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  1. Fulltext Homozygous deletion of six olfactory receptor genes in a subset of individuals with Beta-thalassemia
    Van Ziffle J, Yang W, Chehab FF
    PLoS One, 2011;6(2):e17327.
    PMID: 21390308 DOI: 10.1371/journal.pone.0017327
    Progress in the functional studies of human olfactory receptors has been largely hampered by the lack of a reliable experimental model system. Although transgenic approaches in mice could characterize the function of individual olfactory receptors, the presence of over 300 functional genes in the human genome becomes a daunting task. Thus, the characterization of individuals with a genetic susceptibility to altered olfaction coupled with the absence of particular olfactory receptor genes will allow phenotype/genotype correlations and vindicate the function of specific olfactory receptors with their cognate ligands. We characterized a 118 kb β-globin deletion and found that its 3' end breakpoint extends to the neighboring olfactory receptor region downstream of the β-globin gene cluster. This deletion encompasses six contiguous olfactory receptor genes (OR51V1, OR52Z1, OR51A1P, OR52A1, OR52A5, and OR52A4) all of which are expressed in the brain. Topology analysis of the encoded proteins from these olfactory receptor genes revealed that OR52Z1, OR52A1, OR52A5, and OR52A4 are predicted to be functional receptors as they display integral characteristics of G-proteins coupled receptors. Individuals homozygous for the 118 kb β-globin deletion are afflicted with β-thalassemia due to a homozygous deletion of the β-globin gene and have no alleles for the above mentioned olfactory receptors genes. This is the first example of a homozygous deletion of olfactory receptor genes in human. Although altered olfaction remains to be ascertained in these individuals, such a study can be carried out in β-thalassemia patients from Malaysia, Indonesia and the Philippines where this mutation is common. Furthermore, OR52A1 contains a γ-globin enhancer, which was previously shown to confer continuous expression of the fetal γ-globin genes. Thus, the hypothesis that β-thalassemia individuals, who are homozygous for the 118 kb deletion, may also have an exacerbation of their anemia due to the deletion of two copies of the γ-globin enhancer element is worthy of consideration.
  2. Enhancing erythrocyte-influenza virus specificity by glycan-conjugated gold nanoparticle: Validation of hemagglutination by aptamer and neuraminidases
    Ye M, Lin L, Yang W, Gopinath SCB
    Biotechnol Appl Biochem, 2021 Mar 26.
    PMID: 33769582 DOI: 10.1002/bab.2152
    This study demonstrated the terminated sialo-sugar chains (Neu5Acα2,6Gal and Neu5Acα2,3Gal) mediated specificity enhancement of influenza virus and chicken red blood cell (RBC) by hemagglutination assay. These glycan chains were immobilized on the gold nanoparticle (GNP) to withhold the higher numbers. With the preliminary optimization, a clear button formation with 0.5% RBC was visualized. On the other hand, intact B/Tokio/53/99 with 750 nM hemagglutinin (HA) displayed a nice hemagglutination. The interference on the specificity of RBC and influenza virus was observed by anti-influenza aptamer at the concentration 31 nM, however, there is no hemagglutination prevention was noticed in the presence of complementary aptamer sequences. Spiking GNP conjugated Neu5Acα2,6Gal or Neu5Acα2,3Gal or a mixture of these two to the reaction promoted the hemagglutination to 63 folds higher with 12 nM virus, whereas under the same condition the heat inactivated viruses were lost the hemagglutination. Neuraminidases from Clostridium perfringens and Arthrobacter ureafaciens at 0.0025 neuraminidase units are able to abolish the hemagglutination. Other enzymes, Glycopeptidase F (Elizabethkingia meningoseptica) and Endoglycosidase H (Streptomyces plicatus) did not show the changes with agglutination. Obviously, sialyl-Gal-terminated glycan conjugated GNP amendment has enhanced the specificity of erythrocyte-influenza virus and able to be controlled by aptamer or neuraminidases. This article is protected by copyright. All rights reserved.
  3. Fulltext A Study on Arrhythmia via ECG Signal Classification Using the Convolutional Neural Network
    Wu M, Lu Y, Yang W, Wong SY
    Front Comput Neurosci, 2020;14:564015.
