Plasmodium yoelii Infection Enhances the Expansion of Myeloid-Derived Suppressor Cells via JAK/STAT3 Pathway.

Myeloid-derived suppressor cells (MDSCs), the negative immune regulators, have been demonstrated to be involved in immune responses to a variety of pathological conditions, such as tumors, chronic inflammation, and infectious diseases. However, the roles and mechanisms underlying the expansion of MDSCs in malaria remain unclear. In this study, the phenotypic and functional characteristics of splenic MDSCs during Plasmodium yoelii NSM infection are described. Furthermore, we provide compelling evidence that the sera from P. yoelii-infected C57BL/6 mice containing excess IL-6 and granulocyte-macrophage colony-stimulating factor promote the accumulation of MDSCs by inducing Bcl2 expression. Serum-induced MDSCs exert more potent suppressive effects on T cell responses than control MDSCs within both in vivo P. yoelii infection and in vitro serum-treated bone marrow cells experiments. Serum treatment increases the MDSC inhibitory effect, which is dependent on Arg1 expression. Moreover, mechanistic studies reveal that the serum effects are mediated by JAK/STAT3 signaling. By inhibiting STAT3 phosphorylation with the JAK inhibitor JSI-124, effects of serum on MDSCs are almost eliminated. In vivo depletion of MDSCs with anti-Gr-1 or 5-fluorouracil significantly reduces the parasitemia and promotes Th1 immune response in P. yoelii-infected C57BL/6 mice by upregulating IFN-γ expression. In summary, this study indicates that P. yoelii infection facilitates the accumulation and function of MDSCs by upregulating the expression of Bcl2 and Arg1 via JAK/STAT3 signaling pathway in vivo and in vitro. Manipulating the JAK/STAT3 signaling pathway or depleting MDSCs could be promising therapeutic interventions to treat malaria.

Comparision of nitrogen removal characteristic and microbial community in freshwater and marine recirculating aquaculture systems.

Recirculating aquaculture system (RAS) has a good prospect in aquaculture, but its nitrogen removal characteristics and microbial community changes in freshwater and marine water remain unclear. In this study, six RAS were designed and divided into freshwater group and marine water group with salinity of 0‰ and 32‰, respectively, and operated for 54 days to test changes in nitrogen (NH4+-N, NO2--N, NO3--N), extracellular polymeric substances and microbial communities. The results showed that ammonia nitrogen was rapidly reduced and almost converted to nitrate nitrogen in the freshwater RAS but to nitrite nitrogen in marine RAS. Compared with freshwater RAS, marine RAS had lower tightly bound extracellular polymeric substances and worse stability and settleability condition. 16S rRNA amplicon sequencing reflected significantly lower bacterial diversity and richness in marine RAS. Microbial community structure at phylum level showed lower relative abundance of Proteobacteria, Actinobacteria, Firmicutes, Nitrospirae, but higher abundance of Bacteroidetes under a salinity of 32‰. High salinity decreased the abundance of funtional genera (Nitrosospira, Nitrospira, Pseudomonas, Rhodococcus, Comamonas, Acidovorax, f_Comamonadaceae), which may account for nitrite accumulation and low nitrogen removal capacity in marine RAS. These findings could provide theoretical and practical basis for improving the start-up speed of high-salinity nitrification biofilm.

Psychological stress and associated factors in caring for patients with delirium among intensive care unit nurses: A cross-sectional study.

BACKGROUND: Caring for patients with delirium is challenging and overwhelming for intensive care unit (ICU) nurses. Investigating the psychological impact of delirium care on ICU nurses is crucial to maintaining their psychological health and improving the quality of care. OBJECTIVE: The objective of this study was to investigate the psychological stress of ICU nurses in caring for patients with delirium and potential factors. METHODS: A total of 355 nurses from three tertiary care hospitals in Hunan Province, China, participated in this cross-sectional survey. Data were collected using the demographic sheet, Impact of Event Scale-Revised, Connor-Davidson Resilience Scale, and Occupational Coping Self-Efficacy Scale for Nurses. Descriptive and multiple linear regression analyses were used to examine the factors associated with psychological stress. RESULTS: ICU nurses suffered moderate psychological stress related to delirium care. The recent time to care for patients with delirium (P < 0.001), familiarity with delirium-related knowledge (P = 0.002), satisfaction with delirium-related support (P = 0.046), psychological resilience (P < 0.001), and occupational coping self-efficacy (P < 0.001) were significant contributors to psychological stress. CONCLUSION: Nurse managers and researchers need to focus on the psychological well-being of ICU nurses in caring for patients with delirium, especially those who are currently caring for patients with delirium, and provide tailored support, increase their knowledge of delirium, and also boost psychological resilience and coping skills.

