On the Ramanujan-Nagell type Diophantine equation (Dx^2+k^n=B)

In this paper, we prove that the Ramanujan-Nagell type Diophantine equation (Dx^2+k^n=B) has at most three nonnegative integer solutions ((x, n)) for (k) a prime and (B, D) positive integers

On two Diophantine equations of Ramanujan-Nagell type

In this paper, we prove two conjectures of Ulas ([21]) on two Diophantine equations of Ramanujan-Nagell type. In fact, we show that the following equations x2+(2m+1+1)2n=24(m+1)+23(m+1)+22m+2m+1+1, x2+(22m+6-1)2n/3 = (49 · 42m+5-11· 4m+3+1)/9 have exactly four solutions

A Computationally Efficient Neural Video Compression Accelerator Based on a Sparse CNN-Transformer Hybrid Network

Video compression is widely used in digital television, surveillance systems, and virtual reality. Real-time video decoding is crucial in practical scenarios. Recently, neural video compression (NVC) combines traditional coding with deep learning, achieving impressive compression efficiency. Nevertheless, the NVC models involve high computational costs and complex memory access patterns, challenging real-time hardware implementations. To relieve this burden, we propose an algorithm and hardware co-design framework named NVCA for video decoding on resource-limited devices. Firstly, a CNN-Transformer hybrid network is developed to improve compression performance by capturing multi-scale non-local features. In addition, we propose a fast algorithm-based sparse strategy that leverages the dual advantages of pruning and fast algorithms, sufficiently reducing computational complexity while maintaining video compression efficiency. Secondly, a reconfigurable sparse computing core is designed to flexibly support sparse convolutions and deconvolutions based on the fast algorithm-based sparse strategy. Furthermore, a novel heterogeneous layer chaining dataflow is incorporated to reduce off-chip memory traffic stemming from extensive inter-frame motion and residual information. Thirdly, the overall architecture of NVCA is designed and synthesized in TSMC 28nm CMOS technology. Extensive experiments demonstrate that our design provides superior coding quality and up to 22.7x decoding speed improvements over other video compression designs. Meanwhile, our design achieves up to 2.2x improvements in energy efficiency compared to prior accelerators.Comment: Accepted by DATE 202

Study on Multi-step Forming Paths for Double Curved Parts of 1561 Aluminium Alloy

Recently, corrosion-resistant 1561 aluminium alloy has been widely applied to the production of curved parts. However, the sheets of this material will generate a high amount of springback during multi-point forming, which means that a large amount of springback compensation is required. In this paper, four multi-step forming paths are designed to study the effect of forming paths on the multi-point forming results of double curved parts for 1561 aluminium alloy. Numerical simulation of the multi-step forming of curved sheets is carried out by ABAQUS finite element simulation software. The simulation results indicate that the 1561 aluminium alloy double curved parts produce poor situations such as wrinkling and low forming accuracy in single-step forming, while the accuracy improves significantly and the forming quality increases after four-step forming. Therefore, a four-step forming path was adopted for stamping tests on double curved parts. The results of the accuracy inspection of the formed parts by Gom-inspect demonstrate that the quality of the curved parts can be effectively improved by four-step forming, which has a certain significance in guiding the forming preparation of parts for engineering applications

Quantitative evaluation of gut microbiota composition in pancreatic cancer: a pooled study

Background: Prior research has demonstrated a positive association between the composition of gut microbiota and the incidence of pancreatic cancer. Nevertheless, a thorough quantitative and systematic evaluation of the distinct properties of gut microbiota in individuals diagnosed with pancreatic cancer has yet to be conducted. The objective of this study is to examine alterations in the diversity of intestinal microbiota in individuals diagnosed with pancreatic cancer. Methods: Search for relevant literature published before July 2023 in 4 databases: PubMed, Embase, Web of Science, and Cochrane Library, without any language restrictions. Results: A total of 12 studies were included, including 535 patients with pancreatic cancer and 677 healthy controls. Analysis was conducted on 6 phyla, 16 genera, and 6 species. The study found significant and distinctive changes in the α-diversity of gut microbiota, as well as in the relative abundance of multiple gut bacterial groups at the phylum, genus, and species levels in pancreatic cancer patients. Conclusion: Overall, there are certain characteristic changes in the gut microbiota of pancreatic cancer patients. However, further research is warranted to elucidate the specific mechanism of action and the potential for treatment

Regional variation in NAFLD prevalence and risk factors among people living with HIV in Europe: a meta-analysis

Background and Aim: Europe faces an elevated risk of nonalcoholic fatty liver disease (NAFLD) among people living with HIV (PLWH), contributing to the region’s highest global burden of NAFLD. However, the prevalence of NAFLD across various European countries and regions remains unclear. This study aims to investigate the prevalence and risk factors associated with NAFLD among PLWH across European countries. Methods: A systematic search was conducted across four databases: PubMed, Embase, Web of Science, and Cochrane Library. Data on the prevalence of NAFLD, nonalcoholic steatohepatitis (NASH), and fibrosis, as well as the associated risk factors, were collected among PLWH in Europe. Results: Thirty-six studies from 13 European nations were included. The prevalence of NAFLD, NASH, and fibrosis were 42% (95%CI 37–48), 35% (95%CI 21–50) and 13% (95%CI 10–15), respectively. Male gender, BMI, waist circumference, Diabetes, hypertension, metabolic syndrome, dyslipidemia, triglycerides, HDL, LDL, ALT, AST, and years on antiretroviral therapy (ART) were found to be risk factors for NAFLD. High BMI and triglycerides were associated with NASH. Patients with high BMI and triglycerides are at increased risk of significant liver fibrosis. Conclusion: The high prevalence of NAFLD, NASH, and fibrosis among PLWH in Europe highlights the need for early screening, intervention, and increased research focus on adolescents living with HIV. Furthermore, the significant variations observed between countries and regions underscore the influence of related risk factors

