Reconstruction of Long-Chain Polyunsaturated Acid Synthesis Pathways in Marine Red Microalga Porphyridium cruentum Using Lipidomics and Transcriptomics.

The marine red microalga Porphyridium can simultaneously synthesize long-chain polyunsaturated fatty acids, including eicosapentaenoic acid (C20:5, EPA) and arachidonic acid (C20:4, ARA). However, the distribution and synthesis pathways of EPA and ARA in Porphyridium are not clearly understood. In this study, Porphyridium cruentum CCALA 415 was cultured in nitrogen-replete and nitrogen-limited conditions. Fatty acid content determination, transcriptomic, and lipidomic analyses were used to investigate the synthesis of ARA and EPA. The results show that membrane lipids were the main components of lipids, while storage lipids were present in a small proportion in CCALA 415. Nitrogen limitation enhanced the synthesis of storage lipids and ω6 fatty acids while inhibiting the synthesis of membrane lipids and ω3 fatty acids. A total of 217 glycerolipid molecular species were identified, and the most abundant species included monogalactosyldiglyceride (C16:0/C20:5) (MGDG) and phosphatidylcholine (C16:0/C20:4) (PC). ARA was mainly distributed in PC, and EPA was mainly distributed in MGDG. Among all the fatty acid desaturases (FADs), the expressions of Δ5FAD, Δ6FAD, Δ9FAD, and Δ12FAD were up-regulated, whereas those of Δ15FAD and Δ17FAD were down-regulated. Based on these results, only a small proportion of EPA was synthesized through the ω3 pathway, while the majority of EPA was synthesized through the ω6 pathway. ARA synthesized in the ER was likely shuttled into the chloroplast by DAG and was converted into EPA by Δ17FAD.

The inhibition of enterovirus 71 induced apoptosis by Durvillaea antarctica through P53 and STAT1 signaling pathway.

The infection of enterovirus 71 (EV71) resulted in hand, foot, and mouth disease and may lead to severe nervous system damage and even fatalities. There are no effective drugs to treat the EV71 virus and it is crucial to find novel drugs against it. Polysaccharide isolated from Durvillaea antarctica green algae has an antiviral effect. In this study, D. antarctica polysaccharide (DAPP) inhibited the infection of EV71 was demonstrated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), reverse transcription polymerase chain reaction, flow cytometry, and western blot. MTT assay showed that DAPP had no toxicity on Vero cells at the concentration 250 µg/ml. Furthermore, DAPP significantly reduced the RNA level of EV71 in a dose-dependent manner. Moreover, DAPP inhibited the Vero cells apoptosis induced by EV71 via the P53 signaling pathway. Meanwhile, the expression of signal transducer and activator of transcription 1 and mammalian target of rapamycin were increased and the proinflammatory cytokines were significantly inhibited by DAPP. Taken together, these results suggested that DAPP could be a potential pharmaceutical against the infection of EV71 virus.

Inhibition of enterovirus 71 infection by polysaccharides extracted from Picochlorum sp. 122 via the AKT and ATM/ATR signaling pathways.

Enterovirus 71 (EV71) poses a major threat to public health globally due to severe and even fatal hand, foot, and mouth disease (HFMD). However, no effective antiviral agents are available to treat HFMD caused by this virus. Polysaccharides have been shown to exhibit antiviral activity, and polysaccharides extracted from Picochlorum sp. 122 (PPE) could potentially be used to treat HFMD, but reports on their antiviral activity are limited. In this study, the antiviral activity of PPE against EV71 was verified in Vero cells. PPE was shown to limit EV71 infection, as demonstrated using an MTT assay and by observing the cellular cytopathic effect. In addition, a decrease in VP1 RNA and protein levels indicated that PPE effectively inhibits proliferation of EV71 in Vero cells. An annexin V affinity assay also indicated that PPE protects host cells from apoptosis through the AKT and ATM/ATR signalling pathways. These results demonstrate that PPE has potential as an antiviral drug to treat HFMD caused by EV71.

Selenium-containing protein from selenium-enriched Spirulina platensis antagonizes oxygen glucose deprivation-induced neurotoxicity by inhibiting ROS-mediated oxidative damage through regulating MPTP opening.

