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1.
Curr Microbiol ; 2020 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-32535651

RESUMO

The gut microbiota has long been of research interests due to its nutritional importance for many insects. It has been demonstrated that diversity of gut microbiota in insects can be modulated by many factors, including habitats, feeding preference, etc. Besides, the community structure of gut microbiota could also be altered during the different life stages of host insects. With development of conventional culture-dependent technologies and advanced culture-independent technologies, comprehensive and deep understanding of the functions of gut microbiota and their relationship with host insects were achieved, especially for the nutrient metabolic process mediated by them. In this review, we summarized the gut microbiota composition, major methods for gut microbiota characterization, and vital nutrient metabolic process mediated by gut microbiota in different insects. The increasing knowledge on the modulation of gut microbiota will help us for the comprehension of the contribution of gut microbiota to the nutritional metabolism of insects, prompting their growth and health.

2.
Artigo em Inglês | MEDLINE | ID: mdl-32543765

RESUMO

Modification of the external surfaces of metal organic frameworks offers a new level of control over their adsorption behavior. We have previously shown that capping of MOFs with ethylenediamine (EDA) can effectively retain small gaseous molecules [Nat. Comm. 2016, 7, 13871] at room temperature. Here, we report a temperature-induced variation in the capping-layer gate opening mechanism through a combination of in situ IR experiments and ab initio simulations of the capping layer. We find an atypical acceleration and increase in the loading of weakly adsorbed molecules upon raising the temperature above room temperature. Our findings show the discovery of a novel temperature-dependent kinetics that goes beyond standard kinetics and suggest a new avenue for tailoring selective adsorption by thermally tuning the surface barrier.

3.
Nature ; 582(7810): 129-133, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32494073

RESUMO

Mitochondria take up Ca2+ through the mitochondrial calcium uniporter complex to regulate energy production, cytosolic Ca2+ signalling and cell death1,2. In mammals, the uniporter complex (uniplex) contains four core components: the pore-forming MCU protein, the gatekeepers MICU1 and MICU2, and an auxiliary subunit, EMRE, essential for Ca2+ transport3-8. To prevent detrimental Ca2+ overload, the activity of MCU must be tightly regulated by MICUs, which sense changes in cytosolic Ca2+ concentrations to switch MCU on and off9,10. Here we report cryo-electron microscopic structures of the human mitochondrial calcium uniporter holocomplex in inhibited and Ca2+-activated states. These structures define the architecture of this multicomponent Ca2+-uptake machinery and reveal the gating mechanism by which MICUs control uniporter activity. Our work provides a framework for understanding regulated Ca2+ uptake in mitochondria, and could suggest ways of modulating uniporter activity to treat diseases related to mitochondrial Ca2+ overload.

4.
Indian J Pharmacol ; 52(2): 108-116, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32565598

RESUMO

We investigate the protective effect of Carthamus tinctorius L. (CTL, also known as Honghua in China or Safflower) on cerebral ischemia-reperfusion and explored the possible mechanisms on regulating apoptosis and matrix metalloproteinases (MMPs). High-performance liquid chromatography method with diode array detection analysis was established to analyze the components of CTL. Middle cerebral artery occlusion rats model was established to evaluate Neurological Function Score and hematoxylin-eosin staining, as well as triphenyltetrazolium was used to examine the infarction area ratio. Transferase-mediated dUTP nick-end labeling was performed for the apoptosis. Apoptosis-related factors, including B-cell lymphoma-2 (Bcl-2), Bax and Caspase3, and MMPs-related MMP2, MMP9, tissue inhibitor of metalloproteinases 1 (TIMP1) in ischemic brain, were assayed by Western blot, reverse transcription polymerase chain reaction, and immunohistochemistry. The data showed that CTL (2, 4 g crude drug/kg/d) treatment could significantly reduce the ischemic damage in brain tissue and improve a significant neurological function score. In addition, CTL could also attenuate apoptosis degree of brain tissues and regulate Bcl-2, Bax, and Caspase 3 and also have a significant decrease on MMP-9 expression, followed by a significant increase of TIMP1 protein expression. These findings indicated that regulation of CTL on apoptosis and MMPs contributed to its protective effect on ischemia/reperfusion injury.

