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Discrete Heteropolynuclear Yb/Er Assemblies: Switching on Molecular Upconversion Under Mild Conditions

Wang J, Jiang Y, Liu JY, Xu HB, Zhang YX, Peng X, et al.

Angew Chem Int Ed Engl, 2021 Oct 04;60(41):22368-22375.
PMID: 34383376 DOI: 10.1002/anie.202107637

The salts {[Ln2 Ln*(Hhmq)3 (OAc)3 (hfac)2 ]+ [Ln*(hfac)3 (OAc)(MeOH)]- } (Hhmq=2-methanolquinolin-8-oxide, hfac=hexafluoroacetylacetonate; Ln, Ln*=Er, Gd, Yb) feature a discrete heteronuclear cation consisting of two types of lanthanide atoms. The quinolinoxy O-atom serves as a μ2 -bridge to two Ln atoms and as a μ3 -bridge to all three atoms, with metal⋅⋅⋅metal distances being around 3.7 Å. For 1 ([Yb2 Er]+ ), near-infrared downshifted luminescence is switched to competitive upconversion luminescence upon irradiation by a 980 nm laser under an extremely low excitation power (0.288 W cm-2 ) through introduction of fluoride ions. The stability of 1 after addition of fluoride was confirmed by powder X-ray diffraction and multistage mass spectrometry, associated with the 1 H NMR of 6 ([La2 Eu]+ ). More importantly, the at least 20-fold enhancement of the quantum yield in non-deuterated solvents at room temperature under low power densities (2 W cm-2 ) is the highest among the few molecular examples reported.
An update of aurones: food resource, health benefit, biosynthesis and application

Yang J, Gao Z, Yu Z, Hou Y, Tang D, Yan H, et al.

Crit Rev Food Sci Nutr, 2023 Aug 21.
PMID: 37599623 DOI: 10.1080/10408398.2023.2248244

Aurones are a subclass of active flavonoids characterized with a scaffold of 2-benzylidene-3(2H)-benzofuranone. This type of chemicals are widely distributed in fruit, vegetable and flower, and contribute to human health. In this review, we summarize the natural aurones isolated from dietary plants. Their positive effects on immunomodulation, antioxidation, cancer prevention as well as maintaining the health status of cardiovascular, nervous system and liver organs are highlighted. The biosynthesis strategies of plant-derived aurones are elaborated to provide solutions for their limited natural abundance. The potential application of natural aurones in food coloration are also discussed. This paper combines the up-to-date information and gives a full image of dietary aurones.
Fulltext Discovering Knee Osteoarthritis Imaging Features for Diagnosis and Prognosis: Review of Manual Imaging Grading and Machine Learning Approaches

Teoh YX, Lai KW, Usman J, Goh SL, Mohafez H, Hasikin K, et al.

J Healthc Eng, 2022;2022:4138666.
PMID: 35222885 DOI: 10.1155/2022/4138666

Knee osteoarthritis (OA) is a deliberating joint disorder characterized by cartilage loss that can be captured by imaging modalities and translated into imaging features. Observing imaging features is a well-known objective assessment for knee OA disorder. However, the variety of imaging features is rarely discussed. This study reviews knee OA imaging features with respect to different imaging modalities for traditional OA diagnosis and updates recent image-based machine learning approaches for knee OA diagnosis and prognosis. Although most studies recognized X-ray as standard imaging option for knee OA diagnosis, the imaging features are limited to bony changes and less sensitive to short-term OA changes. Researchers have recommended the usage of MRI to study the hidden OA-related radiomic features in soft tissues and bony structures. Furthermore, ultrasound imaging features should be explored to make it more feasible for point-of-care diagnosis. Traditional knee OA diagnosis mainly relies on manual interpretation of medical images based on the Kellgren-Lawrence (KL) grading scheme, but this approach is consistently prone to human resource and time constraints and less effective for OA prevention. Recent studies revealed the capability of machine learning approaches in automating knee OA diagnosis and prognosis, through three major tasks: knee joint localization (detection and segmentation), classification of OA severity, and prediction of disease progression. AI-aided diagnostic models improved the quality of knee OA diagnosis significantly in terms of time taken, reproducibility, and accuracy. Prognostic ability was demonstrated by several prediction models in terms of estimating possible OA onset, OA deterioration, progressive pain, progressive structural change, progressive structural change with pain, and time to total knee replacement (TKR) incidence. Despite research gaps, machine learning techniques still manifest huge potential to work on demanding tasks such as early knee OA detection and estimation of future disease events, as well as fundamental tasks such as discovering the new imaging features and establishment of novel OA status measure. Continuous machine learning model enhancement may favour the discovery of new OA treatment in future.
Application of Semi-supervised Fuzzy Clustering Based on Knowledge Weighting and Cluster Center Learning to Mammary Molybdenum Target Image Segmentation

