Reconstructive Neuron Pruning for Backdoor Defense

Deep neural networks (DNNs) have been found to be vulnerable to backdoor attacks, raising security concerns about their deployment in mission-critical applications. While existing defense methods have demonstrated promising results, it is still not clear how to effectively remove backdoor-associated neurons in backdoored DNNs. In this paper, we propose a novel defense called \emph{Reconstructive Neuron Pruning} (RNP) to expose and prune backdoor neurons via an unlearning and then recovering process. Specifically, RNP first unlearns the neurons by maximizing the model's error on a small subset of clean samples and then recovers the neurons by minimizing the model's error on the same data. In RNP, unlearning is operated at the neuron level while recovering is operated at the filter level, forming an asymmetric reconstructive learning procedure. We show that such an asymmetric process on only a few clean samples can effectively expose and prune the backdoor neurons implanted by a wide range of attacks, achieving a new state-of-the-art defense performance. Moreover, the unlearned model at the intermediate step of our RNP can be directly used to improve other backdoor defense tasks including backdoor removal, trigger recovery, backdoor label detection, and backdoor sample detection. Code is available at \url{https://github.com/bboylyg/RNP}.Comment: Accepted by ICML2

Programmable Base Editing of the Sheep Genome Revealed No Genome-Wide Off-Target Mutations

Since its emergence, CRISPR/Cas9-mediated base editors (BEs) with cytosine deaminase activity have been used to precisely and efficiently introduce single-base mutations in genomes, including those of human cells, mice, and crop species. Most production traits in livestock are induced by point mutations, and genome editing using BEs without homology-directed repair of double-strand breaks can directly alter single nucleotides. The p.96R > C variant of Suppressor cytokine signaling 2 (SOCS2) has profound effects on body weight, body size, and milk production in sheep. In the present study, we successfully obtained lambs with defined point mutations resulting in a p.96R > C substitution in SOCS2 by the co-injection of BE3 mRNA and a single guide RNA (sgRNA) into sheep zygotes. The observed efficiency of the single nucleotide exchange in newborn animals was as high as 25%. Observations of body size and body weight in the edited group showed that gene modification contributes to enhanced growth traits in sheep. Moreover, targeted deep sequencing and unbiased family trio-based whole genome sequencing revealed undetectable off-target mutations in the edited animals. This study demonstrates the potential for the application of BE-mediated point mutations in large animals for the improvement of production traits in livestock species

Combining the Tyrosine Kinase Inhibitor Cabozantinib and the mTORC1/2 Inhibitor Sapanisertib Blocks ERK Pathway Activity and Suppresses Tumor Growth in Renal Cell Carcinoma.

UNLABELLED: Current treatment approaches for renal cell carcinoma (RCC) face challenges in achieving durable tumor responses due to tumor heterogeneity and drug resistance. Combination therapies that leverage tumor molecular profiles could offer an avenue for enhancing treatment efficacy and addressing the limitations of current therapies. To identify effective strategies for treating RCC, we selected ten drugs guided by tumor biology to test in six RCC patient-derived xenograft (PDX) models. The multitargeted tyrosine kinase inhibitor (TKI) cabozantinib and mTORC1/2 inhibitor sapanisertib emerged as the most effective drugs, particularly when combined. The combination demonstrated favorable tolerability and inhibited tumor growth or induced tumor regression in all models, including two from patients who experienced treatment failure with FDA-approved TKI and immunotherapy combinations. In cabozantinib-treated samples, imaging analysis revealed a significant reduction in vascular density, and single-nucleus RNA sequencing (snRNA-seq) analysis indicated a decreased proportion of endothelial cells in the tumors. SnRNA-seq data further identified a tumor subpopulation enriched with cell-cycle activity that exhibited heightened sensitivity to the cabozantinib and sapanisertib combination. Conversely, activation of the epithelial-mesenchymal transition pathway, detected at the protein level, was associated with drug resistance in residual tumors following combination treatment. The combination effectively restrained ERK phosphorylation and reduced expression of ERK downstream transcription factors and their target genes implicated in cell-cycle control and apoptosis. This study highlights the potential of the cabozantinib plus sapanisertib combination as a promising treatment approach for patients with RCC, particularly those whose tumors progressed on immune checkpoint inhibitors and other TKIs. SIGNIFICANCE: The molecular-guided therapeutic strategy of combining cabozantinib and sapanisertib restrains ERK activity to effectively suppress growth of renal cell carcinomas, including those unresponsive to immune checkpoint inhibitors

