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Fulltext The complete chloroplast genome of Walla Patta, Gyrinops walla (Thymelaeaceae), an agarwood-producing tree species from Sri Lanka

Chen J, Lee SY, Munugoda KD, Mohamed R, Subasinghe SMCUP, Liao W

Mitochondrial DNA B Resour, 2021 May 19;6(6):1699-1701.
PMID: 34104743 DOI: 10.1080/23802359.2021.1926362

Gyrinops walla is an important agarwood-producing tree and threatened species from Sri Lanka. Herein, we assembled and characterized the complete chloroplast (cp) genome of G. walla as a genomic resource for conservation purposes. The 175,130 bp long genome is comprised of 87,376 bp large single-copy (LSC) and 3316 bp small single-copy (SSC) regions, which are separated by two inverted repeat (IR) region, each with a size of 42,291 bp. A total of 140 genes were predicted for the cp genome, which includes 94 protein-coding, 38 tRNA, and eight rRNA genes. Phylogenetic analysis showed that G. walla is fully resolved in a sister position to Aquilaria in the family Thymelaeaceae. The data provided will be useful for study on the molecular phylogenetics and evolution of Thymelaeaceae in the future.
Effect of different implant configurations on biomechanical behavior of full-arch implant-supported mandibular monolithic zirconia fixed prostheses

Zhong J, Guazzato M, Chen J, Zhang Z, Sun G, Huo X, et al.

J Mech Behav Biomed Mater, 2020 02;102:103490.
PMID: 31877512 DOI: 10.1016/j.jmbbm.2019.103490

Mechanical failure of zirconia-based full-arch implant-supported fixed dental prostheses (FAFDPs) remains a critical issue in prosthetic dentistry. The option of full-arch implant treatment and the biomechanical behaviour within a sophisticated screw-retained prosthetic structure have stimulated considerable interest in fundamental and clinical research. This study aimed to analyse the biomechanical responses of zirconia-based FAFDPs with different implant configurations (numbers and distributions), thereby predicting the possible failure sites and the optimum configuration from biomechanical aspect by using finite element method (FEM). Five 3D finite element (FE) models were constructed with patient-specific heterogeneous material properties of mandibular bone. The results were reported using volume-averaged von-Mises stresses (σVMVA) to eliminate numerical singularities. It was found that wider placement of multi-unit copings was preferred as it reduces the cantilever effect on denture. Within the limited areas of implant insertion, the adoption of angled multi-unit abutments allowed the insertion of oblique implants in the bone and wider distribution of the multi-unit copings in the prosthesis, leading to lower stress concentration on both mandibular bone and prosthetic components. Increasing the number of supporting implants in a FAFDPs reduced loading on each implant, although it may not necessarily reduce the stress concentration in the most posterior locations significantly. Overall, the 6-implant configuration was a preferable configuration as it provided the most balanced mechanical performance in this patient-specific case.
A review on polyamide thin film nanocomposite (TFN) membranes: History, applications, challenges and approaches

Lau WJ, Gray S, Matsuura T, Emadzadeh D, Chen JP, Ismail AF

Water Res, 2015 Sep 1;80:306-24.
PMID: 26011136 DOI: 10.1016/j.watres.2015.04.037

This review focuses on the development of polyamide (PA) thin film nanocomposite (TFN) membranes for various aqueous media-based separation processes such as nanofiltration, reverse osmosis and forward osmosis since the concept of TFN was introduced in year 2007. Although the total number of published TFN articles falls far short of the articles of the well-known thin film composite (TFC) membranes, its growth rate is significant, particularly since 2012. Generally, by incorporating an appropriate amount of nanofiller into a thin selective PA layer of a composite membrane, one could produce TFN membranes with enhanced separation characteristics as compared to the conventional TFC membrane. For certain cases, the resulting TFN membranes demonstrate not only excellent antifouling resistance and/or greater antibacterial effect, but also possibly overcome the trade-off effect between water permeability and solute selectivity. Furthermore, this review attempts to give the readers insights into the difficulties of incorporating inorganic nanomaterials into the organic PA layer whose thickness usually falls in a range of several-hundred nanometers. It is also intended to show new possible approaches to overcome these challenges in TFN membrane fabrication.
Evaluating the application of antibiotic treatment using algae-algae/activated sludge system

Xiao G, Chen J, Show PL, Yang Q, Ke J, Zhao Q, et al.

