Reviews on Mechanisms of In Vitro

It is widely acknowledged that the excessive reactive oxygen species (ROS) or reactive nitrogen species (RNS) induced oxidative stress will cause significant damage to cell structure and biomolecular function, directly or indirectly leading to a number of diseases. The overproduction of ROS/RNS will be balanced by nonenzymatic antioxidants and antioxidant enzymes. Polysaccharide or glycoconjugates derived from natural products are of considerable interest from the viewpoint of potent in vivo and in vitro antioxidant activities recently. Particularly, with regard to the in vitro antioxidant systems, polysaccharides are considered as effective free radical scavenger, reducing agent, and ferrous chelator in most of the reports. However, the underlying mechanisms of these antioxidant actions have not been illustrated systematically and sometimes controversial results appeared among various literatures. To address this issue, we summarized the latest discoveries and advancements in the study of antioxidative polysaccharides and gave a detailed description of the possible mechanisms

Arabidopsis IAR4 Modulates Primary Root Growth Under Salt Stress Through ROS-Mediated Modulation of Auxin Distribution

High salinity is one of the major environmental stresses that plants encounter. Roots are the initial and direct organs to perceive the signal. However, how plant roots perceive and respond to salinity at the molecular and physiological levels is still poorly understood. Here, we report that IAA-CONJUGATE-RESISTANT 4 (IAR4) plays a key role in primary root growth under salt stress conditions. Mutation of IAR4 led to increased sensitivity to salt stress conditions, with strongly inhibited primary root growth and reduced survival rate in two iar4 mutant alleles. iar4 mutants accumulated greater Na+ and exhibited a greater Na+/K+ ratio under NaCl treatment. In addition, more reactive oxygen species (ROS) accumulated in the iar4 mutants due to reduced ROS scavenging. NaCl treatment greatly suppressed the expression levels of ProPIN1:PIN1-GFP, ProPIN2:PIN2-GFP, ProPIN3:PIN3-GFP, and ProDR5:GFP, and suppressed root meristem activity in iar4. GSH or auxin treatment greatly recovered the PIN expression, auxin distribution and primary root growth in the iar4 mutants, suggesting ROS is a vital mediator between salt stress and auxin response. Our data support a model in which IAR4 integrates ROS and auxin pathways to modulate primary root growth under salinity stress conditions, by regulation of PIN-mediated auxin transport

Container CT scanner: a solution for modular emergency radiology department during the COVID-19 pandemic

During the coronavirus disease 2019 (COVID-19) pandemic period, container computed tomography (CT) scanners were developed and used for the first time in China to perform CT examinations for patients with clinically mild to moderate COVID-19 who did not need to be hospitalized for comprehensive treatment, but needed to be isolated in Fangcang shelter hospitals (also known as makeshift hospitals) to receive some supportive treatment. The container CT is a multidetector CT scanner installed within a radiation-protected stand-alone container (a detachable lead shielding room) that is deployed outside the makeshift hospital buildings. The container CT approach provided various medical institutions with the solution not only for rapid CT installation and high adaptability to site environments, but also for significantly minimizing the risk of cross-infection between radiological personnel and patients during CT examination in the pandemic. In this article, we described the typical setup of a container CT and how it worked for chest CT examinations in Wuhan city, the epicenter of COVID-19 outbreak

TNF-α and IFN-γ synergistically inhibit the repairing ability of mesenchymal stem cells on mice colitis and colon cancer.

BACKGROUND(#br)Mesenchymal stem cells (MSCs) can be efficiently recruited to wound, inflammatory and tumor sites to repair and regenerate tissue. However, its role in colitis and colitis associated colon cancer is still controversial. This study was designed to evaluate the role and mechanisms of inflammatory cytokines-activated-MSCs in mice colitis and colon cancer.(#br)METHODS(#br)We selected two well-characterized pro-inflammatory cytokines, tumor necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ), to expand the inflammatory microenvironment of MSCs. The severity of colitis and colon cancer was evaluated by measuring colon length, Myeloperoxidase (MPO) activity, Hematoxylin-eosin staining, Western Blot, Immunohistochemistry and Immunofluorescence. These techniques were also performed to analyze the mechanisms of inflammatory cytokines-activated-MSCs in mice colitis and colon cancer. Real-time PCR and Enzyme-linked Immunosorbent Assay (ELISA) were used to measure the secretion of pro-inflammatory factors.(#br)RESULTS(#br)We found that the incubation of MSCs with TNF-α and IFN-γ aggravates colitis, where high levels of pro-inflammatory factors, such as interleukin (IL)-17, IL-8, IL-12, IL-1β, transforming growth factor (TGF)-β, TNF-α and IFN-γ, were secreted. Furthermore, this phenomenon was associated with the activation of the nuclear factor-kappa-B (NF-κB)/Signal transducer and activator of transcription three (STAT3) pathway. In addition, our study demonstrated that TNF-α and IFN-γ pretreated MSCs synergistically exacerbated mice colon cancer, which was closely associated with angiogenesis.(#br)CONCLUSIONS(#br)Taken together, these results indicate that TNF-α and IFN-γ pretreatment effectively inhibited the repair ability of MSCs and accelerated inflammation and tumor progression involving NF-κB/STAT3 pathway and angiogenesis-related factors