CONTEXT: Selenium-containing protein from selenium-enriched Spirulina platensis (Se-SP) (syn. Arthrospira platensis [Microcoleaceae]) showed novel antioxidant activity. However, the protective effect of Se-SP against oxygen glucose deprivation (OGD)-induced neural apoptosis has not been reported yet. OBJECTIVE: To verify whether Se-SP can inhibit OGD-induced neural apoptosis and explore the underlying mechanism. MATERIALS AND METHODS: Primary hippocampal neurons were separated from Sprague-Dawley (SD) rats. 95% N2 + 5% CO2 were employed to establish OGD model. Neurons were treated with 5 and 10 µg/mL Se-SP under OGD condition for 6 h. Neurons without treatment were the control group. Neural viability and apoptosis were detected by MTT, immunofluorescence and western blotting methods. RESULTS: Se-SP significantly improved neuronal viability (from 57.2% to 94.5%) and inhibited apoptosis in OGD-treated primary neurons (from 45.6% to 6.3%), followed by improved neuronal morphology and caspases activation. Se-SP co-treatment also effectively suppressed OGD-induced DNA damage by inhibiting ROS accumulation in neurons (from 225.6% to 106.3%). Additionally, mitochondrial dysfunction was also markedly improved by Se-SP co-treatment via balancing Bcl-2 family expression. Moreover, inhibition of mitochondrial permeability transition pore (MPTP) by CsA (an MPTP inhibitor) dramatically attenuated OGD-induced ROS generation (from 100% to 56.2%), oxidative damage, mitochondrial membrane potential (MPP) loss (from 7.5% to 44.3%), and eventually reversed the neuronal toxicity and apoptosis (from 57.4% to 79.6%). DISCUSSION AND CONCLUSIONS: Se-SP showed enhanced potential to inhibit OGD-induced neurotoxicity and apoptosis by inhibiting ROS-mediated oxidative damage through regulating MPTP opening, indicating that selenium-containing protein showed broad application in the chemoprevention and chemotherapy against human ischaemic brain injury.

Pelagibacterium lentulum sp. nov., a marine bacterium from the culture broth of Picochlorum sp. 122.

A Gram-stain-negative, motile, non-spore-forming, rod-shaped bacterium, designated strain B2T, was isolated from the culture broth of a marine microalga, Picochlorum sp. 122. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain B2T forms a robust cluster with members of the genus Pelagibacterium, and shares the highest sequence similarity of 96.80 % with Pelagibacterium halotolerans CGMCC 1.7692T. Optimal growth of strain B2T was observed at 33 °C, at pH 8 and in the presence of 1 % (w/v) NaCl. The predominant ubiquinone of strain B2T was Q-10, and the G+C content of the genomic DNA was 58.6 mol%. The major fatty acid profile comprised C18 : 1ω7c/ω6c, C19 : 0 cyclo ω8c and C16 : 0. The major polar lipids of strain B2T were diphosphatidylglycerol, phosphatidylglycerol, two unidentified glycolipids and seven unidentified lipids. Comprehensive analyses based on a polyphasic characterization of strain B2T indicated that it represents a novel species of the genus Pelagibacterium, for which the name Pelagibacterium lentulum sp. nov. is proposed. The type strain is B2T (=MCCC 1K03218T=CGMCC 1.15896T=KCTC 52551T).

Butyratibacter algicola gen. nov., sp. nov., a marine bacterium from the culture broth of Picochlorum sp. 122.

A Gram-stain-negative, motile, non-spore-forming, ovoid or rod-shaped bacterium, designated strain B15T, was isolated from the culture broth of a marine microalga, Picochlorum sp. 122. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain B15T forms a stable cluster with Lutibaculum baratangense KCTC 22669T (95.4 % 16S rRNA gene sequence similarity), Tepidamorphus gemmatus CB-27AT (94.9 %) and Microbaculum marinum HSF11T (94.6 %) in the family Rhodobiaceae. Optimal growth of strain B15T was observed at 33 °C, pH 8-9 and in the presence of 3 % (w/v) NaCl. The only detected ubiquinone of strain B15T was Q-10, and the G+C content of the genomic DNA was 66.3 mol%. The major fatty acid profile comprised C19 : 0 cyclo ω8c, C18 : 1ω7c/ω6c and C17 : 1 iso I/anteiso B. The major polar lipids of strain B15T were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, two unidentified aminolipids, and one unidentified lipid. Comprehensive analyses based on polyphasic characterization of strain B15T indicated that it represents a novel species of a new genusin the family Rhodobiaceae, for which the name Butyratibacter algicola gen. nov., sp. nov. is proposed. The type strain of the type species is B15T (=KCTC 52552T=MCCC 1K03221T).

