Infections in long-duration space missions.

As government space agencies and private companies announce plans for deep space exploration and colonisation, prioritisation of medical preparedness is becoming crucial. Among all medical conditions, infections pose one of the biggest threats to astronaut health and mission success. To gain a comprehensive understanding of these risks, we review the measured and estimated incidence of infections in space, effect of space environment on the human immune system and microbial behaviour, current preventive and management strategies for infections, and future perspectives for diagnosis and treatment. This information will enable space agencies to enhance their comprehension of the risk of infection in space, highlight gaps in knowledge, aid better crew preparation, and potentially contribute to sepsis management in terrestrial settings, including not only isolated or austere environments but also conventional clinical settings.

Effect of levothyroxine on the pregnancy outcomes in recurrent pregnancy loss women with subclinical hypothyroidism and thyroperoxidase antibody positivity: a systematic review and meta-analysis.

OBJECTIVE: This study aimed to explore the effects of levothyroxine on pregnancy outcomes and thyroid function in recurrent pregnancy loss (RPL) women with subclinical hypothyroidism (SCH) or thyroperoxidase antibody positivity (TPOAb+). METHODS: Literature search was performed from inception to 24 June 2022. The heterogeneity for each outcome was evaluated using Cochran's Q test and quantified with I-squared (I2). Pooled effect sizes were expressed as relative risk (RR) and weighted mean differences (WMD) with 95% confidence intervals (95% CIs). Stability of the results were assessed using the sensitivity analysis. RESULTS: Fifteen eligible studies with 1911 participants were included in this meta-analysis. The pooled data showed that levothyroxine decreased premature delivery rate (RR = 0.48, 95%CI: 0.32, 0.72), miscarriage rate (RR = 0.59, 95%CI: 0.44, 0.79), premature rupture of membranes (PROM) rate (RR = 0.44, 95%CI: 0.29, 0.66), and fetal growth restriction rate (RR = 0.33, 95%CI: 0.12, 0.89) in RPL women with TPOAb+. In RPL women with SCH, live birth rate was elevated (RR = 1.20, 95%CI: 1.01, 1.42) and miscarriage rate was reduced (RR = 0.65, 95%CI: 0.44, 0.97) by levothyroxine. In addition, levothyroxine substantially decreased TSH level (WMD = -0.23, 95% CI: -0.31, -0.16) and TPO level (WMD = -23.48, 95%CI: -27.50, -19.47). CONCLUSIONS: Levothyroxine improved pregnancy outcomes and thyroid function in RPL women with TPOAb+ or SCH, indicating that levothyroxine may be beneficial for RPL women if TPOAb+ or SCH occurs. Future studies are needed to verify our findings.

Protective effects of berberine against ß-amyloid-induced neurotoxicity in HT22 cells via the Nrf2/HO-1 pathway.

Neuronal apoptosis has been found to have a pivotal role in the course of Alzheimer's disease (AD). Berberine (BBR), a potent antioxidant, occurs in plants such as Berberis, Phellodendron chinense, and Hydrastis canadensis. In this study, a neuronal apoptotic model was established in vitro using HT22 cells induced by Aß25-35 to explore whether BBR contributes to protecting neurons against Aß25-35-induced neurotoxicity, as well as its potential mechanisms. BBR was applied to HT22 cells for 1 h prior to exposing the cells to Aß25-35 for 24 h. A CCK-8 assay was utilized to assess cell viability, and Annexin V - fluorescein isothiocyanate (FITC)/propidium iodide and Hoechst 33342 fluorescence staining were used to measure the rate of cell apoptosis. Existing scientific literature was also reviewed to further determine the effects of BBR on ROS production and mitochondrial function in HT22 cells. Furthermore, the expressions of proteins, including cytochrome C, cleaved caspase-3, p-p65, p65, and Nrf2/HO-1 antioxidant axis were assessed by Western blotting. The data indicated that BBR markedly improved cell viability, inhibited apoptosis and intracellular ROS levels, improved mitochondrial membrane potentials, decreased the rate of p-p65/p65, cytochrome C, and cleaved caspase-3, and intensified the activity of Nrf2/HO-1 antioxidants in HT22 cells. Overall, the findings indicated that BBR provides a certain level of neuroprotectiveness in HT22 cells exposed to Aß25-35 via relieving oxidative stress, as well as by restraining the mitochondrial pathway of cellular apoptosis. In addition, the restraint of NF-κB activity and sensitization of the Nrf2/HO-1 antioxidant axis, which together are intimately involved in the neuroprotection of BBR, may be possible mechanisms accounting for its effectiveness against Aß25-35in vitro.