Effects of Differently Processed Carrots on Ulcerative Colitis in Mice

The incidence of ulcerative colitis (UC) has been increasing in recent years. Due to the limitations of traditional drug therapies for UC, natural foods that can prevent this disease and alleviate its symptoms are becoming a research hot topic, but the effects of processing methods on their activity remain unknown. Therefore, the effects of three different processing methods (pulping, high-temperature cooking, and fermentation) on carotenoid and dietary fiber contents as well as carotenoid bioaccessibility in carrots were explored in this study. C57BL/6J mice were used to create a mouse model of UC induced by dextran sulfate sodium (DSS) and the mice received dietary intervention with freeze dried powder of carrots (5.05%, on a dry mass basis) for 14 days. Body mass change, disease activity index (DAI) and colon parameters (length, pathology, inflammatory factors, oxidative stress level, goblet cell number, tight junction protein expression, and short-chain fatty acid content) were analyzed to evaluate the effects of three differently processed carrots on UC. The results showed compared with pulping, high-temperature cooking and fermentation significantly decreased the soluble, insoluble and total dietary fiber contents of carrots (P < 0.05), increased the bioaccessibility of carotenoids (P < 0.05), while fermentation significantly increased the proportion of soluble dietary fiber in total dietary fiber (P < 0.05). Compared with the model group, all processed carrots could significantly inhibit the change of body mass loss and DAI (P < 0.05), decrease the levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-6 (P < 0.05), increase the level of IL-10 (P < 0.05), and up-regulate the expression of tight junction proteins (ZO-1, claudin-1, and occludin) (P < 0.05). High-temperature cooked or fermented carrots could significantly alleviate colon shortening (P < 0.05), and relieve the pathological damage of colon tissue (P < 0.05). Meanwhile, fermented carrots could significantly inhibit the production of malondialdehyde (MDA) (P < 0.05), improve the decrease in the number of goblet cells (P < 0.05), increase the level of butyric acid (P < 0.05) and possess the best inhibitory effect on IL-6 production. In summary, differently processed carrots could ameliorate ulcerative colitis to different extends, the most pronounced effect being observed with fermented carrots

Energy loss enhancement of very intense proton beams in dense matter due to the beam-density effect

Thoroughly understanding the transport and energy loss of intense ion beams in dense matter is essential for high-energy-density physics and inertial confinement fusion. Here, we report a stopping power experiment with a high-intensity laser-driven proton beam in cold, dense matter. The measured energy loss is one order of magnitude higher than the expectation of individual particle stopping models. We attribute this finding to the proximity of beam ions to each other, which is usually insignificant for relatively-low-current beams from classical accelerators. The ionization of the cold target by the intense ion beam is important for the stopping power calculation and has been considered using proper ionization cross section data. Final theoretical values agree well with the experimental results. Additionally, we extend the stopping power calculation for intense ion beams to plasma scenario based on Ohm's law. Both the proximity- and the Ohmic effect can enhance the energy loss of intense beams in dense matter, which are also summarized as the beam-density effect. This finding is useful for the stopping power estimation of intense beams and significant to fast ignition fusion driven by intense ion beams

Target density effects on charge tansfer of laser-accelerated carbon ions in dense plasma

We report on charge state measurements of laser-accelerated carbon ions in the energy range of several MeV penetrating a dense partially ionized plasma. The plasma was generated by irradiation of a foam target with laser-induced hohlraum radiation in the soft X-ray regime. We used the tri-cellulose acetate (C$_{9}$H$_{16}$O$_{8}$) foam of 2 mg/cm$^{-3}$ density, and $1$-mm interaction length as target material. This kind of plasma is advantageous for high-precision measurements, due to good uniformity and long lifetime compared to the ion pulse length and the interaction duration. The plasma parameters were diagnosed to be T$_{e}$=17 eV and n$_{e}$=4 $\times$ 10$^{20}$ cm$^{-3}$. The average charge states passing through the plasma were observed to be higher than those predicted by the commonly-used semiempirical formula. Through solving the rate equations, we attribute the enhancement to the target density effects which will increase the ionization rates on one hand and reduce the electron capture rates on the other hand. In previsous measurement with partially ionized plasma from gas discharge and z-pinch to laser direct irradiation, no target density effects were ever demonstrated. For the first time, we were able to experimentally prove that target density effects start to play a significant role in plasma near the critical density of Nd-Glass laser radiation. The finding is important for heavy ion beam driven high energy density physics and fast ignitions.Comment: 7 pages, 4 figures, 35 conference

100 essential questions for the future of agriculture

Publication history: Accepted - 8 March 2023; Published online - 11 April 2023.The world is at a crossroad when it comes to agriculture. The global population is growing, and the demand for food is increasing, putting a strain on our agricultural resources and practices. To address this challenge, innovative, sustainable, and inclusive approaches to agriculture are urgently required. In this paper, we launched a call for Essential Questions for the Future of Agriculture and identified a priority list of 100 questions. We focus on 10 primary themes: transforming agri-food systems, enhancing resilience of agriculture to climate change, mitigating climate change through agriculture, exploring resources and technologies for breeding, advancing cultivation methods, sustaining healthy agroecosystems, enabling smart and controlled-environment agriculture for food security, promoting health and nutrition-driven agriculture, exploring economic opportunities and addressing social challenges, and integrating one health and modern agriculture. We emphasise the critical importance of interdisciplinary and multidisciplinary research that integrates both basic and applied sciences and bridges the gaps among various stakeholders for achieving sustainable agriculture. Key points Growing demand and resource limitations pose a critical challenge for agriculture, necessitating innovative and sustainable approaches. The paper identifies 100 priority questions for the future of agriculture, indicating current and future research directions. Sustainable agriculture depends on interdisciplinary and multidisciplinary research that harmonises basic and applied sciences and fosters collaboration among different stakeholders