Gelatiniphilus marinus gen. nov., sp. nov., a bacterium from the culture broth of a microalga, Picochlorum sp. 122, and emended description of the genus Hwangdonia.

A Gram-stain-negative, non-motile, non-spore-forming, rod-shaped bacterium, designated strain GYP-24T, was isolated from the culture broth of a marine microalga, Picochlorum sp. 122. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain GYP-24T forms a robust cluster with H.wangdoniaseohaensis KCTC 32177T (95.8 % sequence similarity) in the family Flavobacteriaceae. Growth of strain GYP-24T was observed at 15, 22, 28, 30, 33 and 37 °C (optimal 30-33 °C), pH 6.0-10.0 (optimal pH 7.0-8.0) and in the presence of 0.5-4 % (w/v) NaCl (optimal 2-3 %). The only menaquinone of strain GYP-24T was MK-6, and the G+C content of the genomic DNA was 36.9 mol%. The major fatty acid profile comprised iso-C17 : 0 3-OH, summed feature 3 (C16 : 1 ω7c/ω6c), iso-C15 : 1 G and iso-C15 : 0. The major polar lipids of strain GYP-24T were phosphatidylethanolamine, one unidentified phospholipid, three unidentified aminolipids and three unidentified lipids. Comprehensive analyses based on polyphasic characterization of GYP-24T indicated that it represents a novel species of a new genus, for which the name Gelatiniphilus marinus gen. nov., sp. nov. is proposed. The type strain is GYP-24T (=KCTC 42903T=MCCC 1K01730T). An emended description of the genus Hwangdonia is also given.

Pyruvatibacter mobilis gen. nov., sp. nov., a marine bacterium from the culture broth of Picochlorum sp. 122.

A Gram-stain-negative, aerobic bacterium, designated strain GYP-11T, was isolated from the culture broth of a marine microalga, Picochloruma sp. 122. Cells were dimorphic rods; free living cells were motile by means of a single polar flagellum, and star-shaped-aggregate-forming cells were attached with stalks and non-motile. Sodium pyruvate or Tween 20 was required for growth on marine agar 2216.16S rRNA gene sequence analysis revealed that this isolate shared 94.07 % similarity with its closest type strain, Parvibaculum hydrocarboniclasticum EPR92T. Phylogenetic analyses indicated that strain GYP-11T represents a distinct lineage in a robust clade consisting of strain GYP-11T, alphaproteobacterium GMD21A06 and Candidatus Phaeomarinobacter ectocarpi Ec32. This clade was close to the genera Parvibaculum and Tepidicaulis in the order Rhizobiales. Chemotaxonomic and physiological characteristics, including cellular fatty acids and carbon source profiles, also readily distinguished strain GYP-11T from all established genera and species. Thus, it is concluded that strain GYP-11T represents a novel species of a new genus in the order Rhizobiales, for which the name Pyruvatibacter mobilis gen. nov., sp. nov. is proposed. The type strain of Pyruvatibacter mobilis is GYP-11T ( = CGMCC 1.15125T = KCTC 42509T).

A Saponification Method for Chlorophyll Removal from Microalgae Biomass as Oil Feedstock.

Microalgae oil is an optimal feedstock for nutraceutical, pharmaceutical and biodiesel production, but its high levels of chlorophyll limit its large-scale application. To date, few effective approaches have been developed to remove chlorophyll from microalgae oil. The main purpose of this study was to present a preprocessing method of algae oil feedstock (Scenedesmus) to remove chlorophyll by saponification. The results showed that 96% of chlorophyll in biomass was removed. High quality orange transparent oil could be extracted from the chlorophyll reduced biomass. Specifically, the proportion of neutral lipids and saturation levels of fatty acids increased, and the pigments composition became carotenoids-based. The critical parameters of chlorophyll reduced biodiesel conformed to the standards of the USA, China and EU. Sodium copper chlorophyllin could be prepared from the bleaching effluent. The results presented herein offer a useful pathway to improve the quality of microalgae oil and reduce the cost of microalgae biodiesel.

Maribacter flavus sp. nov., isolated from a cyanobacterial culture pond.

