Bacteriophage-encoded protein utilization in bacterial ghost production: a mini-review.

Bacterial ghosts (BGs) are described as bacterial cell envelopes that retain their structure but lack cytoplasmic contents. The study of BGs spans multiple disciplinary domains, and the development of BG production techniques to obtain ample and stable BG samples holds significant implications for probing the biological characteristics of BGs, devising novel disease treatment strategies, and leveraging their industrial applications. Numerous products encoded within bacteriophage (phage) genomes possess the capability to lyse bacteria, thereby inducing BG formation primarily via disruption of bacterial cell wall integrity. This review comprehensively surveys the utilization of phage-encoded proteins in BG production techniques, encompassing methodologies such as phage E protein-mediated lysis, perforin protein-induced lysis, and strategies combining E protein with holin-endolysin systems. Additionally, discussions and summaries are provided on the current applications, challenges, and modification strategies associated with different techniques. Through a focused exploration of BG production techniques, with an emphasis on precise manipulation of BG formation using phage-encoded protein technologies, this study aims to furnish robust tools and methodologies for delving into the mechanisms underlying BG formation, as well as for the development of novel therapeutic strategies and applications based on BGs.

Visualizing the Habenula Using 3T High-Resolution MP2RAGE and QSM: A Preliminary Study.

BACKGROUND AND PURPOSE: The habenula is a key node in the regulation of emotion-related behavior. Accurate visualization of the habenula and its reliable quantitative analysis is vital for the assessment of psychiatric disorders. To obtain high-contrast habenula images and allow them to be compatible with clinical applications, this preliminary study compared 3T MP2RAGE and quantitative susceptibility mapping with MPRAGE by evaluating the habenula segmentation performance. MATERIALS AND METHODS: Ten healthy volunteers were scanned twice with 3T MPRAGE and MP2RAGE and once with quantitative susceptibility mapping. Image quality and visibility of habenula anatomic features were analyzed by 3 radiologists using a 5-point scale. Contrast assessments of the habenula and thalamus were also performed. The reproducibility of the habenula volume from MPRAGE and MP2RAGE was evaluated by manual segmentation and the Multiple Automatically Generated Template brain segmentation algorithm (MAGeTbrain). T1 values and susceptibility were measured in the whole habenula and habenula geometric subregion using MP2RAGE T1-mapping and quantitative susceptibility mapping. RESULTS: The 3T MP2RAGE and quantitative susceptibility mapping demonstrated clear boundaries and anatomic features of the habenula compared with MPRAGE, with a higher SNR and contrast-to-noise ratio (all P < .05). Additionally, 3T MP2RAGE provided reliable habenula manual and MAGeTbrain segmentation volume estimates with greater reproducibility. T1-mapping derived from MP2RAGE was highly reliable, and susceptibility contrast was highly nonuniform within the habenula. CONCLUSIONS: We identified an optimized sequence combination (3T MP2RAGE combined with quantitative susceptibility mapping) that may be useful for enhancing habenula visualization and yielding more reliable quantitative data.

ZSP1601, a novel pan-phosphodiesterase inhibitor for the treatment of NAFLD, A randomized, placebo-controlled phase Ib/IIa trial.

Non-alcoholic fatty liver disease is a growing health burden with limited treatment options worldwide. Herein we report a randomized, double-blind, placebo-controlled, multiple-dose trial of a first-in-class pan-phosphodiesterase inhibitor ZSP1601 in 36 NAFLD patients (NCT04140123). There were three cohorts. Each cohort included twelve patients, nine of whom received ZSP1601 50 mg once daily, 50 mg twice daily, or 100 mg twice daily, and three of whom received matching placebos for 28 days. The primary outcomes were the safety and tolerability of ZSP1601. A total of 27 (27/36, 75%) patients experienced at least one treatment-emergent adverse event (TEAE). Most TEAEs were mild to moderate. There was no Serious Adverse Event. Diarrhea, transiently elevated creatinine and adaptive headache were frequently reported adverse drug reaction. We conclude that ZSP1601 is well-tolerated and safe, showing effective improvement in liver chemistries, liver fat content and fibrosis in patients with NAFLD.

Effects of agricultural activities on hydrochemistry in the Shiyang River Basin, China.

