Active Defense System Research Articles

Construction and application of static stability intelligent evaluator for large power grid from the perspective of knowledge graph

Abstract Relying on information technology such as artificial intelligence, knowledge analysis on a large amount of high-dimensional real-time measurement and simulation information, and deep excavation of stable operation situations in the power grid are the core of real time intelligent security defense of large power grid. In this paper, from the perspective of the knowledge graph, considering the stability state evaluation index and optimizing control strategy information of different operation scenarios of power grid comprehensively, using the integration mechanism of information system and knowledge graph, the functional framework of intelligent evaluator for static stability in power grid is proposed, and an evaluator including static evaluation and decision-making, and general intelligent algorithm is designed. Introducing knowledge graph automation engine technology, visual display of intelligent evaluator for large power grid static stability is realized. An application case in a real power grid is given to prove the effectiveness of the proposed method. The research work is helpful to regulate and control operators to grasp the operation situation and improve the efficiency of evaluation and decision-making of the power grid. It has positive exploration application value to improve the construction of intelligent active security defense systems online in large power grids.

Verification and Optimization of Network Security Defense System from the Perspective of Blue Army in Actual Offensive and Defensive Exercises

From the point of view of signal camouflage, this paper proposes an active network defense system. Then, the optimal camouflage target selection scheme is proposed. Its goal is to solve the problems existing in the information constructionof Chinese military equipment support. This method establishes a multistage game model based on weapon support informationnetwork attack and defense. The attack and defense benefits are quantitatively calculated based on the cost of signal concealment. The solution to the refined Bayesian balance problem is given. Then, a multistage optimization algorithm for camouflage signal selection is proposed. Finally, experimental research proves the proposed algorithm to be reasonable and practical.

Changes in Biologically Active Compounds in Pinus sylvestris Needles after Lymantria monacha Outbreaks and Treatment with Foray 76B.

Due to climate warming, the occurrence of Lymantria monacha outbreaks is predicted to become more frequent, causing repeated and severe damage to conifer trees. Currently, the most effective way to control the outbreaks is aerial spraying with the bioinsecticide Foray 76B. The present study aimed to determine the impact of both: (i) L. monacha outbreaks and (ii) treatment with Foray 76B on tree resistance through the synthesis of polyphenols (TPC), flavonoids (TFC), photosynthetic pigments (chlorophyll a and b, carotenoids), lipid peroxidation (MDA), and soluble sugars (TSS) in Pinus sylvestris needles. Samples were collected from visually healthy (control), damaged/untreated, and damaged/Foray 76B-treated plots in 2020 and 2021 (following year after the outbreaks). The results revealed that L. monacha outbreaks contributed to the increase in TPC by 34.1% in 2020 and 26.7% in 2021. TFC negatively correlated with TPC, resulting in 17.6% and 11.1% lower concentrations in L. monacha-damaged plots in 2020 and 2021, respectively. A decrease in MDA was found in the damaged plots in both 2020 and 2021 (10.2% and 23.3%, respectively), which was associated with the increased synthesis of photosynthetic pigments in 2021. The research results also showed that in the following year after the outbreaks, the increase in the synthesis of photosynthetic pigments was also affected by the treatment with Foray 76B. Moreover, the increase in the synthesis of TPC and photosynthetic pigments in the damaged plots in 2021 illustrates the ability of pines to keep an activated defense system to fight biotic stress. Meanwhile, a higher synthesis of photosynthetic pigments in Foray 76B-treated plots indicates a possible effect of the treatment on faster tree growth and forest recovery after L. monacha outbreaks.

Effects of nitric oxide, spermidine, and salicylic acid signaling and their crosstalk with each other in the production of commercially important stevioside content and drought stress responses in Stevia rebaudiana bertoni

The leaves of Stevia rebaudiana Bertoni contain steviol glycosides (SGs), which provide the sweet taste of stevia. However, drought can have a negative impact on the plant's growth and development. To address this issue, signaling molecules such as sodium nitroprusside (SNP), spermidine (SPD), and salicylic acid (SA) are often applied to increase plant tolerance. However, the combined effects of these molecules have not been extensively studied. This research aimed to investigate the effects of controlled elicitation with SA, SNP, SPD, and their combinations on plant performance, SG content, and drought stress mitigation in Stevia rebaudiana under drought stress. The elicitor treatments were found to result in a significant increase in SG content, with 0.1 mM SA being the most effective treatment. Additionally, the treatments were able to reduce the stress effects on growth parameters to non-stress levels. The use of SPD, SA+SNP, and SPD+SNP on stressed plants significantly increased CAT and SOD activity, resulting in a more active antioxidant defense system that lowered MDA contents and H2O2 generation. These findings suggest that stevia cultivation with controlled elicitation could be used to improve plant growth, tolerance, and SG production under drought stress conditions.