A Gram-stain-negative, yellow, non-spore-forming, strictly aerobic bacterium, designated C3T, was isolated from a cyanobacterial culture pond. Cells were halophilic, rod-shaped and able to move by gliding. Growth of strain C3T was observed at 15-30 °C (optimum 25 °C), pH 6.0-9.0 (optimum pH 7.5), and in the presence of 1-7 % (w/v) NaCl (optimum 2-3 %). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain C3T formed a distinct lineage within the family Flavobacteriaceae and exhibited the highest similarity (95.21 %) to the type strains of Maribacter dokdonensis, Maribacter arcticus, Maribacter orientalis and Maribacter stanieri, and 'Maribacter caenipelagi' HD-44. The only isoprenoid quinone present within strain C3T was menaquinone 6 (MK-6). The G+C content of genomic DNA was 41.5 mol%. The major polar lipids were phosphatidylethanolamine and three unidentified lipids. The predominant cellular fatty acids (>5 % of the total fatty acids) were iso-C15 : 1 G, iso-C15 : 0, iso-C15 : 0 3-OH, iso-C17 : 0 3-OH, and summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c). On the basis of the phenotypic, chemotaxonomic and phylogenetic characteristics, strain C3T represents a novel species of the genus Maribacter, for which the name Maribacter flavus sp. nov. is proposed. The type strain is C3T ( = KCTC 42508T = CGMCC 1.15112T).

Optimization of medium using response surface methodology for lipid production by Scenedesmus sp.

Lipid production is an important indicator for assessing microalgal species for biodiesel production. In this work, the effects of medium composition on lipid production by Scenedesmus sp. were investigated using the response surface methodology. The results of a Plackett-Burman design experiment revealed that NaHCO3, NaH2PO4·2H2O and NaNO3 were three factors significantly influencing lipid production, which were further optimized by a Box-Behnken design. The optimal medium was found to contain 3.07 g L⁻¹ NaHCO3, 15.49 mg L⁻¹ NaH2PO4·2H2O and 803.21 mg L⁻¹ NaNO3. Using the optimal conditions previously determined, the lipid production (304.02 mg·L⁻¹) increased 54.64% more than that using the initial medium, which agreed well with the predicted value 309.50 mg L⁻¹. Additionally, lipid analysis found that palmitic acid (C16:0) and oleic acid (C18:1) dominantly constituted the algal fatty acids (about 60% of the total fatty acids) and a much higher content of neutral lipid accounted for 82.32% of total lipids, which strongly proved that Scenedesmus sp. is a very promising feedstock for biodiesel production.

A novel lipid extraction method from wet microalga Picochlorum sp. at room temperature.

A novel method using ethanol was proposed for extracting lipids from wet microalga Picochlorum sp. at room temperature and pressure. In this study, Central Composite design (CCD) was applied to investigate the optimum conditions of lipid extraction. The results revealed that the solvent to biomass ratio had the largest effect on lipid extraction efficiency, followed by extraction time and temperature. A high lipid extraction yield (33.04% of the dry weight) was obtained under the following extraction conditions: 5 mL solvents per gram of wet biomass for 37 min with gentle stirring at room temperature. The extraction yield was comparable to that obtained by the widely used Bligh-Dyer method. Furthermore, no significant differences in the distribution of lipid classes and fatty acid composition were observed according to different extraction methods. In conclusion, these results indicated that the proposed procedure using ethanol could extract lipids from wet biomass efficiently and had giant potential for lipid extraction at large scale.

Multi-Omics Reveals the Effects of Spirulina platensis Powder Replacement of Fish Meal on Intestinal Metabolism and Stress in Zig-Zag Eel (Mastacembelus armatus).