Agricultural water accounts for more than 80% of the available water in arid areas. Agricultural activities have a great impact on surface water and groundwater. If the impact of agricultural activities on hydrochemistry is not prevented, the risk of water quality change in arid areas may be greatly intensified. Based on the hydrochemical data of the whole Shiyang River Basin from April 2014 to October 2019, this paper analyzes the impact of agricultural activities on hydrochemistry in the basin. The results show that (i) in the middle and lower reaches of farmland with high intensity of agricultural activities, the ion concentration of groundwater in summer and autumn is significantly higher than that in winter and spring due to the influence of irrigation; (ii) the runoff ion concentration in the backflow of the river reaches recharged by irrigation water is significantly higher than that of other reaches; (iii) due to strong evaporation, different types of reservoirs will lead to an overall increase in ion concentration, which is more obvious in plain reservoirs and river tail lakes. In addition, the reservoirs have a certain removal effect on nitrates.

Ion migration process and influencing factors in inland river basin of arid area in China: a case study of Shiyang River Basin.

A thorough understanding of the processes and driving factors of ion migration, dilution, and enrichment in arid inland river basins is the basis for implementing water resources management. In this study, we analyzed the water chemistry of streamflow, groundwater, and precipitation and the behavior of main elements in the Shiyang River Basin by means of the hydrochemical diagram and multivariate statistical analysis. The spatial variation of water chemistry was obvious, and the conversion between different water bodies was frequent. The ions migrated from the mountain area to the oasis and desert and accumulated near the terminal lake finally. There were obvious differences in hydrochemistry between surface water and groundwater. From the mountain to the basin, the hydrochemical type of surfer water has varied, and the hydrochemical type of groundwater has changed from Ca-Cl type to Na-Cl type. The hydrochemistry of the basin was controlled by silicate weathering. However, the influence of water-rock interaction on surface water and groundwater was different, and the surface water was more complex. Significantly, agricultural activities and sewage discharge had a negative impact on the water environment. Interbasin water transfer (IBWT) was a form of external ions input from outside the basin, which affected the chemical characteristics of surface water in the lower reaches to a certain extent. In arid areas, human impact on water chemistry needs to be paid attention. These results are helpful to strengthen the understanding of the relationship between different regions and different water bodies in the arid basin.

Biogeomorphological processes and structures facilitate seedling establishment and distribution of annual plants: Implications for coastal restoration.

Biogeomorphological processes and structures (BPS) can affect plant growth and community structure and promote landscape complexity in ecosystems. However, there is a lack of understanding of how BPS facilitates seedling establishment and distribution of annual plants and promotes the success of coastal restoration. We studied the relationships between seedling establishment of a native annual plant species (Suaeda salsa) and BPS resulting from crabs and plants in a middle elevation salt marsh with moderate tides (where inhabited generally high density of plants and crabs) in the Yellow River Delta of China. While there were many crabs but fewer plants in lower elevation areas with more frequent and stronger tides; and in higher elevation areas with weaker tides there were both fewer crabs and plants. Investigations and field manipulation experiments of microtopography, crabs and plants were conducted to determine if and how these BPS influenced seedling establishment and distribution under tidal influence in the middle elevation salt marshes. Results demonstrated that biogeomorphological structures, mainly concave hollows generated by crab burrowing and concave hollows around plant roots and stems under tidal influence, were associated with the trapping of seeds and influenced the establishment and distribution of seedlings. Additionally, upon senescence, maternal plants with unreleased seeds lodged on the ground and influenced seed retention and seedling establishment. The artificial concave hollows that were created experimentally also trapped many seeds and facilitated seedling establishment. Experimental plantings and creation of artificial hollow microtopography attracted crabs that created burrows, resulting in a positive feedback on seedling establishment. We used information obtained from the experimental component of the study to conduct a hollow microtopography manipulation to successfully restore degraded salt marshes. Understanding the associations between seedling establishment and biogeomorphological processes provides important insights for the utilization of natural or human ecosystem engineering to restore coastal vegetation ecosystems.

An integrative perspective to understand the impact of co-occurring ecosystem engineers on macroinvertebrates.