    PMID: 33469423 DOI: 10.3389/fncom.2020.564015
    Cardiovascular diseases (CVDs) are the leading cause of death today. The current identification method of the diseases is analyzing the Electrocardiogram (ECG), which is a medical monitoring technology recording cardiac activity. Unfortunately, looking for experts to analyze a large amount of ECG data consumes too many medical resources. Therefore, the method of identifying ECG characteristics based on machine learning has gradually become prevalent. However, there are some drawbacks to these typical methods, requiring manual feature recognition, complex models, and long training time. This paper proposes a robust and efficient 12-layer deep one-dimensional convolutional neural network on classifying the five micro-classes of heartbeat types in the MIT- BIH Arrhythmia database. The five types of heartbeat features are classified, and wavelet self-adaptive threshold denoising method is used in the experiments. Compared with BP neural network, random forest, and other CNN networks, the results show that the model proposed in this paper has better performance in accuracy, sensitivity, robustness, and anti-noise capability. Its accurate classification effectively saves medical resources, which has a positive effect on clinical practice.
  4. The Family Diet Study: a cross-sectional study into the associations between diet, food habits and body weight status in Malay families
    Yang WY, Burrows T, MacDonald-Wicks L, Williams LT, Collins CE, Chee WS
    J Hum Nutr Diet, 2016 08;29(4):441-8.
    PMID: 26879748 DOI: 10.1111/jhn.12356
    BACKGROUND: Childhood obesity is becoming more common as Malaysia experiences rapid nutrition transition. Current evidence related to parental influences on child dietary intake and body weight status is limited. The present study aimed to report, among Malay families, the prevalence of energy mis-reporting and dietary relationships within family dyads.

    METHODS: The cross-sectional Family Diet Study (n = 236) was conducted at five primary schools in central of Peninsular Malaysia. Each family consisted of a Malay child, aged 8-12 years, and their main caregiver(s). Information on socio-demographics, dietary intake and anthropometry were collected. Correlations and regression analyses were used to assess dietary relationships within family dyads.

    RESULTS: Approximately 29.6% of the children and 75.0% parents were categorised as being overweight or obese. Intakes of nutrients and food groups were below the national recommended targets for majority of children and adults. A large proportion of energy intake mis-reporters were identified: mothers (55.5%), fathers (40.2%) and children (40.2%). Children's body mass index (BMI) was positively associated with parental BMI (fathers, r = 0.37; mothers, r = 0.34; P < 0.01). For dietary intakes, moderate-to-strong (0.35-0.72) and weak-to-moderate (0.16-0.35) correlations were found between mother-father and child-parent dyads, respectively. Multiple regression revealed that maternal percentage energy from fat (β = 0.09, P < 0.01) explained 81% of the variation in children's fat intake.

    CONCLUSIONS: Clear parental dietary relationships, especially child-mother dyads, were found. Despite a significant proportion of families with members who were overweight or obese, the majority reported dietary intakes below recommended levels, distorted by energy mis-reporting. The findings of the present study can inform interventions targeting parent-child relationships to improve family dietary patterns in Malaysia.

  5. Function-driven engineering of 1D carbon nanotubes and 0D carbon dots: mechanism, properties and applications
    Xu Q, Li W, Ding L, Yang W, Xiao H, Ong WJ
    Nanoscale, 2019 Jan 23;11(4):1475-1504.
    PMID: 30620019 DOI: 10.1039/c8nr08738e
    Metal-free carbonaceous nanomaterials have witnessed a renaissance of interest due to the surge in the realm of nanotechnology. Among myriads of carbon-based nanostructures with versatile dimensionality, one-dimensional (1D) carbon nanotubes (CNTs) and zero-dimensional (0D) carbon dots (CDs) have grown into a research frontier in the past few decades. With extraordinary mechanical, thermal, electrical and optical properties, CNTs are utilized in transparent displays, quantum wires, field emission transistors, aerospace materials, etc. Although CNTs possess diverse characteristics, their most attractive property is their unique photoluminescence. On the other hand, another growing family of carbonaceous nanomaterials, which is CDs, has drawn much research attention due to its cost-effectiveness, low toxicity, environmental friendliness, fluorescence, luminescence and simplicity to be synthesized and functionalized with surface passivation. Benefiting from these unprecedented properties, CDs have been widely employed in biosensing, bioimaging, nanomedicine, and catalysis. Herein, we have systematically presented the fascinating properties, preparation methods and multitudinous applications of CNTs and CDs (including graphene quantum dots). We will discuss how CNTs and CDs have emerged as auspicious nanomaterials for potential applications, especially in electronics, sensors, bioimaging, wearable devices, batteries, supercapacitors, catalysis and light-emitting diodes (LEDs). Last but not least, this review is concluded with a summary, outlook and invigorating perspectives for future research horizons in this emerging platform of carbonaceous nanomaterials.