5.
Aging (Albany NY) ; 122020 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-32584787

RESUMO

Emerging studies indicate that long non-coding RNAs (lncRNAs) play crucial roles in colorectal cancer (CRC). Here, we reported lncRNA CASC21, which is induced by FOXP1, functions as an oncogene in CRC. We systematically elucidated its clinical significance and possible molecular mechanism in CRC. LncRNA expression in CRC was analyzed by RNA-sequencing data in TCGA. The expression level of CASC21 in tissues was determined by qRT-PCR. The functions of CASC21 was investigated by in vitro and in vivo assays (CCK8 assay, colony formation assay, EdU assay, xenograft model, flow cytometry assay, immunohistochemistry (IHC) and Western blot). Chromatin immunoprecipitation (ChIP), RNA immunoprecipitation (RIP) and luciferase reporter assays were utilized to demonstrate the potential mechanisms of CASC21. CASC21 is overexpressed in CRC and high CASC21 expression is associated with poor survival. Functional experiments revealed that CASC21 promotes CRC cell growth. Mechanistically, we found that CASC21 expressed predominantly in the cytoplasm. CASC21 could interact with miR-539-5p and regulate its target CDK6. Together, our study elucidated that CASC21 acted as an oncogene in CRC, which might serve as a novel target for CRC diagnosis and therapy.

6.
Med Sci Monit ; 26: e923559, 2020 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-32406388

RESUMO

BACKGROUND MicroRNAs (miRNAs) have a significant regulatory effect on the proliferation, migration, and invasion of cells, and have been widely reported to have oncogenic or tumor-suppressive impacts on various tumors. In the present study we assessed the regulation and function of miR-20a on colorectal cancer (CRC) cell lines. MATERIAL AND METHODS qPCR was used to quantify miR-20a expression. Luciferase reporter assay was conducted to confirm Foxj2 3'UTR associations. In addition, the function of miR-20a and Foxj2 in CRC was detected using MTT, colony formation, transwell assays, and cell cycle analysis. RESULTS Our data revealed that miR-20a expression was elevated in the CRC cell lines, and cell migration, proliferation, and invasion abilities were promoted by the overexpression of miR-20a. Moreover, Foxj2 was authenticated as a direct target gene of miR-20a in CRC cells. Furthermore, we found that the ectopic Foxj2 dramatically suppressed miR-20a-promoted proliferation, migration, invasion, and xenografts in vitro and in vivo, and induced cell cycle arrest at G1 stage. CONCLUSIONS Our results showing the roles of miR-20a/Foxj2 in carcinogenesis of CRC may help improve treatment of CRC.

7.
Science ; 368(6492): 760-763, 2020 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-32409473

RESUMO

The orbital angular momentum (OAM) intrinsically carried by vortex light beams holds a promise for multidimensional high-capacity data multiplexing, meeting the ever-increasing demands for information. Development of a dynamically tunable OAM light source is a critical step in the realization of OAM modulation and multiplexing. By harnessing the properties of total momentum conservation, spin-orbit interaction, and optical non-Hermitian symmetry breaking, we demonstrate an OAM-tunable vortex microlaser, providing chiral light states of variable topological charges at a single telecommunication wavelength. The scheme of the non-Hermitian-controlled chiral light emission at room temperature can be further scaled up for simultaneous multivortex emissions in a flexible manner. Our work provides a route for the development of the next generation of multidimensional OAM-spin-wavelength division multiplexing technology.

8.
Science ; 368(6492): 763-767, 2020 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-32409474

RESUMO

Applications that use the orbital angular momentum (OAM) of light show promise for increasing the bandwidth of optical communication networks. However, direct photocurrent detection of different OAM modes has not yet been demonstrated. Most studies of current responses to electromagnetic fields have focused on optical intensity-related effects, but phase information has been lost. In this study, we designed a photodetector based on tungsten ditelluride (WTe2) with carefully fabricated electrode geometries to facilitate direct characterization of the topological charge of OAM of light. This orbital photogalvanic effect, driven by the helical phase gradient, is distinguished by a current winding around the optical beam axis with a magnitude proportional to its quantized OAM mode number. Our study provides a route to develop on-chip detection of optical OAM modes, which can enable the development of next-generation photonic circuits.