Invasion of habitat-modifying nonnative species and alteration of ecosystem engineer by exploitation are two of the dominant human impacts on natural ecosystem functioning. The effects of these co-occurring ecosystem engineers may act simultaneously and vary independently depending on ambient environmental conditions they modify. Using a saltmarsh ecosystem with continuing invasion of nonnative cordgrass and aggregation of native bivalve shells, we tested whether the ecosystem engineering effects of shell aggregation on macroinvertebrates depended on the plants due to their ability to trap shell debris. We found habitats covered with shell aggregation and vegetated cordgrass significantly increase the biodiversity but decrease the biomass of macroinvertebrates comparing to the tidal bare flats, whereas no differences were detected among shell covered, cordgrass vegetated and their coexistent habitats. Our study highlights the importance of considering multiple, potentially conflicting management goals, which may require flexibility and trade-offs to integrate nonnative and native resources into ecosystem management.

Tolerance between non-resource stress and an invader determines competition intensity and importance in an invaded estuary.

The competition-to-stress hypothesis suggests that some competitively disadvantaged species are excluded from higher inundation estuaries due to abiotic stress (high flooding level) and from lower inundation estuaries by competition. How abiotic and biotic stress interactions affect plant growth and whether competition intensity and importance are stable along environmental gradients is a controversial subject. We explored the influence of two factors, and we clarified that inundation stress and invasion competition are the main reasons leading to the traits exhibited by target plant Suaeda salsa and population presence changes. Our results indicated that when the flooding height exceeded 13.4 cm, the S. salsa mortality rate was 90%-100%. At the lower flooding heights (<13.4 cm), the S. salsa mortality rate when neighboring plants were present was 77.7%-100%, whereas, without neighbors it was 30.9%-83.7%. The invader Spartina alterniflora inhibited S. salsa plant height by 48%-77%, whereas the S. alterniflora inhibited S. salsa density by 11%-98% and reduced its biomass by 50.5%-90.1%. The changes in competition intensity and importance showed that the S. alterniflora had a distinct impact from the early germinant period to growing period (from May to July), finally stable no differences along the flooding height in the maturity period. At the same flooding level, the analysis of above and belowground competition by S. alterniflora showed that aboveground and belowground competition are the main causes of individual S. salsa inhibition. Our results confirm the competitive stress hypothesis, which is that competition shapes individual traits and population presence in the context of abiotic stress. This conclusion can guide the management and protection of native plants under biological invasion in a stressful environment.

Trait and density responses of Spartina alterniflora to inundation in the Yellow River Delta, China.

Understanding plant traits in response to physical stress has been an important issue in the study of coastal saltmarshes. For plants that reproduce both sexually and asexually, whether and how seedlings (sexual reproduction) and clonal ramets (asexual reproduction) may differentially respond to tidal inundation is still unclear. We investigated the growth and morphology of sexual and asexual propagules of an exotic saltmarsh plant (Spartina alterniflora) along a gradient of tidal submergence in the Yellow River Delta. Our results showed that the density, height and basal diameter of clonal ramets or sexual seedlings increased with tidal inundation. The patch amplification edge clonal ramets are superior than patch center plants. The differences response of plants to tidal inundation highlight the sensitivity of S. alterniflora to future tidal regime shifts and can help predict and evaluate the impacts of changes in inundation conditions due to sea level rise, coastal erosion and human activities.

How vegetation influence the macrobenthos distribution in different saltmarsh zones along coastal topographic gradients.

Macrobenthos are a key constituent of coastal salt marsh ecosystems and have often been used as sensitive indicators of the environment quality. In this study, field investigations in vegetated regions and adjacent bare patches of low, middle and high marshes were conducted to explore whether and how vegetation influence the macrobenthos distribution in different saltmarsh zones along coastal topographic gradients. Results showed that vegetation positively or negatively influenced macrobenthos mainly by changing their environment in different saltmarsh zones, as there were different degrees of physical stresses and food supply for the macrobenthos from the low to the high marsh. In the low marsh, no major differences in macrobenthos indices between the bare and vegetated sediments were found, yet density and biomass of the molluscs were higher in the bare patches. In the middle marsh, vegetation promoted the biomass and diversity indices but not the density and species richness of the macrobenthos, and vegetation was beneficial for some types of crustaceans but was detrimental for some types of polychaetes. In the high marsh, vegetation promoted the biomass, density, and species richness of the macrobenthos compared to those of adjacent bare patches. Coastal topographic gradients also had effects on macrobenthos distribution consistently with different habitat preferences and ecological niches, and the low marsh had the highest species richness, Shannon diversity, Pielou evenness and Margalef richness. This study also provided scientific implications for the management and restoration of the ecosystems in different intertidal saltmarsh zones.