  6. Fulltext Checklist of the coral fish fauna of Xisha Islands, China
    Qiu S, Chen B, Du J, Loh KH, Liao J, Liu X, et al.
    Biodivers Data J, 2021;9:e63945.
    PMID: 33732033 DOI: 10.3897/BDJ.9.e63945
    Background: The Xisha Islands are composed of the Yongle Islands and the Xuande Islands in Hainan Province, China. It has one of the highest species diversity in the world and is also a typical oceanic distribution area of coral reefs globally. The ichthyofauna of the Xisha Islands were recorded by underwater visual census in May 2019 and July 2020. The survey data were combined with previous records of species into the checklist of the Xisha Islands presented herein. A total of 691 species, belonging to 24 orders and 97 families, was recorded. The major families were Labridae, Pomacentridae, Serranidae, Chaetodontidae, Hexanchidae, Lutjanidae, Scaridae, Gobiidae, Scorpaenidae and Carangidae. In this study, the Coral Fish iversity Index (CFDI) of six families (Chaetodontidae, Pomacanthidae, Pomacentridae, Labridae, Scaridae and Acanthuridae) was 229, indicating 756 coral fishes. In terms of the IUCN Red List, one species is Critically Endangered (Glyphis gangeticus), six species are Endangered (Stegostoma fasciatum, Aetomylaeus maculatus, Aetomylaeus vespertilio, Epinephelus akaara, Cheilinusundulatus sp. and Xiphias gladius), 16 species are Vulnerable, and 13 species are Near Threatened in the Xisha Archipelago, so conservation should be strengthened in this area in the future.

    New information: One species is a new record for China (Dischistodus pseudochrysopoecilus) and 23 species are newly found in the Xisha Islands.

  7. Fulltext Cervical Cancer Surgery: Current State of Affairs
    Yang FC, Huang W, Yang W, Liu J, Ai G, Luo N, et al.
    Gynecol Minim Invasive Ther, 2021 04 30;10(2):75-83.
    PMID: 34040965 DOI: 10.4103/GMIT.GMIT_81_20
    Cervical cancer surgery has a history of more than 100-years whereby it has transitioned from the open approach to minimally invasive surgery (MIS). From the era of clinical exploration and practice, minimally invasive gynecologic surgeons have never ceased to explore new frontiers in the field of gynecologic surgery. MIS has fewer postoperative complications, including reduction of treatment-related morbidity and length of hospital stay than laparotomy; this forms the mainstay of treatment for early-stage cervical cancer. However, in November 2018, the New England Journal of Medicine had published two clinical studies on cervical cancer surgery (Laparoscopic Approach to Cervical Cancer [LACC]). Following these publications, laparoscopic surgery for early-stage cervical cancer has come under intense scrutiny and negative perceptions. Many studies began to explore the concept of standardized surgery for early-stage cervical cancer. In this article, we performed a review of the history of cervical cancer surgery, outlined the standardization of cervical cancer surgery, and analyzed the current state of affairs revolving around cervical cancer surgery in the post-LACC era.
  8. Effects of dairy processing on phospholipidome, in-vitro digestion and Caco-2 cellular uptake of bovine milk
    Mou B, Liu Y, Yang W, Song S, Shen C, Lai OM, et al.
    Food Chem, 2021 Dec 01;364:130426.
