Search Results (42)

A skid-to-turn (STT) missile is an axisymmetric structure missile, and its control system consists of a pitch channel and a yaw channel with an axisymmetric structure. To achieve the fast response of the STT missile system, a compound control method of aerodynamic force and lateral thrust based on regional pole assignment (RPA) is proposed. In the aerodynamic control system, the linear quadratic regulator (LQR) is used to design the controller, and the sliding mode control method is used to design the controller of the lateral thrust system. The regional pole assignment is introduced into the aerodynamic system to improve the compound control system response speed. The problems of regional pole assignment and system stability are solved by a linear matrix inequality (LMI). Considering that the missile flies at different altitudes, the missile system is controlled by gain scheduling. Compared to previous designs of time-varying compound control systems for STT missiles or hypersonic vehicles, in order to meet the practical requirement of a fast response for the vehicle, this time-varying compound control strategy can achieve faster tracking response and attitude control for the STT missile. Finally, through simulations of the pitch channel and yaw channel control systems of the STT missile, the effectiveness of the designed compound control system in achieving a fast response is verified. Full article

Mucinous epithelial ovarian cancer (mEOC) is a rare subtype of epithelial ovarian cancer, characterized by poor responses to standard platinum-based chemotherapy. Polo-like kinase 1 (PLK1) is a key regulator of mitosis and cell cycle progression and its inhibition has been recently identified as a target in mEOC. In this study, we aimed to identify further therapeutic targets in mEOC using a CRISPR/Cas9 library targeting 3015 genes, with and without treatment with onvansertib, a PLK1 inhibitor. We identified twelve genes associated with cell survival (ZC2HC1C, RPA2, KIN17, TUBG1, SMC2, CDC26, CDC42, HOXA9, TAF10, SENP1, MRPS31, and COPS2) and three genes (JUND, CARD9, and BCL2L2) in synthetic lethality with onvansertib treatment. We validated that SENP1 downregulation is important for the growth of mEOC cells through esiRNA interference and the use of a pharmacological inhibitor Momordin Ic. The downregulation of CARD9 and BCL2L2 combined with subtoxic doses of onvansertib interfered with mEOC cell growth. Interestingly, the combination of navitoclax, an inhibitor of BcL2 family members including BCL2L2, was synergistic in all four of the mEOC cell lines tested and substantially induced cell death through apoptosis. These data support the use of a combination of navitoclax and onvansertib as a new therapeutic strategy for mEOC. Full article

Genetically modified (GM) herbicide-tolerant soybean ‘Zhonghuang 6106’, which introduces a glyphosate-resistant gene, ensures soybean yield while allowing farmers to reduce the use of other herbicides, thereby reducing weed management costs. To protect consumer rights and facilitate government supervision, we have established a simple and rapid on-site nucleic acid detection method for GM soybean ‘Zhonghuang 6106’. This method leverages the isothermal amplification characteristics of RPA technology and the high specificity of CRISPR-Cas12a to achieve high sensitivity and accuracy in detecting GM soybean components. By optimizing experimental conditions, the platform can quickly produce visual detection results, significantly reducing detection time and improving efficiency. The system can detect down to 10 copies/μL of ‘Zhonghuang 6106’ DNA templates, and the entire detection process takes about 1 h. The technology also has strong editing capabilities; by redesigning the primers and crRNA in the method, it can become a specific detection method for other GM samples, providing strong technical support for the regulation and safety evaluation of GM crops. Full article