The booming aquaculture industry has created a strong demand for fishmeal and increased environmental pressures. Spirulina, as a potential alternative to fishmeal, has been shown to have growth-promoting and animal health-enhancing properties. In this study, 600 large spiny loaches, divided into five experimental groups, F0, F1, F2, F3, and F4, were reared for 10 weeks using Spirulina platensis powder (SPP) as a substitute for 0%, 5%, 10%, 15%, and 20% of fishmeal, respectively. The results of intestinal physiological indexes showed that superoxide dismutase was lower than F0 in all treatment groups, and the activity of F3 was significantly lower than F0 (p < 0.05). The activity of malondialdehyde was significantly higher than that of F0 in all groups except F3 (p < 0.05). The addition of SPP also led to a decrease in the activity of acid phosphatase in the intestine, which was significantly lower in all treatment groups compared to the F0 group (p < 0.05). The results of serum physiology showed that the activity of superoxide dismutase in serum gradually increased with the increase in the percentage of SPP addition, and the F3 group produced a significant difference from the F0 group (p < 0.05). The transcriptomics results showed that DEGs in the low percentage substitution group (<15%) were mostly enriched in metabolism-related pathways, such as bile secretion; DEGs in the high percentage substitution group (>15%) were mostly enriched in inflammation-related pathways, such as complement p and coagulation cascades. Metabolomics confirmed that nicotinate and nicotinamide metabolism and glycerophospholipid metabolism were the two pathways that were significantly enriched in the treatment groups of fishmeal replacement by SPP. The present study demonstrated that a low percentage (<15%) of fishmeal replacement by SPP in feed mobilized MA digestive metabolism, whereas a high percentage (>15%) of replacement induced intestinal stress. Considering the health and farm efficiency aspects, the proportion of SPP in feed formulation for MA should be less than 15%.

Nonhongiella spirulinensis gen. nov., sp. nov., a bacterium isolated from a cultivation pond of Spirulina platensis in Sanya, China.

A Gram-negative, aerobic, motile rod strain, designated Ma-20(T), was isolated from a pool of marine Spirulina platensis cultivation, Sanya, China, and was subjected to a polyphasic taxonomy study. Strain Ma-20(T) can grow in the presence of 0.5-11 % (w/v) NaCl, 10-43 °C and pH 6-10, and grew optimally at 30 °C, pH 7.5-9.0 in natural seawater medium. The polar lipids were composed of phosphatidylethanolamine, three unidentified phospholipids and three unidentified polar lipids. The respiratory quinone was ubiquinone 8 (Q-8) and the major fatty acids were C18:1ω6c/C18:1ω7c (summed feature 8, 32.84 %), C16:1ω6c/C16:1ω7c (summed feature 3, 30.76 %), C16:0 (13.54 %), C12:03-OH (4.63 %), and C12:0 (4.09 %). The DNA G+C content of strain Ma-20(T) was 58 mol %. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain Ma-20(T) belonging to Gammaproteobacteria, it shared 88.46-91.55 and 89.21-91.26 % 16S rRNA gene sequence similarity to the type strains in genus Hahella and Marinobacter, respectively. In addition to the large 16S rRNA gene sequence difference, Ma-20(T) can also be distinguished from the reference type strains Hahella ganghwensis FR1050(T) and Marinobacter hydrocarbonoclasticus sp. 17(T) by several phenotypic characteristics and chemotaxonomic properties. On the basis of phenotypic, chemotaxonomic and phylogenetic properties, strain Ma-20(T) is suggested to represent a novel species of a new genus in Gammaproteobacteria, for which the name Nonhongiella spirulinensis gen. nov., sp. nov. is proposed. The type strain is Ma-20(T) (=KCTC 32221(T)=LMG 27470(T)).

Aliidiomarina sanyensis sp. nov., a hexabromocyclododecane assimilating bacterium from the pool of Spirulina platensis cultivation, Sanya, China.

A novel Gram-negative, rod shaped, motile, non-spore-forming, aerobic, brominated flame retardant hexabromocyclododecane-assimilating bacterium, designated strain GYP-17(T), was isolated from a pool of marine Spirulina platensis cultivation, Sanya, China. Colonies on 1/10 strength of marine Glycerol Enriched Medium plates were circular, dark-brown, 1-2 mm in diameter, and with regular margins. Growth occurred at 10-45 °C, 1-10 % (w/v) NaCl and pH of 7-9. The polar lipids were composed of phosphatidylethanolamine, three unidentified phospholipids and one unidentified polar lipid. The major fatty acids were iso-C17:1ω9c/10-methyl-C16:0 (summed feature 9, 20.75 %), iso-C15:0 (17.70 %) and C16:0 (6.40 %). The major respiratory quinone was Q-8. The DNA G + C content of the type strain was 53.6 mol%. Phylogenetic analysis revealed that strain GYP-17(T) was a member of the genus Aliidiomarina and closely related to Aliidiomarina haloalkalitolerans with a 16S rDNA sequence similarity of 96.36 %. Results from the polyphasic taxonomy study support the conclusion that strain GYP-17(T) represents a novel Aliidiomarina species, for which the name Aliidiomarina sanyensis sp. nov. is proposed. The type strain of A. sanyensis is GYP-17(T) (=KCTC 32218(T) =LMG 27471(T)).

