Carbon nanosol promotes plant growth and broad-spectrum resistance.

Carbon nanosol (CNS) is a carbon-based nanomaterial capable of promoting plant growth while the underlying mechanism involved in this process remains unknown. This study demonstrates that CNS promotes rice seedling growth under restricted concentrations. Macroelement transporter mutants were investigated to further investigate the CNS-mediated promotion of rice seedling growth. The genetic and physiological findings revealed that nitrate transporter 1.1B (NRT1.1B) and ammonium transporter 1 (AMT1) mutants inhibited the CNS-induced growth development of rice seedlings, whereas potassium transporter (AKT1) and phosphate transporter 8 (PT8) did not exhibit any inhibitory effects. Further investigations demonstrated the inhibition of CNS-mediated growth promotion via glutamine synthetase 1;1 (gs1;1) mutants. Additionally, the administration of CNS resulted in enhanced accumulation of chlorophyll in plants, and the promotion of CNS-induced growth was inhibited by yellow-green leaf 8 (YGL8) mutants and the chlorophyll biosynthetic gene divinyl reductase (DVR) mutants. According to these findings, the CNS promotes plant growth by stimulating chlorophyll biosynthesis. Furthermore, the presence of CNS enhanced the ability of rice to withstand blast, sheath blight (ShB), and bacterial blight. The nrt1.1b, amt1, dvr, and ygl8 mutants did not exhibit a broad spectrum effect. The positive regulation of broad-spectrum resistance in rice by GS1;1 suggests the requirement of N assimilation for CNS-mediated broad-spectrum resistance. In addition, an in vitro assay demonstrated that CNS inhibits the growth of pathogens responsible for blast, ShB, and bacterial blight, namely Magnaporthe oryzae, Rhizoctonia solani AG1-IA, and Xanthomonas oryzae pv. Oryzae, respectively. CNS application may also induce broad-spectrum resistance against bacterial and fungal pathogens, indicating that in addition to its antifungal and antibacterial properties, CNS application may also stimulate N assimilation. Collectively, the results indicate that CNS may be a potential nano-therapeutic agent for improved plant growth promotion while also providing broad-spectrum resistance.

Policies enacted during COVID-19 came with unintended health benefits: why go back?

OBJECTIVES: To explore the impact of COVID-19 on the implementation of bundled interventions to improve the engagement and retention of Black women in HIV care. METHODS: Pre-implementation interviews conducted between January and April 202 L with 12 demonstration sites implementing bundled interventions for Black women with HIV. Directed content analysis was employed to examine the site interview transcripts. RESULTS: The pandemic intensified barriers to care and harmful social conditions. However, COVID-19 also forced pivots in health care and social service delivery and some of these changes benefited Black women living with HIV. CONCLUSIONS: The continuation of policies that support the material needs of Black women with HIV and ease access to care is critical. Racial capitalism impedes the enactment of these policies and thus threatens public health.

Leveling the Research Playing Field: Decolonizing Global Health Research Through Web-Based Platforms.

Global health research has traditionally been rooted in colonialism, with some investigators in high-income countries leading and managing research and investigators in low- and middle-income countries serving as implementing partners. The Community Health Worker-Led Intervention for Vaccine Information and Confidence (CIVIC) Project, conducted in India and led jointly by India- and US-based investigators, leveraged web-based platforms to facilitate a more horizontal, inclusive, and balanced approach to partnerships between researchers and the community. Using web-based platforms to conduct research was found to be an effective strategy to engage researchers at all levels and combat systemic barriers associated with in-person activities such as power, economic, social, and gender dynamics. Connecting online for research meetings created a more equitable environment for community members to engage meaningfully with research. Further, by conducting research through web-based platforms, we found that we were able to strengthen the diversity of participants, provide a space for more marginalized groups to speak up, and minimize logistical barriers to attendance. Harnessing web-based approaches in research provides a pathway toward opportunities to promote equity and contribute to the decolonization of global health spaces.

Design, Synthesis and Biological Evaluation of Multi-Target Anti-Cancer Agent PYR26.