Chemosphere, 2021 Nov;282:130966.
PMID: 34082314 DOI: 10.1016/j.chemosphere.2021.130966

Biological methods are promising treatment methods to remove pollutants from wastewater. Recently, microalgae have been proved to be of strong application potential in wastewater treatment. In this study, a microalga - antibiotic treatment system was built to evaluate the treatment capacity of microalgae in antibiotic wastewater. In the group with Chlorella pyrenoidosa, the removal rate of cefradine was 41.47 ± 0.62% after 24 h of treatment, which was 3.4 times higher than that without microalgae (12.37 ± 2.30%). Algal decomposition was the main removal mechanism. Meanwhile, the effect of multiple microalgae species on antibiotic treatment was studied. The removal rates of cefradine by C. pyrenoidosa cultivated in the filtered fluid of Microcystis aeruginosa were 75.48 ± 0.29%, which was significantly higher than those by C. pyrenoidosa only. Those indicated that multiple microalgae species strategy was a potential enhancement strategy for algae-based antibiotic treatment. Finally, amoxicillin and norfloxacin were used to study the treatment potential of this technology for more different kinds antibiotics and the integration of microalgae with activated sludge was also investigated. Amoxicillin can be quickly removed by microalgae, but the removal effect of norfloxacin by microalgae is poor. The refractory antibiotic norfloxacin can be treated by co-culturing microalgae and activated sludge. Those showed the good expansibility of microalgae-based technology. The findings indicated that with microalgae-based antibiotic removal method has good application potential, and combined with other technologies, it can effectively remove the refractory antibiotics.
Fulltext Design and experimental analysis of dual-band polarization converting metasurface for microwave applications

Khan B, Kamal B, Ullah S, Khan I, Shah JA, Chen J

Sci Rep, 2020 Sep 21;10(1):15393.
PMID: 32958835 DOI: 10.1038/s41598-020-71959-y

The manipulation of polarization state of electromagnetic waves is of great importance in many practical applications. In this paper, the reflection characteristics of a thin and dual-band metasurface are examined in the microwave frequency regime. The metasurface consists of a 22 × 22 element array of periodic unit cells. The geometry of the unit cell consists of three layers, including a 45° inclined dipole shape metal patch on top, which is backed by a 1.6 mm thick FR-4 substrate in the middle, and a fully reflective metallic mirror at the bottom. The proposed surface is exposed to horizontally (x) or vertically (y) polarized plane waves and the co and cross polarization reflection coefficients of the reflected waves are investigated experimentally in the 6-26 GHz frequency range. The metasurface is designed to convert incident waves of known polarization state (horizontal or vertical) to orthogonal polarization state (vertical and horizontal) in two distinct frequency bands, i.e. 7.1-8 GHz and 13.3-25.8 GHz. In these two frequency bands the simulated and experimental results are in good agreement. The polarization conversion ratio (PCR) of the surface is greater than 95% in the targeted frequency bands. A detailed parametric analysis of the metasurface is also discussed in this work and it has been estimated that the surface has the additional ability to convert linearly polarized waves to circularly polarized waves at several distinct frequencies. The proposed metasurface can be utilized in sensor applications, stealth technology, electromagnetic measurements, and antennas design.
Comparative Cost-Effectiveness Analysis of Two Different Two-Dose Human Papillomavirus Vaccines in Malaysia

Van Kriekinge G, Sohn WY, Aljunid SM, Soon R, Yong CM, Chen J, et al.