9.
Sci Total Environ ; 731: 139080, 2020 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-32417477

RESUMO

Aerobic denitrification is a novel biological nitrogen removal technology, which has been widely investigated as an alternative to the conventional denitrification and for its unique advantages. To fully comprehend aerobic denitrification, it is essential to clarify the regulatory mechanisms of intracellular electron transfer during aerobic denitrification. However, reports on intracellular electron transfer during aerobic denitrification are rather limited. Thus, the purpose of this review is to discuss the molecular mechanism of aerobic denitrification from the perspective of electron transfer, by summarizing the advancements in current research on electron transfer based on conventional denitrification. Firstly, the implication of aerobic denitrification is briefly discussed, and the status of current research on aerobic denitrification is summarized. Then, the occurring foundation and significance of aerobic denitrification are discussed based on a brief review of the key components involved in the electron transfer of denitrifying enzymes. Moreover, a strategy for enhancing the efficiency of aerobic denitrification is proposed on the basis of the regulatory mechanisms of denitrification enzymes. Finally, scientific outlooks are given for further investigation on aerobic denitrification in the future. This review could help clarify the mechanism of aerobic denitrification from the perspective of electron transfer.

10.
Artigo em Inglês | MEDLINE | ID: mdl-32382941

RESUMO

Xylanases are extensively used as industrial enzymes for its ability of hydrolyzing xylan to oligosaccharides. Here, XynHB, a thermo and alkaline stable xylanase derived from Bacillus pumilus HBP8, was extracellularly produced in E. coli cells through N-terminal-fused signal peptides. We found that the matured XynHB itself could be auto-secreted out of E. coli BL21(DE3) cells at a very low level, and two Sec-pathway signal peptides, PelB and OmpA, and one dual Sec-Tat-pathway signal peptide, FhuD, could effectively prompt its extracellular production up to 12-fold. Our results showed that PelB signal peptide led to the highest extracellular production of XynHB for approximately 54.1 µg/mL, and FhuD-fused XynHB possessed the highest specific activity of 1746.0 U/mg at 70 °C. Meanwhile, our studies also indicated that PelB- and FhuD-fused XynHB might disrupt E. coli cells' periplasm during their secretion process, thus causing cell lysis to facilitate their extracellular production. Moreover, further characterization revealed that the extracellular production of XynHB was not affected by the outer membrane permeability of E. coli cells. Our studies provided an advantageous strategy for the extracellular production of xylanase in E. coli, which may also be used for E. coli autolysis in the future.

11.
Hum Psychopharmacol ; : e2736, 2020 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-32352600

RESUMO

OBJECTIVE: Withdrawal symptoms are common during methamphetamine (METH) abstinence. This study aimed to explore the association between serum interleukins and withdrawal symptoms during METH abstinence. METHODS: This study recruited 120 METH users, and 94 of them completed the 2-week follow-up. Serum interleukin-1ß, 6,8,10 were tested at admission. Withdrawal symptoms were assessed by the Methamphetamine Withdrawal Questionnaire (MAWQ). RESULTS: Serum IL-8 levels were positively correlated with MAWQ scores at the 2-week endpoint (r = .257, p = .013). The variation of the MAWQ scores during the 2-week follow-up was negatively correlated with serum IL-8 levels at admission (r = -.249, p = .026). Serum IL-8 levels remained associated with the severity of METH withdrawal symptoms (ß = .363, p = .023), after adjusting for potential confounders. LIMITATIONS: This study did not include normal controls. Most patients were male and cigarette smokers. Patients were only followed up for 2 weeks, and their toxicology data were not collected. Interleukins were only measured at admission, and were tested in serum, not in the cerebrospinal fluid. CONCLUSIONS: Our study demonstrated that higher serum IL-8 levels may predict more severe withdrawal symptoms at 2 weeks after METH abstinence.

