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1.
Neural Regen Res ; 16(1): 80-92, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32788451

RESUMO

Stroke is a main cause of death and disability worldwide. The ability of the brain to self-repair in the acute and chronic phases after stroke is minimal; however, promising stem cell-based interventions are emerging that may give substantial and possibly complete recovery of brain function after stroke. Many animal models and clinical trials have demonstrated that neural stem cells (NSCs) in the central nervous system can orchestrate neurological repair through nerve regeneration, neuron polarization, axon pruning, neurite outgrowth, repair of myelin, and remodeling of the microenvironment and brain networks. Compared with other types of stem cells, NSCs have unique advantages in cell replacement, paracrine action, inflammatory regulation and neuroprotection. Our review summarizes NSC origins, characteristics, therapeutic mechanisms and repair processes, then highlights current research findings and clinical evidence for NSC therapy. These results may be helpful to inform the direction of future stroke research and to guide clinical decision-making.

2.
Global Spine J ; : 2192568220972080, 2020 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-33203246

RESUMO

STUDY DESIGN: Retrospective case series. OBJECTIVES: To present outcomes concerning patients with early-onset mixed-type congenital scoliosis (EOMTCS) treated with the traditional single growing rod (TSGR), focusing on the growth of unsegmented levels (USLs). METHODS: Patients with EOMTCS who underwent TSGR and had a minimum of 4 USLs, 4 distractions, and 3-year follow-up were enrolled. Spine radiographs before and after index surgery and at the latest follow-up were evaluated. The length of the concave and convex side of USLs and thoracic parameters were measured. The absolute value and percentage of growth were calculated. RESULTS: Fourteen patients (mean age, 7.3 ± 2.8 years) were enrolled. The average follow-up duration was 4.9 ± 1.2 years, during which time 84 distractions and 8 final fusions were performed. The average number of USLs was 6.3 ± 2.2. The total and annual percent growth of concave side of USLs was significantly higher than convex side (32.2 ± 13.3% vs. 23.9 ± 9.5%, p = 0.007; 6.8 ± 2.7%/year vs. 5.1% ± 2.2%/year, p = 0.007, respectively). The concave-to-convex ratio of USLs increased from 58.6 ± 6.4 ± 7.6% at baseline to 68.8 ± 9.3% at the latest follow-up (p < 0.001). The Campbell's space available for lung ratio increased from 74.9 ± 11.1% at baseline to 89.6 ± 7.0% at the latest follow-up (p < 0.001). CONCLUSIONS: In patients with EOMTCS, unilateral repetitive lengthening with TSGR can accelerate the growth of the concave side of USLs and improve the symmetry of the thorax.

3.
Brief Bioinform ; 2020 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-33190150

RESUMO

Patients with spinal muscular atrophy (SMA) are susceptible to the respiratory infections and might be at a heightened risk of poor clinical outcomes upon contracting coronavirus disease 2019 (COVID-19). In the face of the COVID-19 pandemic, the potential associations of SMA with the susceptibility to and prognostication of COVID-19 need to be clarified. We documented an SMA case who contracted COVID-19 but only developed mild-to-moderate clinical and radiological manifestations of pneumonia, which were relieved by a combined antiviral and supportive treatment. We then reviewed a cohort of patients with SMA who had been living in the Hubei province since November 2019, among which the only 1 out of 56 was diagnosed with COVID-19 (1.79%, 1/56). Bioinformatic analysis was carried out to delineate the potential genetic crosstalk between SMN1 (mutation of which leads to SMA) and COVID-19/lung injury-associated pathways. Protein-protein interaction analysis by STRING suggested that loss-of-function of SMN1 might modulate COVID-19 pathogenesis through CFTR, CXCL8, TNF and ACE. Expression quantitative trait loci analysis also revealed a link between SMN1 and ACE2, despite low-confidence protein-protein interactions as suggested by STRING. This bioinformatic analysis could give hint on why SMA might not necessarily lead to poor outcomes in patients with COVID-19.

