Hot spots and trends in microbial disease research on cultural heritage: a bibliometric analysis.

This study is to understand and analyze the development history, research hotspots, and research trends in the study of microbial diseases of cultural heritage through bibliometric analyses in order to fill the current gap of no literature review in this research field and to make certain contributions to the research in this field and the protection of cultural heritage. Bibliometric and visual analyses of the literature on cultural heritage microbial diseases in the Web of Science (WoS) core collection were carried out using VOSviewer and R-bibliometrix, choosing the two main literature types of papers and reviews. The emphasis was placed on analyzing and summarizing core research strengths, hotspots, and trends. Six hundred sixty-seven documents (573 articles and 94 reviews) were retrieved. αIn the WoS core collection, the first literature on cultural heritage microbial disease research was published in January 2000, and the annual number of publications from 2000 to 2009 did not exceed one; the annual number of publications from 2010 onwards increased rapidly, and after 2018, the number of publications per year exceeded 60, reaching 94 in 2020, which indicates that cultural heritage microbial disease research is booming. Our research showed that Italy, the USA, and China were the leading research countries, and Univ Milan was the institution with the most publications. International Biodeterioration &Biodegradation was the most published and co-cited journal, and Gu JD was the most prolific author. The research hotspots in the study of microbial diseases of cultural heritage mainly include biological degradation of cultural heritage; identification of diseased microorganisms and disease mechanisms; cultural heritage microbial disease prevention and control methods; monitoring, prevention, and control of diseased microorganisms in indoor air; antibacterial agents, especially essential oils, nanoparticles, and other safe and efficient antibacterial products research and development; and exploration of the mechanisms of biofilm protection of cultural heritage on cultural heritage surfaces. Monitoring and identifying cultural heritage microbial communities, identifying disease mechanisms, and researching safe and efficient bacteriostatic products such as essential oils and nanoparticles will be the main research directions in the field of cultural heritage microbial disease prevention and control in the future.

Fabrication of a Disposable Amperometric Sensor for the Determination of Nitrite in Food.

Silver nanoparticles (AgNPs) were synthesized through an environmentally friendly method with tea extract as a reduction agent. By immobilizing them on the surface of a low-cost pencil graphite electrode (PGE) with the aid of a simple and well-controlled in-situ electropolymerization method, a novel nanosensing interface for nitrite was constructed. The film-modified PGE showed good electrocatalytic effects on the oxidation of nitrite and was characterized through scanning electron microscopy, X-ray photoelectron spectroscopy, and electrochemical techniques. Characterization results clearly show that the successful modification of AgNPs improved the surface area and conductivity of PGEs, which is beneficial to the high sensitivity and short response time of the nitrite sensor. Under the optimal detection conditions, the oxidation peak current of nitrite had a good linear relationship with its concentration in the range of 0.02-1160 µmol/L with a detection limit of 4 nmol/L and a response time of 2 s. Moreover, the sensor had high sensitivity, a wide linear range, a good anti-interference capability, and stability and reproducibility. Additionally, it can be used for the determination of nitrite in food.

Apolipoprotein H induces sex-specific steatohepatitis and gut dysbiosis during chronic hepatitis B infection.

Apolipoprotein H (APOH) is involved in lipid metabolism and functions as an acute-phase protein during hepatitis B virus (HBV) infection. Herein, we explored whether APOH acts on the development of fatty liver upon chronic HBV infection. Serum APOH level was significantly lower in cirrhosis patients than in healthy controls or patients with chronic infection. It showed sex bias, with elevated levels in female patients with chronic infection. Also, serum APOH levels were negatively correlated with HBV surface antigen (HBsAg) but positively correlated with albumin and triglyceride levels. In In vitro HBV infection model, HBV upregulated APOH expression in a non-temporal manner, and HBsAg levels were elevated by silencing APOH. RNA sequencing (RNA-seq) demonstrated bidirectional expression of APOH, which impacted the immunoregulation upon infection or the metabolic regulation in HepG2.2.15 cells. Then, ApoH -/- mice with persistent HBV replication displayed steatohepatitis and gut microbiota dysbiosis with synergistic sex differences. Our study deciphers the roles of APOH in chronic liver diseases.

Improvement of aquaculture water quality by mixed Bacillus and its effects on microbial community structure.