This study investigates the synthesis of a new compound, PYR26, and the multi-target mechanism of PYR26 inhibiting the proliferation of HepG2 human hepatocellular carcinoma cells. PYR26 significantly inhibits the growth of HepG2 cells (p < 0.0001) and this inhibition has a concentration effect. There was no significant change in ROS release from HepG2 cells after PYR26 treatment. The mRNA expressions of CDK4, c-Met and Bak genes in HepG2 cells were significantly inhibited (p < 0.05), while mRNA expression of pro-apoptotic factors such as caspase-3 and Cyt c was significantly increased (p < 0.01). The expression of PI3K, CDK4 and pERK proteins decreased. The expression level of caspase-3 protein was increased. PI3K is a kind of intracellular phosphatidylinositol kinase. PI3K signaling pathway is involved in signal transduction of a variety of growth factors, cytokines and extracellular matrix and plays an important role in preventing cell apoptosis, promoting cell survival and influencing cell glucose metabolism. CDK4 is a catalytic subunit of the protein kinase complex and is important for G1 phase progression of the cell cycle. PERK refers to phosphorylated activated ERK, which is translocated from cytoplasm to the nucleus after activation, and then participates in various biological reactions such as cell proliferation and differentiation, cell morphology maintenance, cytoskeleton construction, cell apoptosis and cell canceration. Compared with the model group and the positive control group, the tumor volume of the nude mice in the low-concentration PYR26 group, the medium-concentration group and the high-concentration group was smaller, and the organ volume was smaller than that in the model group and the positive control group. The tumor inhibition rates of low-concentration group PYR26, medium-concentration group and high-concentration group reached 50.46%, 80.66% and 74.59%, respectively. The results showed that PYR26 inhibited the proliferation of HepG2 cells and induced apoptosis of HepG2 cells by down-regulating c-Met, CDK4 and Bak, up-regulating the mRNA expression of caspase-3 and Cyt c genes, down-regulating PI3K, pERK and CDK4 proteins and up-regulating the protein level of caspase-3. In a certain range, with the increase in PYR26 concentration, the tumor growth was slower and the tumor volume was smaller. Preliminary results showed that PYR26 also had an inhibitory effect on the tumors of Hepa1-6 tumor-bearing mice. These results suggest that PYR26 has an inhibitory effect on the growth of liver cancer cells, therefore it has potential to be developed into a new anti-liver cancer drug.

How to become a successful scientist: the 2022 CSMB Arthur Wynne Gold Medal Lecture.

There are many pathways to success. Mine followed a traditional one to an academic faculty position, but this pathway is not the one most life sciences PhD graduates will follow today. We have all had time during the COVID-19 pandemic to reflect on our personal pathway-where we are and where we are going. In this reflection, I outline five steps on my pathway to success: Train with the best. Discover something. Mentor others. Go beyond. Promote science. I will provide examples from my personal journey that I hope will resonate with the reader as they create their pathway to success.

Treatments for elderly cancer patients and reforms to social security systems in Japan.

In Japan, the population aged 65 years and above accounts for 29% of the total population. Furthermore, the number of cancer patients among the elderly is increasing. Geriatric oncology is a discipline that deals with appropriate care for elderly cancer patients based on their characteristics. The International Society of Geriatric Oncology considers education, treatment, research, and partnership building areas of significance and priority for policy goals. In Japan, the Third Term of the Basic Plan to Promote Cancer Control is an initiative to improve the infrastructure and health services involved in cancer care. Content related to "cancer in the elderly" was added to establish guidelines for treating cancer in the elderly. Thus far, "Clinical Practice Guidelines of Cancer Drug Therapies for the Elderly" have been published. With the increasing age of the population, social security expenditures will increase substantially after the fiscal year 2022. Reforms to social security systems, such as pensions, medical care, and nursing care, are underway. It is important to enhance cooperation between oncology and geriatrics and to support cooperative systems among families and medical professionals to promote geriatric oncology. Since the working-age population and the total population have begun to decline, Japan is facing many challenges. As a leader of a super-aging society, Japan has the potential to share its experience on a global scale and address potential long-term outcomes.

Phenotypic responses and potential genetic mechanism of lepidopteran insects under exposure to graphene oxide.