4.
Pediatr Transplant ; : e13825, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-33131184

RESUMO

BACKGROUND: HSCT is the only proven curative therapy for JMML. Matching donor and recipient HLA alleles is considered optimal to reduce the risk of GVHD after HSCT but is not always possible. Only a limited number of studies have compared the influence of HLA disparities on HSCT outcomes for patients with JMML. METHODS: We conducted a retrospective study among 47 children with JMML who received related or unrelated unmanipulated HSCT (March 2010-October 2018). Among our participants, 27 (57.4%) donor-recipient pairs had 0-1 HLA disparities (Group 1: HLA-matched or ≤1 allele/antigen mismatch donor) and 20 (42.6%) had ≥2 HLA disparities (Group 2: 2-3 mismatched/haploidentical donors). RESULTS: The median follow-up period was 26.0 months (range: 1-105 months), and the 5-year probabilities of DFS and RI for the whole cohort were 54.6 ± 7.7% and 34.8 ± 15.0%, respectively. Compared to Group 1, Group 2 patients had a significantly lower RI (5.3 ± 10.5% vs 55.5 ± 20.9%, P Ë‚ .001), though similar rates of grade II-IV acute GVHD (60.0 ± 22.4% vs 33.3 ± 18.2%, P = .08), grade III-IV acute GVHD (25.0 ± 19.5% vs 7.4 ± 10.1%, P = .08), chronic GVHD (30.0 ± 20.9% vs 34.9 ± 18.8%, P = .85), NRM (20.0 ± 18.0% vs 3.9 ± 7.7%, P = .07), and DFS (74.4 ± 9.9% vs 41.3 ± 10.0%, P = .08). CONCLUSIONS: Disease relapse remains the major cause of treatment failure in JMML patients, especially in patients receiving HLA-matched and limited HLA-mismatched HSCT. Our findings suggest that donor-recipient HLA disparities may improve the outcome of HSCT in children with JMML.

5.
J Am Chem Soc ; 2020 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-33180476

RESUMO

Suitanes are a class of mechanically interlocked molecules (MIMs) that consist of two components: a body with limbs protruding outward and a suit that fits appropriately around it, so that there is no easy way for the suit to be removed from the body. Herein, we report the synthesis and characterization of a suit[3]ane, which contains a benzotrithiophene derivative (THBTT) with three protruding hexyl chains as the body and a 3-fold symmetric, extended pyridinium-based cage, namely, HexaCage6+, as the suit. Central to its realization is effective templation, provided by THBTT during cage formation, an observation that has been supported by the strong binding constant between benzotrithiophene (BTT) and the empty cage. The solid-state structure of the suit[3]ane reveals that the body is confined within the suit's cavity with its alkyl chains protruding outward through the orifices in the cage. Notably, such a seemingly unstable molecule, having three flexible alkyl chains as its only protruding limbs, does not dissociate after prolonged heating in CD3CN at 100 °C under pressure for 7 days. No evidence for guest exchange with the host was observed at this temperature in a 2:1 mixture of THBTT and HexaCage6+ in CD3CN. The results indicate that flexible protruding limbs are sufficient for a suit[3]ane to remain mechanically stable even at high temperatures in solution.

6.
Environ Pollut ; : 115890, 2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-33176947

RESUMO

Nanoplastics are common pollutants in aquatic environments and have attracted widespread research attention. However, few studies focus on the effects of nanoplastic exposure on energy metabolism in crustaceans. Accordingly, we exposed juvenile oriental river prawns (Macrobrachium nipponense) to different concentrations of 75-nm polystyrene nanoplastics (0, 5, 10, 20, and 40 mg/L) for 7, 14, 21, or 28 days. Thereafter, the effects of nanoplastic exposure on metabolite content, energy metabolism-related enzyme activity, and gene expression were evaluated. Our results showed that (1) with increasing nanoplastic concentration and exposure time, the survival rate decreased, while weight gain rate and molting number increased and then decreased; glycogen, triglyceride, and total cholesterol content all declined while lactic acid content increased with higher exposure to nanoplastic concentrations; (2) the activities of acetyl-CoA carboxylase (ACC), hexokinase (HK), carnitine palmitoyl transferase-1, pyruvate kinase (PK), lipase, and fatty acid synthase tended to decrease, while the activity of lactate dehydrogenase (LDH) increased. In particular, the activity of 6-phosphofructokinase exposed to 5 mg/L nanoplastics increased significantly (P < 0.05). (3) Expression of the metabolism-related genes 6-phosphate glucokinase (G-6-Pase), HK, PK, ACC, Acetyl-CoA-binding protein (ACBP), CPT-1, and fatty-acid-binding protein 10 (FABP 10) increased and then decreased, while expression of the LDH gene showed an upward trend. These results indicate that nanoplastics affect growth, enzyme activity, and the gene expression of energy metabolism in M. nipponense, and that high concentrations of nanoplastics have a negative impact on energy metabolism.