A facile one-pot room-temperature growth of self-supported ultrathin rhodium-iridium nanosheets as high-efficiency electrocatalysts for hydrogen evolution reaction.

The development of low-cost and high-efficiency electrocatalysts is very important for electrocatalytic hydrogen evolution reaction (HER) in water splitting system. Herein, ultrathin rhodium-iridium nanosheets were facilely in-situ grown on nickel foam (RhIr NSs/NF) by a one-pot aqueous strategy at room temperature. The sheet-like structures with the film thickness of 78 nm were identified by scanning electron microscopy and transmission electron microscopy. The catalyst showed greatly high HER features in both 1.0 M KOH and 0.5 M H2SO4 with the overpotentials of 15 and 14 mV to achieve 10 mA cm-2, respectively, surpassing most Pt-free catalysts. Also, the RhIr NSs/NF exhibited amazing catalytic stability during the long-term operation. This study offers a facile and rational pathway for design and synthesis of advanced HER electrocatalysts for energy conversion devices.

Iron, manganese co-doped Ni3S2 nanoflowers in situ assembled by ultrathin nanosheets as a robust electrocatalyst for oxygen evolution reaction.

Exploring high-performance and stable transition metal electrocatalysts is prerequisite for boosting overall water splitting efficiency. In this study, iron (Fe), manganese (Mn) co-doped three-dimensional (3D) Ni3S2 nanoflowers were in situ assembled by many inter-connected 2D nanosheets on nickel foam (NF) via hydrothermal and sulfuration treatment. By virtue of the introduced Fe and Mn elements and unique flower-like structures, the as-prepared catalyst displayed high activity and stability for oxygen evolution reaction (OER), coupled with a small Tafel slope (63.29 mV dec-1) and a low overpotential of 216 mV to reach the current density of 30 mA cm-2. This study would shed some lights for facile synthesis of exceptional OER catalyst by tailoring the electronic structure and doping transition metal(s).

Walnut kernel-like iron-cobalt-nickel sulfide nanosheets directly grown on nickel foam: A binder-free electrocatalyst for high-efficiency oxygen evolution reaction.

Developing earth-rich and high-efficiency nonprecious metal catalysts is critical but extremely challenging for oxygen evolution reaction (OER). Herein, a simple room-temperature sulfuration method was developed for in situ synthesis of walnut kernel-like iron-cobalt-nickel sulfide nanosheets on nickel foam (FeCoNiSx/NF). The unique nanosheets exposed abundant active sites and provided large electrochemically active surface area. The as-built FeCoNiSx/NF exhibited high OER performances with the small overpotentials of 231 and 268 mV to afford 10 and 50 mA cm-2 in 1.0 M KOH, respectively, coupled with a small Tafel slope of 55 mV dec-1. Furthermore, the FeCoNiSx/NF acted as the anode towards overall water electrolysis with acceptable results, where commercial Pt/C dropped on the NF worked as the cathode. This study provides some valuable insights for rational construction of nonprecious electrocatalysts in electrochemical energy technologies.

Facile synthesis of nanoflower-like phosphorus-doped Ni3S2/CoFe2O4 arrays on nickel foam as a superior electrocatalyst for efficient oxygen evolution reaction.

Developing cost-effectiveness and superior electrocatalysts is crucial to improve the efficiency of oxygen evolution reaction (OER) in water splitting system. Hence, flower-like phosphorus doped Ni3S2/CoFe2O4 arrays (P-Ni3S2/CoFe2O4/NF) were generated on three-dimensional (3D) nickel foam (NF) via the two-step hydrothermal treatment and subsequent phosphorization. Additionally, a series of control experiments were conducted to investigate the formation mechanism. By virtue of the unique 3D configurations and multi-compositions, the as-prepared catalyst exhibited greatly improved OER performance in 1.0 M KOH solution, with the overpotential of only 254 mV at 50 mA cm-2 and low Tafel slope of 54.43 mV dec-1. This study provides a feasible approach for preparing advanced electrocatalyst in energy conversion and storage devices.