Asian Pac J Cancer Prev, 2018 Apr 25;19(4):933-940.
PMID: 29693347

Purpose: To comparatively evaluate the results of a 2-dose human papillomavirus (HPV) vaccination programme
with the AS04-adjuvanted HPV16/18 vaccine (AS04-HPV-16/18v) or HPV-6/11/16/18 vaccine (4vHPVv), in addition
to cervical cancer (CC) screening, in Malaysia. Methods: A lifetime Markov model replicating the natural history of
HPV in 13-year-old girls was adapted to Malaysia to assess the impact of vaccination on pre-cancerous lesions, genital
warts and CC cases, CC deaths, quality-adjusted life years (QALYs), and costs from the perspective of the Malaysian
Ministry of Health. Vaccine effectiveness was based on efficacy and HPV type distribution. Both vaccines were assumed
to have equal efficacy against vaccine-type HPV but differed for protection against non-vaccine types. Vaccine price
parity was used and health and cost outcomes were discounted at 3%/annum. Sensitivity analyses tested the robustness
of the results. Results: The model predicted that AS04-HPV-16/18v would result in 361 fewer CC cases and 115 fewer
CC deaths than 4vHPVv, whereas 4vHPVv averted 4,241 cases of genital warts over the cohort’s lifetime. Discounted
total costs showed savings of 18.50 million Malaysian Ringgits and 246 QALYs in favour of AS04-HPV-16/18v. In
one-way sensitivity analyses, the discount rate was the most influential variable for costs and QALYs, but AS04-HPV-
16/18v remained dominant throughout. A two-way sensitivity analysis to assess the longevity of cross-protection for both
vaccines confirmed the base-case. Conclusions: In Malaysia, the use of AS04-HPV-16/18v, in addition to screening,
was modelled to be dominant over 4vHPVv, with greater estimated CC benefits and lower costs.
Safety and efficacy of endoscopic submucosal dissection of large (≥3 cm) subepithelial tumors located in the cardia

Li J, Tang J, Lua GW, Chen J, Shi X, Liu F, et al.

Surg Endosc, 2017 12;31(12):5183-5191.
PMID: 28597288 DOI: 10.1007/s00464-017-5585-y

BACKGROUND: Upper gastrointestinal subepithelial tumors (SETs) may harbor potential malignancy. Although it is well recognized that large SETs should be resected, the treatment strategy remains controversial. Compared to surgical resection, endoscopic resection has many advantages such as less invasive, shorter hospital stay, lower costs, and better quality of life. However, Endoscopic resection of large SETs in the cardia is challenging. The purpose of this study was to evaluate the safety and efficacy of endoscopic submucosal dissection (ESD) in the treatment of such SETs.
METHODS: A total of 41 patients with large SETs (≥3 cm in diameter) located in the cardia were involved in the study. All patients underwent ESD. Data on therapeutic outcomes and follow-up were collected, for analysis of risk factors of complication rates.
RESULTS: The average tumor size was 4.7 ± 1.7 cm. The average procedure time was 69.3 ± 32.7 min and the average postoperative hospital stay was 3.5 ± 1.1 days. A total of 41 tumors were removed successfully, in which 35 were leiomyomas, three were gastrointestinal stromal tumors, two were lipomas, and one was gastritis cystica profunda. The en bloc resection rate was 90.2%, and was significantly higher for tumors with a round or oval shape (100%) than for those with an irregular shape (75.0%) (P
Traditional uses, phytochemistry, pharmacology and toxicology of the genus Gynura (Compositae): A comprehensive review

Meng X, Li J, Li M, Wang H, Ren B, Chen J, et al.

J Ethnopharmacol, 2021 Aug 10;276:114145.
PMID: 33932518 DOI: 10.1016/j.jep.2021.114145