7.
Artigo em Inglês | MEDLINE | ID: mdl-33187996

RESUMO

Nicotine is a toxic environmental pollutant that widely exists in tobacco wastes. As a natural nicotine-degrading strain, Pseudomonas sp. JY-Q still has difficulties to degrade high-concentrations of nicotine. In this study, we investigated the effect of two homologous transcriptional regulators and endogenous ectopic strong promoters on the efficiency of nicotine degradation. Comparative genomics analysis showed that two homologous transcriptional regulators NicR2A and NicR2Bs can repress nicotine-degrading genes expression. When both of nicR2A and nicR2Bs were deleted, the resulting mutant QΔnicR2AΔnicR2B1ΔnicR2B2 exhibit 17% higher nicotine degradation efficiency than wide type JY-Q. The RNA-seq analysis showed that the transcription level (FPKM value) of six genes was particularly higher than the other genes in JY-Q. Based on the genetic organization of these genes, three putative promoters, PRS28250 , PRS09985 and PRS24685 , were identified. Their promoter activities were evaluated by comparing their expression levels using RT-qPCR. We found that the transcription levels of RS28250, RS09985 and RS24685 were 16.8-, 2.6-, and 1.6-times higher than that of hspB2, encoding 6-hydroxy-3-succinylpyridine hydroxylase involved in nicotine degradation. Thus, two strong endogenous promoters PRS28250 and PRS09985 were selected to replace the original promoters of Nic2 gene clusters. The effect of endogenous ectopic promoter was also related to the replaced position of target gene clusters. When the promoter PRS28250 replaced the promoter of hspB2, the resultant mutant, QΔABs-ΔPhspB2 ::PRS28250, exhibited 69% higher nicotine degrading efficiency than the JY-Q. This research suggests a feasible strategy to enhance strain ability by removal of repressing regulatory proteins and replacing target promoter with strong endogenous ectopic promoters.IMPORTANCE This study evaluated the differential effects of homologous NicR2A/NicR2Bs and endogenous ectopic strong promoters on nicotine metabolism in Pseudomonas sp. JY-Q. Based on our differential analysis, a feasible strategy is presented to modify wild type strain JY-Q by removing repressing regulatory proteins, NicR2A/NicR2Bs, and replacing the target promoter with strong endogenous ectopic promoters. The resulting mutants exhibited high tolerance and degradation of nicotine. These findings should be beneficial for improving pollutant-degrading capacity of naturally strains through genomic modification.

8.
Radiat Res ; 2020 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-33045079

RESUMO

Radiation-induced skin injury remains a serious concern for cancer radiotherapy, radiation accidents and occupational exposure, and the damage mainly occurs due to apoptosis and reactive oxygen species (ROS) generation. There is currently no effective treatment for this disorder. The ß-catenin signaling pathway is involved in the repair and regeneration of injured tissues. However, the role of the ß-catenin signaling pathway in radiation-induced skin injury has not been reported. In this study, we demonstrated that the ß-catenin signaling pathway was activated in response to radiation and that its activation by Wnt3a, a ligand-protein involved in the ß-catenin signaling pathway, inhibited apoptosis and the production of ROS in irradiated human keratinocyte HaCaT cells and skin fibroblast WS1 cells. Additionally, Wnt3a promoted cell migration after irradiation. In a mouse model of full-thickness skin wounds combined with total-body irradiation, Wnt3a was shown to facilitate skin wound healing. The results from RNA-Seq revealed that 24 genes were upregulated and 154 were downregulated in Wnt3a-treated irradiated skin cells, and these dysregulated genes were mainly enriched in the tight junction pathway. Among them, Marvel D3 showed the most obvious difference. We further found that the activated ß-catenin signaling pathway stimulated the phosphorylation of JNK by silencing Marvel D3. Treatment of irradiated cells with SP600125, a JNK inhibitor, augmented ROS production and impeded cell migration. Furthermore, treatment with Wnt3a or transfection with Marvel D3-specific siRNAs could reverse the above effects. Taken together, these findings illustrate that activated ß-catenin signaling stimulates the activation of JNK by negatively regulating Marvel D3 to ameliorate radiation-induced skin injury.