Facile synthesis of porous iridium-palladium-plumbum wire-like nanonetworks with boosted catalytic performance for hydrogen evolution reaction.

Exploring advanced nanocatalysts are of importance for hydrogen evolution reaction (HER) in alkaline electrolyte (e.g. 1.0 M KOH). Herein, porous iridium-palladium-plumbum wire-like nanonetworks (IrPdPb WNNs) were prepared by a facile one-pot aqueous method with octylphenoxypolyethoxyethanol (NP-40) as the structure-director. The resultant IrPdPb WNNs exhibited superior HER performance in the alkaline electrolyte, such as ultra-low overpotential (21 mV) to drive a current density of 10 mA cm-2, small Tafel slope (66 mV dec-1), and high exchange current density (4.87 mA cm-2), surpassing commercial Pt/C. This study provides a simple strategy for synthesis of advanced multi-metallic electrocatalysts in energy storage and conversion.

Ultrathin PdFePb nanowires: One-pot aqueous synthesis and efficient electrocatalysis for polyhydric alcohol oxidation reaction.

Synthesis of high-efficiency catalysts for alcohol oxidation reaction caused great interest in direct alcohol fuel cells (DAFCs). Ultrathin PdFePb nanowires (NWs) with an average diameter of 2.3 nm were synthesized by a simple and fast one-pot aqueous synthesis, using octylphenoxypolyethoxyethanol (NP-40) as the structure-directing agent. The as-prepared PdFePb NWs displayed an increscent electrochemically active surface area (ECSA, 121.18 m2 g-1 Pd). For ethylene glycol oxidation reaction (EGOR) and glycerol oxidation reaction (GOR), PdFePb NWs exhibited much higher activity and superior stability, outperforming those of homemade PdFe NWs, PdPb NWs, commercial Pd black and Pd/C (20 wt%). These results reveal dramatically high catalytic activity and durability of ultrathin PdFePb NWs in enhancing polyols electrooxidation.

Alcohol ethoxylate degradation of activated sludge is enhanced by bioaugmentation with Pseudomonas sp. LZ-B.

An effective bioaugmentation strategy was developed for the removal of alcohol ethoxylates (AEs) from municipal wastewater. An AE-degrading strain, Pseudomonas sp. LZ-B, was isolated from an activated sludge. Strain LZ-B was able to degrade 96.8% of 200 mg/L C12E4 (Brij 30) within 24 h and showed significant biomass increase and removal of total oxygen concentration (TOC). The optimal degradation temperature and pH value were 37 °C and 6.0, respectively. The strain demonstrated greater potential to degrade five different molecular weight AEs within 5 days. HPLC-MS/MS analysis demonstrated that the major metabolites obtained were polyethylene glycol (PEG) and carboxylated AE chains. Activated sludge has a low ability to remove AEs. After inoculation of strain LZ-B into the activated sludge reactor, Strain LZ-B successfully colonized the activated sludge, and AE removal efficiency increased to more than 95% when the hydraulic retention time (HRT) was 10 h. After strain LZ-B cleaved the AE chains, the sludge microbial communities easily removed PEG fragments to facilitate complete biodegradation of AEs. This is the first report describing bioaugmentation to increase AE degradation in an activated sludge system.

The retromer complex safeguards against neural progenitor-derived tumorigenesis by regulating Notch receptor trafficking.