An active defense model based on situational awareness and firewalls

SummaryWith the rapid development of the internet, cyberspace security issues have become increasingly prominent. The importance of constructing a cyberspace security system is self‐evident, but compared with attackers, defenders in cyberspace are in a castle‐like passive defense state in most cases. Therefore, building a reliable, accurate, timely, and active defense system is challenging. The key is to accurately focus on defense priorities, the anticipation of attackers who will likely succeed, and blocking attacks in a timely manner. In this article, we propose an active defense model based on the interaction of situational awareness and firewalls. First, by biasing the integrity, confidentiality, and availability of assets to get the score of assets, and using the Common Vulnerability Scoring System to assess the threat level of assets, we combine the two to determine the maximum system damage that the asset will suffer if it is lost, and then focus on defense. Meanwhile, log analysis of the network situational awareness platform can predict successful attackers, and then the linked firewall strategy can block these attacks in time before the attackers obtain attack gains. After that, we force the attackers to give up their attacks on the target by increasing the attack cost. We compared our model with iptables auto‐blocking and nginx auto‐blocking, and our model excelled them across the board in terms of comprehensiveness and false positive rate. The experimental results verify thar our active defense model proposed in this article can better reduce the defense cost and increase the attack cost, thus achieving the relatively defense goal.

Acclimatization of non-cultivated rice landraces to early moisture stress mediated by enzymatic antioxidants and osmolyte accumulation

Moisture stress affects the physiological and biochemical characteristics of plants such as the propensity for cellular water, induces stomatal closure, and reduces photosynthetic capacity, nitrate assimilation and substantial anabolic metabolism. In this study we assessed the antioxidative enzymes and osmolyte accumulation of fifty traditional non-cultivated rice landraces from Tamil Nadu, India. Artificial moisture stress was imposed in a hydroponic setup with maximum osmotic potential of (−) 15 bars. On the basis of drought and leaf rolling scores at 26 d, thirteen landraces were carried forward for further studies. The root/shoot ratio (R/S) was also significant for the selected landraces against IR64 as drought-susceptible check. The genotypes Kuliyadichan, Chandaikar, Mallikar, Nootripathu and Rajalakshmi were able to withstand intense moisture stress at 26 d with a score of 0 and 1, according to standard evaluation system for rice. Photosynthetic pigment and proline content of the above landraces increased during moisture stress in accordance with the positive check IR 64 (Drt1), however differential responses observed in all the landraces. Enzymatic antioxidant markers such as superoxide dismutase, catalase and peroxidase in shoots of all the selected landraces were greater than IR 64 (Drt1), under moisture stress. We identified Kuliyadichan, Rajalakshmi and Nootripathu as promising landraces with substantial moisture stress tolerance. Further, a positive correlation between overall seedling development and antioxidant enzymes as well as proline accumulation was observed under moisture stress. The mechanisms governing drought tolerance/avoidance in these moisture stress tolerant rice landraces might be attributed to active antioxidant defense system and proline accumulation for alleviating induced oxidative stress. Thus, the identified non-cultivated traditional rice landraces may be employed as potential donors for rice improvement programme towards climate resilience.