Investigation of the formation mechanism and ß-carotene encapsulation stability of emulsion gels based on egg yolk granules and sodium alginate.

The formation mechanism of heat-induced egg yolk granules (EYGs)/sodium alginate (SA) emulsion gel was studied under pH 6.2 and 7.5. Particle size, water holding capacity, LF NMR, and protein solubility revealed that pH 7.5 increased the surface charge of EYGs and enhanced non-covalent interaction with SA, and hydrogen bonding dominated of the gel formation process. Microscopy and rheological analysis indicated that samples with 0.75% SA had the smallest particle size and highest G', with chain-like oil droplets. Excess SA (1%) led to depletion flocculation due to SA structural rearrangements around oil droplets caused by the increase in negatively charged, causing uneven network structure. The in vitro release property and storage stability of ß-carotene loaded in the EYGs/SA emulsion gel showed that SA increased storage stability and decreased bioaccessibility of ß-carotene with delayed digestion rate. These results provide a theoretical basis for the nutrient delivery system in gel foods.

Ginsenoside Rg1 interferes with the progression of diabetic osteoporosis by promoting type H angiogenesis modulating vasculogenic and osteogenic coupling.

Ginsenoside Rg1 (Rg1) has been demonstrated to have antidiabetic and antiosteoporotic activities. The aim of this study was to investigate the protective effect of Rg1 against diabetic osteoporosis and the underlying mechanism. In vitro, we found that Rg1 increased the number of osteoprogenitors and alleviated high glucose (HG) induced apoptosis of osteoprogenitors by MTT assays and flow cytometry. qRT‒PCR and western blot analysis suggested that Rg1 can also promote the secretion of vascular endothelial growth factor (VEGF) by osteoprogenitors and promote the coupling of osteogenesis and angiogenesis. Rg1 can also promote the proliferation of human umbilical vein endothelial cells (HUVECs) cultured in high glucose, enhance the angiogenic ability of endothelial cells, and activate the Notch pathway to promote endothelial cells to secrete the osteogenesis-related factor Noggin to regulate osteogenesis, providing further feedback coupling of angiogenesis and osteogenesis. Therefore, we speculated that Rg1 may have similar effects on type H vessels. We used the Goto-Kakizaki (GK) rat model to perform immunofluorescence staining analysis on two markers of type H vessels, Endomucin (Emcn) and CD31, and the osteoblast-specific transcription factor Osterix, and found that Rg1 stimulates type H angiogenesis and bone formation. In vivo experiments also demonstrated that Rg1 promotes VEGF secretion, activates the Noggin/Notch pathway, increases the level of coupling between type H vessels and osteogenesis, and improves the bone structure of GK rats. All of these data reveal that Rg1 is a promising candidate drug for treating diabetic osteoporosis as a potentially bioactive molecule that promotes angiogenesis and osteointegration coupling.

The process of contemporary gay identity development in China: The influence of internet use.