Microbial remediation, especially the application of probiotics, has recently gained popularity in improving water quality and maintaining aquatic animal health. The efficacy and mechanism of mixed Bacillus for improvement of water quality and its effects on aquatic microbial community structure remain unknown. To elucidate these issues, we applied two groups of mixed Bacillus (Bacillus megaterium and Bacillus subtilis (A0 + BS) and Bacillus megaterium and Bacillus coagulans (A0 + BC)) to the aquaculture system of Crucian carp. Our results showed that the improvement effect of mixed Bacillus A0 + BS on water quality was better than that of A0 + BC, and the NH4+-N, NO2--N, NO3--N, and total phosphorus (TP) concentrations were reduced by 46.3%, 76.3%, 35.6%, and 80.3%, respectively. In addition, both groups of mixed Bacillus increased the diversity of the bacterial community and decreased the diversity of the fungal community. Microbial community analysis showed that mixed Bacillus A0 + BS increased the relative abundance of bacteria related with nitrogen and phosphorus removal, such as Proteobacteria, Actinobacteria, Comamonas, and Stenotrophomonas, but decreased the relative abundance of pathogenic bacteria (Acinetobacter and Pseudomonas) and fungi (Epicoccum and Fusarium). Redundancy analysis showed that NH4+-N, NO2--N, and TP were the primary environmental factors affecting the microbial community in aquaculture water. PICRUST analysis indicated that all functional pathways in the A0 + BS group were richer than those in other groups. These results indicated that mixed Bacillus A0 + BS addition produced good results in reducing nitrogenous and phosphorus compounds and shaped a favorable microbial community structure to further improve water quality.

Cross-species tropism and antigenic landscapes of circulating SARS-CoV-2 variants.

Mutations in the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike receptor-binding domain (RBD) may alter viral host tropism and affect the activities of neutralizing antibodies. Here, we investigated 153 RBD mutants and 11 globally circulating variants of concern (VOCs) and variants of interest (VOIs) (including Omicron) for their antigenic changes and cross-species tropism in cells expressing 18 ACE2 orthologs. Several RBD mutations strengthened viral infectivity in cells expressing ACE2 orthologs of non-human animals, particularly those less susceptible to the ancestral strain. The mutations surrounding amino acids (aas) 439-448 and aa 484 are more likely to cause neutralization resistance. Strikingly, enhanced cross-species infection potential in the mouse and ferret, instead of the neutralization-escape scores of the mutations, account for the positive correlation with the cumulative prevalence of mutations in humans. These findings present insights for potential drivers of circulating SARS-CoV-2 variants and provide informative parameters for tracking and forecasting spreading mutations.

A broad-spectrum nanobody targeting the C-terminus of the hepatitis B surface antigen for chronic hepatitis B infection therapy.

Sustainable viral suppression with hepatitis B surface antigen (HBsAg) loss is the new treatment goal for chronic hepatitis B (CHB). The role of antibodies in therapies for persistent hepatitis B virus (HBV) infection has received constant attention. While immunotherapy holds great promise, challenges for the antibody-based prevention and control of HBV in CHB include broad HBV antigenic diversity and the need for long-term viral suppression. In this study, we identified a new anti-HBsAg nanobody (Nb), 125s, isolated from HBsAg-immunized alpaca and confirmed its excellent potency in HBsAg clearance and broad-spectrum therapeutic activity against three HBV subtypes in vivo. In addition, we characterized a novel epitope at the C-terminus of the HBsAg surface motif from amino acids 157 to 174. A 125s-based long-term passive immunization program was efficacious at HBsAg clearance and inducing cellular immune responses, offering a promising outlook for CHB immunotherapy.

Virus-Free and Live-Cell Visualizing SARS-CoV-2 Cell Entry for Studies of Neutralizing Antibodies and Compound Inhibitors.

The ongoing corona virus disease 2019 (COVID-19) pandemic, caused by SARS-CoV-2 infection, has resulted in hundreds of thousands of deaths. Cellular entry of SARS-CoV-2, which is mediated by the viral spike protein and ACE2 receptor, is an essential target for the development of vaccines, therapeutic antibodies, and drugs. Using a mammalian cell expression system, a genetically engineered sensor of fluorescent protein (Gamillus)-fused SARS-CoV-2 spike trimer (STG) to probe the viral entry process is developed. In ACE2-expressing cells, it is found that the STG probe has excellent performance in the live-cell visualization of receptor binding, cellular uptake, and intracellular trafficking of SARS-CoV-2 under virus-free conditions. The new system allows quantitative analyses of the inhibition potentials and detailed influence of COVID-19-convalescent human plasmas, neutralizing antibodies and compounds, providing a versatile tool for high-throughput screening and phenotypic characterization of SARS-CoV-2 entry inhibitors. This approach may also be adapted to develop a viral entry visualization system for other viruses.