Bioinspired Machine‐Learning‐Assisted Early‐Fire Perception System Based on VO2 Optical Switch

AbstractThe continuation of human civilization has always been accompanied by symbiosis and confrontation with fire. Particularly, humans can comprehensively recognize fire situations based on various sensory receptors in organs (eyes, skin, nose, etc.), further forming a sound fire perception system by in‐the‐brain recording, modeling, and understanding fire behaviors, leading to the most accurate fire treatments. If a sensing perception system can mimic human perceptual behavior and carry out real‐time fire recognition, such an active defense system can achieve real fire safety. Here, inspired by the brain‐centered perception system, an early‐fire perception system enabled by a VO2‐based temperature‐flame‐modulated optical switch, and a machine‐learning‐assistant demodulation algorithm is reported. This approach creates real‐time monitoring composed of early fire warning (1 s for candle flame and 4 s for 130 °C heat flow), fire cause recognition (95.7% accuracy in identification), and evacuation advice provision, advancing the technologies in the perception system that enable future sensors the comprehensive perception capability for fire state.

Review of active defense methods against power CPS false data injection attacks from the multiple spatiotemporal perspective

The power cyber–physical system (CPS) realizes the wide-area interconnection of new energy sources and multiple loads and the dynamic interaction of information and energy flows; however it faces increasingly severe security threats of false data injection attacks (FDIAs). In this context, the active defense methods against power CPS FDIAs from the multiple spatiotemporal perspective are summarized and analyzed in this paper. First, the architecture of a power CPS is abstracted and its multiple spatiotemporal coordination characteristic and FDIAs security risk are expounded upon. Then, the active defense system against FDIAs is conceived in the spatiotemporal coordinate system, and based on different spatiotemporal intersections, the six active defense methods and application examples – namely network deception, data encryption protection, vulnerability policy protection, false identification correction, traffic anomaly detection, and fault prevention control – are summarized. Finally, the limitations of existing active defense methods against FDIAs are discussed, and the linked defense methods with multiple spatiotemporal coordination are prospected.

Carboxylated ε-Poly-L-Lysine Supplementation of the Freezing Extender Improves the Post-Thawing Boar Sperm Quality.

Frozen boar sperm is used on a minimal scale in consequence of the cryo-injuries induced by biochemical and physical modifications during the freezing and thawing processes. The present study investigates whether the addition of carboxylated ε-poly-L-lysine (CPLL) to the freezing medium could improve post-thaw boar sperm quality or not. Boar sperm was diluted with freezing medium contained different doses of carboxylated ε-poly-L-lysine (0, 0.125%, 0.25%, 0.5%, and 1%; v/v). The motility patterns, membrane integrity, acrosome integrity, mitochondrial membrane potential, NADH-CoQ activity, ATP level, malondialdehyde (MDA) level, and antioxidant defense system, as well as apoptosis in post-thaw boar sperm, were measured. It was observed that 0.25% CPLL treatment significantly improved the post-thaw boar sperm total motility, progressive motility, straight-linear velocity (VSL), curvilinear velocity (VCL), average path velocity (VAP), linearity (LIN), straightness (STR), membrane integrity, and acrosome integrity. Interestingly, the addition of CPLL also significantly increased the post-thaw sperm mitochondrial membrane potential, NADH-CoQ activity, and ATP level. Moreover, post-thaw boar sperm catalase (CAT) activity, glutathione peroxidase (GPx) activity, and superoxide dismutase (SOD) activity were increased with the addition of CPLL from 0.125% to 0.5% concentration levels. Furthermore, reduction of post-thaw sperm MDA level and apoptosis in 0.25% CPLL treatment was also observed. Those observations suggested that the addition of 0.25% CPLL to the freezing medium increased post-thaw boar sperm quality by protecting sperm mitochondrial function and antioxidant defense system. These findings provided novel insights that CPLL can be used as an efficient cryoprotectant to improve the post-thaw boar sperm quality during cryopreservation.

How abiotic stress-induced socialization leads to the formation of massive aggregates in Chlamydomonas.

Multicellular organisms implement a set of reactions involving signaling and cooperation between different types of cells. Unicellular organisms, on the other hand, activate defense systems that involve collective behaviors between individual organisms. In the unicellular model alga Chlamydomonas (Chlamydomonas reinhardtii), the existence and the function of collective behaviors mechanisms in response to stress remain mostly at the level of the formation of small structures called palmelloids. Here, we report the characterization of a mechanism of abiotic stress response that Chlamydomonas can trigger to form massive multicellular structures. We showed that these aggregates constitute an effective bulwark within which the cells are efficiently protected from the toxic environment. We generated a family of mutants that aggregate spontaneously, the socializer (saz) mutants, of which saz1 is described here in detail. We took advantage of the saz mutants to implement a large-scale multiomics approach that allowed us to show that aggregation is not the result of passive agglutination, but rather genetic reprogramming and substantial modification of the secretome. The reverse genetic analysis we conducted allowed us to identify positive and negative regulators of aggregation and to make hypotheses on how this process is controlled in Chlamydomonas.