Background/Objectives: The emergence of the mobilized colistin resistance 1 (mcr-1) gene, which causes colistin resistance, is a serious concern in animal husbandry, particularly in pigs. Although antibiotic regulations in many countries have prohibited the use of colistin in livestock, the persistence and dissemination of this plasmid-mediated gene require effective and rapid monitoring. Therefore, a rapid, sensitive, and specific method combining recombinase polymerase amplification (RPA) with an in-house lateral flow assay (LFA) for the mcr-1 gene detection was developed. Methods: The colistin agar test and broth microdilution were employed to screen 152 E. coli isolates from pig fecal samples of five antibiotic-used farms. The established RPA-in-house LFA was validated with PCR for mcr-1 gene detection. Results: The RPA-in-house LFA was completed within 35 min (20 min of amplification and 5–15 min on LFA detection) at 37 °C. The sensitivity, specificity, and accuracy were entirely 100% in concordance with PCR results. No cross-reactivity was detected with seven common pathogenic bacteria or other mcr gene variants. Conclusions: Therefore, the in-house RPA-LFA serves as a point-of-care testing tool that is rapid, simple, and portable, facilitating effective surveillance of colistin resistance in both veterinary and clinical settings, thereby enhancing health outcomes. Full article

Pancreatic cancer (PanCa) is one of the deadliest cancers, with limited therapeutic response. Various molecular oncogenic events, including dysregulation of ribosome biogenesis, are linked to the induction, progression, and metastasis of PanCa. Thus, the discovery of new therapies suppressing these oncogenic events and ribosome biogenesis could be a novel therapeutic approach for the prevention and treatment of PanCa. The current study was designed to investigate the anti-cancer effect of honey against PanCa. Our results indicated that honey markedly inhibited the growth and invasive characteristics of pancreatic cancer cells by suppressing the mRNA expression and protein levels of key components of ribosome biogenesis, including RNA Pol-I subunits (RPA194 and RPA135) along with its transcriptional regulators, i.e., UBTF and c-Myc. Honey also induced nucleolar stress in PanCa cells by reducing the expression of various nucleolar proteins (NCL, FBL, and NPM). Honey-mediated regulation on ribosome biogenesis components and nucleolar organization-associated proteins significantly arrested the cell cycle in the G2M phase and induced apoptosis in PanCa cells. These results, for the first time, demonstrated that honey, being a natural remedy, has the potential to induce apoptosis and inhibit the growth and metastatic phenotypes of PanCa by targeting ribosome biogenesis. Full article

The Mexican Caribbean coastal dune is protected by national and international environmental legislation. However, through permits, concessions and authorizations for changes in land use, the coastal dune has been fragmented or suppressed, mainly for touristic activities, causing a decline in protective and ecological ecosystem services. In this study, we evaluated the strength and weakness of Mexican legislation to protect the Caribbean coastal dune ecosystem and estimated the historical and current effects on coastal dune vegetation and dune geomorphology, associated with legal allowances of land use change in the Sian Ka’an Biosphere Reserve (SKBR). Legislation at the federal, state and local level were critically reviewed, and with remote sensing techniques and the Remotely Piloted Aircraft System (RPAS), we conducted a case study in the SKBR to estimate coastal dune vegetation alteration trends during the period 2011–2020 and modifications on the dune geomorphology associated with land use change allowances. At the federal (four laws), state (eight laws) and local (nine Local and Territorial Planning Programs (POEL and POET) levels, we found a lack of consensus and alignment between regulations, starting with a lack of definition of ecosystems subject to protection. For coastal dunes, none of them consider topography, ecological function and a way to identify it in the field, making the surveillance highly complex and favoring land use changes, the removal of vegetation and dune geomorphology alteration. Remote sensing techniques showed that areas with land use authorizations exhibit negative vegetation cover trends (Mann–Kendall <−0.4), indicating a decline in vegetation cover density that is mostly anthropogenically induced. The RPAS analysis demonstrated drastic alterations to complete elimination of the coastal dune geomorphology in areas with land use change. In the Mexican Caribbean, the loss of coastal dune and associated ecosystem by the lack of congruent legislation threatens the environmental stability of the coastal areas. Full article