12.
Pediatr Res ; 2020 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-32392577

RESUMO

BACKGROUND: Autonomic dysfunction is a key trait in the development of obstructive sleep apnea syndrome (OSAS) in adults. However, few similar studies focused on children and adolescents. We investigated if there was any association between heart rate recovery (HRR) and the severity of OSAS in children and adolescents. METHODS: A total of 161 subjects were included: 87 healthy controls, 35 mild OSAS patients (M-OSAS) and 39 moderate-severe OSAS (M-S-OSAS) patients. Clinical parameters, cardiopulmonary exercise test (CPET) indexes including HRR and polysomnographic records including apnea-hypopnea index (AHI) were compared among the three groups. Pearson correlation analysis and multivariable linear regression analysis were used to detect the relationship between HRR and polysomnographic parameters. RESULTS: HRR values in either the OSAS group were lower than those of the control group, and the values in the M-S OSAS group were even lower than those of the M-OSAS group (P < 0.05). Correlation analysis showed that HRR was inversely correlated with AHI (r = -0.190, P < 0.01). Moreover, multivariable linear regression analyses showed the association between HRR and AHI was significant (ß = 0.174, P < 0.01). CONCLUSIONS: HRR was closely associated with OSAS severity, which suggested that HRR might be a promising index for risk stratification and clinical management in children and adolescents with OSAS. IMPACT: Heart rate recovery (HRR), a noninvasive and reliable index of automatic nervous system, is closely associated with the severity of obstructive sleep apnea syndrome (OSAS) in children and adolescents.To our knowledge, our study was the first study in China focusing on evaluating the role of HRR in children with OSAS.We found HRR was closely associated with OSAS severity in children and adolescents, and it suggested that HRR might be a promising index for risk stratification and clinical management in children and adolescents with OSAS.

13.
Artigo em Inglês | MEDLINE | ID: mdl-32453449

RESUMO

BACKGROUND: The effectiveness and portability of the collaborative care model in the primary care treatment of depression has not been demonstrated in many randomized controlled trials in healthcare settings across the world. We determined the effectiveness of collaborative care management of elderly depression in the primary care setting in Singapore. METHOD: Eligible participants with depressive symptoms were randomized to 6-month duration usual care (UC, N = 112) or collaborative care (CC, N = 102). Outcome measures were HDRS-17, GDS, BDI and SF-12 MCS QOL measured at 3, 6, and 12-month, care satisfaction at 6-month, and also measured on 120 participants who refused referral (non-receipt of care, NC). Primary outcome was HDRS-17 measure of depression severity, response and remission at 6-month. RESULTS: HDRS scores in CC group compared to UC group were reduced more at 6-month (1.5 points difference in change from baseline), and also at 3 and 12-month, with similar observations of differences for GDS and BDI. There was significantly greater improvement for both CC and UC groups compared to NC group. The CC group was about 1.5 times more likely to show HDRS treatment response and remission, and more than two times likely to show GDS treatment response and remission than the UC and NC groups, as well as better quality of life improvement (P < .001) and better care satisfaction (P < .001). CONCLUSION: Collaborative care is effective for primary care treatment of older persons with depression and is portable in diverse health care settings.

14.
Nucl Med Commun ; 41(7): 651-658, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32404643

RESUMO

INTRODUCTION: The key point for botulinum toxin type A injection in treating cervical dystonia is to accurately identify dystonic muscles. This study aimed to evaluate the efficacy of technetium-sestamibi single-photon emission computed tomography in identifying target muscles in cervical dystonia. METHODS: In the study group (n = 18), target muscles were selected according to clinical evaluation combined with technetium-sestamibi single-photon emission computed tomography, while in the control group (n = 18), target muscles were selected by clinical evaluation alone. All patients were followed-up at 2 weeks, 1, 3 and 6 months after botulinum toxin type A injection. The primary outcomes were the reduction rates in Toronto Western Spasmodic Torticollis Rating Scale and Tsui score at 1 month. RESULTS: Although the reduction rates in Toronto Western Spasmodic Torticollis Rating Scale and Tsui scores were not different between the two groups at 2 weeks and 1 month, the reduction rates in both scores were significantly higher in the study group at 3 and 6 months. The number of patients receiving re-injection within 6 months was significantly lower in the study group. Also, the re-injection interval was significantly longer in the study group. In the study group, more deep cervical muscles were injected, which concerns especially semispinalis capitis, longissimus capitis, and obliques capitis inferior muscles. CONCLUSION: technetium-sestamibi single-photon emission computed tomography is a useful method for screening target muscles in cervical dystonia. It helps clinicians draw a 'blueprint' for the distribution of dystonic muscles before botulinum toxin type A injection.