ETHNOPHARMACOLOGICAL RELEVANCE: Gynura cass., belonging to the tribe Senecoineae of the family Compositae, contains more than 40 accepted species as annual or perennial herbs, mainly distributed in Asia, Africa and Australia. Among them, 11 species are distributed in China. Many of the Gynura species have been used as traditional herbal medicines for the treatment of diabetes mellitus, rheumatism, eruptive fever, gastric ulcer, bleeding, abscesses, bruises, burning pains, rashes and herpes zoster infection in tropical Asia countries such as China, Thailand, Indonesia, Malaysia, and Vietnam. Some of the species have been used as vegetables, tea beverage or ornamental plants by the local people.
AIM OF THE STUDY: A more comprehensive and in-depth review about the geographical distribution, traditional uses, chemical constituents and pharmacological activities as well as safe and toxicity of Gynura species has been summarized, hoping to provide a scientific basis for rational development and utilization as well as to foster further research of these important medicinal plant resources in the future.
MATERIALS AND METHODS: A review of the literature was performed based on the existing peer-reviewed researches by consulting scientific databases including Web of Science, PubMed, Elsevier, Google Scholar, SciFinder and China National Knowledge Infrastructure.
RESULTS: Many of the Gynura species have been phytochemically studied, which led to the isolation of more than 338 compounds including phenolics, flavonoids, alkaloids, terpenoids, steroids, cerebrosides, aliphatics and other compounds. Pharmacological studies in vitro and in vivo have also confirmed the various bioactive potentials of extracts or pure compounds from many Gynura plants, based on their claimed ethnomedicinal and anecdotal uses, including antioxidant, anti-inflammation, anticancer, antidiabetic, antihypertension, antibacterial and other activities. However, pyrrolizidine alkaloids (PAs) pose a threat to the medication safety and edible security of Gynura plants because of toxicity issues, requiring the need to pay great attention to this phenomenon.
CONCLUSION: The traditional uses, phytochemistry and pharmacology of Gynura species described in this review demonstrated that these plants contain a great number of active constituents and display a diversity of pharmacological activities. However, the mechanism of action, structure-activity relationship, potential synergistic effects and pharmacokinetics of these components need to be further elucidated. Moreover, further detailed research is urgently needed to explain the mechanisms of toxicity induced by PAs. In this respect, effective detoxification strategies need to be worked out, so as to support the safe and reasonable utilization of Gynura plant resources in the future.
Fulltext Antibiotics: An overview on the environmental occurrence, toxicity, degradation, and removal methods

Yang Q, Gao Y, Ke J, Show PL, Ge Y, Liu Y, et al.

Bioengineered, 2021 12;12(1):7376-7416.
PMID: 34612807 DOI: 10.1080/21655979.2021.1974657

Antibiotics, as antimicrobial drugs, have been widely applied as human and veterinary medicines. Recently, many antibiotics have been detected in the environments due to their mass production, widespread use, but a lack of adequate treatment processes. The environmental occurrence of antibiotics has received worldwide attention due to their potential harm to the ecosystem and human health. Research status of antibiotics in the environment field is presented by bibliometrics. Herein, we provided a comprehensive overview on the following important issues: (1) occurrence of antibiotics in different environmental compartments, such as wastewater, surface water, and soil; (2) toxicity of antibiotics toward non-target organisms, including aquatic and terrestrial organisms; (3) current treatment technologies for the degradation and removal of antibiotics, including adsorption, hydrolysis, photodegradation and oxidation, and biodegradation. It was found that macrolides, fluoroquinolones, tetracyclines, and sulfonamides were most frequently detected in the environment. Compared to surface and groundwaters, wastewater contained a high concentration of antibiotic residues. Both antibiotics and their metabolites exhibited toxicity to non-target organisms, especially aquatic organisms (e.g., algae and fish). Fluoroquinolones, tetracyclines, and sulfonamides can be removed through abiotic process, such as adsorption, photodegradation, and oxidation. Fluoroquinolones and sulfonamides can directly undergo biodegradation. Further studies on the chronic effects of antibiotics at environmentally relevant concentrations on the ecosystem were urgently needed to fully understand the hazards of antibiotics and help the government to establish the permissible limits. Biodegradation is a promising technology; it has numerous advantages such as cost-effectiveness and environmental friendliness.
A novel machine learning scheme for classification of medicinal herbs based on 2D-FTIR fingerprints

Yoon TL, Yeap ZQ, Tan CS, Chen Y, Chen J, Yam MF

Spectrochim Acta A Mol Biomol Spectrosc, 2022 Feb 05;266:120440.
PMID: 34627017 DOI: 10.1016/j.saa.2021.120440