The Relative impact of mandatory versus voluntary formation of audit committees

Audit committees are increasingly viewed as a key element of good corporate governance. In some countries their formation is mandatory, and in others it is voluntary. In the Australian setting, only the largest listed companies are required to form an audit committee, although many smaller companies do so voluntarily. There are few regulations over smaller companies, and the operations of audit committees. In a jurisdiction which combines mandatory and voluntary regulatory regimes, this study examines the relative impact of the regimes on audit committee diligence, on corporate governance and on board decision-making. It finds that mandatory audit committees are more diligent than voluntary ones, in terms of meeting frequency, but trade-offs are made between meeting frequency and the use of a Big 4 auditor, and the board’s decision-making is not consistently better. There is evidence that voluntary audit committees are established for legitimacy.33 page(s

Pulmonary endarterectomy in patients with occlusive isolated pulmonary vasculitis

Abstract Background Isolated pulmonary vasculitis (IPV) is a rare, insidious, and localized inflammatory disease affecting the pulmonary arteries, often leading to severe luminal obstruction. The prognosis for patients with occlusive IPV is poor, and there is currently a lack of effective treatments. The objective of this study was to evaluate the performance of pulmonary endarterectomy (PEA) as a treatment for occlusive IPV. Methods This single-center retrospective analysis included patients who received PEA for occlusive IPV between January 2018 and June 2022. Clinical characteristics and hemodynamic parameters were evaluated at baseline and follow-up. Results Among 114 consecutive patients who underwent PEA, occlusive IPV was identified in 7 patients. Two patients underwent bilateral PEA for the involvement of both pulmonary arteries. Patch angioplasty was performed to treat four severe constrictions. One patient died from residual pulmonary hypertension after limited PEA of a transmural vascular lesion. In addition, no obvious surgical complications were observed. Three months after PEA, a substantial relief in symptoms was achieved. Also, there is a decrease in the mean pulmonary artery pressure (median 33 [20–48] mmHg before versus median 21 [16–26] mmHg after; P < 0.018) and pulmonary arterial resistance (median 234 [131–843] dyn.s.cm−5 versus median 180 [150–372] dyn.s.cm−5; P = 0.310). Three patients experienced a relapse of restenosis of the treated arteries within a 6-month follow-up period, despite daily oral prednisolone administration. They were treated with balloon pulmonary angioplasty of both the main pulmonary arteries and branches. Conclusions PEA is a valuable choice for treating occlusive IPV, with notable hemodynamic and clinical advantages. To increase long-term vascular patency, complete management should be optimized

Experimental Study on the Stability of a Novel Nanocomposite-Enhanced Viscoelastic Surfactant Solution as a Fracturing Fluid under Unconventional Reservoir Stimulation

Fe3O4@ZnO nanocomposites (NCs) were synthesized to improve the stability of the wormlike micelle (WLM) network structure of viscoelastic surfactant (VES) fracturing fluid and were characterized by Fourier transform infrared spectrometry (FT-IR), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), X-ray diffraction (XRD) and vibrating sample magnetometry (VSM). Then, an NC-enhanced viscoelastic surfactant solution as a fracturing fluid (NC-VES) was prepared, and its properties, including settlement stability, interactions between NCs and WLMs, proppant-transporting performance and gel-breaking properties, were systematically studied. More importantly, the influences of the NC concentration, shear rate, temperature and pH level on the stability of NC-VES were systematically investigated. The experimental results show that the NC-VES with a suitable content of NCs (0.1 wt.%) shows superior stability at 95 &deg;C or at a high shear rate. Meanwhile, the NC-VES has an acceptable wide pH stability range of 6&ndash;9. In addition, the NC-VES possesses good sand-carrying performance and gel-breaking properties, while the NCs can be easily separated and recycled by applying a magnetic field. The temperature-resistant, stable and environmentally friendly fracturing fluid opens an opportunity for the future hydraulic fracturing of unconventional reservoirs

Expression of TLR5 in Different Types of Non-small Cell Lung Cancer Cell Lines and its Activation Mechanism