Cadmium induced BEAS-2B cells apoptosis and mitochondria damage via MAPK signaling pathway.

Cadmium, a heavy metal pollutant in industrial production, is found in air, water and soil, which is harmful to human health and can lead to diseases, such as asthma, lung cancer, and emphysema. In this study, the toxicity of cadmium on human bronchial epithelial cells (BEAS-2B) was investigated. Cell viability, mitochondrial membrane potential, reactive oxygen species (ROS) level, apoptosis and the related signaling pathways were detected with MTT assay, Rhodamine staining, DCFH-DA staining, Hoechst33258 staining and Western blot methods respectively. The results showed that the cell viability decreased, the mitochondrial membrane potential declined, ROS was accumulated and apoptotic rate raised in BEAS-2B cells. Meanwhile, the expression of B-cell lymphoma-2 (Bcl-2) was downregulated, while the expression of Bcl-2-associated X protein (Bax) and the cleaved caspase-3 was upregulated, which indicated mitochondria-mediated intrinsic apoptosis pathway was activated. Furthermore, the phosphorylation of JNK, ERK and p38 was enhanced respectively, which manifested that MAPK signaling pathways were activated. Therefore, it could be concluded that cadmium could increase intracellular ROS, result in cellular oxidative stress, activate JNK, ERK and p38 MAPK pathways and ultimately lead to apoptosis of BEAS-2B cells by activating mitochondria-mediated intrinsic apoptosis pathway. This study provided useful information to elucidate the toxicity of cadmium and revealed the possible mechanism for the occurrence of lung disease induced by cadmium.

Robust neutralization assay based on SARS-CoV-2 S-protein-bearing vesicular stomatitis virus (VSV) pseudovirus and ACE2-overexpressing BHK21 cells.

The global pandemic of coronavirus disease 2019 (COVID-19) is a disaster for human society. A convenient and reliable neutralization assay is very important for the development of vaccines and novel drugs. In this study, a G protein-deficient vesicular stomatitis virus (VSVdG) bearing a truncated spike protein (S with C-terminal 18 amino acid truncation) was compared to that bearing the full-length spike protein of SARS-CoV-2 and showed much higher efficiency. A neutralization assay was established based on VSV-SARS-CoV-2-Sdel18 pseudovirus and hACE2-overexpressing BHK21 cells (BHK21-hACE2 cells). The experimental results can be obtained by automatically counting the number of EGFP-positive cells at 12 h after infection, making the assay convenient and high-throughput. The serum neutralizing titer measured by the VSV-SARS-CoV-2-Sdel18 pseudovirus assay has a good correlation with that measured by the wild type SARS-CoV-2 assay. Seven neutralizing monoclonal antibodies targeting the receptor binding domain (RBD) of the SARS-CoV-2 S protein were obtained. This efficient and reliable pseudovirus assay model could facilitate the development of new drugs and vaccines.

Isolation and characterization of a salt-tolerant denitrifying bacterium Alishewanella sp. F2 from seawall muddy water.

A salt-tolerant denitrifying bacterium strain F2 was isolated from seawall muddy water in Dalian City, Liaoning Province, China. Strain F2 was identified by morphological observations, physiological and biochemical characteristics and 16 S rDNA identification. The salt tolerance of strain F2 was verified and the factors affecting the removal ability of strain F2 to nitrous nitrogen (NO2-N) and nitrate nitrogen (NO3-N) in saline conditions were investigated. Strain F2 was identified as Alishewanella sp., named Alishewanella sp. F2. Strain F2 can tolerate NaCl concentrations up to 70 g/L, and its most efficient denitrification capacity was observed at NaCl concentrations of 0-30 g/L. In the medium with NaCl concentrations of 0-30 g/L, strain F2 exhibited high removal efficiencies of NO2-N and NO3-N, with the removal percentages for both NO2-N and NO3-N of approximately 99%. In saline conditions with 30 g/L NaCl, the optimum culture pH, NaNO2 initial concentrations and inoculation sizes of strain F2 were 8-10, 0.4-0.8 g/L and 5-7%, respectively. Strain F2 was highly effective in removing NO2-N and NO3-N in saline conditions, and it has a good application potential in saline wastewater treatment.