A proof-of-concept medicinal herbs identification scheme using machine learning classifiers is proposed in the form of an automated computational package. The scheme makes use of two-dimensional correlation Fourier Transformed Infrared (FTIR) fingerprinting maps derived from the FTIR of raw herb spectra as digital input. The prototype package admits a collection of 11 machine learning classifiers to form a voting pool. A common set of oversampled dataset containing 5 different herbal classes is used to train the pool of classifiers on a one-verses-others manner. The collections of trained models, dubbed the voting classifiers, are deployed in a collective manner to cast their votes to support or against a given inference fingerprint whether it belongs to a particular class. By collecting the votes casted by all voting classifiers, a logically designed scoring system will select out the most probable guess of the identity of the inference fingerprint. The same scoring system is also capable of discriminating an inference fingerprint that does not belong to any of the classes the voting classifiers are trained for as the 'others' type. The proposed classification scheme is stress-tested to evaluate its performance and expected consistency. Our experimental runs show that, by and large, a satisfactory performance of the classification scheme of up to 90 % accuracy is achieved, providing a proof-of-concept viability that the proposed scheme is a feasible, practical, and convenient tool for herbal classification. The scheme is implemented in the form of a packaged Python code, dubbed the "Collective Voting" (CV) package, which is easily scalable, maintained and used in practice.
Recent advances in nanomaterials for water protection and monitoring

Das R, Vecitis CD, Schulze A, Cao B, Ismail AF, Lu X, et al.

Chem Soc Rev, 2017 Sep 29.
PMID: 28959815 DOI: 10.1039/c6cs00921b

The efficient handling of wastewater pollutants is a must, since they are continuously defiling limited fresh water resources, seriously affecting the terrestrial, aquatic, and aerial flora and fauna. Our vision is to undertake an exhaustive examination of current research trends with a focus on nanomaterials (NMs) to considerably improve the performance of classical wastewater treatment technologies, e.g. adsorption, catalysis, separation, and disinfection. Additionally, NM-based sensor technologies are considered, since they have been significantly used for monitoring water contaminants. We also suggest future directions to inform investigators of potentially disruptive NM technologies that have to be investigated in more detail. The fate and environmental transformations of NMs, which need to be addressed before large-scale implementation of NMs for water purification, are also highlighted.
Characterization of Eleusine indica with gene mutation or amplification in EPSPS to glyphosate

Chen J, Jiang C, Huang H, Wei S, Huang Z, Wang H, et al.

Pestic Biochem Physiol, 2017 Nov;143:201-206.
PMID: 29183593 DOI: 10.1016/j.pestbp.2017.09.012

The evolution of weed-resistant species threatens the sustainable use of glyphosate, which is the most important herbicide widely used in agriculture worldwide. Moreover, the high glyphosate resistance (>180-fold based on LD50) of Eleusine indica found in Malaysia, which carries a double mutation in its 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), made the control of this species more difficult. By contrast, the same species carrying the same double mutation in EPSPS (T102I+P106S) but found in China only shows a resistance level of not more than 14-fold based on GR50. The resistance level of this population is four times higher than that of the population carrying a single mutation (P106L). Although the members of this population survive under a high glyphosate dosage of 10,080gaeha-1, their growth was significantly inhibited by glyphosate under the recommend dose (840gaeha-1), where in the fresh weight was 85.4% of the control. EPSPS expression, relative copy number, and EPSPS activity in this population were similar to those of the susceptible population. In addition, the expression of two glutathione transferase (GST) genes (GST-U8 and GST-23) and the enzyme activity of the GST in this population did not significantly differ from those of the susceptible population. This finding is important in elucidating the resistance of the naturally evolved glyphosate-resistant (GR) weed species carrying a double mutation in EPSPS to glyphosate.
Fulltext Influence of psychological capital on core competency for new nurses

Wang J, Chen J, Zheng L, Zeng B, Yan X, Xia M, et al.

