254 research outputs found
Comparison of Rooting Strategies to Explore Rock Fractures for Shallow Soil-Adapted Tree Species with Contrasting Aboveground Growth Rates: A Greenhouse Microcosm Experiment
For tree species adapted to shallow soil environments, rooting strategies that efficiently explore rock fractures are important because soil water depletion occurs frequently. However, two questions: (a) to what extent shallow soil-adapted species rely on exploring rock fractures and (b) what outcomes result from drought stress, have rarely been tested. Therefore, based on the expectation that early development of roots into deep soil layers is at the cost of aboveground growth, seedlings of three tree species (Cyclobalanopsis glauca, Delavaya toxocarpa, and Acer cinnamomifolium) with distinct aboveground growth rates were selected from a typical shallow soil region. In a greenhouse experiment that mimics the basic features of shallow soil environments, 1-year-old seedlings were transplanted into simulated microcosms of shallow soil overlaying fractured bedrock. Root biomass allocation and leaf physiological activities, as well as leaf δ13C values were investigated and compared for two treatments: regular irrigation and repeated cycles of drought stress. Our results show that the three species differed in their rooting strategies in the context of encountering rock fractures, however, these strategies were not closely related to the aboveground growth rate. For the slowest-growing seedling, C. glauca, percentages of root mass in the fractures, as well as in the soil layer between soil and bedrock increased significantly under both treatments, indicating a specialized rooting strategy that facilitated the exploration of rock fractures. Early investment in deep root growth was likely critical to the establishment of this drought-vulnerable species. For the intermediate-growing, A. cinnamomifolium, percentages of root mass in the bedrock and interface soil layers were relatively low and exhibited no obvious change under either treatment. This limited need to explore rock fractures was compensated by a conservative water use strategy. For the fast-growing, D. toxocarpa, percentages of root mass in the bedrock and interface layers increased simultaneously under drought conditions, but not under irrigated conditions. This drought-induced rooting plasticity was associated with drought avoidance by this species. Although, root development might have been affected by the simulated microcosm, contrasting results among the three species indicated that efficient use of rock fractures is not a necessary or specialized strategy of shallow-soil adapted species. The establishment and persistence of these species relied on the mutual complementation between their species-specific rooting strategies and drought adaptations
Cellular Basis of Potato Spindle Tuber Viroid Systemic Movement
AbstractViroids are small, nontranslatable pathogenic RNAs that replicate autonomously and traffic systemically in their host plants. We have used in situ hybridization to analyze the trafficking pattern of Potato spindle tuber viroid (PSTVd) in tomato and Nicotiana benthamiana. When PSTVd was inoculated onto the stem of a plant, it replicated and trafficked to sink, but not source, leaves. PSTVd was absent from shoot apical meristems. In the flowers of infected plants, PSTVd was present in the sepals, but was absent in the petals, stamens, and ovary. The replicative form of PSTVd was detected in the phloem. Our data demonstrate that (i) PSTVd traffics long distance in the phloem and this trafficking is likely sustained by replication of the viroid in the phloem, and (ii) PSTVd trafficking is governed by plant developmental and cellular factors. The dependency of PSTVd and other viroids on cellular mechanisms for RNA trafficking makes them excellent tools to study such mechanisms
miR-181a increases FoxO1 acetylation and promotes granulosa cell apoptosis via SIRT1 downregulation.