[Effect of early off-bed mobility on diaphragm function in intensive care unit patients undergoing mechanical ventilation].

OBJECTIVE: To explore the improvement of diaphragm function after early off-bed mobility intervention in intensive care unit (ICU) patients undergoing mechanical ventilation. METHODS: A randomized controlled trial was conducted. A total of 147 adult patients undergoing mechanical ventilation admitted to ICU of Affiliated Hospital of Zunyi Medical University from October 2019 to March 2022 were enrolled. The patients were divided into control group and observation group by convenient sampling. Except for the different intervention programs of early mobility, other treatment and nursing of the patients in the two groups were carried out according to ICU routine. Progressive early activities were performed in the control group, while early off-bed mobility was performed in the observation group. The changes of diaphragm thickness at the end of inspiratory (DTei), diaphragm thickness at the end of expiratory (DTee) and diaphragm thickening fraction (DTF) before and 24, 48, 72 and 96 hours of intervention, and the duration of mechanical ventilation, length of ICU stay and 24-hour re-intubation rate after intervention were compared between the two groups. RESULTS: Among the 147 patients, there were 4 cases of detachment in the control group and 5 cases of detachment in the observation group. Finally, 138 patients were enrolled, 69 cases in the control group and 69 cases in the observation group. There was no significant difference in gender, age, diagnosis of ICU, sedatives, muscle strength, ventilator model, acute physiology and chronic health evaluation II (APACHE II) score and DTei, DTee, DTF before intervention between the two groups. The DTei, DTee and DTF in both groups were increased gradually with the extension of intervention time, especially in the observation group [DTei (cm) at 24, 48, 72 and 96 hours of intervention in the observation group were 0.247±0.014, 0.275±0.016, 0.300±0.013 and 0.329±0.013, while in the control group were 0.242±0.015, 0.258±0.013, 0.269±0.014, and 0.290±0.017, effect of time: F = 993.825, P = 0.000, effect of intervention: F = 82.304, P = 0.000, interaction effect between intervention and time: F = 84.457, P = 0.000; DTee (cm) of the observation group were 0.213±0.014, 0.227±0.013, 0.243±0.016, 0.264±0.010, while in the control group were 0.213±0.016, 0.218±0.013, 0.224±0.013, 0.234±0.014, effect of time: F = 385.552, P = 0.000, effect of intervention: F = 28.161, P = 0.000, interaction effect between intervention and time: F = 45.012, P = 0.000; DTF of the observation group were (15.98±4.23)%, (21.35±4.67)%, (24.09±4.44)% and (25.24±3.74)%, while in the control group were (14.17±4.66)%, (18.11±3.92)%, (20.22±4.19)% and (20.98±4.12)%, effect of time: F = 161.552, P = 0.000, effect of intervention: F = 49.224, P = 0.000, interaction effect between intervention and time: F = -4.507, P = 0.000]. The duration of mechanical ventilation and length of ICU stay in the observation group were significantly shorter than those in the control group [duration of mechanical ventilation (hours): 112.68±12.25 vs. 135.32±22.10, length of ICU stay (days): 7.84±1.78 vs. 10.23±2.43, both P < 0.01]. However, there was no significant difference in 24-hour re-intubation rate between the observation group and the control group (0% vs. 2.90%, P > 0.05). CONCLUSIONS: Both early off-bed mobility and progressive early activities can prevent diaphragm weakness in ICU patients undergoing mechanical ventilation, and the effect of early off-bed mobility is better. Early off-bed mobility can significantly shorten the duration of mechanical ventilation and length of ICU stay, and it is safe and feasible.

ICU quasi-speciality nurses' knowledge, attitudes and practices regarding early mobilization: A cross-sectional survey.