Background: Adolescence and emerging adulthood are critical periods for an individual's sexual identity development. The internet has become a primary avenue for gay identity exploration. The purpose of this study was to examine the role of the internet in Chinese young gay male's sexual identity development. Methods: Qualitative interviews were conducted with 37 gay males aged 16 to 29. Data were analyzed using grounded theory methods. Results: Three categories of identity development in relation to use of the internet were identified: (1) Gay identity confirming, which includes verifying same-sex attraction and connecting the attraction feeling to gay identity through consumption of pornography, Tanbi (boy's love) materials, and searching for information online. (2) Gay identity practicing, includes interacting with the gay community to gain understandings of gay subcultures and make close gay friends, engaging in same-sex sexual and romantic relationship development through online group and interpersonal interactions. The internet practice impact on an individual's cognition and behavior by presenting same-sex sexual contact is normal and common, facilitating longing for a romantic relationship, and facilitating relationship development; and (3) Gay identity coping, includes increasing self-acceptance of gay identity, gaining a sense of belonging in the gay community, increasing autonomy in sexual and romantic relationship development, and growing consideration of coming out to parents. Young gay males' coping efficacy was gained through the lessons learned from identity practice. Conclusion: The findings indicate that an individual's internet practice facilitates gay identity confirmation, enriches identity practice, and promotes the transition from self-identification to identity disclosure and integration. Internet practice also threatens to young gay males' sexual risk behavior, emotional hurts from failed romantic relationships. Interventions including sexual identity education and healthy internet use strategies need to be developed tailored to the developmental characteristics.

Prevalence and genetic diversity of porcine circovirus type 2 in northern Guangdong Province during 2016-2021.

The emergence and widespread of porcine circovirus-associated diseases (PCVADs), mainly caused by porcine circovirus type 2 (PCV2), threatens the Chinese swine industry. In this study, to investigate the recent prevalence of PCV2 in northern Guangdong Province of China, 573 tissue samples from 132 pig farms were collected during 2016-2021 and analyzed via PCR. Overall, 51.38% (297/573, 95%CI 47.74-55.92) samples were tested PCV2 positive. The detection rate of PCV2 was significantly lower in samples collected before 2016-2018 than after the outbreak of African Swine Fever (2019-2021), being 59.85% (158/264, 95%CI 53.94-65.76) and 41.47% (141/340, 95%CI 36.43-46.71), respectively. On the other end, the genetic characteristics of 26 PCV2 strains were further analyzed. These PCV2 strains belonged to three genotypes, including PCV2a, PCV2b, and PCV2d. Specifically, the predominant genotype prevalent during two periods (2016-2018 and 2019-2021) wasPCV2b (81.82%, 9/11) and PCV2d (80.0%, 12/15), respectively. The results above illustrated the high prevalence and the genetic evolution feature of PCV2 in Guangdong Province in recent years.

Characteristics of a novel heterotrophic nitrification-aerobic denitrification yeast, Barnettozyma californica K1.

Yeast strain K1, isolated from surface sediment, was identified as Barnettozyma californica. The strain showed efficient heterotrophic nitrification and aerobic denitrification (HN-AD) at initial ammonium, nitrite and nitrate concentrations of 14-140 mg/L. Additionally, the optimum carbon source for its growth and nitrogen removal activity was sucrose, followed by glucose, acetate and citrate. The maximum removal efficiencies of ammonium, nitrite and nitrate were 99.11%, 99.13% and 98.84% under 48 h of culture with sucrose at 140 mg/L nitrogen and the corresponding removal efficiencies of total nitrogen were 90.16%, 86.65% and 81.48%, respectively. The optimum conditions for the inorganic nitrogen removal and growth of strain K1 were a C/N of 18 and a salinity of 5-15 ppt. The amoA, nirK and nosZ genes of K1 were detected. All the results suggest that B. californica K1 is capable of HN-AD and has the potential to remove inorganic nitrogen from wastewater.

Multiresidue determination of antibiotics in ready-to-eat duck eggs marketed through e-commerce stores in China and subsequent assessment of dietary risks to consumers.