The correct establishment and maintenance of unidirectional Notch signaling are critical for the homeostasis of various stem cell lineages. However, the molecular mechanisms that prevent cell-autonomous ectopic Notch signaling activation and deleterious cell fate decisions remain unclear. Here we show that the retromer complex directly and specifically regulates Notch receptor retrograde trafficking in Drosophila neuroblast lineages to ensure the unidirectional Notch signaling from neural progenitors to neuroblasts. Notch polyubiquitination mediated by E3 ubiquitin ligase Itch/Su(dx) is inherently inefficient within neural progenitors, relying on retromer-mediated trafficking to avoid aberrant endosomal accumulation of Notch and cell-autonomous signaling activation. Upon retromer dysfunction, hypo-ubiquitinated Notch accumulates in Rab7+ enlarged endosomes, where it is ectopically processed and activated in a ligand-dependent manner, causing progenitor-originated tumorigenesis. Our results therefore unveil a safeguard mechanism whereby retromer retrieves potentially harmful Notch receptors in a timely manner to prevent aberrant Notch activation-induced neural progenitor dedifferentiation and brain tumor formation.

Effect of loss of plant functional group and simulated nitrogen deposition on subalpine ecosystem properties on the Tibetan Plateau.

Biodiversity loss impacts on ecosystem functioning can vary greatly among ecosystems types and different ecosystem processes can respond differently. Here we conducted a plant functional group removal experiment with and without nitrogen (N) addition (5gNm-2year-1) to examine the effects of plant functional group types presence, nitrogen deposition and their interaction effects on plant diversity, aboveground biomass, soil nutrients, soil microbial biomass and soil enzyme activity. After 4years, the removal of dominant grass did increase subordinates, forb richness, and decreased total aboveground biomass significantly. However, the removal of forb resulted in a rapid decline in species richness, which did not change strongly the aboveground biomass, regardless of N addition. This pattern suggests that the dominant grass can compensate for the loss of forb removal with respect to production, but cannot compensate with respect to species loss. Forb cannot compensate for grass removal with respect to production, but can compensate with respect to species loss. Nitrogen addition only has a small effect on species richness, and also not enhances aboveground biomass. In addition, the majority of soil properties did not respond to either plant functional group removal, or N addition. Only soil CO2 efflux and soil NO3--N content significantly changed with plant functional group removal. Soil respiration rate was positively correlated with both plant species richness (R2=0.97) and aboveground biomass (R2=0.64). Our results show that the short-term losses of plant functional group have significant effects on plant diversity and productivity, and only minor impact on soil properties.

Geniposide attenuates Aß25-35-induced neurotoxicity via the TLR4/NF-κB pathway in HT22 cells.

Alzheimer's disease (AD), a neurodegenerative disorder, is marked by the accumulation of amyloid-ß (Aß) and neuroinflammation which promote the development of AD. Geniposide, the main ingredient isolated from Chinese herbal medicine Gardenia jasminoides Ellis, has a variety of pharmacological functions such as anti-apoptosis and anti-inflammatory activity. Hence, we estimated the inflammatory cytotoxicity caused by Aß25-35 and the neuroprotective effects of geniposide in HT22 cells. In this research, following incubation with Aß25-35 (40 µM, 24 h) in HT22 cells, the methylthiazolyl tetrazolium (MTT) and lactate dehydrogenase (LDH) release assays showed that the cell survival rate was significantly decreased. In contrast, the reactive oxygen species (ROS) assay indicated that Aß25-35 enhanced ROS accumulation and apoptosis showed in both hoechst 33342 staining and annexin V-FITC/PI double staining. And then, immunofluorescence test revealed that Aß25-35 promoted p65 to transfer into the nucleus indicating p65 was activated by Aß25-35. Moreover, western blot analysis proved that Aß25-35 increased the expression of nitric oxide species (iNOS), tumor necrosis factor-α (TNF-α), cyclooxygenase-2 (COX-2) and interleukin-1ß (IL-1ß). Simultaneously, Aß25-35 also promoted the expression of toll-like receptor 4 (TLR4), p-p65 and p-IκB-α accompanied with the increase in the level of beta-secretase 1 (BACE1) and caspase-3 which further supported Aß25-35 induced apoptosis and inflammation. Fortunately, this up-regulation was reversed by geniposide. In conclusion, our data suggest that geniposide can alleviate Aß25-35-induced inflammatory response to protect neurons, which is possibly involved with the inhibition of the TLR4/NF-κB pathway in HT22 cells. Geniposide may be the latent treatment for AD induced by neuroinflammation and apoptosis.