15.
Cell Commun Signal ; 18(1): 58, 2020 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-32264893

RESUMO

BACKGROUND: Magnolia extract (ME) is known to inhibit cancer growth and metastasis in several cell types in vitro and in animal models. However, there is no detailed study on the preventive efficacy of ME for oral cancer, and the key components in ME and their exact mechanisms of action are not clear. The overall goal of this study is to characterize ME preclinically as a potent oral cancer chemopreventive agent and to determine the key components and their molecular mechanism(s) that underlie its chemopreventive efficacy. METHODS: The antitumor efficacy of ME in oral cancer was investigated in a 4-nitroquinoline-1-oxide (4NQO)-induced mouse model and in two oral cancer orthotopic models. The effects of ME on mitochondrial electron transport chain activity and ROS production in mouse oral tumors was also investigated. RESULTS: ME did not cause detectable side effects indicating that it is a promising and safe chemopreventive agent for oral cancer. Three major key active compounds in ME (honokiol, magnolol and 4-O-methylhonokiol) contribute to its chemopreventive effects. ME inhibits mitochondrial respiration at complex I of the electron transport chain, oxidizes peroxiredoxins, activates AMPK, and inhibits STAT3 phosphorylation, resulting in inhibition of the growth and proliferation of oral cancer cells. CONCLUSION: Our data using highly relevant preclinical oral cancer models, which share histopathological features seen in human oral carcinogenesis, suggest a novel signaling and regulatory role for mitochondria-generated superoxide and hydrogen peroxide in suppressing oral cancer cell proliferation, progression, and metastasis. Video abstract.

16.
Zhongguo Zhong Yao Za Zhi ; 45(3): 531-538, 2020 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-32237510

RESUMO

Diabetes mellitus is a serious chronic metabolic disease, and the patient's hyperglycemia is often accompanied by complications. In the circles of medical science, traditional Chinese medicine(TCM) has the earliest knowledge and research about diabetes. According to TCM, the clinical characteristics of diabetes mellitus were basically the same as "Xiaoke". TCM also believes that "Yin deficiency and dryness heat" was the main pathogenesis of diabetes. Therefore, Yin-tonifying TCMs is widely used in clinical treatment of diabetes mellitus, including Dendrobii Caulis, Lilii Bulbus, Ophiopogonis Radix, Polygonati Rhizome. The effective component for treating diabetes in the above Chinese materia medica is polysaccharides, which is used to treat complications of diabetes mellitus, like vascular disease, nephropathy, retinopathy, peripheral neuropathy. According to literature reports, except for specific some Yin-tonifying TCMs with effective ingredients for preventing and treating diabetes, other Yin-tonifying TCMs only contain water, alcohol extracts or polysaccharides in the treatment of diabetes. However, due to unclear material basis, dose-effect relationship and mechanism target of hypoglycemic drugs, Yin-tonifying TCMs are restricted in clinical application, with certain difficulties in in-depth studies. In this paper, the literatures related to the treatment of diabetes mellitus and its complications with Yin-tonifying TCM are analyzed and summarized, the existing problems are analyzed, and the research ideas and methods based on chromatographic technology and metabonomics are put forward, in order to provide reference for the application and development of Yin-tonifying TCM.