Peng P, Wu D, Huang LJ, Wang J, Zhang L, Wu Y, et al.

Interdiscip Sci, 2024 Mar;16(1):39-57.
PMID: 37486420 DOI: 10.1007/s12539-023-00580-0

Breast cancer is commonly diagnosed with mammography. Using image segmentation algorithms to separate lesion areas in mammography can facilitate diagnosis by doctors and reduce their workload, which has important clinical significance. Because large, accurately labeled medical image datasets are difficult to obtain, traditional clustering algorithms are widely used in medical image segmentation as an unsupervised model. Traditional unsupervised clustering algorithms have limited learning knowledge. Moreover, some semi-supervised fuzzy clustering algorithms cannot fully mine the information of labeled samples, which results in insufficient supervision. When faced with complex mammography images, the above algorithms cannot accurately segment lesion areas. To address this, a semi-supervised fuzzy clustering based on knowledge weighting and cluster center learning (WSFCM_V) is presented. According to prior knowledge, three learning modes are proposed: a knowledge weighting method for cluster centers, Euclidean distance weights for unlabeled samples, and learning from the cluster centers of labeled sample sets. These strategies improve the clustering performance. On real breast molybdenum target images, the WSFCM_V algorithm is compared with currently popular semi-supervised and unsupervised clustering algorithms. WSFCM_V has the best evaluation index values. Experimental results demonstrate that compared with the existing clustering algorithms, WSFCM_V has a higher segmentation accuracy than other clustering algorithms, both for larger lesion regions like tumor areas and for smaller lesion areas like calcification point areas.
Structure identification of a polysaccharide purified from Lycium barbarium fruit

Yuan Y, Wang YB, Jiang Y, Prasad KN, Yang J, Qu H, et al.

Int J Biol Macromol, 2016 Jan;82:696-701.
PMID: 26505952 DOI: 10.1016/j.ijbiomac.2015.10.069

The water-soluble bioactive polysaccharides can contribute to the health benefits of Lycium barbarium fruit. However, the structure characteristics of these polysaccharides remain unclear yet. An important polysaccharide (LBPA) was isolated and purified from L. barbarium in this work. It was identified by chemical and spectroscopic methods as arabinogalactan with β-d-(1→6)-galactan as backbone, which was different to any reported polysaccharides from this species before. This arabinogalactan was comprised of Araf, Galp, GlcpA and Rhap with a molar ratio of 9.2:6.6:1.0:0.9. The side chains, including α-l-Araf-(1→, α-l-Araf-(1→5)-α-l-Araf-(1→, β-l-Araf-(1→5)-α-l-Araf-(1→ and α-l-Rhap-(1→4)-β-d-GlcpA-(1→6)-β-d-Galp-(1→, were linked to β-d-(1→6)-galactan at O-3. The putative structure was drawn as below. The molecular weight was determined to be 470,000g/mol by gel permeation chromatography.
Research advances in detection of food adulteration and application of MALDI-TOF MS: A review

Song D, Dong K, Liu S, Fu S, Zhao F, Man C, et al.