Oxidative stress impairs follicular development by inducing granulosa cell (GC) apoptosis, which involves enhancement of the transcriptional activity of the pro-apoptotic factor Forkhead box O1 (FoxO1). However, the mechanism by which oxidative stress promotes FoxO1 activity is still unclear. Here, we found that miR-181a was upregulated in hydrogen peroxide (
New environmental dependent modelling with Gaussian particle filtering based implementation for ground vehicle tracking
This paper proposes a new domain knowledge aided Gaussian particle filtering based approach for the ground vehicle tracking application. Firstly, a new form of modelling is proposed to reflect the influences of different types of environmental domain knowledge on the vehicle dynamic: i) a non-Markov jump model is applied with multiple models while transition probabilities between models are environmental dependent ii) for a particular model, both the constraints and potential forces obtained from the surrounding environment have been applied to refine the vehicle state distribution. Based on the proposed modelling approach, a Gaussian particle filtering based method is developed to implement the related Bayesian inference for the target state estimation. Simulation studies from multiple Monte Carlo simulations confirm the advantages of the proposed method over traditional ones, from both the modelling and implementation aspects
Pediatric High Risk Leukemia — Molecular Insights
Acute leukemia comprises of 31% of all cancers in children making it the most common childhood malignancy. Significant strides have been made in treatment, partly through risk stratification and intensified therapy. A number of subtypes remain at high risk for relapse and poor outcome, despite current therapies. Here we describe risk stratification and molecular diagnosis used to identify high risk leukemias and guide treatment. Specific cytogenetic alterations that contribute to high risk B and T cell acute lymphoblastic leukemia (ALL), as well as infant leukemia are discussed. Particular attention is given to genetic alterations in IKZF1, CRLF2, and JAK, that have been identified by whole genome sequencing and recently associated with Ph-like ALL. Ongoing studies of disease mechanisms and challenges in developing pre-clinical patient-derived xenograft models to evaluate therapies are discussed
Ultrasound assessment of gastric content in patients undergoing laparoscopic cholecystectomy after preoperative oral carbohydrates: a prospective, randomized controlled, double-blind study
BackgroundTo evaluate the gastric volume and nature after drinking preoperative oral carbohydrates in patients undergoing laparoscopic cholecystectomy via ultrasonography.MethodsOne hundred patients who had been scheduled for elective laparoscopic cholecystectomy were enrolled and randomized into the traditional fasting group (Control group, n = 50) and the carbohydrate group (CHO group, n = 50). Patients in the Control group fasted solids and drink from midnight, the day before surgery. Patients in the CHO group drank 800 ml and 400 ml of oral carbohydrates 11 and 3 h before surgery, respectively. At 2 h after oral carbohydrates (T1), all patients underwent an ultrasound examination of residual gastric contents; if the patients had a full stomach, the assessment was performed again 1 h later (T2). A stomach containing solid contents or >1.5 ml/kg of liquid was considered “full”. The primary outcome was full stomach incidences at the above time points. The secondary outcomes included gastric antral CSA in the right lateral decubitus (RLD) and semi-sitting positions, as well as gastric volume (GV), GV per weight (GV/kg), and Perla's grade at T1.ResultsCompared with the Control group, the incidence of entire stomach was significantly high in the CHO group 2 h after oral carbohydrates. At the T1 time point, 6 patients (13.3%) in the Control group and 14 patients (30.4%) in the CHO group presented with a full stomach [95% confidence interval (CI), (0.96–5.41), P = 0.049]. At T2, 3 patients (6.7%) in the Control group and 4 patients (8.7%) in the CHO group had a full stomach, with no marked differences between the two groups [95% CI, (0.31–5.50), P = 0.716]. Compared with the Control group, CSA in the semi-sitting and RLD positions, GV and GV/W were significantly high in the CHO group at T1 (P < 0.05). The median (interquartile range) of the Perlas grade was 1 (0–1) in the Control group and 1(1–1.25) in the CHO group (P = 0.004).ConclusionCholecystectomy patients experience a 2 h delay in gastric emptying after receiving preoperative carbohydrates. In LC patients, the fasting window for oral carbohydrates before surgery should be adequately prolonged.Clinical Trail registrationChinese Clinical Trail Registry, No: ChiCTR2200055245
A Rotating Disc Electrochemical Reactor to Produce Iron Powder for the Co2-Free Iron Fuel Cycle
Iron (Fe) is a promising candidate for energy carriers due to its high energy density, abundance, and transportability. Energy is released during the combustion of iron powder. Iron oxide particles are the product of combustion, which can be easily collected and reduced back to metallic iron, thus enforcing an iron fuel cycle. Electrochemical reduction of iron oxide in alkaline media is a promising approach for the reduction process as it is CO2-free and requires low temperature/energy. In the context of the iron fuel cycle, we promote electroreduction with dendrite-rich structures rather than compact deposit layers for easy harvesting and conversion of deposits to iron powder. This study presents the design and performance of an electrochemical reactor with a rotating disc system, designed for the continuous production of electrolytic iron powder. The reactor facilitates an integrated and automated process of electroreduction of iron oxide (from electroreduction to cleaning, drying, and dendrite/powder harvesting). Our proof of concept experiments show that iron deposits with dendritic structures can be produced in various conditions (anode configurations and rotating speeds), and are mainly located on the disc edge. The growth of dendrites at the edge of the disc favour harvesting and conversion to iron powder. Current efficiencies of more than 85-90 % are achieved in this study. Insights from the present study open new perspectives for the circularity of the iron fuel cycle. Furthermore, this technique provides a novel contribution to powder production in sustainable iron/steel-making technologies