In this work, the occurrence of 34 common antibiotic (15 sulfonamides and 19 quinolones) residues were evaluated in 236 ready-to-eat duck eggs (salted and preserved duck eggs) marketed through e-commerce stores by ultra-performance liquid chromatography coupled to tandem mass spectrometry, and subsequent dietary risk assessments for Chinese consumers were conducted. Among violated positives in duck egg samples, 11 analytes were found including sulfamethazine, sulfaquinoxaline, sulfamethoxazole, sulfadiazine, sulfamonomethoxine, ciprofloxacin, enrofloxacin, ofloxacin, flumequine, sarafloxacin, and nalidixic acid. A higher number of antibiotics were detected in salted duck eggs (five sulfonamides and six quinolones) than in preserved duck eggs (one sulfonamide and two quinolones). The maximum contamination of sulfonamides and quniolones was 448.0 µg/kg (sulfaquinoxaline) and 563.7 µg/kg (enrofloxacin) in salted duck eggs, respectively. Dietary exposure was evaluated through the estimated daily intake (EDI) of risky antibiotics (sulfamethazine, ciprofloxacin, and enrofloxacin) and hazard quotients (HQs). The results showed that EDIs and HQs were in the range of 0.0004 to 0.0099 µg/kg bw/day and 0.0009 to 0.1594%, respectively. The risk was low since HQs obtained were less than 100%. However, a special attention should be paid to ready-to-eat duck egg products high percentile consumers with the prosperity of e-commerce market in China. PRACTICAL APPLICATION: The present analytical method could be used for multiresidue determination of antibiotics in ready-to-eat duck eggs, and dietary risk assessments of risky antibiotics provided a support for the work of regulatory bodies to conduct surveillance programs regarding food safety evaluation of ready-to-eat foods.

Effects of Banana Resistant Starch on the Biochemical Indexes and Intestinal Flora of Obese Rats Induced by a High-Fat Diet and Their Correlation Analysis.

The effects of banana resistant starch (BRS) on obesity-related metabolic and intestinal flora were investigated in a high-fat diet-induced obesity model. After 6 weeks of intervention, the glucolipid metabolism index [blood glucose (GLU), total cholesterol (TC), triacylglycerol (TG), low density lipoprotein-cholesterol (LDL-C), and high density lipoprotein-cholesterol (HDL-C)], hormone index [leptin (LEP), insulin (INS), ghrelin, adiponectin (ADP), and thyroxine (T4)], and 16S rRNA sequencing analyses were performed for each group to explore the regulating effect of intestinal flora and the mechanism of weight loss in obese rats. The results showed that (1) BRS intervention significantly reduced the levels of GLU, TG, TC, LDL-C, LEP, and INS (p < 0.01) and increased the contents of ghrelin (p < 0.05) and ADP (p < 0.01). (2) BRS could improve the diversity of intestinal flora and regulate the overall structure of intestinal microorganisms, mainly by upregulating the Bacteroides/Firmicutes ratio and the relative abundance of Cyanobacteria and downregulating the relative abundances of Deferribacteres and Tenericutes (at the phylum level). BRS could inhibit the proliferation of Turicibacter, Romboutsia, and Oligella and increase the abundances of Bacteroides, Ruminococcaceae, and Lachnospiraceae (at the genus level). (3) Some significant correlations were observed between the gut microbiota and biomarkers. Turicibacter, Romboutsia, and Oligella were positively correlated with GLU, TG, TC, LEP, and INS and negatively correlated with ghrelin and ADP. Bacteroides, Parabacteroides, and Akkermansia were negatively correlated with GLU, TG, and TC. Conclusion: BRS had promising effects on weight loss, which could be associated with the improvement in host metabolism by regulating intestinal flora.

Preferences for an HIV prevention mobile phone app: a qualitative study among men who have sex with men in China.

BACKGROUND: Men who have sex with men (MSM) have a disproportionate burden of HIV infection. Mobile phone apps provide a promising means of improving HIV prevention among MSM. But this has received little examination in China. The objective of this study was to explore MSM's preferences for an HIV prevention mobile phone app. METHODS: Qualitative semi-structured personal interviews were conducted with 19 MSM to determine their preferences for features and content to inform the design of an app aimed at HIV prevention in China. RESULTS: Five categories were identified under the main category preferences for features of the app: target population, attributes, language used, potential user access, and perceived usefulness. Five categories were identified under the main category preferences for content of the app: functions to facilitate HIV testing behavior, HIV post-exposure prevention, warning against substance use, psychological support, and areas for communication. CONCLUSIONS: Findings suggest that the design of an app targeting MSM in China should use an integrated framework addressing behavioral and psychological aspects, satisfy common needs of potential users, avoid perpetuating negative stereotypes and stigma, and avoid possible increase of risk behavior due to using the app.