    PMID: 34175616 DOI: 10.1016/j.foodchem.2021.130426
    Present work investigated the effects of processing (homogenization, sterilization) and cold storage on physicochemical properties, in vitro digestion and Caco-2 cellular uptake of bovine milk. Extreme heat sterilization and low temperature storage have significant impact on particle size and phospholipidome of bovine milk. In addition, cold storage of bovine milks led to formation of β' polymorphs crystals and endothermic peak with Toffset higher than body temperature. Processing and cold storage also increased the initial digestibility but reduced the overall digestibility of bovine milk. This might be related to the decreased particle size of the milk fat globules, changed in the phospholipidome of the MFGM and formation of β' polymorphs crystals in frozen milk. It is interesting to note that PE has relatively faster digestion meanwhile SM has relatively slower digestion. HTST milk which demonstrated lesser changed in terms of phospholipidome demonstrated highest cellular uptakes of most fatty acids.
  9. Cryptic diversity within the harmful dinoflagellate Akashiwo sanguinea in coastal Chinese waters is related to differentiated ecological niches
    Luo Z, Yang W, Leaw CP, Pospelova V, Bilien G, Liow GR, et al.
    Harmful Algae, 2017 06;66:88-96.
    PMID: 28602257 DOI: 10.1016/j.hal.2017.05.008
    Blooms of the harmful dinoflagellate Akashiwo sanguinea are responsible for the mass mortality of fish and invertebrates in coastal waters. This cosmopolitan species includes several genetically differentiated clades. Four clonal cultures were established by isolating single cells from Xiamen Harbour (the East China Sea) for morphological and genetic analyses. The cultures displayed identical morphology but were genetically different, thus revealing presence of cryptic diversity in the study area. New details of the apical structure complex of Akashiwo sanguinea were also found. To investigate whether the observed cryptic diversity was related to environmental differentiation, 634 cells were obtained from seasonal water samples collected from 2008 to 2012. These cells were sequenced by single-cell PCR. For comparison with Chinese material, additional large subunit ribosomal DNA sequences were obtained for three established strains from Malaysian and French waters. To examine potential ecological differentiation of the distinct genotypes, growth responses of the studied strains were tested under laboratory conditions at temperatures of 12°C to 33°C. These experiments showed four distinct ribotypes of A. sanguinea globally, with the ribotypes A and B co-occuring in Xiamen Harbour. Ribotype A of A. sanguinea was present year-round in Xiamen Harbour, but it only bloomed in the winter and spring, thus corresponding to the winter type. In contrast, A. sanguinea ribotype B bloomed only in the summer, corresponding to the summer type. This differentiation supports the temperature optimum conditions that were established for these two ribotypes in the laboratory. Ribotype A grew better at lower temperatures compared to ribotype B which preferred higher temperatures. These findings support the idea that various ribotypes of A. sanguinea correspond to distinct ecotypes and allopatric speciation occurred in different climatic regions followed by dispersal.
  10. Collagenofibrotic glomerulopathy- report of a rare renal disease with serial biopsies
    Ng YF, Chow CY, Yang WS, Lye WC, Loh HL
    Malays J Pathol, 2020 Apr;42(1):131-135.
    PMID: 32342943
    INTRODUCTION: Collagenofibrotic glomerulopathy or collagen type-III glomerulopathy is a rare glomerular disease characterised by the deposition of type III collagen fibres in the subendothelial space and mesangium of the glomerulus.

    CASE REPORT: Here, we present a case of collagenofibrotic glomerulopathy in a 49-year-old Indian female, the first to be reported from Singapore. Renal biopsy showed PAS (periodic acid-Schiff), silver and Congo red negative, amorphous extracellular material that expanded mesangial and subendothelial regions. Such materials were strongly positive for anti-collagen III immunofluorescent staining. Under electron microscopy, the mesangial and some subendothelial regions were greatly expanded by abundant collagen fibres which were different from normal collagen III fibres in both appearance and periodicity.

    DISCUSSION: The availability of past renal biopsies for reference offered insight into disease progression. From the initial diagnosis of focal segmental glomerulosclerosis to eventually collagenofibrotic glomerulopathy over a time span of more than 10 years, this case highlights the gradual accumulation of collagen fibres in the glomeruli before classical features are apparent. It also emphasises the importance of electron microscopy in the diagnosis of this disease.

  11. Phospholipidomics of bovine milk subjected to homogenization, thermal treatment and cold storage
    Mou B, Yang W, Song S, Shen C, Panpipat W, Lai OM, et al.
    Food Chem, 2022 Jan 31;381:132288.