PLoS One, 2023;18(8):e0289105.
PMID: 37561799 DOI: 10.1371/journal.pone.0289105

BACKGROUND: The development of core competency is crucial for the success of new nurses, enabling them to deliver high-quality care. Psychological capital (PsyCap), encompassing self-efficacy, optimism, hope, and resilience, significantly influences individuals' abilities and achievements across various professions. However, limited research has specifically examined the impact of PsyCap on the core competency of new nurses. This study aims to bridge this gap by investigating the relationship between PsyCap and core competency development in new nurses, providing valuable strategic insights for improving PsyCap and promoting core competence acquisition.
METHODS: 142 new nurses were chosen for the investigation using a convenient cluster sampling method. The questionnaire included components on socio-demographic characteristics, the Competency Inventory for Registered Nurses (CIRN), and the PsyCap Questionnaire-24 (PCQ-24). The t-test, One-Way ANOVA, Pearson correlation analysis and hierarchical multiple regression were used for statistical analysis.
RESULT: The number of valid questionnaires was 138, and the effective return rate was 97.2%. The overall mean score for core competencies was 171.01 (SD 25.34), and the PsyCap score was 104.76(SD 13.71). The PsyCap of new nurses was highly correlated with core competency, with a correlation coefficient of r = 0.7, p < 0.01. Self-efficacy of PsyCap is a significant independent predictor of core competency (adjust R2 = 0.49).
CONCLUSION: Self-efficacy in PsyCap is an important predictor of new nurses' core competency. Nursing managers should pay sufficient attention to the cultivation and development of new nurses' PsyCap, with particular emphasis on enhancing self-efficacy to improve their core competency.
10H-3,6-Diazaphenothiazines triggered the mitochondrial-dependent and cell death receptor-dependent apoptosis pathways and further increased the chemosensitivity of MCF-7 breast cancer cells via inhibition of AKT1 pathways

Ren G, Hao X, Yang S, Chen J, Qiu G, Ang KP, et al.

J Biochem Mol Toxicol, 2020 Sep;34(9):e22544.
PMID: 32619082 DOI: 10.1002/jbt.22544

Breast cancer is one of the leading causes of death in cancer categories, followed by lung, colorectal, and ovarian among the female gender across the world. 10H-3,6-diazaphenothiazine (PTZ) is a thiazine derivative compound that exhibits many pharmacological activities. Herein, we proceed to investigate the pharmacological activities of PTZ toward breast cancer MCF-7 cells as a representative in vitro breast cancer cell model. The PTZ exhibited a proliferation inhibition (IC50 = 0.895 µM) toward MCF-7 cells. Further, cell cycle analysis illustrated that the S-phase checkpoint was activated to achieve proliferation inhibition. In vitro cytotoxicity test on three normal cell lines (HEK293 normal kidney cells, MCF-10A normal breast cells, and H9C2 normal heart cells) demonstrated that PTZ was more potent toward cancer cells. Increase in the levels of reactive oxygen species results in polarization of mitochondrial membrane potential (ΔΨm), together with suppression of mitochondrial thioredoxin reductase enzymatic activity suggested that PTZ induced oxidative damages toward mitochondria and contributed to improved drug efficacy toward treatment. The RT2 PCR Profiler Array (human apoptosis pathways) proved that PTZ induced cell death via mitochondria-dependent and cell death receptor-dependent pathways, through a series of modulation of caspases, and the respective morphology of apoptosis was observed. Mechanistic studies of apoptosis suggested that PTZ inhibited AKT1 pathways resulting in enhanced drug efficacy despite it preventing invasion of cancer cells. These results showed the effectiveness of PTZ in initiation of apoptosis, programmed cell death, toward highly chemoresistant MCF-7 cells, thus suggesting its potential as a chemotherapeutic drug.
siRNA Silencing of FpVtg Induces Ovarian Cell Apoptosis in Redtail Prawn, Fenneropenaeus penicillatus

Tan K, Dong Y, Tan K, Lim LS, Waiho K, Chen J, et al.

Mar Biotechnol (NY), 2023 Dec;25(6):1176-1190.
PMID: 38010485 DOI: 10.1007/s10126-023-10269-6

Inadequate gonadal maturation and poor spawning performance increasingly threaten the sustainability of shrimp aquaculture. Unraveling the mechanisms regulating ovarian development and maturation hence is critical to address industry challenges. Vitellogenin (Vtg), a precursor of yolk protein found in the hepatopancreas and ovary of shrimp, plays a key role in facilitating shrimp's oocyte maturation and embryonic development after oviposition. This study found that FpVtg was specifically expressed in F. penicillatus hepatopancreas and ovary. FpVtg was localized predominantly in the oocyte cytoplasm and distributed uniformly in the hepatopancreas tissue. Silencing FpVtg led to apoptosis in both hepatopancreas and ovary tissues. Furthermore, FpVtg depletion upregulated the expression of ovarian peritrophin 1, ovarian peritrophin 2, serine proteinase inhibitor 6, and juvenile hormone esterase-like carboxylesterase 1, while downregulated that of vitellogenin, delta-9 desaturase, and insulin-like receptor. KEGG pathway analysis implicated such as PI3K-AKT signaling, RNA transport, ECM-receptor interaction, hippo signaling, oocyte meiosis, and apoptosis were enriched and involved in ovarian development. These findings have provided insights into the FpVtg's reproductive role and the associated regulatory genes and pathways in F. penicillatus. This knowledge can contribute to establishing strategies to improve the breeding and aquaculture production of F. penicillatus by elucidating its vitellogenesis regulation in redtail prawn and other penaeid species. Further characterization of the implicated pathways and genes will clarify the intricacies underlying ovarian maturation.
The regulation of Cytochrome f by mannose treatment in broccoli and its relationship with programmed cell death in tobacco BY-2 cells