9.
Wei Sheng Yan Jiu ; 49(5): 738-743, 2020 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-33070816

RESUMO

OBJECTIVE: To understand the status of health literacy and its influencing factors among the residents in Haidian District of Beijing, and to provide references for targeted health education intervention. METHODS: A multi-staged probability proportionate to size sampling(PPS) sampling method was used to collect 7034 residents that aged 15-69 years old in Haidian District in 2018. RESULTS: The standardized rate of health literacy among the residents of Haidian District was 28. 56%. The standardized health literacy rate of basic health knowledge and concept literacy, health lifestyle and behavior literacy, basic health skill were 35. 79%, 30. 90% and 36. 39%, respectively. The standardized health literacy rate of 6 health literacy issues from high to low were safety and first aid(66. 39%), scientific health perspectives(51. 24%), infectious diseases prevention and treatment(39. 78%), health information(30. 25%), chronic disease control and prevention(13. 33%), and basic medical care(11. 23%), respectively. The result of multiple logistic regression showed that aged between 30-39 years old, female, high school education and above, the teacher, medical and government staff, staff of other institutions, staff of other enterprises, other employees and the annual income of the family>45000 RMB were protective factors for health literacy. Aged between 50-69 years old was risk factor for health literacy. CONCLUSION: The level of health literacy in Haidian District was low. Various forms of intervention activities should be carried out to improve the residents' health literacy, especially focused on health lifestyle and behavior literacy, chronic disease control and prevention and basic medical care.


Assuntos
Letramento em Saúde , Adulto , Idoso , Pequim , Cidades , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Pessoa de Meia-Idade , Inquéritos e Questionários
10.
Phys Chem Chem Phys ; 2020 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-33015690

RESUMO

Dense packings of hard particles are useful models for condensed matters including crystalline and glassy state of solids, simple liquids, granular materials and composites. It is very challenging to devise predictive theories of random packings, due to the intrinsic non-equilibrium and non-local nature of the system. Here, we develop a formalism for accurately predicting the density (i.e., fraction of space covered by the particles) ηMRJ of the maximally random jammed (MRJ) packing state of a wide spectrum of congruent non-spherical hard particles in three-dimensional Euclidean space [Doublestruck R]3, via analytical continuation of the corresponding fluid equation of state (EOS). This formalism is based on the assumption that the fluid branch of the EOS can be analytically extended into the meta-stable region, which leads to a diverging pressure at the jamming point (i.e., the MRJ state). This allows us to estimate ηMRJ as the pole in the EOS, which can be expressed in terms of the virial coefficients encoding intrinsic local n-body packing information of the particles, and depending alone on particle shape. The accuracy of our formalism is verified using the hard sphere system and is subsequently applied to a wide spectrum of non-spherical shapes. The predictions are compared to numerical results whenever possible, and excellent agreements are found.

12.
Artigo em Inglês | MEDLINE | ID: mdl-33054176

RESUMO

Solvent effects are important for photovoltaic systems like dye-sensitized solar cells (DSCs) but remain largely unexplored, partly due to the complexity of explicitly including solvent molecules in atomistic simulations. To address these issues, we have systematically investigated the solvent effects in practical solar cells using ab initio excited state dynamics simulations. In this computational protocol and the extended model system, we considered giving a novel perspective on the excited state changes in response to solvation and finite temperature at the heterointerface of DSCs. By directly comparing the geometric stability of interface bonding, photoabsorption, interfacial electronic structure, and dynamics of vacuum and solvent systems, we obtain useful insights into how solvents influence the key factors that determine the efficiency of DSCs. Solvents significantly enhance the intensity of visible light absorption of chromophores (∼2 times) through two effects: (a) by inducing changes to the dye molecule structure due to intermolecular dye-solvent interactions, and (b) by the dielectric screening of the solvent. Furthermore, by adsorbing onto the TiO2 surface, solvent molecules adjust the interfacial band alignment to a favorable level and screen out the attraction force between injected electrons in the semiconductor substrate and holes left on the chromophore to a large extent, dramatically slowing down the recombination process (>8 times). Our findings provide a comprehensive picture of the explicit solvent effects on individual energy conversion steps in DSCs at the microscopic scale and lead to more accurate prediction of the performance of nanodevices in practical environments, contributing to the optimization of realistic renewable energy devices.