Food Chem, 2024 Oct 30;456:140070.
PMID: 38917694 DOI: 10.1016/j.foodchem.2024.140070

Food adulteration and illegal supplementations have always been one of the major problems in the world. The threat of food adulteration to the health of consumers cannot be ignored. Food of questionable origin causes economic losses to consumers, but the potential health risks cannot be ignored. However, the traditional detection methods are time-consuming and complex. This review mainly discusses the types of adulteration and technologies used to detect adulteration. Matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) is also emphasized in the detection of adulteration and authenticity of origin analysis of various types of food (milk, meat, edible oil, etc.), and the future application direction and feasibility of this technology are analyzed. On this basis, MALDI-TOF MS was compared with other detection methods, highlighting the advantages of this technology in the detection of food adulteration. The future development prospect and direction of this technology are also emphasized.
Fulltext A network analysis of the heterogeneity and associated risk and protective factors of depression and anxiety among college students

Niu C, Jiang Y, Li Y, Wang X, Zhao H, Cheng Z, et al.

Sci Rep, 2025 Feb 25;15(1):6699.
PMID: 40000716 DOI: 10.1038/s41598-025-91025-9

BACKGROUND: Comorbidity of depression and anxiety is common among adolescents and can lead to adverse outcomes. However, there is limited understanding of the latent characteristics and mechanisms governing these disorders and their interactions. Moreover, few studies have examined the impacts of relevant risk and protective factors.
METHODS: This cross-sectional study involved 1,719 students. Mplus 8.0 software was used to conduct latent profile analysis to explore the potential categories of depression and anxiety comorbidities. R4.3.2 software was used to explore the network of core depression and anxiety symptoms, bridge these disorders, and evaluate the effects of risk and protective factors.
RESULTS: Three categories were established: "healthy" (57.8%), "mild depression-mild anxiety" (36.6%), and "moderately severe depression-moderate anxiety" (5.6%). "Depressed mood", "nervousness", and "difficulty relaxing" were core symptoms in both the depression-anxiety comorbidity network and the network of risk and protective factors. Stress perception and neuroticism serve as bridging nodes connecting some symptoms of depression and anxiety and are thus considered the most prominent risk factors.
CONCLUSIONS: According to the core and bridging symptoms identified in this study, targeted intervention and treatment can be provided to groups with comorbid depression and anxiety, thereby reducing the risk of these comorbidities in adolescents.
Measurement differences explain much of the variation in adherence and persistence after ischemic stroke, and standardized estimates are lower: a systematic review with meta-regression

Jiang Y, Chen J, Liu L, Lee WL, Pan R, Qian Q, et al.

J Clin Epidemiol, 2026 Oct 22.
PMID: 42914064 DOI: 10.1016/j.jclinepi.2026.112571

OBJECTIVE: Continued use of secondary prevention medications after ischemic stroke or transient ischemic attack is an important component of long-term management. Reported estimates of adherence and persistence vary considerably across studies, limiting comparison and interpretability. Although some variation may reflect differences in patient behavior, inconsistencies in operational definitions and measurement approaches are also likely to contribute. We sought to examine sources of heterogeneity and to derive standardized estimates using a common reference measurement framework.
STUDY DESIGN AND SETTING: We searched bibliographic databases, dissertations, and trial registries from inception to September 10, 2025, for routine-care studies reporting adherence or persistence to secondary prevention medications after ischemic stroke or transient ischemic attack. Cutoff-based proportions were extracted. We used 3-level hierarchical Bayesian models to characterize heterogeneity and multivariable meta-regression to evaluate associations with measurement specifications, follow-up window, medication class, region, and study-level characteristics. From the fitted model, we derived estimates standardized to a prespecified reference specification: pharmacy or administrative data, moderate definition stringency, and a 9- to 15-month follow-up window.
RESULTS: The review included 141 studies; 101 (432 estimates; 976,020 participants) contributed to the quantitative synthesis. Unstandardized pooled estimates suggested that 74.1% of patients were adherent and 76.8% were persistent. Heterogeneity was substantial, with explained variation concentrated more in the measurement-related Assessment and Administration domains than in reported Patient characteristics. Under the common reference specification, the model-based estimates were lower, at 53.7% for adherence and 48.2% for persistence. Standardized persistence declined from 63.3% at 1 to 4 months to 28.1% beyond 30 months. Adjusted estimates were generally lower in Asia; persistence was numerically lowest for anticoagulants, although credible intervals were wide and overlapping.
CONCLUSION: A large proportion of the heterogeneity reported in medication adherence and persistence after ischemic stroke or transient ischemic attack appears to be attributable to methodological non-equivalence in how these outcomes are defined and measured. When evaluated within a standardized framework, suboptimal medication continuation appears more common than conventional pooled estimates indicate. Meaningful surveillance and benchmarking require longitudinal, standardized, and transparent measures of medication continuation rather than reliance on discharge prescribing alone.
Fulltext Characterization and genomic analysis of the first Oceanospirillum phage, vB_OliS_GJ44, representing a novel siphoviral cluster