Methyl Jasmonate Alleviated the Adverse Effects of Cadmium Stress in Pea (Pisum sativum L.): A Nexus of Photosystem II Activity and Dynamics of Redox Balance.

The accumulation of cadmium (Cd) in leaves reduces photosynthetic capacity by degrading photosynthetic pigments, reducing photosystem II activity, and producing reactive oxygen species (ROS). Though it was demonstrated that the application of Methyl Jasmonate (MeJA) induces heavy metal (HM) stress tolerance in plants, its role in adjusting redox balance and photosynthetic machinery is unclear. In this study, the role of MeJA in modulating photosystem II (PSII) activity and antioxidant defense system was investigated to reduce the toxic effects of Cd on the growth of pea (Pisum sativum L.) cultivars. One-week-old seedlings of three pea varieties were subjected to Cd stress (0, 50, 100 μm), and MeJA (0, 1, 5, 10 μm) was applied as a foliar spray for 2 weeks. Cadmium stress reduced the growth of all three pea varieties. Cadmium stress decreased photosynthetic pigments [Chl a (58.15%), Chl b (48.97%), total Chl (51.9%) and carotenoids (44.01%)] and efficiency of photosystem II [Fv/Fm (19.52%) and Y(II; 67.67%)], while it substantially increased Cd accumulation along with an increase in ROS (79.09%) and lipid peroxidation (129.28%). However, such adverse effects of Cd stress varied in different pea varieties. Exogenous application of MeJA increased the activity of a battery of antioxidant enzymes [superoxide dismutase (33.68%), peroxidase (29.75%), and catalase (38.86%)], improved photosynthetic pigments and PSII efficiency. This led to improved growth of pea varieties under Cd stress, such as increased fresh and dry weights of shoots and roots. In addition, improvement in root biomass by MeJA was more significant than that of shoot biomass. Thus, the mitigating effect of MeJA was attributed to its role in cellular redox balance and photosynthetic machinery of pea plants when exposed to Cd stress.

An intrusion detection mechanism for IPv6-based wireless sensor networks

With the advancement of IPv6 technology, many nodes in wireless sensor networks realize seamless connections with the Internet via IPv6 addresses. Security issues are a significant obstacle to the widespread adoption of IPv6 technology. Resource-constrained IPv6 nodes face dual attacks: local and Internet-based. Moreover, constructing an active cyber defense system for IPv6-based wireless sensor networks is difficult. In this article, we propose a K-nearest neighbor-based intrusion detection mechanism and design a secure network framework. This mechanism trains an intrusion detection algorithm using a feature data set to create a normal profile. The intrusion detection algorithm uses the normal profile to perform real-time detection of network traffic data to achieve rapid detections connecting many devices in a wireless sensor network. In addition, we develop a test platform to verify this mechanism. Experimental results show that this mechanism is appropriate for IPv6-based wireless sensor networks and achieves a low false-positive rate and good intrusion detection accuracy at an acceptable resource cost.

Considerations on Countering the Actions Aimed at Banning Access and Restricting Freedom of Action (A2AD)

Abstract Each state seeks to protect its territory from external threats using a wide range of forces and means, which combine the strike power with increased possibilities of detection given by the use of modern technologies. In this regard, we can see that some states have developed complex active and passive defense systems with the purpose of banning access and controlling certain key areas and aimed at both discouraging potential aggressors and protecting vital interests. For states with regional or global ambitions, the successful conduct of access operations in the area of operations, in a permissive, semi-permissive or hostile environment must be a priority. Access operations in a semi-permissive or hostile environment involve the use of tailored capabilities to deal with the opponent’s defense system and to overcome A2AD’s abilities.