Background and objective It has been proven that toll-like receptor 5 (TLR5) plaied an important role in the development of tumor. In our previous study, we found that the expression of TLR5 was remarkably higher in non-small cell lung cancer (NSCLC) tissues than that in normal tissues, but the activation of TLR5 signaling pathway in NSCLC was still unknown. The aim of this study is to investigate the expression of TLR5 in different types of NSCLC cell lines, and analyze the activity of the signaling pathway after stimulated by its specific exogenous ligand flagellin. Methods The TLR5 protein was detected by immunofluorescence and Western blot in three kinds of NSCLC cell lines, and the TLR5 mRNA was detected by RT-PCR. Select the cell line of TLR5 highest expression as the research object, and select the suitable concentration of flagellin. NF-κB luciferase activity was detected to validate the TLR5 activation pathway through inhibitory signaling pathways by 0 μg/mL, 0.01 μg/mL, 0.1 μg/mL, 1 μg/mL, 10 μg/mL TLR5 antibody. The chosen cell line was transfected by TLR5 shRNA plasmid, and p-IKBα, IKBα, p-ERK1/2, ERK1/2 and p-JNK of untrasfected and transfected cells were detected in the activity of TLR5 signaling pathway by Western blot at 0 min, 10 min, 30 min and 60 min, respectively. Results The expression of TLR5 was the highest in the lung adenocarcinoma cell line SPC-A-1 by immunofluorescence, mainly expressed on the cell membrane. NF-κB luciferase activity of SPC-A-1 cells was the highest, and the activity was increased in a dose-dependent manner. 0.1 μg/mL flagellin could significantly increase the NF-κB luciferase activity (P0.05). SPC-A-1 cells transfected TLR5-shRNA were also stimulated by flagellin (0.1 μg/mL). At 0 min, 10 min, 30 min and 60 min, p-IKBα and p-JNK proteins could not be detected, and the levels of IKBα and ERK1/2 had no significant changes (P>0.05), but the levels of p-ERK1/2 significantly increased as time went on (P<0.05). Conclusion Exogenous ligand flagellin can activate TLR5 protein in NSCLC cell lines and initiate downstream signaling pathways. It may be relative to the development of NSCLC

M6P-modified solid lipid nanoparticles loaded with matrine for the treatment of fibrotic liver

AbstractLiver fibrosis is a key pathological process shared by the progression of various chronic liver diseases. Treatment of liver fibrosis can effectively block the occurrence and development of hepatic cirrhosis or even carcinoma. Currently, there is no effective drug delivery vehicle for curing liver fibrosis. In this study, we designed matrine (MT)-loaded mannose 6-phosphate (M6P) modified human serum albumin (HSA) conjugated solid lipid nanoparticles (SLN), named M6P-HSA-MT-SLN for treatment of hepatic fibrosis. We demonstrated that M6P-HSA-MT-SLN exhibited controlled and sustained release properties and good stability over 7 days. The drug release experiments showed that M6P-HSA-MT-SLN exhibited slow and controlled drug release characteristics. In addition, M6P-HSA-MT-SLN showed a significant targeted ability to fibrotic liver. Importantly, in vivo studies indicated that M6P-HSA-MT-SLN could significantly improve histopathological morphology and inhibit the fibrotic phenotype. In addition, in vivo experiments demonstrate that M6P-HSA-MT-SLN could reduce the expression of fibrosis markers and alleviate the damage of liver structure. Hence, the M6P-HSA-MT-SLN provide a promising strategy to deliver therapeutic agents to fibrotic liver to prevent liver fibrosis

Transition Metal Catalysts for Atmospheric Heavy Metal Removal: A Review of Current Innovations and Advances

Atmospheric heavy metal pollution presents a severe threat to public health and environmental stability. Transition metal catalysts have emerged as a potent solution for the selective capture and removal of these pollutants. This review provides a comprehensive summary of current advancements in the field, emphasizing the efficiency and specificity of nanostructured transition metals, including manganese, iron, cobalt, nickel, copper, and zinc. Looking forward, we delve into the prospective trajectory of catalyst development, underscoring the need for materials with enhanced stability, regenerability, and environmental compatibility. We project that advancements in computational materials science, nanotechnology, and green chemistry will be pivotal in discovering innovative catalysts that are economically and environmentally sustainable. The integration of smart technologies for real-time monitoring and adaptive control is anticipated to revolutionize heavy metal remediation, ensuring efficient and responsive pollution abatement strategies in the face of evolving industrial scenarios and regulatory landscapes