The regulatory framework of Remotely Piloted Aircraft Systems (RPASs) has recently experienced an extraordinary evolution. This article seeks to improve the integration of certification considerations in RPAS conceptual design approaches so as to enhance the safety, certifiability and competitiveness of their resulting designs. The first part of the research conducts a two-stage analysis of contemporary regulations related to an RPAS’s initial airworthiness. In the first stage, the broad international regulation paradigm is evaluated attending to a set of criteria that are tightly related to both airworthiness and design considerations. The second stage keeps the most promising documents from a design–integration standpoint, which are assessed according to their applicability considering both design and operational aspects. The results of this analysis provide insights regarding the main issues in airworthiness design criteria extraction and integration in design methodologies. To aid the designer in surmounting these challenges, a flexible procedure named DECEX is developed. Considering the documents and findings from the survey, and attending to the scope of the design methodology being developed, it aids in establishing a complete regulatory document corpus and in comparing and extracting the applicable airworthiness design criteria. Two case studies for different RPAS types are conducted to demonstrate its application. Full article

This study explores the potential of micro-credentialing and digital badges in developing and validating the knowledge, skills, and other attributes (KSaOs) required for diverse Remotely Piloted Aircraft Systems (RPAS) operations. The rapid proliferation of drone usage has outpaced the development of necessary KSaOs for safe and efficient drone operations. This research aims to bridge this gap by identifying the unique and specific KSaOs required for different types of drone operations and examining how micro-credentialing and digital badges can provide tangible evidence of these KSaOs. The study also investigates the potential benefits and challenges of implementing digital badges in the RPAS sector and how these challenges can be addressed. Furthermore, it explores how digital badges can contribute to the standardization and recognition of RPAS competencies across different national regulatory bodies. The methodology involves observational studies of publicly available videos of drone operations, with a focus on agriculture spraying operations. The findings highlight the importance of both generic and specific KSaOs in RPAS operations and suggest that digital badges may provide an effective means of evidencing mastery of these competencies. This research contributes to the ongoing discourse on drone regulation and competency development, offering practical insights for regulators, training providers, and drone operators. Full article

Targeting CDC20 can enhance the radiosensitivity of tumor cells, but the function and mechanism of CDC20 on DNA damage repair response remains vague. To examine that issue, tumor cell lines, including KYSE200, KYSE450, and HCT116, were utilized to detect the expression, function, and underlying mechanism of CDC20 in radio-chemoresistance. Western blot and immunofluorescence staining were employed to confirm CDC20 expression and location, and radiation could upregulate the expression of CDC20 in the cell nucleus. The homologous recombination (HR) and non-homologous end joining (NHEJ) reporter gene systems were utilized to explore the impact of CDC20 on DNA damage repair, indicating that CDC20 could promote HR repair and radio/chemo-resistance. In the early stages of DNA damage, CDC20 stabilizes the RPA1 protein through protein-protein interactions, activating the ATR-mediated signaling cascade, thereby aiding in genomic repair. In the later stages, CDC20 assists in the subsequent steps of damage repair by the ubiquitin-mediated degradation of RPA1. CCK-8 and colony formation assay were used to detect the function of CDC20 in cell vitality and proliferation, and targeting CDC20 can exacerbate the increase in DNA damage levels caused by cisplatin or etoposide. A tumor xenograft model was conducted in BALB/c-nu/nu mice to confirm the function of CDC20 in vivo, confirming the in vitro results. In conclusion, this study provides further validation of the potential clinical significance of CDC20 as a strategy to overcome radio-chemoresistance via uncovering a novel role of CDC20 in regulating RPA1 during DNA damage repair. Full article