Clarification of the interactions between engineered nanomaterials and multiple generations of insects is crucial to understanding the impact of nanotechnology on the environment and agriculture, particularly in toxicity management, pest management and genetic engineering. To date, there has been very limited information about nanoparticle-insect interactions at the genetic and proteomic levels. Here, we examined the phenotypic responses and potential mechanism of a lepidopteran insect Asian corn borer (ACB) to graphene oxide (GO). It was demonstrated that GO could significantly promote the growth of ACB. The transcriptomic and proteomic results consistently verified that GO might activate trypsin-like serine protease, glutathione S-transferase, heat shock protein and glycosyltransferase to further influence the development of ACB. RNA interference results indicated that the trypsin gene was one of the critical genes to accelerate the growth of ACB fed with GO diet. Moreover, physiological analysis showed potential alterations of the expression levels of genes and proteins, and more cholesterol (CE), triacylglycerides (TG) and lipids were accumulated in GO-exposed ACB. Our findings may help to reveal the phenotypic, physiological and genetic responses of insects under exposure to nanomaterials and to assess the environmental risks of other nanomaterials.

Beneficial bacteria activate nutrients and promote wheat growth under conditions of reduced fertilizer application.

BACKGROUND: Excessive application of chemical fertilizer has exerted a great threat to soil quality and the environment. The inoculation of plants with plant-growth-promoting rhizobacteria (PGPR) has emerged as a great prospect for ecosystem recovery. The aim of this work to isolate PGPRs and highlights the effect of bacterial inoculants on available N/P/K content in soil and on the growth of wheat under conditions of reduced fertilizer application. RESULTS: Thirty-nine PGPRs were isolated and tested for their growth-promoting potential. Thirteen isolates had nitrogen fixation ability, of which N9 (Azotobacter chroococcum) had the highest acetylene reduction activity of 156.26 nmol/gh. Eleven isolates had efficient phosphate solubilizing ability, of which P5 (Klebsiella variicola) released the most available phosphorus in liquid medium (231.68 mg/L). Fifteen isolates had efficient potassium solubilizing ability, of which K13 (Rhizobium larrymoorei) released the most available potassium in liquid medium (224.66 mg/L). In culture medium supplemented with tryptophan, P9 (Klebsiella pneumoniae) produced the greatest amount of IAA. Inoculation with the bacterial combination K14 + 176 + P9 + N8 + P5 increased the alkali-hydrolysed nitrogen, available phosphorus and available potassium in the soil by 49.46, 99.51 and 19.38%, respectively, and enhanced the N, P, and K content of wheat by 97.7, 96.4 and 42.1%, respectively. Moreover, reducing fertilizer application by 25% did not decrease the available nitrogen, phosphorus, and potassium in the soil and N/P/K content, plant height, and dry weight of wheat. CONCLUSIONS: The bacterial combination K14 + 176 + P9 + N8 + P5 is superior candidates for biofertilizers that may reduce chemical fertilizer application without influencing the normal growth of wheat.

Indoor nanoscale particulate matter-induced coagulation abnormality based on a human 3D microvascular model on a microfluidic chip.

BACKGROUND: A growing body of evidence shows that indoor concentrations of airborne particles are often higher than is typically encountered outdoors. Since exposure to indoor PM2.5 is thought to be associated with cardiovascular disease, the health impacts of indoor air pollution need to be explored. Based on animal models, ambient particulate matter has been proved to promote coagulation which is very likely involved in the pathogenic development of cardiovascular disease. However, animal models are insufficient to predict what will happen with any certainty in humans. For this reason, the precise pathogenic mechanisms behind the development of cardiovascular disease in humans have not yet been determined. RESULTS: We generated a 3D functional human microvascular network in a microfluidic device. This model enables human vascular endothelial cells to form tissue-like microvessels that behave very similarly to human blood vessels. The perfusable microvasculature allows the delivery of particles introduced into these generated human-like microvessels to follow the fluid flow. This exposure path effectively simulates the dynamic movement of airborne nanoscale particles (ANPs) within human vessels. In this study, we first identified the existence of ANPs in indoor air pollution. We then showed that ANPs could activate endothelial cells via ROS induced inflammation, and further resulted in abnormal expression of the coagulation factors (TF, TM and t-PA) involved in coagulation cascades. In addition, we found that a protein could cover ANPs, and this biointeraction could interfere with heparan sulfate (HS). Human organotypic 3D microvessel models provide a bridge for how research outcomes can translate to humans. CONCLUSIONS: The 3D human microvessel model was used to determine the physiological responses of human vessels to ANP stimulation. Based on the obtained data, we concluded that ANPs not only disrupts normal coagulation functions, but also act directly on anticoagulant factors in human vessels. These experimental observations provide a potential biological explanation for the epidemiologically established link between ANPs and coagulation abnormality. This organ-on-chip model may provide a bridge from in vitro results to human responses.