Suckling Piglet Intestinal Enterocyte Nutrient Metabolism Changes
Background/Aims: Intestinal morphology and the types of enterocytes are changed in piglets during the suckling period, but it is unclear whether these changes are associated with metabolic changes in epithelium. The present study was conducted to test the hypothesis that glucose, fatty acids, and amino acid metabolism in differentiated piglet enterocytes changed during suckling. Methods: Twenty-four piglets (Duroc Ă— [Landrace Ă— Yorkshire]) from 8 litters (3 piglets/litter) were selected. A single piglet from each litter was randomly selected and euthanized at days 7, 14, and 21. Differentiated enterocytes (DE) were isolated from their mid-jejunum. Isobaric tags for relative and absolute quantification and subsequent liquid chromatography-tandem mass spectrometry were used to identify and measure protein synthesis. Results: The results showed that various activities, including: cellular processes; metabolic processes; biological regulation; pigmentation; and, localization, in DEs changed during suckling. Metabolic process analyses revealed that protein expression related to glycolysis and citrate cycle was decreased from day 7 to day 14. The number of differentiated enterocytes of 21 d piglets increased compared to 7 d piglets. Most of the proteins involved in fatty acid and amino acids metabolism had decreased DE expression between day 7 and day 14. Some, but not all, detected proteins down-regulated in DEs of 21 day piglets compared to 7 day piglets. Conclusion: These results indicate that glucose, fatty acids, and amino acids metabolism changed during suckling. This may provide useful information for designing feed formulas and regulating piglet intestinal growth and development
Comprehensive analysis of the prognosis and immune effect of the oncogenic protein Four Jointed Box 1
BackgroundThe Four Jointed Box 1 (FJX1) gene has been implicated in the upregulation of various cancers, highlighting its crucial role in oncology and immunity. In order to better understand the biological function of FJX1 and identify new immunotherapy targets for cancer, we conducted a comprehensive analysis of this gene.MethodsWe analyzed the expression profiles and prognostic value of FJX1 using data from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx). Copy number alterations (CNAs), mutations, and DNA methylation were analyzed through cBioPortal. The Immune Cell Abundance Identifier (ImmuCellAI) was used to examine the correlation between FJX1 expression and immune cell infiltration. The relationship between FJX1 expression and immune-related genes and immunosuppressive pathway-related genes was analyzed using The Tumor Immune Estimation Resource version 2 (TIMER2). Tumor mutational burden (TMB) and microsatellite instability (MSI) were obtained from TCGA pan-cancer data. The effect of immunotherapy and the IC50 were assessed using IMvigor210CoreBiologies and Genomics For Drug Sensitivity in Cancer (GDSC). Finally, we evaluated the impact of FJX1 on colon cancer cell proliferation and migration through in vitro functional experiments.ResultsOur study indicated that FJX1 expression was high in most cancers and was significantly associated with poor prognosis. High FJX1 expression was also linked to significant alterations in CNA, DNA methylation, TMB, and MSI. Positive correlations were found between FJX1 expression and tumor-associated macrophages (TAMs) and with immune-related genes such as TGFB1 and IL-10 and immunosuppressive pathway-related genes such as TGFB1 and WNT1. On the other hand, FJX1 expression showed a negative relationship with CD8+ T cells. Furthermore, high FJX1 expression led to reduced effectiveness of immunotherapy and drug resistance. In colon cancer cells, FJX1 knockdown was found to decrease cell proliferation and migration.ConclusionOur research findings demonstrate that FJX1 is a new prognostic factor with a significant role in tumor immunity. Our results highlight the importance of further exploring the potential of targeting FJX1 as a therapeutic strategy in cancer
Combined KRAS-MAPK pathway inhibitors and HER2-directed drug conjugate is efficacious in pancreatic cancer
Targeting the mitogen-activated protein kinase (MAPK) cascade in pancreatic ductal adenocarcinoma (PDAC) remains clinically unsuccessful. We aim to develop a MAPK inhibitor-based therapeutic combination with strong preclinical efficacy. Utilizing a reverse-phase protein array, we observe rapid phospho-activation of human epidermal growth factor receptor 2 (HER2) in PDAC cells upon pharmacological MAPK inhibition. Mechanistically, MAPK inhibitors lead to swift proteasomal degradation of dual-specificity phosphatase 6 (DUSP6). The carboxy terminus of HER2, containing a TEY motif also present in extracellular signal-regulated kinase 1/2 (ERK1/2), facilitates binding with DUSP6, enhancing its phosphatase activity to dephosphorylate HER2. In the presence of MAPK inhibitors, DUSP6 dissociates from the protective effect of the RING E3 ligase tripartite motif containing 21, resulting in its degradation. In PDAC patient-derived xenograft (PDX) models, combining ERK and HER inhibitors slows tumour growth and requires cytotoxic chemotherapy to achieve tumour regression. Alternatively, MAPK inhibitors with trastuzumab deruxtecan, an anti-HER2 antibody conjugated with cytotoxic chemotherapy, lead to sustained tumour regression in most tested PDXs without causing noticeable toxicity. Additionally, KRAS inhibitors also activate HER2, supporting testing the combination of KRAS inhibitors and trastuzumab deruxtecan in PDAC. This study identifies a rational and promising therapeutic combination for clinical testing in PDAC patients
- …