Changes in the level of oxidative stress markers in Indian catfish (Wallago attu) infected with Isoparorchis hypselobagri

BackgroundHelminth infection and infestation in fishes are detrimental and have a major effect on fish health and fish production. Among various factors, parasitic infections are known to modulate antioxidant defences in fish. Similar to other aerobic animals, fish are also susceptible to the effect of reactive oxygen species and thus have well established intrinsic and efficient antioxidant defences. ‘Oxidative stress markers are an important indicator of the physiological state of the parasite and its host’. Indian catfish,Wallago attu is a freshwater fish that serves as the definitive host of the adult piscine trematode Isoparorchis hypselobagri. Our two years prevalence data signifies the intensity of the problem revealing a minimum of 5.5% and a maximum of 54% I. hypselobagri infection in Indian catfish W. attu (unpublished data). The present study aimed to achieve baseline data attributed to changes in some oxidative markers due to parasitic infection.ResultsDuring the present study, the level of enzyme activities of Catalase (CAT), Glutathione reductase (GR), Glutathione-S-transferase (GST), Glutathione peroxidase (GPx), Superoxide dismutase (SOD) and lipid peroxidation was investigated to explore the pathogenic impact on the fish host. The level of these oxidative stress markers was monitored in the swim bladder, liver, intestine and muscle of the host. We also recorded the enzyme activities in the parasite I. hypselobagri. Analysis of data revealed an elevation in GST, SOD, GR, GPx and CAT activity in the infected host tissue as compared to the non-infected fish. Further, we observed presence of GST, SOD, GR and GPx enzymes in the parasite I. hypselobagri while CAT did not show any enzyme activity.ConclusionsIncreased level of enzyme activity in liver, muscle and intestine of infected host has been recorded which indicates increased oxidative stress in the host due to parasitic invasion. The presence of antioxidant enzymes in the parasites suggests an active antioxidant defence system to avoid immune responses to long term survival and establishment in their host.

Endothelium-Mimicking Surface Combats Thrombosis and Biofouling via Synergistic Long- and Short-Distance Defense Strategy.

Thrombosis and infections are the main causes of implant failures (e.g., extracorporeal circuits and indwelling medical devices), which induce significant morbidity and mortality. In this work, an endothelium-mimicking surface is engineered, which combines the nitric oxide (NO)-generating property and anti-fouling function of a healthy endothelium. The released gas signal molecules NO and the glycocalyx matrix macromolecules hyaluronic acid (HA) jointly combine long- and short-distance defense actions against thrombogenicity and biofouling. The biomimetic surface is efficiently fabricated by cografting a NO-generating species (i.e., Tri-tert-butyl 1,4,7,10-Tetraazacyclododecane-1,4,7,10-tetraacetate-chelated Cu2+ , DTris@Cu) and the macromolecular HA on an aminated tube surface through one-pot amide condensation chemistry. The active attack (i.e., NO release) and zone defense (i.e., HA tethering) system endow the tubing surface with significant inhibition of platelets, fibrinogen, and bacteria adhesion, finally leading to long-term anti-thrombogenic and anti-fouling properties over 1 month. It is envisioned that this endothelium-mimicking surface engineering strategy will provide a promising solution to address the clinical issues of long-term blood-contacting devices associated with thrombosis and infection.

Network Security Model Based on Active and Passive Defense Hybrid Strategy

This paper studies a new network information security system and its evaluation method based on the security threat situation network security model. This paper expounds the application of active defense system and passive defense system in network security, and uses advanced technical support platform and network security model. In this paper, the active defense system and the passive defense system are organically combined to form a new model of computer network security with characteristics. At the same time, based on the idea of security threat situation evaluation, this paper extends the traditional PDRR security model and proposes a network active defense security model and defense in depth security strategy. On this basis, a hybrid architecture of active and passive defense is proposed. The architecture integrates some new network active defense technologies, and constructs a comprehensive and deep network defense system together with network passive defense means. The experimental results show that the proposed defense model improves the security defense efficiency and effective defense rate of the traditional PDRR security model.

Industrial Control Trusted Computing Platform for Power Monitoring System

The traditional network security protection methods are not enough to cope with the increasingly harsh network environment. It is of great significance to construct the active defense system of power monitoring network through trusted computing technology. Based on trusted computing technology, this paper studies the trusted computing platform for power monitoring system, mainly studies the trusted computing platform of master station and the trusted enhancement of field measurement and control equipment. Trusted platform of master station and trusted enhancement of field measurement and control.