17.
Zhongguo Zhong Yao Za Zhi ; 45(3): 548-554, 2020 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-32237512

RESUMO

Study the suitability of organic film for salvianolic acid in the ultrafiltration process of Danshen Dizhuye. UPLC was used to analyze the migration of nine phenolic active ingredients in Danshen Dizhuye during ultrafiltration of PES hollow fiber membrane and PS hollow fiber membrane. The structural composition of multi-components was analyzed by three different batches of Danshen Dizhuye before and after ultrafiltration of the two membranes. The results showed that 9 phenolic active ingredients in Danshen Dizhuye did not change significantly after ultrafiltration through PES membrane. However, after ultrafiltration through PS membrane, the content of sodium danshensu, protocatechualdehyde, caffeic acid, 3-hydroxy-4-methoxycinnamic acid and rosmarinic acid in Danshen Dizhuye did not change significantly, while salvianolic acid D, salvianolic acid B and lithospermic acid decreased by about 20%, and the content of salvianolic acid A decreased significantly. The final content in equilibrium was only about 20% of the original solution. Therefore, an in-depth study on the migration particularity of salvianolic acid A in ultrafiltration membrane was the focuse. The results showed that the loss of salvianolic acid A was caused by both membranes during ultrafiltration, and salvianolic acid A was lost more in PS membrane. When the membrane was washed and regenerated, it was found that salvianolic acid A was detected in the ethanol washing solution, but not in the washing liquid, indicating that the loss of salvianolic acid A during the ultrafiltration was mainly adsorptive action. The results suggested that the migration of phenolic active ingredients in Danshen Dizhuye during the membrane ultrafiltration process did not completely follow the molecular weight passing rule of the membrane pore size. At the same time, it may be affected by factors, such as the structure of the membrane material, and the interaction between the membrane structure and the structure of components, and exhibit different migration behaviors during the ultrafiltration of the membrane.

18.
Wei Sheng Yan Jiu ; 49(2): 267-271, 2020 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-32290944

RESUMO

OBJECTIVE: To establish a method for determination of thiram, propineb and metiram in mushroom samples by gas chromatography-mass spectrometry(GC-MS). METHODS: Insoluble heavy metal salts were converted into water-soluble sodium salts by alkaline buffer with strong chelating agents. Dithiocarbamates can be converted into different methyl ester compounds with ion pair methylation. The GC separation was performed on a DB-5 MS capillary column(30 m×0. 25 mm, 0. 25 µm). The pesticides were detected by GC-MS with selective ion monitoring(SIM) and quantified by external standard of working curve method. Methodsological verification was carried out based on optimized sample pretreatment and GC-MS condition. RESULTS: The concentrations of dithiocarbamates exhibited a good linear relationship with GC-MS within a certain range. The limits of detection of thiram, propineb and metiram were 0. 01, 0. 05 and 0. 05 mg/kg, respectively. Furthermore, the average recoveries were from 76. 98% to 93. 52%, and the maximum relative standard deviation was 11. 54%(n=6). CONCLUSION: This method is simple, sensitive, accurate and reliable. All the indices meet the requirements of pesticide residue detection.

19.
Artigo em Inglês | MEDLINE | ID: mdl-32243687

RESUMO

Hierarchically porous metal-organic frameworks (HP-MOFs) facilitate mass transfer due to mesoporosity while preserving the advantage of microporosity. This unique feature endows HP-MOFs with remarkable application potential in multiple fields. Recently, new methods such as linker labilization for the construction of HP-MOFs have emerged. To further enrich the synthetic toolkit of MOFs, we report a controlled photolytic removal of linkers to create mesopores within microporous MOFs at tens of milliseconds. Ultraviolet (UV) laser has been applied to eliminate "photolabile" linkers without affecting the overall crystallinity and integrity of the original framework. Presumably, the creation of mesopores can be attributed to the missing-cluster defects, which can be tuned through varying the time of laser exposure and ratio of photolabile/robust linkers. Upon laser exposure, MOF crystals shrank while metal oxide nanoparticles formed giving rise to the HP-MOFs. In addition, photolysis can also be utilized for the fabrication of complicated patterns with high precision, paving the way towards MOF lithography, which has enormous potential in sensing and catalysis.

20.
IEEE Trans Cybern ; 2020 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-32275633

RESUMO

This article mainly focuses on the problem of synchronization in finite and fixed time for fully complex-variable delayed neural networks involving discontinuous activations and time-varying delays without dividing the original complex-variable neural networks into two subsystems in the real domain. To avoid the separation method, a complex-valued sign function is proposed and its properties are established. By means of the introduced sign function, two discontinuous control strategies are developed under the quadratic norm and a new norm based on absolute values of real and imaginary parts. By applying nonsmooth analysis and some novel inequality techniques in the complex field, several synchronization criteria and the estimates of the settling time are derived. In particular, under the new norm framework, a unified control strategy is designed and it is revealed that a parameter value in the controller completely decides the networks are synchronized whether in finite time or in fixed time. Finally, some numerical results for an example are provided to support the established theoretical results.

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