Zhang W, Liang Y, Zheng K, Gu C, Liu Y, Wang Z, et al.

BMC Genomics, 2021 Sep 20;22(1):675.
PMID: 34544379 DOI: 10.1186/s12864-021-07978-4

BACKGROUND: Marine bacteriophages play key roles in the community structure of microorganisms, biogeochemical cycles, and the mediation of genetic diversity through horizontal gene transfer. Recently, traditional isolation methods, complemented by high-throughput sequencing metagenomics technology, have greatly increased our understanding of the diversity of bacteriophages. Oceanospirillum, within the order Oceanospirillales, are important symbiotic marine bacteria associated with hydrocarbon degradation and algal blooms, especially in polar regions. However, until now there has been no isolate of an Oceanospirillum bacteriophage, and so details of their metagenome has remained unknown.
RESULTS: Here, we reported the first Oceanospirillum phage, vB_OliS_GJ44, which was assembled into a 33,786 bp linear dsDNA genome, which includes abundant tail-related and recombinant proteins. The recombinant module was highly adapted to the host, according to the tetranucleotides correlations. Genomic and morphological analyses identified vB_OliS_GJ44 as a siphovirus, however, due to the distant evolutionary relationship with any other known siphovirus, it is proposed that this virus could be classified as the type phage of a new Oceanospirivirus genus within the Siphoviridae family. vB_OliS_GJ44 showed synteny with six uncultured phages, which supports its representation in uncultured environmental viral contigs from metagenomics. Homologs of several vB_OliS_GJ44 genes have mostly been found in marine metagenomes, suggesting the prevalence of this phage genus in the oceans.
CONCLUSIONS: These results describe the first Oceanospirillum phage, vB_OliS_GJ44, that represents a novel viral cluster and exhibits interesting genetic features related to phage-host interactions and evolution. Thus, we propose a new viral genus Oceanospirivirus within the Siphoviridae family to reconcile this cluster, with vB_OliS_GJ44 as a representative member.
Nutritional compositions and bioactivities of Dacryodes species: a review

Tee LH, Yang B, Nagendra KP, Ramanan RN, Sun J, Chan ES, et al.

Food Chem, 2014 Dec 15;165:247-55.
PMID: 25038673 DOI: 10.1016/j.foodchem.2014.05.084

Dacryodes species are evergreen, perennial trees with fleshy fruits and belong to the family Buseraseae. Many Dacryodes species are underutilized but are widely applied in traditional folk medicine to treat malaria, fever and skin diseases. The nutritional compositions, phytochemicals and biological activities of Dacryodes edulis, Dacryodes rostrata, Dacryodes buettneri, Dacryodes klaineana and Dacryodes hexandra are presented. The edible fruits of D. edulis are rich in lipids, proteins, vitamins, fatty acids and amino acids. Its extracts (leaf, fruit and resin) exhibit antioxidant, anti-microbial, anti-carcinogenic and other bioactivities. D. rostrata fruit has significant nutrient content, and is rich in proteins, lipids and minerals. These fruits are also highly rich in polyphenols, anthocyanins and antioxidant activities. This comprehensive review will assist the reader in understanding the nutritional benefits of Dacryodes species and in identifying current research needs.
Fulltext Time perspective as a predictor of smoking status: findings from the International Tobacco Control (ITC) Surveys in Scotland, France, Germany, China, and Malaysia

Sansone G, Fong GT, Hall PA, Guignard R, Beck F, Mons U, et al.