    PMID: 35124494 DOI: 10.1016/j.foodchem.2022.132288
    Milk processing technology disrupts milk fat globule membrane (MFGM) structures and decreases the phospholipid content in MFGM. The present study aimed to evaluate the effects of homogenization, thermal treatment, and cold storage on milk phospholipids. A total of 175 phospholipid molecular species were identified and quantified. Phosphatidylcholine was the most abundant phospholipid, and sphingomyelin accounted for only a small amount of phospholipid in bovine milk. In addition, a total of 37 plasmalogens (167.5 μg/mL) were identified in bovine milk with lysophosphatidylcholine plasmalogen being the most abundant. Processing technologies decreased the phospholipid content with both boiled and frozen milk demonstrating the highest reduction. Compared to raw milk, only 70% of phospholipid remained in frozen milk. Both S-plot and volcano-plot showed that heat treatment and subsequent cold storage decreased the phosphatidylserine and lysophospholipid contents.
  12. Changes of Facial Features After Bariatric Surgery: a Systematic Review
    Wong ZY, Ramasamy P, Ingels KJAO, Parmar C, Yang W, Pouwels S, et al.
    Obes Surg, 2023 Jan;33(1):332-338.
    PMID: 36434358 DOI: 10.1007/s11695-022-06363-8
    This study aims to provide an overview of the facial features and structure after bariatric surgery in the existing literature. A systematic literature search was performed in electronic databases until 15th February 2022. Four cohort studies including 129 patients from 3 countries were included between time period 2011 and 2020. Overall, bariatric surgery would promote massive weight loss associated with positive effects on facial aging. Analysis revealed a proportional relationship between body mass index (BMI) and faster facial aging and more attractive. Undergoing bariatric surgery would result in facial skin sagging and a favorable effect on the upper airway. Bariatric surgery was found to have a significant impact on changes in facial features but the current evidence remains inconclusive and further studies are required to illustrate facial changes post-bariatric surgery.
  13. A Colorimetric/Fluorescent Dual-Mode Aptasensor for Salmonella Based on the Magnetic Separation of Aptamers and a DNA-Nanotriangle Programmed Multivalent Aptamer
    Ma N, Sun M, Shi H, Xue L, Zhang M, Yang W, et al.
    Foods, 2023 Oct 20;12(20).
    PMID: 37893744 DOI: 10.3390/foods12203853
    Salmonella infection has emerged as a global health threat, causing death, disability, and socioeconomic disruption worldwide. The rapid and sensitive detection of Salmonella is of great significance in guaranteeing food safety. Herein, we developed a colorimetric/fluorescent dual-mode method based on a DNA-nanotriangle programmed multivalent aptamer for the sensitive detection of Salmonella. In this system, aptamers are precisely controlled and assembled on a DNA nanotriangle structure to fabricate a multivalent aptamer (NTri-Multi-Apt) with enhanced binding affinity and specificity toward Salmonella. The NTri-Multi-Apt was designed to carry many streptavidin-HRPs for colorimetric read-outs and a large load of Sybr green I in the dsDNA scaffold for the output of a fluorescent signal. Therefore, combined with the magnetic separation of aptamers and the prefabricated NTri-Multi-Apt, the dual-mode approach achieved simple and sensitive detection, with LODs of 316 and 60 CFU/mL for colorimetric and fluorescent detection, respectively. Notably, the fluorescent mode provided a self-calibrated and fivefold-improved sensitivity over colorimetric detection. Systematic results also revealed that the proposed dual-mode method exhibited high specificity and applicability for milk, egg white, and chicken meat samples, serving as a promising tool for real bacterial sample testing. As a result, the innovative dual-mode detection method showed new insights for the detection of other pathogens.
  14. Fulltext Molecular Mechanism of Citrate Efflux by the Mitochondrial Citrate Transporter CT in Filamentous Fungus Mucor circinelloides WJ11
    Yang W, Dong S, Yang J, Mohamed H, Shah AM, Nazir Y, et al.
    Front Microbiol, 2021;12:673881.