Pospiviroids infect a wide range of plant species, and many pospiviroids can be transmitted to potato and tomato. Pospiviroids continue to be a major production constraint as well as of quarantine concern for the movement of germplasm, and are regulated in several countries/regions. The USDA APHIS issued a federal order requiring all imported tomato and pepper seeds be certified free of six pospiviroids of quarantine significance. The six pospiviroids of quarantine interest include CLVd, PCFVd, PSTVd, TASVd, TCDVd, TPMVd. Currently, those six viroids are detected by real-time RT-PCR. CRISPR/Cas-based genome editing has been increasingly used for virus detection in the past five years. We used a rapid Cas13-based Specific High-sensitivity Enzymatic Reporter unLOCKing (SHERLOCK) platform for pospiviroid detection, determined the limits of detection and specificity of CRISPR-Cas13a assays. This platform combines recombinase polymerase amplification (RPA) with CRISPR and CRISPR-associated (CRISPR-Cas) RNA-guided endoribonuclease that is rapid and does not require expensive equipment, and can be adapted for on-site detection. Full article

Mycobacterium bovis (M. bovis), the microorganism responsible for bovine tuberculosis (bTB), is transferred to people by the ingestion of unpasteurized milk and unprocessed fermented milk products obtained from animals with the infection. The identification of M. bovis in milk samples is of the utmost importance to successfully prevent zoonotic diseases and maintain food safety. This study presents a comprehensive description of a highly efficient molecular test utilizing recombinase-aided amplification (RPA)–clustered regularly interspaced short palindromic repeat (CRISPR)-associated protein (Cas) 13a–lateral flow detection (LFD) for M. bovis detection. In contrast to ELISA, RPA–CRISPR–Cas13a–LFD exhibited greater accuracy and sensitivity in the detection of M. bovis in milk, presenting a detection limit of 2 × 10⁰ copies/μL within a 2 h time frame. The two tests exhibited a moderate level of agreement, as shown by a kappa value of 0.452 (95%CI: 0.287–0.617, p < 0.001). RPA–CRISPR–Cas13a–LFD holds significant potential as a robust platform for pathogen detection in complex samples, thereby enabling the more dependable regulation of food safety examination, epidemiology research, and medical diagnosis. Full article

P53 overexpression plays a critical role in cancer pathogenesis by disrupting the intricate regulation of cellular proliferation. Despite its firmly established function as a tumor suppressor, elevated p53 levels can paradoxically contribute to tumorigenesis, influenced by factors such as exposure to carcinogens, genetic mutations, and viral infections. This phenomenon is observed across a spectrum of cancer types, including bladder (BLCA), ovarian (OV), cervical (CESC), cholangiocarcinoma (CHOL), colon adenocarcinoma (COAD), diffuse large B-cell lymphoma (DLBC), esophageal carcinoma (ESCA), head and neck squamous cell carcinoma (HNSC), kidney chromophobe (KICH), kidney renal clear cell carcinoma (KIRC), liver hepatocellular carcinoma (LIHC), lung adenocarcinoma (LUAD), lung squamous cell carcinoma (LUSC), and uterine corpus endometrial carcinoma (UCEC). This broad spectrum of cancers is often associated with increased aggressiveness and recurrence risk. Effective therapeutic strategies targeting tumors with p53 overexpression require a comprehensive approach, integrating targeted interventions aimed at the p53 gene with conventional modalities such as chemotherapy, radiation therapy, and targeted drugs. In this extensive study, we present a detailed analysis shedding light on the multifaceted role of TP53 across various cancers, with a specific emphasis on its impact on disease-free survival (DFS). Leveraging data from the TCGA database and the GTEx dataset, along with GEPIA, UALCAN, and STRING, we identify TP53 overexpression as a significant prognostic indicator, notably pronounced in prostate adenocarcinoma (PRAD). Supported by compelling statistical significance (p < 0.05), our analysis reveals the distinct influence of TP53 overexpression on DFS outcomes in PRAD. Additionally, graphical representations of overall survival (OS) underscore the notable disparity in OS duration between tumors exhibiting elevated TP53 expression (depicted by the red line) and those with lower TP53 levels (indicated by the blue line). The hazard ratio (HR) further emphasizes the profound impact of TP53 on overall survival. Moreover, our investigation delves into the intricate TP53 protein network, unveiling genes exhibiting robust positive correlations with TP53 expression across 13 out of 27 cancers. Remarkably, negative correlations emerge with pivotal tumor suppressor genes. This network analysis elucidates critical proteins, including SIRT1, CBP, p300, ATM, DAXX, HSP 90-alpha, Mdm2, RPA70, 14-3-3 protein sigma, p53, and ASPP2, pivotal in regulating cell cycle dynamics, DNA damage response, and transcriptional regulation. Our study underscores the paramount importance of deciphering TP53 dynamics in cancer, providing invaluable insights into tumor behavior, disease-free survival, and potential therapeutic avenues. Full article