Characterization and identification of the integrin family in silkworm, Bombyx mori

YesAs an important economic insect, Bombyx mori is also a useful model organism for lepidopteran insect. Integrins are evolutionarily conserved fromsponges to humans, and play vital roles inmany physiological and pathological processes. To explore their diverse functions of integrins in insect, eleven integrins including sixα and five β subunitswere cloned and characterized fromsilkworm. Our results showed that integrins fromsilkwormown more family members compared to other invertebrates. Among those α subunits, integrins α1, α2, and the other four subunits belong to PS1, PS2, and PS3 groups, respectively. The β subunits mainly gather in the insect βν group except the β1 subunit which belongs to the insect β group. Expression profiles demonstrated that the integrins exhibited distinct patterns, but were mainly expressed in hemocytes. α1 and β2 subunits are the predominant ones either in the embryogenesis or larva stages. Interestingly, integrins were significantly up-regulated after stimulated by 20-hydroxyecdysone (20-E) in vivo. These results indicate that integrins performdiverse functions in hemocytes of silkworm. Overall, our results provide a newinsight into the functional and evolutionary features of integrins.National Basic Research Programof China (No. 2012cb114603), the Research Fund for the Doctoral Program of Higher Education of China (20130182110003), the Natural Science Foundation of Chongqing (cstc2013jcyjys0007), and the Fundamental Research Funds for the Central Universities (SWU111014)

Signature of the coexistence of ferromagnetism and superconductivity at KTaO3_3 heterointerfaces

The coexistence of superconductivity and ferromagnetism is a long-standing issue in the realm of unconventional superconductivity due to the antagonistic nature of these two ordered states. Experimentally identifying and characterizing novel heterointerface superconductors that coexist with magnetism is challenging. Here, we report the experimental observation of long-range ferromagnetic order at the verge of two-dimensional superconductivity at KTaO$_3$ heterointerfaces. Remarkably, we observe in-plane magnetization hysteresis loop persisting up to room temperature with direct current superconducting quantum interference device measurements. Furthermore, first-principles calculations suggest that the observed robust ferromagnetism is attributed to the presence of oxygen vacancies that localize electrons in nearby Ta 5$d$ states. Our findings not only indicate KTaO$_3$ heterointerfaces as unconventional superconductors with time-reversal symmetry breaking, but also inject a new momentum to the study of the delicate interplay between superconductivity and magnetism boosted by strong spin-orbit coupling inherent to the heavy Ta in 5$d$ orbitals of KTaO$_3$ heterointerfaces.Comment: 7 pages, 3 figure

A Fast and Efficient SIKE Co-Design: Coarse-Grained Reconfigurable Accelerators with Custom RISC-V Microcontroller on FPGA

This paper proposes a fast and efficient FPGA-based hardware-software co-design for the supersingular isogeny key encapsulation (SIKE) protocol controlled by a custom RISC-V processor. Firstly, we highly optimize the core unit, the polynomial-based field arithmetic logic unit (FALU), with the proposed fast convolution-like multiplier (FCM) to significantly reduce the resource consumption while still maintaining low latency and constant time for all the four SIKE parameters. Secondly, we pack the small isogeny and point operations in hardware, devise a coarse-grained reconfigurable hardware architecture (CGRHA) based on FALU as the co-processor, and apply it to the RISC-V core with customized instructions, effectively avoiding extra time consumption for the data exchange with the software side and meanwhile increasing flexibility. Finally, we code the hardware in SystemVerilog language and the software in C language and run experiments on FPGAs. In the co-processor implementation, the experiment results show that our design for the four SIKE parameters achieves 2.6-4.4x speedup and obtains comparable or better area-time product to or than the state-of-the-art. In the hardware-software co-design experiments, we still have the superiority in speed and only <10\% of extra time is introduced by mutual communication

Speeding up Preimage and Key-Recovery Attacks with Highly Biased Differential-Linear Approximations

We present a framework for speeding up the search for preimages of candidate one-way functions based on highly biased differential-linear distinguishers. It is naturally applicable to preimage attacks on hash functions. Further, a variant of this framework applied to keyed functions leads to accelerated key-recovery attacks. Interestingly, our technique is able to exploit related-key differential-linear distinguishers in the single-key model without querying the target encryption oracle with unknown but related keys. This is in essence similar to how we speed up the key search based on the well known complementation property of DES, which calls for caution from the designers in building primitives meant to be secure in the single-key setting without a thorough cryptanalysis in the related-key model. We apply the method to sponge-based hash function Ascon-HASH, XOFs XOEsch/Ascon-XOF and AEAD Schwaemm, etc. Accelerated preimage or key-recovery attacks are obtained. Note that all the differential-linear distinguishers employed in this work are highly biased and thus can be experimentally verified