Research progresses in roles of LncRNA and its relationships with breast cancer.

Some progresses have been made in research of long non-coding RNA (hereunder referred to as LncRNA) related to breast cancer. Lots of data about LncRNA transcription concerning breast cancer have been obtained from large-scale omics research (e.g. transcriptomes and chips). Some LncRNAs would become indices for detecting breast cancer and judging its development and prognosis. LncRNAs may affect genesis and development of breast cancer in multiple ways. Perhaps they could develop into potential targets for treating breast cancer if they are carcinogenic. Like those from other studies of breast cancer, many data gained from omics research remain to be validated by much experimental work. For instance, it is still necessary to demonstrate reliability of LncRNAs as indices for diagnosing breast cancer and judging its prognosis (particularly for various subtypes of breast cancer), effectiveness and feasibility of these genes for treating breast cancer as targets. In this paper, recent years' literatures about LncRNAs which are related to breast cancer are summarized and sorted out to review the research progresses in relationships between LncRNAs and breast cancer.

The effects of fulvic acid on microbial denitrification: promotion of NADH generation, electron transfer, and consumption.

The heterotrophic denitrification requires the participation of electrons which are derived from direct electron donor (usually nicotinamide adenine dinucleotide (NADH)), and the electrons are transferred via electron transport system in denitrifiers and then consumed by denitrifying enzymes. Despite the reported electron transfer ability of humic substances (HS), the influences of fulvic acid (FA), an ubiquitous major component of HS, on promoting NADH generation, electron transfer, and consumption in denitrification process have never been reported. The presence of FA, compared with the control, was found not only significantly improved the total nitrogen (TN) removal efficiency (99.9 % versus 74.8 %) but remarkably reduced the nitrite accumulation (0.2 against 43.8 mg/L) and N2O emission (0.003 against 0.240 mg nitrogen/mg TN removed). The mechanisms study showed that FA increased the metabolism of carbon source via glycolysis and tricarboxylic acid (TCA) cycle pathways to produce more available NADH. FA also facilitated the electron transfer activities from NADH to denitrifying enzymes via complex I and complex III in electron transport system, which improved the reduction of nitrate and accelerated the transformations of nitrite and N2O, and lower nitrite and N2O accumulations were therefore observed. In addition, the consumption of electrons in denitrification was enhanced due to FA stimulating the synthesis and the catalytic activity of key denitrifying enzymes, especially nitrite reductase and N2O reductase. It will provide an important new insight into the potential effect of FA on microbial denitrification metabolism process and even nitrogen cycle in nature niches.

Low concentration of formononetin stimulates the proliferation of nasopharyngeal carcinoma cell line CNE2 by upregulating bcl-2 and p-ERK1/2 expression.

Context Formononetin is a typical phytoestrogen, which is a bioactive component found in red clover plants. Previous studies have shown that formononetin inhibits the proliferation of several types of cancer cells, including prostate cancer and osteosarcoma. However, how formononetin affects the proliferation of CNE2 is not clear. Objective The objective of this study is to investigate the effects of formononetin on nasopharyngeal carcinoma cells in vitro, along with the underlying mechanism. Materials and methods CNE2 cells were incubated with various concentrations of formononetin (0, 0.1, 0.2, 0.3 and 1 µM) for 48 h. Cell proliferation was measured by [3-(4,5-dimethylthiazol-2-yl)]-2,5-diphenyltetrazolium bromide (MTT) assay, while the rate of apoptosis was measured by flow cytometry. Bcl-2 and bax mRNA expression levels were determined by real time polymerase chain reaction (RT-PCR), while p-ERK1/2 and bcl-2 protein expression levels were quantified by Western blotting. Results Formononetin promoted the proliferation of CNE2 cells at low concentrations (0, 0.05, 0.1, 0.2, 0.5, 1, 2 and 5 µM), OD values increased from 0.27 ± 0.01 to 0.30 ± 0.01, 0.30 ± 0.01,0.36 ± 0.01, 0.35 ± 0.01, 0.34 ± 0.01, 0.34 ± 0.01 and 0.32 ± 0.01, respectively. The percentage of late apoptosis declined from 6.77% ± 0.73% (0 µM group) to 6.2% ± 0.4% (0.1 µM group), 3.83% ± 0.71% (0.3 µM group) and 5.1% ± 0.52% (1M group). The mRNA levels of bax and bcl-2 were down- and upregulated, respectively, by formononetin. Bcl-2 and p-ERK1/2 protein levels were also upregulated. Conclusions Formononetin stimulates CNE2 cell proliferation and has an inhibitory effect on CNE2 cells apoptosis, which is mediated by the activation of the ERK1/2 signaling pathways.