Polyomavirus (PyV) Large T-antigen (LT) is the major viral regulatory protein that targets numerous cellular pathways for cellular transformation and viral replication. LT directly recruits the cellular replication factors involved in initiation of viral DNA replication through mutual interactions between LT, DNA polymerase alpha-primase (Polprim), and single-stranded DNA binding complex, (RPA). Activities and interactions of these complexes are known to be modulated by post-translational modifications; however, high-sensitivity proteomic analyses of the PTMs and proteins associated have been lacking. High-resolution liquid chromatography tandem mass spectrometry (LC–MS/MS) of the immunoprecipitated factors (IPMS) identified 479 novel phosphorylated amino acid residues (PAARs) on the three factors; the function of one has been validated. IPMS revealed 374, 453, and 183 novel proteins associated with the three, respectively. A significant transcription-related process network identified by Gene Ontology (GO) enrichment analysis was unique to LT. Although unidentified by IPMS, the ETS protooncogene 1, transcription factor (ETS1) was significantly overconnected to our dataset indicating its involvement in PyV processes. This result was validated by demonstrating that ETS1 coimmunoprecipitates with LT. Identification of a novel PAAR that regulates PyV replication and LT’s association with the protooncogenic Ets1 transcription factor demonstrates the value of these results for studies in PyV biology. Full article

Telomeres act as the protective caps of eukaryotic linear chromosomes; thus, proper telomere maintenance is crucial for genome stability. Successful telomere replication is a cornerstone of telomere length regulation, but this process can be fraught due to the many intrinsic challenges telomeres pose to the replication machinery. In addition to the famous “end replication” problem due to the discontinuous nature of lagging strand synthesis, telomeres require various telomere-specific steps for maintaining the proper 3′ overhang length. Bulk telomere replication also encounters its own difficulties as telomeres are prone to various forms of replication roadblocks. These roadblocks can result in an increase in replication stress that can cause replication forks to slow, stall, or become reversed. Ultimately, this leads to excess single-stranded DNA (ssDNA) that needs to be managed and protected for replication to continue and to prevent DNA damage and genome instability. RPA and CST are single-stranded DNA-binding protein complexes that play key roles in performing this task and help stabilize stalled forks for continued replication. The interplay between RPA and CST, their functions at telomeres during replication, and their specialized features for helping overcome replication stress at telomeres are the focus of this review. Full article

Human Replication Protein A (RPA) was historically discovered as one of the six components needed to reconstitute simian virus 40 DNA replication from purified components. RPA is now known to be involved in all DNA metabolism pathways that involve single-stranded DNA (ssDNA). Heterotrimeric RPA comprises several domains connected by flexible linkers and is heavily regulated by post-translational modifications (PTMs). The structure of RPA has been challenging to obtain. Various structural methods have been applied, but a complete understanding of RPA’s flexible structure, its function, and how it is regulated by PTMs has yet to be obtained. This review will summarize recent literature concerning how RPA is phosphorylated in the cell cycle, the structural analysis of RPA, DNA and protein interactions involving RPA, and how PTMs regulate RPA activity and complex formation in double-strand break repair. There are many holes in our understanding of this research area. We will conclude with perspectives for future research on how RPA PTMs control double-strand break repair in the cell cycle. Full article