BMC Public Health, 2013;13:346.
PMID: 23587205 DOI: 10.1186/1471-2458-13-346

Prior studies have demonstrated that time perspective-the propensity to consider short-versus long-term consequences of one's actions-is a potentially important predictor of health-related behaviors, including smoking. However, most prior studies have been conducted within single high-income countries. The aim of this study was to examine whether time perspective was associated with the likelihood of being a smoker or non-smoker across five countries that vary in smoking behavior and strength of tobacco control policies.
Fulltext The hidden risk of microplastic-associated pathogens in aquatic environments

Zhong H, Wu M, Sonne C, Lam SS, Kwong RWM, Jiang Y, et al.

Eco Environ Health, 2023 Sep;2(3):142-151.
PMID: 38074987 DOI: 10.1016/j.eehl.2023.07.004

Increasing studies of plastisphere have raised public concern about microplastics (MPs) as vectors for pathogens, especially in aquatic environments. However, the extent to which pathogens affect human health through MPs remains unclear, as controversies persist regarding the distinct pathogen colonization on MPs as well as the transmission routes and infection probability of MP-associated pathogens from water to humans. In this review, we critically discuss whether and how pathogens approach humans via MPs, shedding light on the potential health risks involved. Drawing on cutting-edge multidisciplinary research, we show that some MPs may facilitate the growth and long-range transmission of specific pathogens in aquatic environments, ultimately increasing the risk of infection in humans. We identify MP- and pathogen-rich settings, such as wastewater treatment plants, aquaculture farms, and swimming pools, as possible sites for human exposure to MP-associated pathogens. This review emphasizes the need for further research and targeted interventions to better understand and mitigate the potential health risks associated with MP-mediated pathogen transmission.
Fulltext Acupuncture alleviates CUMS-induced depression-like behaviors of rats by regulating oxidative stress, neuroinflammation and ferroptosis

Shen J, Hao C, Yuan S, Chen W, Tong T, Chen Y, et al.

Brain Res, 2024 Mar 01;1826:148715.
PMID: 38142722 DOI: 10.1016/j.brainres.2023.148715

BACKGROUND: The treatment of depression with acupuncture has been documented. The mechanism behind acupuncture's curative and preventative effects is still unknown.
METHODS: The current study examined the effects of acupuncture on depression-like behaviors in a rat model of chronic unpredictable mild stress (CUMS), while also exploring its potential mechanisms. A total of six groups of rats were randomly assigned: control, CUMS, acupuncture, fluoxetine, acupoint catgut embedding and sham acupoint catgut embedding. Fluoxetine (2.1 mg/kg) and acupoint catgut embedding were used for comparative research to acupuncture. The modelling evaluation is measured by body weight and behavior tests. Western blotting and reverse transcription-polymerase chain reaction were used to detect the proteins and mRNA expression of Silent information regulator 1 (Sirt1)/ nuclear factor-erythroid 2-related factor 2 (Nrf2)/ heme oxygenase-1 (HO-1)/ Glutathione peroxidase 4 (GPX4) pathway in the hippocampus. The expression of oxidative stress (OS)-related proteins and inflammatory cytokines in the serum was detected with ELISA. Immunofluorescence showed microglia and astrocytes activity in the hippocampus.
RESULTS: Acupuncture and fluoxetine could alleviate CUMS-induced depression-like behaviors. Acupuncture was also found to effectively reverse the levels of MDA, SOD, GSH, GSH-PX and T-AOC, IL-1β, IL-6 and TNF-α in the serum of CUMS-induced rats. Rats with CUMS showed decreased levels of Sirt1, Nrf2, HO-1 and GPX4 in the hippocampus, while acupuncture treatment could partly reverse the diminished effects. In addition, acupuncture treatment significantly reduced the activation of hippocampal microglia and astrocytes in CUMS-induced rats.
CONCLUSION: The study's findings indicate that acupuncture has the potential to mitigate depression-like behaviors in rats induced with CUMS by mitigating OS and reducing neuroinflammation.
The lower effectiveness of text-only health warnings in China compared to pictorial health warnings in Malaysia

Elton-Marshall T, Xu SS, Meng G, Quah AC, Sansone GC, Feng G, et al.