    PMID: 34054781 DOI: 10.3389/fmicb.2021.673881
    The mitochondrial citrate transporter (MCT) plays an important role in citrate efflux from the mitochondria in eukaryotes, and hence provides a direct correlation between carbohydrate metabolism and lipid synthesis. Our previous studies on transporters confirmed the presence of two MCTs (TCT and CT) in oleaginous Mucor circinelloides WJ11 associated with high lipid accumulation. However, the molecular mechanism of citrate efflux from the mitochondria by MCT in M. circinelloides is still unclear. To study the citrate transport mechanism of CT, the citrate transporter gene was expressed in Escherichia coli, and its product was purified. The citrate transport activity of the protein was studied in CT reconstituted liposomes. Our results showed high efficiency of CT for [14C] citrate/citrate exchange with K m 0.01 mM at 25°C. Besides citrate, other molecules such as oxaloacetate, malate, fumarate, succinate aconitate, oxoadipate, isocitrate, and glutamate also promote citrate transport. In addition, the ct overexpression and knockout plasmids were constructed and transferred into M. circinelloides WJ11, and the mitochondria were isolated, and the transport activity was studied. Our findings showed that in the presence of 10 mM malate, the mitochondria of ct-overexpressing transformant showed 51% increase in the efflux rate of [14C] citrate, whereas the mitochondria of the ct-knockout transformant showed 18% decrease in citrate efflux compared to the mitochondria of wild-type WJ11. This study provided the first mechanistic evidence of citrate efflux from the mitochondria by citrate transporter in oleaginous filamentous fungus M. circinelloides, which is associated with high lipid accumulation.
  15. Fulltext Inhibition of Heterogeneous Nucleation in Water by Hydrogel Coating
    Li S, Zhu P, Xue Y, Wang L, Wong TW, Yang X, et al.
    Research (Wash D C), 2023;6:0190.
    PMID: 37426472 DOI: 10.34133/research.0190
    Heterogeneous nucleation plays a critical role in the phase transition of water, which can cause damage in various systems. Here, we report that heterogeneous nucleation can be inhibited by utilizing hydrogel coatings to isolate solid surfaces and water. Hydrogels, which contain over 90% water when fully swelled, exhibit a high degree of similarity to water. Due to this similarity, there is a great energy barrier for heterogeneous nucleation along the water-hydrogel interface. Additionally, hydrogel coatings, which possess polymer networks, exhibit higher fracture energy and more robust adhesion to solid surfaces compared to water. This high fracture and adhesion energy acts as a deterrent for fracture nucleation within the hydrogel or along the hydrogel-solid interface. With a hydrogel layer approximately 100 μm thick, the boiling temperature of water under atmospheric pressure can be raised from 100 to 108 °C. Notably, hydrogel coatings also result in remarkable reductions in cavitation pressure on multiple solid surfaces. We have demonstrated the efficacy of hydrogel coatings in preventing damages resulting from acceleration-induced cavitation. Hydrogel coatings have the potential to alter the energy landscape of heterogeneous nucleation on the water-solid interface, making them an exciting avenue for innovation in heat transfer and fluidic systems.
  16. Comparative investigation of various modification methods on Trachypenaeus Curvirostris surimi gel: Gelling properties, rheological behaviors and structure characteristics
    Hu Q, Ma F, Wei H, Yang W, Deng S, Yu X, et al.
    J Texture Stud, 2023 Aug;54(4):582-594.
    PMID: 37400374 DOI: 10.1111/jtxs.12785
    The aim of this study was to compare the investigations of various contents of egg white protein (2.0%-8.0%, EWP), microbial transglutaminase (0.1%-0.4%, MTGase), and konjac glucomannan (0.5%-2.0%, KGM) on the gelling properties and rheological behavior of Trachypenaeus Curvirostris shrimp surimi gel (SSG), and assessed the modification mechanisms through the analysis of structure characteristics. The findings suggested that all modified SSG samples (expect SSG-KGM2.0% ) had the higher gelling properties and the denser network structure than those of unmodified SSG. Meanwhile, EWP could give SSG a better appearance than MTGase and KGM. Rheological results showed that SSG-EWP6% and SSG-KGM1.0% had the highest G' and G″, demonstrating that the formation of higher levels of elasticity and hardness. All modifications could increase gelation rates of SSG along with the reduction of G″ during the degeneration of protein. According to the FTIR results, three modification methods changed SSG protein conformation with the increasing α-helix and β-sheet contents and the decreasing of random coil content. LF-NMR results indicated that more free water could be transformed into immobilized water in the modified SSG gels, which contributed to improve the gelling properties. Furthermore, molecular forces showed that EWP and KGM could further increase the hydrogen bonds and hydrophobic interaction in SSG gels, while MTGase could induce the formation of more disulfide bonds. Thus, compared with another two modifications, EWP modified SSG gels showed the highest gelling properties.
