A blockchain based privacy-preserving federated learning scheme for Internet of Vehicles

The application of artificial intelligence technology in Internet of Vehicles(lov)has attracted great research interests with the goal of enabling smart transportation and traffic management.Meanwhile,concerns have been raised over the security and privacy of the tons of traffic and vehicle data.In this regard,Federated Learning(FL)with privacy protection features is considered a highly promising solution.However,in the FL process,the server side may take advantage of its dominant role in model aggregation to steal sensitive information of users,while the client side may also upload malicious data to compromise the training of the global model.Most existing privacy-preserving FL schemes in IoV fail to deal with threats from both of these two sides at the same time.In this paper,we propose a Blockchain based Privacy-preserving Federated Learning scheme named BPFL,which uses blockchain as the underlying distributed framework of FL.We improve the Multi-Krum technology and combine it with the homomorphic encryption to achieve ciphertext-level model aggregation and model filtering,which can enable the verifiability of the local models while achieving privacy-preservation.Additionally,we develop a reputation-based incentive mechanism to encourage users in IoV to actively participate in the federated learning and to practice honesty.The security analysis and performance evaluations are conducted to show that the proposed scheme can meet the security requirements and improve the performance of the FL model.

Opportunities of endovascular treatment for cerebral venous thrombosis

Cerebral venous thrombosis(CVT)is a rare condition that can be fatal in severe cases.The limited occurrence of CVT poses challenges in conducting randomized controlled trials,leading to uncertainty regarding the effectiveness of endovascular thrombectomy(EVT)in specific subgroups of patients with CVT.Currently,a growing body of new evidence has been published on various aspects of CVT diagnosis and treatment,including studies on prognosis assessment scales and EVT therapy.Anticoagulation remains the primary treatment during the acute phase of CVT,as demonstrated by the thrombolysis or anticoagulation for cerebral venous thrombosis(TOACT)clinical trial.This study revealed that EVT combined with standard medical care did not improve functional outcomes for patients with severe CVT.Several risk screening scores have been developed to predict CVT prognosis,and some of these scales have been shown to perform adequately.The question of whether EVT is beneficial for patients with CVT,and to which subgroups of patients it should be offered,still remains unsettled.Large global research collaborations should be established to address current challenges and facilitate the execution of clinical trials.

Aphanomyces euteiches： A Threat to Canadian Field Pea Production

Field pea （Pisum sativum var. arvense L.） is an important legume crop around the world. It produces grains with high protein content and can improve the amount of available nitrogen in the soil. Aphanomyces root rot （ARR）, caused by the soil-borne oomycete Aphanomyces euteiches Drechs. （A. euteiches）, is a major threat to pea production in many pea-growing regions including Canada; it can cause severe root damage, wilting, and considerable yield losses under wet soil conditions. Traditional disease management strategies, such as crop rotations and seed treatments, cannot fully prevent ARR under conditions conducive for the disease, due to the longevity of the pathogen oospores, which can infect field pea plants at any growth stage. The development of pea cultivars with partial resistance or tolerance to ARR may be a promising approach to analyze the variability and physiologic specialization ofA. euteiches in field pea and to improve the management of this disease. As such, the detection of quantitative trait loci （QTL） for resistance is essential to field pea-breeding programs. In this paper, the pathogenic characteristics of A. euteiches are reviewed along with various ARR management strategies and the QTL associated with partial resistance to ARR.

Evaluation of host resistance and fungicide application as tools for the management of root rot of field pea caused by Aphanomyces euteiches