Negative impact of long-term exposure of salinity and drought stress on native Tetraena mandavillei L.

Tetraena mandavillei L. is a perennial shrub native to the Middle Eastern countries of Asia, which is extensively regarded as a drought-tolerant plant. However, the plant reduces growth and biomass when grown in high concentrations of sodium chloride in the soil. We conducted a pot experiment to influence the negative impact of different levels of salinity (0, 10, and 20 dSm-1 ) and drought stress (100, 80, 60, and 40% water field capacity), to study different growth-related parameters, physiological alterations and ion uptake by T. mandavillei. Both salinity and drought stress caused a negative impact by affecting several attributes of T. mandavillei, but the plants showed some resistance against drought stress conditions in terms of growth and biomass. In addition to that, we noticed that a combinatorial and individual impact of drought and salinity stress decreased photosynthetic pigments and gas exchange parameters in T. mandavillei. Results also depicted that the combination of the abiotic stress conditions drought and salinity induced reactive oxygen species (ROS), indicating that the plants undergo oxidative damaged. However, due to the active plant defense system, the plant enhanced its performance under abiotic stress conditions, but due to the severe drought condition (40% water field capacity), a significant (P < 0.05) decrease in the activities of antioxidant compounds was caused. Furthermore, osmolytes also increased under both salinity and drought stress conditions in this study. Our results also showed that increased salinity and drought stress in the soil caused a significant increase in sodium (Na+ ) and chloride (Cl- ) ions in roots and shoots of T. mandavillei. In contrast to that, the contents of Calcium (Ca2+ ) and potassium (K+ ) were decreased in all organs of the plants with increasing levels of salinity and drought stress. Taken together, T. mandavillei can be classified as a facultative halophyte with the ability to tolerate drought stress and using salt accumulation mechanisms to tolerate salinity stress.

Abstract IA23: Marker-guided targeted therapy, PARP inhibitors, and novel post-translational modification of PD-L1

