SiNWs were 6.02 to 7.51 V/μm, higher than that of the as-grown silicon nanowires, which is about 5.01 V/μm. Meanwhile, after being annealed above 650°C, Au-Si nano-particles were synthesized on the top surface of the silicon nanowire arrays and the one-dimensional Au-Si nano-particle-decorated SiNWs had a much lower turn-on field, 1.95 V/μm. The results demonstrated that annealed composite silicon nanowire array-based electron field emitters may have great advantages over many other emitters
Oxidative stress promotes autophagic cell death in human neuroblastoma cells with ectopic transfer of mitochondrial PPP2R2B (Bβ2)
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