Tob Control, 2015 Nov;24 Suppl 4:iv6-13.
PMID: 26420242 DOI: 10.1136/tobaccocontrol-2015-052616

In 2009, China changed its health warnings on cigarette packs from side-only text warnings to two text-only warnings on 30% of the bottom of the front and back of the pack. Also in 2009, Malaysia changed from similar text warnings to pictorial health warnings consistent with Framework Convention on Tobacco Control (FCTC) Article 11 Guidelines.
Fulltext Wolbachia infection in field-collected Aedes aegypti in Yunnan Province, southwestern China

Zhang H, Gao J, Ma Z, Liu Y, Wang G, Liu Q, et al.

Front Cell Infect Microbiol, 2022;12:1082809.
PMID: 36530420 DOI: 10.3389/fcimb.2022.1082809

BACKGROUND: Wolbachia is gram-negative and common intracellular bacteria, which is maternally inherited endosymbionts and could expand their propagation in host populations by means of various manipulations. Recent reports reveal the natural infection of Wolbachia in Aedes Aegypti in Malaysia, India, Philippines, Thailand and the United States. At present, none of Wolbachia natural infection in Ae. aegypti has been reported in China.
METHODS: A total of 480 Ae. aegypti adult mosquitoes were collected from October and November 2018 based on the results of previous investigations and the distribution of Ae. aegypti in Yunnan. Each individual sample was processed and screened for the presence of Wolbachia by PCR with wsp primers. Phylogenetic trees for the wsp gene was constructed using the neighbour-joining method with 1,000 bootstrap replicates, and the p-distance distribution model of molecular evolution was applied.
RESULTS: 24 individual adult mosquito samples and 10 sample sites were positive for Wolbachia infection. The Wolbachia infection rate (IR) of each population ranged from 0 - 41.7%. The infection rate of group A alone was 0%-10%, the infection rate of group B alone was 0%-7.7%, and the infection rate of co-infection with A and B was 0-33.3%.
CONCLUSIONS: Wolbachia infection in wild Ae. aegypti in China is the first report based on PCR amplification of the Wolbachia wsp gene. The Wolbachia infection is 5%, and the wAlbA and wAlbB strains were found to be prevalent in the natural population of Ae. aegypti in Yunnan Province.
PARP1 promotes tumor proliferation in lenalidomide-resistant multiple myeloma via the downregulation of microRNA-192-5p-AKT signaling

Luo Y, Chen Y, Ai C, Huang X, Perna F, Kale BJ, et al.

Transl Cancer Res, 2024 Nov 30;13(11):6273-6281.
PMID: 39697751 DOI: 10.21037/tcr-24-1543

BACKGROUND: Lenalidomide-based therapies are recommended as first-line treatment for multiple myeloma (MM) patients, regardless of the transplant eligibility. Resistance to lenalidomide is a clinical problem that urgently needs to be addressed. The expression of poly(ADP-ribose) polymerase 1 (PARP1) is abnormally high in a variety of tumor tissues including MM. However, in lenalidomide-resistant MM, it is not yet known whether the abnormally high expression of PARP1 is involved in the occurrence of drug resistance, and whether the inhibition of PARP1 can reverse lenalidomide resistance. The aim of this study was to investigate the mechanism of PARP1 promoting lenalidomide-resistant in MM patients.
METHODS: Samples of bone marrow from patients with MM who were sensitive or resistant to lenalidomide were collected. The expression levels of PARP1 at the messenger RNA and protein levels were detected through polymerase chain reaction and western blot. MM cell lines were cultivated in vitro, cell lines resistant to lenalidomide were screened out, and the expression levels of PARP1 in the resistant cell lines were detected. The apoptosis level was also detected in the lenalidomide-resistant MM cell lines treated with a PARP1 inhibitor. The proliferation rates of the two groups of cells at different time points were evaluated by mono-methyl terephthalate (MMT) experiments. Finally, the effect of PARP1 on the proliferation of lenalidomide-resistant MM through the microRNA-192-5p-AKT signaling pathway was analyzed.
RESULTS: In the lenalidomide-resistant cell lines, the expression level of PARP1 was higher, the proliferation more rapid, and the apoptosis rate was lower than lenalidomide-sensitive cell lines. Additionally, the activated AKT pathway was suppressed by downregulating the expression of microRNA-192-5p. MM resistance can be inhibited to some extent by impacting PARP1.
CONCLUSIONS: PARP1 is involved in the production of lenalidomide resistance in MM, and could serve as a potential target for the treatment of MM in the future.
Viral Characteristics of the Warm Atlantic and Cold Arctic Water Masses in the Nordic Seas