[Recognition of priority area of biodiversity conservation in Liaoning Province, Northeast China]. / è¾½å®çœç”Ÿç‰©å¤šæ ·æ€§ä¿æŠ¤ä¼˜å ˆåŒºè¯†åˆ«.

Priority areas of biodiversity conservation (PABC) were classified to strengthen biodiversity conservation in China. As there are no such priority areas in Liaoning Province, China, it is important to make up this gap. After calculation of seven indices at three composition levels (ecosystem conservation, human interference, and regionalization for biodiversity conservation), index values, composition values, and comprehensive recognition value for PABCs in Liaoning Province were obtained successively. Suggested territorial scopes of Western Liaoning Priority Area (WPA) and Eastern Liaoning Priority Area (EPA) were then determined in terms of administrative boundaries of towns, counties, and nature reserves. Among them, WPA covers an area of 12951 km2, with 53.6% of forest coverage and nine national or provincial nature reserves. The main ecological function of WPA is soil and water conservation. EPA is 20057 km2 in area, with 78.9% of forest cove-rage and eight national or provincial nature reserves. Water resource conservation is the main ecological function of EPA. Key protected species at national or provincial level and the important ecosystems are densely distributed in those priority areas. It is urgent to carry out biodiversity conservation in these PABCs.

Identification and denitrification characteristics of a salt-tolerant denitrifying bacterium Pannonibacter phragmitetus F1.

A salt-tolerant denitrifying bacterium F1 was isolated in this study, which has high nitrite (NO2--N) and nitrate (NO3--N) removal abilities. The salt tolerance capacity of strain F1 was further verified and the effects of initial pH, initial NaNO2 concentration and inoculation size on the denitrification capacity of strain F1 under saline conditions were evaluated. Strain F1 was identified as Pannonibacter phragmitetus and named Pannonibacter phragmitetus F1. This strain can tolerate NaCl concentrations up to 70 g/L, and its most efficient denitrification capacity was observed at NaCl concentrations of 0-10 g/L. Under non-saline condition, the removal percentages of NO2--N and NO3--N by strain Pannonibacter phragmitetus F1 at pH of 10 and inoculation size of 5% were 100% and 83%, respectively, after cultivation for 5 days. Gas generation was observed during the cultivation, indicating that an efficient denitrification performance was achieved. When pH was 10 and the inoculation size was 5%, both the highest removal percentages of NO2--N (99%) and NO3--N (95%) by strain Pannonibacter phragmitetus F1 were observed at NaCl concentration of 10 g/L. When the NaCl concentration was 10 g/L, strain Pannonibacter phragmitetus F1 can adapt to a wide range of neutral and alkaline environments (pH of 7-10) and is highly tolerant of NaNO2 concentration (0.4-1.6 g/L). In conclusion, strain Pannonibacter phragmitetus F1 has a great potential to be applied in the treatment of saline wastewater containing high nitrogen concentrations, e.g. coastal aquaculture wastewater.

Nanobody-based sandwich reporter system for living cell sensing influenza A virus infection.

The influenza epidemic is a huge burden to public health. Current influenza vaccines provide limited protection against new variants due to frequent mutation of the virus. The continual emergence of novel variants necessitates the method rapidly monitoring influenza virus infection in experimental systems. Although several replication-competent reporter viruses carrying fluorescent proteins or small luciferase have been generated in previous studies, visualizing influenza virus infection via such strategy requires reverse genetic modification for each viral strain which is usually time-consuming and inconvenient. Here, we created a novel influenza A nucleoprotein (NP) dependent reporter gene transcription activation module using NP-specific nanobodies. Our results demonstrated the modular design allowed reporter genes (mNeonGreen fluorescent protein and Gaussia luciferase) specifically expressing to detect intracellular NP protein, and therefore acts as a universal biosensor to monitor infection of various influenza A subtypes in living cells. The new system may provide a powerful tool to analyze influenza A infections at the cellular level to facilitate new antiviral drug discovery. Moreover, this approach may easily extend to develop live-cell biosensors for other viruses.