Abstract Poly (ADP-ribose) polymerase (PARP) inhibitors have emerged as promising therapeutics for many diseases, including cancer, in clinical trials. Three PARP inhibitors have been approved by the FDA to treat ovarian cancer with (olaparib and rucaparib) or without BRCA mutations (niraparib). BRCA1 and BRCA2 play essential roles in repairing DNA double-strand breaks, and a deficiency of BRCA proteins sensitizes cancer cells to PARP inhibition. My group recently demonstrated that receptor tyrosine kinase c-Met associates with and phosphorylates PARP1 at Tyr907. Phosphorylation of PARP1 Tyr907 increases PARP1 enzymatic activity and reduces binding to a PARP inhibitor, thereby rendering cancer cells resistant to PARP inhibition. Combining c-Met and PARP1 inhibitors synergized to suppress growth of breast cancer cells in vitro and xenograft tumor models. Similar synergistic effects were observed in a lung cancer xenograft tumor model. These results suggest that PARP1 pTyr907 abundance may predict tumor resistance to PARP inhibitors, and that treatment with a combination of c-Met and PARP inhibitors may benefit patients bearing tumors with high c-Met expression who do not respond to PARP inhibition alone (Nature Medicine 2016;22:194). We are working with clinicians at MD Anderson to initiate marker-guided clinical trials using combinational therapy of PARP and c-MET inhibitors. Extracellular interaction between programmed death ligand-1 (PD-L1) and programmed cell death protein-1 (PD-1) leads to tumor-associated immune escape. We further explored whether a cross-talk exists between PARP inhibition and PD-L1/PD-1 immune checkpoint axis and determined whether blockade of PD-L1/PD-1 potentiates PARP inhibitor (PARPi) in tumor suppression. PARP inhibitor (PARPi) treatment upregulates tumor cell PD-L1 expression, which attenuates PARPi efficacy via cancer-associated immunosuppression. The blockade of PD-L1 can restore the attenuated antitumor immunity and potentiate PARPi in tumor suppression (Clinical Cancer Res 2017;23:3711). My group also conducted a highly translational study, which identified a link between the ubiquitination and glycosylation pathways that regulate the immunosuppressive activity of PD-L1 (Nature Communications 2016;7:12632). We showed that glycosylation of PD-L1 is required for its protein stability and interaction with PD-1. In addition, we demonstrated that metformin-activated AMPK kinase downregulates PD-L1 through phosphorylation of Ser-195, which alters glycosylation of PD-L1 and functionally mimics anti-PD-L1 to block PD-L1/PD-1 interaction. It exhibited a highly potent synergistic effect of combination therapy of metformin, a drug that has been used to treat patients with diabetes and anti-CTLA4. The therapeutic efficacy could reach to survival rate of 50-70% in different syngeneic mouse models, which were treated by this combination therapy (Molecular Cell 2018;71:606). We also demonstrated that epithelial-mesenchymal transition (EMT) enhances PD-L1 in cancer stem-like cells (CSCs) by the EMT/β-catenin/STT3-PD-L1 signaling axis. Etoposide, a commonly used anticancer chemotherapy drug, is able to suppress this signaling axis, resulting in downregulation of PD-L1 to sensitize cancer cells to anti-Tim 3 therapy (Nature Communications 2018;9:1908). These findings provide potential therapeutic strategies to enhance cancer immune therapy efficacy by targeting PD-L1 stabilization to combat multiple cancer types. We identified TNFα as a major factor triggering cancer cell immunosuppression against T-cell surveillance via stabilization of programmed cell death-ligand 1 (PD-L1) (Cancer Cell 2016;30:925). To this end, in collaboration with StCube Pharmaceuticals Inc., we have developed monoclonal antibodies against glycosylation-specific PD-L1. Impressive therapeutic effect was observed through antibody-drug-conjugate approach (Cancer Cell 2018;33:187). Most recently, we unraveled an active defense system of PD-L1, previously known to only associate with passive defense activity. We discovered that cancer cells that express PD-L1 can secrete exosomes containing PD-L1 (exosome-PD-L1). The exosome-PD-L1 is able to directly interact with PD-1 to inhibit T-cell activation as well as T-cell killing activity (Cell Res 2018;28:862). Our new discoveries provide a new means to enhance therapeutic efficacy of immune checkpoint therapy. Citation Format: Mien-Chie Hung. Marker-guided targeted therapy, PARP inhibitors, and novel post-translational modification of PD-L1 [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2018 Nov 27-30; Miami Beach, FL. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(4 Suppl):Abstract nr IA23.

Copper Uptake and Accumulation, Ultra-Structural Alteration, and Bast Fibre Yield and Quality of Fibrous Jute (Corchorus capsularis L.) Plants Grown Under Two Different Soils of China.

Copper (Cu) is an essential heavy metal for plants, but high Cu concentration in the soil causes phytotoxicity. Some plants, however, possess a system that can overcome Cu toxicity, such as Cu localization, and an active antioxidant defence system to reduce oxidative damage induced by high Cu concentration. The present study was conducted to explore the phytoremediation potential, morpho-physiological traits, antioxidant capacity, and fibre quality of jute (Corchorus capsularis) grown in a mixture of Cu-contaminated soil and natural soil at ratios of 0:1 (control), 1:0, 1:1, 1:2 and 1:4. Our results showed that high Cu concentration in the soil decreased plant growth, plant biomass, chlorophyll content, gaseous exchange, and fibre yield while increasing reactive oxygen species (ROS), which indicated oxidative stress induced by high Cu concentration in the soil. Antioxidant enzymes, such as superoxidase dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) scavenge ROS in plant cells/tissues. Furthermore, high Cu concentration did not significantly worsen the fibre quality of C. capsularis, and this plant was able to accumulate a large amount of Cu, with higher Cu accumulation in its shoots than in its roots. Transmission electron microscopy (TEM) revealed that Cu toxicity affected different organelles of C. capsularis, with the chloroplast as the most affected organelle. On the basis of these results, we concluded that high Cu concentration was toxic to C. capsularis, reducing crop yield and plant productivity, but showing little effect on plant fibre yield. Hence, C. capsularis, as a fibrous crop, can accumulate a high concentration of Cu when grown in Cu-contaminated sites.