Aphanomyces root rot(ARR) of field pea(Pisum sativum), caused by Aphanomyces euteiches, can cause severe root damage, wilting, and large yield losses under wet soil conditions. To identify ways to manage this disease, the effect of A. euteiches inoculum density on field pea was studied under greenhouse and field conditions in 2015 and 2016. Increases in inoculum density reduced seedling emergence, root nodulation, and plant vigor, and resulted in increased root rot severity in both field and greenhouse tests. Seed treatments with the fungicides Apron Advance(thiabendazole + fludioxonil + metalaxyl) + Vibrance(difenoconazole + metalaxylM + sedaxane), INTEGO Solo(ethaboxam), BAS 516F(boscalid + pyraclostrobin), BAS 720F(metalaxyl + pyraclostrobin + fluxapyroxad), and BAS 516F + BAS 720F(3:1) were evaluated for their efficacy against ARR. All seed treatments except Apron Advance + Vibrance reduced root rot severity under controlled conditions. BAS 516F, BAS 720F and INTEGO Solo improved plant vigor and all treatments reduced seedling blight to varying degrees under greenhouse conditions, but not in the field. A collection of 22 pea genotypes was evaluated for resistance to root rot in field plot experiments. Line 00–2067 showed the least severe root rot symptoms,whereas ‘Spring D' showed the lowest reduction in yield. The results suggest that there may be an opportunity to combine partial host resistance and fungicidal seed treatments to adequately manage ARR of field pea.

Direct Ischemic Postconditioning Following Stroke Thrombectomy:A Promising Therapy for Reperfusion Injury

Recanalization of occluded vessels and timely reperfusion are the primary therapies for acute ischemic stroke(AIS),with endovascular thrombectomy proven as the most effective therapy for large-vessel recanalization and improved outcomes of AIS patients.However,despite a high recanalization rate of 90% or even higher,the rate of 3-month functional independence is approximately 50%,while mortality remains around 15%[1].

低温自体血靶向回输对于非人灵长类脑卒中模型的神经保护作用

近几十年来,虽然研究已经证明治疗性低温在啮齿类动物脑卒中模型中有神经保护作用,但其临床转化却未能成功.可能的原因是不同物种之间的生物学差异以及转化研究中治疗性低温诱导难以有效实施.本研究介绍了一种基于非人灵长类动物缺血再灌注模型的选择性治疗性低温疗法,即将自体血于体外循环中冷却,在血管再通后立即通过微导管向缺血区域回输低温自体血.低温自体血将目标脑区迅速冷却至34℃以下,而核心温度可以维持在36℃左右.低温自体血回输减少了梗死面积,保留了白质完整性,改善了神经功能且未引发低温相关并发症.本研究结果表明,在非人灵长类动物脑卒中模型中,通过冷自体输血诱导治疗性低温是一种可行、快速和安全的方法.这提示低温自体血靶向回输是一种具有临床转化潜力的新型低温脑保护疗法.

Dual-sized hollow particle incorporated fibroin thermal insulating coatings on catheter for cerebral therapeutic hypothermia

Selective endovascular hypothermia has been used to provide cooling-induced cerebral neuroprotection,but current catheters do not support thermally-insulated transfer of cold infusate,which results in an increased exit temperature,causes hemodilution,and limits its cooling efficiency.Herein,air-sprayed fibroin/silica-based coatings combined with chemical vapor deposited parylene-C capping film was prepared on catheter.This coating features in dual-sized-hollow-microparticle incorporated structures with low thermal conductivity.The infusate exit temperature is tunable by adjusting the coating thickness and infusion rate.No peeling or cracking was observed on the coatings under bending and rotational scenarios in the vascular models.Its efficiency was verified in a swine model,and the outlet temperature of coated catheter(75μm thickness)was 1.8-2.0◦C lower than that of the uncoated one.This pioneering work on catheter thermal insulation coatings may facilitate the clinical translation of selective endovascular hypothermia for neuroprotection in patients with acute ischemic stroke.