  17. Fulltext Nelson Bay Reovirus Isolated from Bats and Blood-Sucking Arthropods Collected in Yunnan Province, China
    Kuang G, Xu Z, Wang J, Gao Z, Yang W, Wu W, et al.
    Microbiol Spectr, 2023 Aug 17;11(4):e0512222.
    PMID: 37306586 DOI: 10.1128/spectrum.05122-22
    Nelson Bay reovirus (NBV) is an emerging zoonotic virus that can cause acute respiratory disease in humans. These viruses are mainly discovered in Oceania, Africa, and Asia, and bats have been identified as their main animal reservoir. However, despite recent expansion of diversity for NBVs, the transmission dynamics and evolutionary history of NBVs are still unclear. This study successfully isolated two NBV strains (MLBC1302 and MLBC1313) from blood-sucking bat fly specimens (Eucampsipoda sundaica) and one (WDBP1716) from the spleen specimen of a fruit bat (Rousettus leschenaultii), which were collected at the China-Myanmar border area of Yunnan Province. Syncytia cytopathic effects (CPE) were observed in BHK-21 and Vero E6 cells infected with the three strains at 48 h postinfection. Electron micrographs of ultrathin sections showed numerous spherical virions with a diameter of approximately 70 nm in the cytoplasm of infected cells. The complete genome nucleotide sequence of the viruses was determined by metatranscriptomic sequencing of infected cells. Phylogenetic analysis demonstrated that the novel strains were closely related to Cangyuan orthoreovirus, Melaka orthoreovirus, and human-infecting Pteropine orthoreovirus HK23629/07. Simplot analysis revealed the strains originated from complex genomic reassortment among different NBVs, suggesting the viruses experienced a high reassortment rate. In addition, strains successfully isolated from bat flies also implied that blood-sucking arthropods might serve as potential transmission vectors. IMPORTANCE Bats are the reservoir of many viral pathogens with strong pathogenicity, including NBVs. Nevertheless, it is unclear whether arthropod vectors are involved in transmitting NBVs. In this study, we successfully isolated two NBV strains from bat flies collected from the body surface of bats, which implies that they may be vectors for virus transmission between bats. While the potential threat to humans remains to be determined, evolutionary analyses involving different segments revealed that the novel strains had complex reassortment histories, with S1, S2, and M1 segments highly similar to human pathogens. Further experiments are required to determine whether more NBVs are vectored by bat flies, their potential threat to humans, and transmission dynamics.
  18. Fulltext Coculturing of Mucor plumbeus and Bacillus subtilis bacterium as an efficient fermentation strategy to enhance fungal lipid and gamma-linolenic acid (GLA) production
    Mohamed H, Awad MF, Shah AM, Sadaqat B, Nazir Y, Naz T, et al.
    Sci Rep, 2022 Jul 30;12(1):13111.
    PMID: 35908106 DOI: 10.1038/s41598-022-17442-2
    This study aimed to improve lipid and gamma-linolenic acid (GLA) production of an oleaginous fungus, Mucor plumbeus, through coculturing with Bacillus subtilis bacteria, optimising the environmental and nutritional culture conditions, and scaling them for batch fermentation. The maximum levels of biomass, lipid, fatty acid, and GLA in a 5 L bioreactor containing cellobiose and ammonium sulfate as the optimal carbon and nitrogen sources, respectively, achieved during the coculturing processes were 14.5 ± 0.4 g/L, 41.5 ± 1.3, 24 ± 0.8, and 20 ± 0.5%, respectively. This strategy uses cellobiose in place of glucose, decreasing production costs. The nutritional and abiotic factor results suggest that the highest production efficiency is achieved at 6.5 pH, 30 °C temperature, 10% (v/v) inoculum composition, 200 rpm agitation speed, and a 5-day incubation period. Interestingly, the GLA concentration of cocultures (20.0 ± 0.5%) was twofold higher than that of monocultures (8.27 ± 0.11%). More importantly, the GC chromatograms of cocultures indicated the presence of one additional peak corresponding to decanoic acid (5.32 ± 0.20%) that is absent in monocultures, indicating activation of silent gene clusters via cocultivation with bacteria. This study is the first to show that coculturing of Mucor plumbeus with Bacillus subtilis is a promising strategy with industrialisation potential for the production of GLA-rich microbial lipids and prospective biosynthesis of new products.