Promoting the psychological well-being of Italian youth: a pilot study of a high school mental health program.

School is potentially one of the most important and effective agencies for the promotion of mental health. For this reason, in Italy, the Mental Health Department of The National Health Institute has developed an intervention based on a structured handbook. The aim of this intervention is to promote the psychological well-being of the students. In this study, we have evaluated the efficacy of this intervention through a quasi-experimental study design of four classes (two were control) of secondary education, including 79 students aged 14 to 16 years (15.35 ± 0.68). Assessments were administered before and after the intervention. The results showed improvement in perceived self-efficacy (p ≤ .001), emotional coping (p = .003), and overall well-being (p < .05). The students' perception of usefulness was also increased (p < .05); the intervention successfully promoted the idea of life as a continuous process of learning, in change and growth (p < .05). The intervention was effective despite some limitations described by authors related to a lack of involvement of relatives and the team teachers, as well as the absence of homework; however, the adoption of a program promoting life skills, problem solving, and goal definition training is recommended with the use of a revised handbook.

"I'm not sure if it works": School nurses' experiences of sleep-promoting work in Sweden.

OBJECTIVES: Lack of sleep is a common problem in children and adolescents of school age (students), and it is a health aspect that affects the ability to assimilate into the school's education and thereby falls within the school nurses promoting work. This study aimed to describe school nurses' experiences of sleep-promoting work. METHOD: Data were collected by n = 61 school nurses' written narratives of their sleep-promotion work. Data were analyzed using qualitative content analysis. RESULTS: The results describe school nurses' experiences of sleep-promoting work in three main categories: (1) Informing and providing knowledge is the primary task. School nurses do it systematically, through dialogs with an individual student, with several students simultaneously, or with parents. (2) Benefits take place when the needs of the student guide the work. Through curiosity about the personal story, the keys to sleep-promoting work can be found, appropriate strategies can be given, and the student can be guided further if needed. (3) Barriers challenge the outcome of the work. The school nurses experience these barriers in the form of unmotivated students, unsupportive parents, and lack of prerequisites, which make the school nurses unsure of their performance. CONCLUSIONS: School nurses experience a significant benefit in their sleep-promoting work when the needs of the student guide the sleep-promoting information, strategies, and follow-ups. To avoid feeling insecure in sleep-promoting work, school nurses need updates on the state of knowledge and evidence-based tools. Further research on sleep-promoting work at school is necessary.

Biodegradation of phenol-contaminated soil and plant growth promotion by Myroides xuanwuensis H13.