AIM: Early mobilization (EM) improves critical illness survivors' clinical outcomes. This study examines ICU quasi-specialty nurses' EM-related knowledge, attitudes and practices (KAP). DESIGN: This cross-sectional study was conducted at a provincial ICU specialty nurse training site from 2019 to 2021. KAP data were collected using a self-report questionnaire. METHODS: Participants were registered nurses enrolled in the training programme; 485 nurses from 188 hospitals completed the questionnaire. RESULTS: Of the participants, 37.7% had EM training, and 30.7% reported their wards performed EM. Median (IQR) scores for knowledge, attitudes and practices were 14.0 (4.0), 47.0 (9.0) and 37.0 (8.0), belonging to medium, high and medium levels. Scores were lowest for EM scope, implementation indicators and out-of-bed mobilization. There were significant deviations in KAP scores amongst nurses at different levels of hospitals with EM training and whose departments performed EM. Significant positive correlations between knowledge and practice, and attitude and practice were identified.

Rapid Screening of Microalgae as Potential Sources of Natural Antioxidants.

In order to rapidly screen microalgae species as feedstocks for antioxidants, extracts were obtained from 16 microalgae strains (under 11 genera, 7 classes) using two methods: a one-step extraction with ethanol/water and a three-step fractionating procedure using hexane, ethylacetate, and water successively. Measuring the total phenol content (TPC), total carotenoid content (TCC), and antioxidant activity of the extracts, indicating TPC and TCC, played an important role in determining the antioxidant activity of the microalgae. A weighted scoring system was used to evaluate the antioxidant activity, and the scores of microalgal samples from two extraction methods were calculated using the same system. Among the investigated microalgae, Euglena gracilis SCSIO-46781 had the highest antioxidant score, contributing to high TPC and TCC, followed by Arthrospira platensis SCSIO-44012, Nannochloropsis sp. SCSIO-45224, Phaeodactylum tricornutum SCSIO-45120, and Nannochloropsis sp. SCSIO-45006, respectively. Additionally, the above-mentioned five strains are currently being applied in commercial production, indicating this system could be effective not only for screening microalgal antioxidants, but also for screening microalgal species/strains with strong adaptation to environmental stress, which is a critical trait for their commercial cultivation.

Inhibition of H1N1 by Picochlorum sp. 122 via AKT and p53 signaling pathways.

Influenza viruses cause a severe threat to global health, which can lead to annual epidemics and cause pandemics occasionally. However, the number of anti-influenza therapeutic agents is very limited. Polysaccharides, extracted from Picochlorum sp. (PPE), seaweed Polysaccharides, have exhibited antiviral activity and were expected to be used for influenza treatment. In our research, the capability of PPE to inhibit H1N1 infection was proved in MDCK cells. PPE could make MDCK cells avoid being infected with H1N1 and inhibited nuclear fragmentation and condensation of chromatin. PPE evidently inhibited the generation of reactive oxygen species in MDCK cells. Mechanism study revealed that PPE prevented MDCK cells from H1N1 infection through induction of apoptosis by stimulating AKT signaling pathway and suppressing p-p53 signaling pathway. In conclusion, PPE turns out to act as a prospective antiviral drug for H1N1 influenza.

[Spectrometric characteristics and underlying mechanisms of protective effects of selenium on Spirulina platensis against oxidative stress].

To investigate the possibility and the underlying mechanisms of sodium selenite as antagonist for oxidative stress, the authors examined the effects of pretreatment with selenium on the growth, morphology, spectrometric characteristics and content of reactive oxygen species (ROS) in Spirulina platensis (S. platensis) exposed to H2O2 stress for 24 h in the present study. The results showed that H2O2 induced obvious inhibition of growth and serious morphological damage. The intensity of absorbance peak at 440 nm increased, whereas the peaks at 620 and 680 nm decreased after exposed to H2O2. The emission and excitation spectrum of S. platensis decreased dramatically after H2O2 treatment, and the emission peak from phycocyanin exhibited blue-shift from 660 to 650 nm. The results of FTIR analysis showed that the positions of transmission peaks had no shift, but the relative intensity of characteristic bands from protein and polypeptides including amide I and amide II decreased. Furthermore, the intracellular ROS generation in S. platensis increased significantly in response to H2O2 treatment. In contrast, pretreatments of the cells with selenium for 24 h significantly prevented the H2O2-induced oxidative damages in a dose-dependent manner. Taken together, our results indicate that pretreatments with selenium could prevent ROS overproduction in S. platensis and improve its antioxidant ability. Moreover, selenium could also reduce the effects of free radicals on energy harvest and energy transfer in S. platensis that play vital roles in its photosynthesis.