Zhao S, Chen J, Cao S, Wang H, Chen H, Wei Y, et al.

Plant Physiol Biochem, 2024 Mar;208:108480.
PMID: 38437751 DOI: 10.1016/j.plaphy.2024.108480

It is well established that programmed cell death (PCD) occurred in broccoli during postharvest senescence, but no studies have been conducted on the regulation of broccoli cytochrome f by mannose treatment and its relationship with PCD. In this study, we treated broccoli buds with mannose to investigate the changes in color, total chlorophyll content, gene expression related to chlorophyll metabolism, chloroplast structure, and cytochrome f determination during postharvest storage. In addition, to investigate the effect of cytochrome f on PCD, we extracted cytochrome f from broccoli and treated Nicotiana tabacum L. cv Bright Yellow 2 (BY-2) cells with extracted cytochrome f from broccoli at various concentrations. The results showed that cytochrome f can induce PCD in tobacco BY-2 cells, as evidenced by altered cell morphology, nuclear chromatin disintegration, DNA degradation, decreased cell viability, and increased caspase-3-like protease production. Taken together, our study indicated that mannose could effectively delay senescence of postharvest broccoli by inhibiting the expression of gene encoding cytochrome f which could induce PCD.
Influence of flavonoids from Sedum aizoon L. on mitochondrial function of Rhizopus nigricans in strawberry

Ge Q, Zhao S, Shao X, Wei Y, Chen J, Wang H, et al.

World J Microbiol Biotechnol, 2024 Apr 13;40(5):161.
PMID: 38613738 DOI: 10.1007/s11274-024-03967-3

Rhizopus nigricans (R. nigricans), one of the fungi that grows the fastest, is frequently discovered in postharvest fruits, it's the main pathogen of strawberry root rot. Flavonoids in Sedum aizoon L. (FSAL) is a kind of green and safe natural substance extracted from Sedum aizoon L. which has antifungal activity. In this study, the minimum inhibitory concentration (MIC) of FSAL on R. nigricans and cell apoptosis tests were studied to explore the inhibitory effect of FSAL on R. nigricans. The effects of FSAL on mitochondria of R. nigricans were investigated through the changes of mitochondrial permeability transition pore(mPTP), mitochondrial membrane potential(MMP), Ca2+ content, H2O2 content, cytochrome c (Cyt c) content, the related enzyme activity and related genes of mitochondria. The results showed that the MIC of FSAL on R. nigricans was 1.800 mg/mL, with the addition of FSAL (1.800 mg/mL), the mPTP openness of R. nigricans increased and the MMP reduced. Resulting in an increase in Ca2+ content, accumulation of H2O2 content and decrease of Cyt c content, the activity of related enzymes was inhibited and related genes were up-regulated (VDAC1, ANT) or down-regulated (SDHA, NOX2). This suggests that FSAL may achieve the inhibitory effect of fungi by damaging mitochondria, thereby realizing the postharvest freshness preservation of strawberries. This lays the foundation for the development of a new plant-derived antimicrobial agent.
Molecular identification of the first local dengue fever outbreak in Shenzhen city, China: a potential imported vertical transmission from Southeast Asia?

Yang F, Guo GZ, Chen JQ, Ma HW, Liu T, Huang DN, et al.