Dynamic Model and Motion Mechanism of Magnetotactic Bacteria with Two Lateral Flagellar Bundles

Magnetotactic Bacteria （MTB） propel themselves by rotating their flagella and swim along the magnetic field lines. To analyze the motion of MTB, MTB magneto-ovoid strain MO-1 cells, each with two bundles of flagella, were taken as research object. The six-degrees-of-freedom （6-DoF） dynamic model of MO-1 was established based on the Newton-Euler dynamic equations. In particular, the interaction between the flagellum and fluid was considered by the resistive force theory. The simulated motion trajectory of MTB was found to consist of two kinds of helices： small helices restilting from the imbalance of force due to flagellar rotation, and large helices arising from the different directions of the rotation axis of the cell body and the propulsion axis of the flagellum. The motion behaviours of MTB in various magnetic fields were studied, and the simulation results agree well with the experiment results. In addition, the rotation frequency of the flagella was estimated at 1100 Hz, which is consistent with the average rotation rate for Na^＋-driven flagellar motors. The included angle of the magnetosome chain was predicted at 40° that is located within 20° to 60° range of the observed results. The results indicate the correctness of the dynamic model, which may aid research on the operation and control of MTB-propelled micro-actuators. Meanwhile, the motion behaviours of MTB may inspire the development of micro-robots with new driving mechanisms.

Flexible distributed feedback lasers based on nanoimprinted cellulose diacetate with efficient multiple wavelength lasing

Here we present the assembly of novel transparent all-polymer distributed feedback(DFB)lasers.Flexible and highly transparent cellulose diacetate(CdA)was employed as substrate on which gratings with different periods were engraved by thermal nanoimprinting with high fidelity.Highly luminescent conjugated polymers(CP),poly(9,9-dioctylfluorene)(PFO),poly(9,9-dioctylfluorene-alt-benzothiadiazole)(F8BT),and a blend of F8BT and poly(3-hexylthiophene)-poly(9,9-dioctylfluorene-altbenzothiadiazole)(P3HT:F8BT)were deposited by spin coating onto the nanostructured plastic surfaces,giving rise to perpendicular single-mode lasing emission in the blue,green,and red wavelength ranges,respectively.These lasers show linewidths below 1 nm and low thresholds(≈6μJcm^(−2) for blue and red lasing emission),comparable to other state-of-the-art lasers obtained from similar optical gain materials on rigid substrates.The followed strategy is scalable and versatile,enabling the development of large area nanoimprinted DFB lasers(>1cm^(2))on plastic,which is highly relevant for applications in various markets.

dBrms1 Acts as a Positive Regulator of Notch Signaling in Drosophila Wing

The highly conserved Notch signaling is precisely regulated at different steps in a series of developmental events. However, little is known about the regulation of Notch receptor at transcriptional level. Here, we demonstrate that dBrmsl is involved in regulating Notch signaling in Drosophila wing. We show that knockdown of dBrmsl by RNA interference （RNAi） in wing disc suppresses the expression of Notch signaling target genes wingless （wg）, cut and Enhancer of split m8 [E（spl）m8]. Consistently, the levels of Wg and Cut are reduced in the dBrmsl mutant clones. Importantly, loss of dBrmsl leads to significant reduction of Notch proteins. Furthermore, depletion of dBrmsl results in apparent downregulation of Notch transcription in the wing disc. Moreover, we find that dBrmsl is functionally conserved with human Breast cancer metastasis suppressor 1 like （hBRMSIL） in the modulation of Notch signaling. Taken together, our data provide important insights into the biological function of dBrmsl in regulating Notch signaling.

Reversible hydrogenation restores defected graphene to graphene

Graphene as a two-dimensional material is prone to hydrocarbon contaminations,which can significantly alter its intrinsic electrical properties.Herein,we implement a facile hydrogenation-dehydrogenation strategy to remove hydrocarbon contaminations and preserve the excellent transport properties of monolayer graphene.Using electron microscopy we quantitatively characterized the improved cleanness of hydrogenated graphene compared to untreated samples.In situ spectroscopic investigations revealed that the hydrogenation treatment promoted the adsorption of water at the graphene surface,resulting in a protective layer against the re-deposition of hydrocarbon molecules.Additionally,the further dehydrogenation of hydrogenated graphene rendered a more pristine-like basal plane with improved carrier mobility compared to untreated pristine graphene.Our findings provide a practical post-growth cleaning protocol for graphene with maintained surface cleanness and lattice integrity to systematically carry a range of surface chemistry in the form of a well-performing and reproducible transistor.