Microtopographical modification by a herbivore facilitates the growth of a coastal saltmarsh plant.

Increasing evidence shows that herbivores can facilitate plant growth and maintain the resistance of plant communities to trophic consumption in a variety of ecosystems. However, the positive effects of herbivores on annual saltmarsh plants in coastal ecosystems are relatively understudied. In this study, field investigations and manipulative experiments were conducted to explore whether and how microtopographical modification by the herbivorous crab Helice tientsinensis stimulates the growth of the saltmarsh plant Suaeda salsa. Results showed that, despite grazing on S. salsa, H. tientsinensis can promote density, total biomass, average plant height, average root length, and average biomass through burrowing-generated concave-convex microtopography, which can improve the edaphic environment (decreased soil hardness and salinity, and increased soil moisture content, oxidation-reduction potential, and carbon and nitrogen content), and provide plants more clustered growth opportunities that could facilitate positive intraspecific plant interactions. This study can provide scientific guidance for ecosystem restoration in coastal intertidal saltmarshes.

Removal efficiency of particulate matters at different underlying surfaces in Beijing.

Particulate matter (PM) pollution has been increasingly becoming serious in Beijing and has drawn the attention of the local government and general public. This study was conducted during early spring of 2013 and 2014 to monitor the concentration of PM at three different land surfaces (bare land, urban forest, and lake) in the Olympic Park in Beijing and to analyze its effect on the concentration of meteorological factors and the dry deposition onto different land cover types. The results showed that diurnal variation of PM concentrations at the three different land surfaces had no significant regulations, and sharp short-term increases in PM10 (particulate matter having an aerodynamic diameter <10 µm) occurred occasionally. The concentrations also differed from one land cover type to another at the same time, but the regulation was insignificant. The most important meteorological factor influencing the PM concentration is relative humidity; it is positively correlated with the PM concentration. While in the forests, the wind speed and irradiance also influenced the PM concentration by affecting the capture capacity of trees and dry deposition velocity. Other factors were not correlated with or influenced by the PM concentration. In addition, the hourly dry deposition in unit area (µg/m(2)) onto the three types of land surfaces and the removal efficiency based on the ratio of dry deposition and PM concentration were calculated. The results showed that the forest has the best removal capacity for both PM2.5 (particulate matter having an aerodynamic diameter <2.5 µm) and PM10 because of the faster deposition velocity and relatively low resuspension rate. The lake's PM10 removal efficiency is higher than that of the bare land because of the relatively higher PM resuspension rates on the bare land. However, the PM2.5 removal efficiency is lower than that of the bare land because of the significantly lower dry deposition velocity.

Particulate matter assessment of a wetland in Beijing.

To increase the knowledge on the particulate matter of a wetland in Beijing, an experimental study on the concentration and composition of PM10 and PM2.5 was implemented in Beijing Olympic Forest Park from 2013 to 2014. This study analyzed the meteorological factors and deposition fluxes at different heights and in different periods in the wetlands. The results showed that the mean mass concentrations of PM10 and PM2.5 were the highest at 06:00-09:00 and the lowest at 15:00-18:00. And the annual concentration of PM10 and PM2.5 in the wetland followed the order of dry period (winter)>normal water period (spring and autumn)>wet period (summer), with the concentration in the dry period significantly higher than that in the normal water and wet periods. The chemical composition of PM2.5 in the wetlands included NH4(+), K(+), Na(+), Mg(2+), SO4(2-), NO3(-), and Cl(-), which respectively accounted for 12.7%, 1.0%, 0.8%, 0.7%, 46.6%, 33.2%, and 5.1% of the average annual composition. The concentration of PM10 and PM2.5 in the wetlands had a significant positive correlation with relative humidity, a negative correlation with wind speed, and an insignificant negative correlation with temperature and radiation. The daily average dry deposition amount of PM10 in the different periods followed the order of dry period>normal water period>wet period, and the daily average dry deposition amount of PM2.5 in the different periods was dry period>wet period>normal water period.