Physicochemical methods for remediating phenol-contaminated soils are costly and inefficient, making biodegradation an environmentally friendly alternative approach. This study aims to screen for potential phenol-degrading bacteria and to verify the removal capacities of a selected strain in a bioaugmentation experiment at the greenhouse level using Brassica chinensis L. (Chinese cabbage) as the model plant and phenol-contaminated soil. In parallel, pot experiments were conducted using a collaborative approach based on this model system. We found that Myroides xuanwuensis strain H13 showed a high degradation capability, with a 97.67% efficiency in degrading 100 mg/L phenol. Under shaking flask conditions, H13 facilitated the solubilization of tricalcium phosphate and potassium feldspar powder. Pot experiments suggested a phenol removal percentage of 89.22% and enhanced availability of soil phosphorus and potassium for plants with H13 inoculation. In this case, the abundance of soil microbes and the activity of soil enzymes significantly increased as well. Furthermore, both photosynthesis and the antioxidant system in Chinese cabbage were enhanced following H13 inoculation, resulting in its increased yield and quality. Partial least squares path modeling revealed that H13 can primarily affect plant root growth, with a secondary impact on photosynthesis. These findings highlight the potential of biodegradation from phenol-degrading bacteria as a promising strategy for efficient phenol removal from soil while promoting plant growth and health.IMPORTANCEThis study is significant for environmental remediation and agriculture by its exploration of a more environmentally friendly and cost-effective bio-strategy in treating phenol-contaminated soil. These findings have essential implications for environmental remediation efforts and sustainable agriculture. By utilizing the biodegradation capabilities of Myroides xuanwuensis strain H13, it is possible to remove phenol contaminants from the soil efficiently, reducing their negative effects. Furthermore, the enhanced growth and health of the Chinese cabbage plants indicate the potential of this approach to promote sustainable crop production.

Silica nanoparticles containing nano-silver and chlorhexidine respond to pH to suppress biofilm acids and modulate biofilms toward a non-cariogenic composition.

OBJECTIVES: Dental caries is caused by acids from biofilms. pH-sensitive nanoparticle carriers could achieve improved targeted effectiveness. The objectives of this study were to develop novel mesoporous silica nanoparticles carrying nanosilver and chlorhexidine (nMS-nAg-Chx), and investigate the inhibition of biofilms as well as the modulation of biofilm to suppress acidogenic and promote benign species for the first time. METHODS: nMS-nAg was synthesized via a modified sol-gel method. Carboxylate group functionalized nMS-nAg (COOH-nMS-nAg) was prepared and Chx was added via electrostatic interaction. Minimal inhibitory concentration (MIC), inhibition zone, and growth curves were evaluated. Streptococcus mutans (S. mutans), Streptococcus gordonii (S. gordonii), and Streptococcus sanguinis (S. sanguinis) formed multispecies biofilms. Metabolic activity, biofilm lactic acid, exopolysaccharides (EPS), and TaqMan real-time polymerase chain reaction (RT-PCR) were tested. Biofilm structures and biomass were observed by scanning electron microscopy (SEM) and live/dead bacteria staining. RESULTS: nMS-nAg-Chx possessed pH-responsive properties, where Chx release increased at lower pH. nMS-nAg-Chx showed good biocompatibility. nMS-nAg-Chx exhibited a strong antibacterial function, reducing biofilm metabolic activity and lactic acid as compared to control (p < 0.05, n = 6). Moreso, biofilm biomass was dramatically suppressed in nMS-nAg-Chx groups. In control group, there was an increasing trend of S. mutans proportion in the multispecies biofilm, with S. mutans reaching 89.1% at 72 h. In sharp contrast, in nMS-nAg-Chx group of 25 µg/mL, the ratio of S. mutans dropped to 43.7% and the proportion of S. gordonii and S. sanguinis increased from 19.8% and 10.9 to 69.8% and 56.3%, correspondingly. CONCLUSION: pH-sensitive nMS-nAg-Chx had potent antibacterial effects and modulated biofilm toward a non-cariogenic tendency, decreasing the cariogenic species nearly halved and increasing the benign species approximately twofold. nMS-nAg-Chx is promising for applications in mouth rinse and endodontic irrigants, and as fillers in resins to prevent caries.

The photocatalytic wastewater hydrogen production process with superior performance to the overall water splitting.

The utilization of a cost-free sacrificial agent is a novel approach to significantly enhance the efficiency of photocatalytic hydrogen (H2) production by water splitting. Wastewater contains various organic pollutants, which have the potential to be used as hole sacrificial agents to promote H2 production. Our studies on different pollutants reveals that not all pollutants can effectively promote H2 production. However, when using the same pollutants, not all photocatalysts achieved a higher H2 evolution rate than pure water. Only when the primary oxidizing active species of the photocatalyst are •OH radicals, which are generated by photogenerated holes, and when the pollutants are easily attacked and degraded by •OH radicals, can the production of H2 be effectively promoted. It is noteworthy that the porous brookite TiO2 photocatalyst exhibits a significantly higher H2 evolution rate in Reactive Red X-3B and Congo Red, reaching as high as 26.46 mmol⋅g-1⋅h-1 and 32.85 mmol⋅g-1 ⋅h-1, respectively, which is 2-3 times greater than that observed in pure water and is 10 times greater than most reported studies. The great significance of this work lies in the potential for efficient H2 production through the utilization of wastewater.