  19. Fulltext Role of Snf-β in lipid accumulation in the high lipid-producing fungus Mucor circinelloides WJ11
    Nosheen S, Naz T, Yang J, Hussain SA, Fazili ABA, Nazir Y, et al.
    Microb Cell Fact, 2021 Feb 27;20(1):52.
    PMID: 33639948 DOI: 10.1186/s12934-021-01545-y
    BACKGROUND: Mucor circinelloides WJ11 is a high-lipid producing strain and an excellent producer of γ-linolenic acid (GLA) which is crucial for human health. We have previously identified genes that encode for AMP-activated protein kinase (AMPK) complex in M. circinelloides which is an important regulator for lipid accumulation. Comparative transcriptional analysis between the high and low lipid-producing strains of M. circinelloides showed a direct correlation in the transcriptional level of AMPK genes with lipid metabolism. Thus, the role of Snf-β, which encodes for β subunit of AMPK complex, in lipid accumulation of the WJ11 strain was evaluated in the present study.

    RESULTS: The results showed that lipid content of cell dry weight in Snf-β knockout strain was increased by 32 % (from 19 to 25 %). However, in Snf-β overexpressing strain, lipid content of cell dry weight was decreased about 25 % (from 19 to 14.2 %) compared to the control strain. Total fatty acid analysis revealed that the expression of the Snf-β gene did not significantly affect the fatty acid composition of the strains. However, GLA content in biomass was increased from 2.5 % in control strain to 3.3 % in Snf-β knockout strain due to increased lipid accumulation and decreased to 1.83 % in Snf-β overexpressing strain. AMPK is known to inactivate acetyl-CoA carboxylase (ACC) which catalyzes the rate-limiting step in lipid synthesis. Snf-β manipulation also altered the expression level of the ACC1 gene which may indicate that Snf-β control lipid metabolism by regulating ACC1 gene.

    CONCLUSIONS: Our results suggested that Snf-β gene plays an important role in regulating lipid accumulation in M. circinelloides WJ11. Moreover, it will be interesting to evaluate the potential of other key subunits of AMPK related to lipid metabolism. Better insight can show us the way to manipulate these subunits effectively for upscaling the lipid production. Up to our knowledge, it is the first study to investigate the role of Snf-β in lipid accumulation in M. circinelloides.

  20. Dual-Functional Tetrahedron Multivalent Aptamer Assisted Amplification-Free CRISPR/Cas12a Assay for Sensitive Detection of Salmonella
    Qiao Z, Xue L, Sun M, Ma N, Shi H, Yang W, et al.
    J Agric Food Chem, 2024 Jan 10;72(1):857-864.
    PMID: 38134022 DOI: 10.1021/acs.jafc.3c07582
    Salmonellosis continues to impose a significant economic burden globally. Rapid and sensitive detection of Salmonella is crucial to preventing the outbreaks of foodborne illnesses, yet it remains a formidable challenge. Herein, a dual-functional tetrahedron multivalent aptamer assisted amplification-free CRISPR/Cas12a assay was developed for Salmonella detection. In the system, the aptamer was programmatically assembled on the tetrahedral DNA nanostructure to fabricate a multivalent aptamer (TDN-multiApt), which displayed a 3.5-fold enhanced avidity over the monovalent aptamer and possessed four CRISPR/Cas12a targeting fragments to amplify signal. Therefore, TDN-multiApt could directly activate Cas12a to achieve the second signal amplification without any nucleic acid amplification. By virtue of the synergism of high avidity and cascaded signal amplifications, the proposed method allowed the ultrasensitive detection of Salmonella as low as 7 cfu mL-1. Meanwhile, this novel platform also exhibited excellent specificity against target bacteria and performed well in the detection of various samples, indicating its potential application in real samples.
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