Gao C, Xia J, Zhou X, Liang Y, Jiang Y, Wang M, et al.

Appl Environ Microbiol, 2021 10 28;87(22):e0116021.
PMID: 34469192 DOI: 10.1128/AEM.01160-21

Nordic Seas are the subarctic seas connecting the Arctic Ocean and North Atlantic Ocean with complex water masses, experiencing an abrupt climate change. Though knowledge of the marine virosphere has expanded rapidly, the diversity of viruses and their relationships with host cells and water masses in the Nordic Seas remain to be fully revealed. Here, we establish the Nordic Sea DNA virome (NSV) data set of 55,315 viral contigs including 1,478 unique viral populations from seven stations influenced by both the warm Atlantic and cold Arctic water masses. Caudovirales dominated in the seven NSVs, especially in the warm Atlantic waters. The major giant nucleocytoplasmic large DNA viruses (NCLDVs) contributed a significant proportion of the classified viral contigs in the NSVs (32.2%), especially in the cold Arctic waters (44.9%). The distribution patterns of Caudovirales and NCLDVs were a reflection of the community structure of their hosts in the corresponding water masses and currents. Latitude, pH, and flow speed were found to be key factors influencing the microbial communities and coinfluencing the variation of viral communities. Network analysis illustrated the tight coupling between the variation of viral communities and microbial communities in the Nordic Seas. This study suggests a probable linkage between viromes, host cells, and surface water masses from both the cool Arctic and warm Atlantic Oceans. IMPORTANCE This is a systematic study of Nordic Sea viromes using metagenomic analysis. The viral diversity, community structure, and their relationships with host cells and the complex water masses from both the cool Arctic and the warm Atlantic oceans were illustrated. The NCLDVs and Caudovirales are proposed as the viral characteristics of the cold Arctic and warm Atlantic waters, respectively. This study provides an important background for the viromes in the subarctic seas connecting the Arctic Ocean and North Atlantic Ocean and sheds light on their responses to abrupt climate change in the future.
Fulltext Characterization and Genomic Analysis of Marinobacter Phage vB_MalS-PS3, Representing a New Lambda-Like Temperate Siphoviral Genus Infecting Algae-Associated Bacteria

Liu Y, Zheng K, Liu B, Liang Y, You S, Zhang W, et al.

Front Microbiol, 2021;12:726074.
PMID: 34512604 DOI: 10.3389/fmicb.2021.726074

Marinobacter is the abundant and important algal-associated and hydrocarbon biodegradation bacteria in the ocean. However, little knowledge about their phages has been reported. Here, a novel siphovirus, vB_MalS-PS3, infecting Marinobacter algicola DG893(T), was isolated from the surface waters of the western Pacific Ocean. Transmission electron microscopy (TEM) indicated that vB_MalS-PS3 has the morphology of siphoviruses. VB_MalS-PS3 was stable from -20 to 55°C, and with the latent and rise periods of about 80 and 10 min, respectively. The genome sequence of VB_MalS-PS3 contains a linear, double-strand 42,168-bp DNA molecule with a G + C content of 56.23% and 54 putative open reading frames (ORFs). Nineteen conserved domains were predicted by BLASTp in NCBI. We found that vB_MalS-PS3 represent an understudied viral group with only one known isolate. The phylogenetic tree based on the amino acid sequences of whole genomes revealed that vB_MalS-PS3 has a distant evolutionary relationship with other siphoviruses, and can be grouped into a novel viral genus cluster with six uncultured assembled viral genomes from metagenomics, named here as Marinovirus. This study of the Marinobacter phage vB_MalS-PS3 genome enriched the genetic database of marine bacteriophages, in addition, will provide useful information for further research on the interaction between Marinobacter phages and their hosts, and their relationship with algal blooms and hydrocarbon biodegradation in the ocean.
Fulltext Genome and Ecology of a Novel Alteromonas Podovirus, ZP6, Representing a New Viral Genus, Mareflavirus