Epidemiol Infect, 2014 Feb;142(2):225-33.
PMID: 23587429 DOI: 10.1017/S0950268813000897

A suspected dengue fever outbreak occurred in 2010 at a solitary construction site in Shenzhen city, China. To investigate this epidemic, we used serological, molecular biological, and bioinformatics techniques. Of nine serum samples from suspected patients, we detected seven positive for dengue virus (DENV) antibodies, eight for DENV-1 RNA, and three containing live viruses. The isolated virus, SZ1029 strain, was sequenced and confirmed as DENV-1, showing the highest E-gene homology to D1/Malaysia/36000/05 and SG(EHI)DED142808 strains recently reported in Southeast Asia. Further phylogenetic tree analysis confirmed their close relationship. At the epidemic site, we also detected 14 asymptomatic co-workers (out of 291) positive for DENV antibody, and DENV-1-positive mosquitoes. Thus, we concluded that DENV-1 caused the first local dengue fever outbreak in Shenzhen. Because no imported case was identified, the molecular fingerprints of the SZ1029 strain suggest this outbreak may be due to vertical transmission imported from Southeast Asia.
Fulltext A neurotoxin that specifically targets Anopheles mosquitoes

Contreras E, Masuyer G, Qureshi N, Chawla S, Dhillon HS, Lee HL, et al.

Nat Commun, 2019 06 28;10(1):2869.
PMID: 31253776 DOI: 10.1038/s41467-019-10732-w

Clostridial neurotoxins, including tetanus and botulinum neurotoxins, generally target vertebrates. We show here that this family of toxins has a much broader host spectrum, by identifying PMP1, a clostridial-like neurotoxin that selectively targets anopheline mosquitoes. Isolation of PMP1 from Paraclostridium bifermentans strains collected in anopheline endemic areas on two continents indicates it is widely distributed. The toxin likely evolved from an ancestral form that targets the nervous system of similar organisms, using a common mechanism that disrupts SNARE-mediated exocytosis. It cleaves the mosquito syntaxin and employs a unique receptor recognition strategy. Our research has an important impact on the study of the evolution of clostridial neurotoxins and provides the basis for the use of P. bifermentans strains and PMP1 as innovative, environmentally friendly approaches to reduce malaria through anopheline control.
Fulltext Molecular characterization of the viral structural protein genes in the first outbreak of dengue virus type 2 in Hunan Province, inland China in 2018

Guan J, He Z, Qin M, Deng X, Chen J, Duan S, et al.

BMC Infect Dis, 2021 Feb 10;21(1):166.
PMID: 33568111 DOI: 10.1186/s12879-021-05823-3

BACKGROUND: An unexpected dengue outbreak occurred in Hunan Province in 2018. This was the first dengue outbreak in this area of inland China, and 172 cases were reported.
METHODS: To verify the causative agent of this outbreak and characterise the viral genes, the genes encoding the structural proteins C/prM/E of viruses isolated from local residents were sequenced followed by mutation and phylogenetic analysis. Recombination, selection pressure, potential secondary structure and three-dimensional structure analyses were also performed.
RESULTS: Phylogenetic analysis revealed that all epidemic strains were of the cosmopolitan DENV-2 genotype and were most closely related to the Zhejiang strain (MH010629, 2017) and then the Malaysia strain (KJ806803, 2013). Compared with the sequence of DENV-2SS, 151 base substitutions were found in the sequences of 89 isolates; these substitutions resulted in 20 non-synonymous mutations, of which 17 mutations existed in all samples (two in the capsid protein, six in the prM/M proteins, and nine in the envelope proteins). Moreover, amino acid substitutions at the 602nd (E322:Q → H) and 670th (E390: N → S) amino acids may have enhanced the virulence of the epidemic strains. One new DNA binding site and five new protein binding sites were observed. Two polynucleotide binding sites and seven protein binding sites were lost in the epidemic strains compared with DENV-2SS. Meanwhile, five changes were found in helical regions. Minor changes were observed in helical transmembrane and disordered regions. The 429th amino acid of the E protein switched from a histamine (positively charged) to an asparagine (neutral) in all 89 isolated strains. No recombination events or positive selection pressure sites were observed. To our knowledge, this study is the first to analyse the genetic characteristics of epidemic strains in the first dengue outbreak in Hunan Province in inland China.
CONCLUSIONS: The causative agent is likely to come from Zhejiang Province, a neighbouring province where dengue fever broke out in 2017. This study may help clarify the intrinsic geographical relatedness of DENV-2 and contribute to further research on pathogenicity and vaccine development.

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