A novel strategy of artificially regulating plant rhizosphere microbial community to promote plant tolerance to cold stress.

Artificial regulation of plant rhizosphere microbial communities through the synthesis of microbial communities is one of the effective ways to improve plant stress resistance. However, the process of synthesizing stress resistant microbial communities with excellent performance is complex, time-consuming, and costly. To address this issue, we proposed a novel strategy for preparing functional microbial communities. We isolated a cultivable cold tolerant bacterial community (PRCBC) from the rhizosphere of peas, and studied its effectiveness in assisting rice to resist stress. The results indicate that PRCBC can not only improve the ability of rice to resist cold stress, but also promote the increase of rice yield after cold stress relieved. This is partly because PRCBC increases the nitrogen content in the rhizosphere soil, and promotes rice's absorption of nitrogen elements, thereby promoting rice growth and enhancing its ability to resist osmotic stress. More importantly, the application of PRCBC drives the succession of rice rhizosphere microbial communities, and promotes the succession of rice rhizosphere microbial communities towards stress resistance. Surprisingly, PRCBC drives the succession of rice rhizosphere microbial communities towards a composition similar to PRCBC. This provides a feasible novel method for artificially and directionally driving microbial succession. In summary, we not only proposed a novel and efficient strategy for preparing stress resistant microbial communities to promote plant stress resistance, but also unexpectedly discovered a possible directionally driving method for soil microbial community succession.

Biocompatibility and osteogenic potential of choline phosphate chitosan-coated biodegradable Zn1Mg.

Zinc alloys have demonstrated considerable potentials as implant materials for biodegradable vascular and orthopedic applications. However, the high initial release of Zn2+ can trigger intense immune responses that impede tissue healing. To address this challenge and enhance the osteogenic capacity of zinc alloys, the surface of Zn1Mg was subjected to CO2 plasma modification (Zn1Mg-PP) followed by grafting with choline phosphate chitosan (Zn1Mg-PP-PCCs). This study aims to investigate the in vitro and in vivo biocompatibility of the surface-modified Zn1Mg. The effect of the surface modification on the inflammatory response and osteogenic repair process was investigated. Compared with unmodified Zn1Mg, the degradation rate of Zn1Mg-PP-PCCs was significantly decreased, avoiding the cytotoxicity triggered by the release of large amounts of Zn2+. Moreover, PCCs significantly enhanced the cell-material adhesion, promoted the proliferation of osteoblasts (MC3T3-E1) and upregulated the expression of key osteogenic factors in vitro. Notably, the in vivo experiments revealed that the surface modification of Zn1Mg suppressed inhibited the expression of inflammatory cytokines, promoting the secretion of anti-inflammatory factors, thereby reducing inflammation and promoting bone tissue repair. Furthermore, histological analysis of tissue sections exhibited strong integration between the material and the bone, along with well-defined new bone formation and reduced osteoclast aggregation on the surface. This was attributed to the improved immune microenvironment by PCCs, which promoted osteogenic differentiation of osteoblasts. These findings highlight that the preparation of PCCs coatings on zinc alloy surfaces effectively inhibited ion release and modulated the immune environment to promote bone tissue repair. STATEMENT OF SIGNIFICANCE: Surface modification of biodegradable Zn alloys facilitates the suppression of intense immune responses caused by excessive ion release concentrations from implants. We modified the surface of Zn1Mg with choline phosphate chitosan (PCCs) and investigated the effects of surface modification on the inflammatory response and osteogenic repair process. In vitro results showed that the PCCs coating effectively reduced the degradation rate of Zn1Mg to avoid cytotoxicity caused by high Zn2+ concentration, favoring the proliferation of osteoblasts. In addition, in vivo results indicated that Zn1Mg-PP-PCCs attenuated inflammation to promote bone repair by modulating the release of inflammation-related factors. The surface-modified Zn1Mg implants demonstrated strong osseointegration, indicating that the PCCs coating effectively modulated the immune microenvironment and promoted bone healing.