Wang Z, Zhang F, Liang Y, Zheng K, Gu C, Zhang W, et al.

Microbiol Spectr, 2021 10 31;9(2):e0046321.
PMID: 34643440 DOI: 10.1128/Spectrum.00463-21

Alteromonas is a ubiquitous, abundant, copiotrophic and phytoplankton-associated marine member of the Gammaproteobacteria with a range extending from tropical waters to polar regions and including hadal zones. Here, we describe a novel Alteromonas phage, ZP6, that was isolated from surface coastal waters of Qingdao, China. ZP6 contains a linear, double-stranded, 38,080-bp DNA molecule with 50.1% G+C content and 47 putative open reading frames (ORFs). Three auxiliary metabolic genes were identified, encoding metal-dependent phosphohydrolase, diaminopurine synthetase, and nucleotide pyrophosphohydrolase. The first two ORFs facilitate the replacement of adenine (A) by diaminopurine (Z) in phage genomes and help phages to evade attack from host restriction enzymes. The nucleotide pyrophosphohydrolase enables the host cells to stop programmed cell death and improves the survival rate of the host in a nutrient-depleted environment. Phylogenetic analysis based on the amino acid sequences of whole genomes and comparative genomic analysis revealed that ZP6 is most closely related to Enhodamvirus but with low similarity (shared genes, <30%, and average nucleotide sequence identity, <65%); it is distinct from other bacteriophages. Together, these results suggest that ZP6 could represent a novel viral genus, here named Mareflavirus. Combining its ability to infect Alteromonas, its harboring of a diaminopurine genome-biosynthetic system, and its representativeness of an understudied viral group, ZP6 could be an important and novel model system for marine virus research. IMPORTANCE Alteromonas is an important symbiotic bacterium of phytoplankton, but research on its bacteriophages is still at an elementary level. Our isolation and genome characterization of a novel Alteromonas podovirus, ZP6, identified a new viral genus of podovirus, namely, Mareflavirus. The ZP6 genome, with a diaminopurine genome-biosynthetic system, is different from those of other isolated Alteromonas phages and will bring new impetus to the development of virus classification and provide important insights into novel viral sequences from metagenomic data sets.
Fulltext Saline lakes on the Qinghai-Tibet Plateau harbor unique viral assemblages mediating microbial environmental adaption

Gu C, Liang Y, Li J, Shao H, Jiang Y, Zhou X, et al.

iScience, 2021 Dec 17;24(12):103439.
PMID: 34988389 DOI: 10.1016/j.isci.2021.103439

The highest plateau on Earth, Qinghai-Tibet Plateau, contains thousands of lakes with broad salinity and diverse and unique microbial communities. However, little is known about their co-occurring viruses. Herein, we identify 4,560 viral Operational Taxonomic Units (vOTUs) from six viromes of three saline lakes on Qinghai-Tibet Plateau, with less than 1% that could be classified. Most of the predicted vOTUs were associated with the dominant bacterial and archaeal phyla. Virus-encoded auxiliary metabolic genes suggest that viruses influence microbial metabolisms of carbon, nitrogen, sulfur, and lipid; the antibiotic resistance mediation; and their salinity adaption. The six viromes clustered together with the ice core viromes and bathypelagic ocean viromes and might represent a new viral habitat. This study has revealed the unique characteristics and potential ecological roles of DNA viromes in the lakes of the highest plateau and established a foundation for the recognition of the viral roles in plateau lake ecosystems.

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