13.
Clin Rheumatol ; 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-33057918

RESUMO

Although lupus induced by penicillamine, the first-line medication for Wilson's disease, is well-documented, primary systematic lupus erythematosus (SLE) co-occurring with Wilson's disease has only rarely been reported. Symptom overlap can add to difficulties in making the correct and complete diagnosis of these two systemic diseases. An 18-year-old female was diagnosed with simultaneous Wilson's disease and SLE and was successfully treated with hydroxychloroquine and oral zinc. We also reviewed the literature for cases of Wilson's disease co-occurring with SLE not induced by penicillamine and found six other cases. Clinical presentations, diagnoses, treatments, and outcomes were analyzed and summarized to expand our understanding of this rare condition. The most frequent diagnostic clues to Wilson's disease in patients with SLE included unexplained liver damage despite well-controlled SLE, extrapyramidal symptoms and signs, hyper-intense signals of the basal ganglia bilaterally on T2-weighted and fluid-attenuated inversion recovery (FLAIR) MRI images, and Kayser-Fleischer (K-F) rings on physical examination. Penicillamine should be avoided or used cautiously in Wilson's disease patients complicated by SLE. The overall prognosis is good if treated in a timely manner. Key Points • SLE complicated by Wilson's disease or the co-occurrence of the two conditions in the absence of penicillamine may exist in rare conditions. • The diagnostic clues for identifying Wilson's disease in SLE patients may include unexplained liver damage despite well-controlled SLE, extrapyramidal symptoms and signs, and K-F rings found by physical examination. • Penicillamine should be avoided or used cautiously in Wilson's patients with SLE.

14.
Int Dent J ; 2020 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-33027847

RESUMO

BACKGROUND: In mid-March 2020, the World Health Organization declared that COVID-19 was to be characterised as a pandemic. The purpose of this article is to recommend emergency management procedures for dental clinics during this public health emergency. MATERIALS AND METHODS: We have implemented a series of emergency management measures to prevent cross-infection in our dental clinic during the COVID-19 pandemic, including personnel scheduling, division of the clinic into functional areas, limitation or delay of non-emergency patients, staff protection and infection controls, clinical environmental disinfection, and the use of online consultation services, among others. RESULTS: Due to public health policy and dental emergency management, the number of dental visitors to our clinic dropped sharply, and no COVID-19 suspected cases or high-risk patients received treatment. There have been no reports of infection of dental staff or patients during dental treatment in China to date. CONCLUSION: These public health policies and dental emergency management measures were effective in controlling cross-infection of COVID-19 in the dental clinic. PRACTICAL IMPLICATIONS: We share control measures for COVID-19, and hope that they will be helpful for dental professionals worldwide to continue to provide dental care in a safe and orderly manner.

15.
Int Immunopharmacol ; 89(Pt A): 107014, 2020 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-33039959

RESUMO

Acute lung injury (ALI) is a life-threatening disorder with high rates of morbidity and mortality. Up to now, there are still no effective drugs for its therapies due to the complexity of its etiology and pathogenesis. In this present study, we investigated the protective effect of Nervilifordin F (NF) on ALI induced by intestinal ischemia/reperfusion (II/R) and its related mechanism. Firstly, the ALI model rats were induced through II/R, and treated with NF. Then, the pathological and cytokine level changes in the lung tissue of ALI rats were evaluated by hematoxylin and eosin and enzyme-linked immunosorbent assay (ELISA). The related genes expression level of mammalian target of rapamycin (mTOR) pathway and inflammasome were measured by real-time quantitative polymerase chain reaction (RT-qPCR), western blot and immunohistochemistry. Finally, the NF-protein complexes were predicted by SYBYL-X 2.0. The results indicated that NF can significant reduces the levels of tumor necrosis factor-alpha (TNF-α), interleukin (IL)-6 and IL-1ß, and inhibits the expression of inflammasome related genes (such as toll-like receptor 4 (TLR4), p65, NOD-like receptor protein 3 (NLRP3) and Caspase 1), thereby reduce inflammation in II/R-induced ALI rats. Moreover, NF can activate the expression of FK506 binding protein 25 (FKBP25) and down-regulate the expression of mTOR and p70 ribosomal protein S6 kinase 1 (p70S6K). In addition, molecular docking results showed that NF can be combined well with p70S6K, TLR4, mTOR and NLRP3, which further verified the inhibitory effect of NF on ALI inflammation. Therefore, the findings indicate that NF can alleviates II/R-induced inflammation of ALI rats by inhibiting inflammasome related genes and mTOR pathway, which expected to use as a potential drug for the treatment of ALI.

16.
J Cell Mol Med ; 2020 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-32990414

RESUMO

Microglia are rapidly activated following ischaemic stroke and participate in the induction of neuroinflammation, which exacerbates the injury of ischaemic stroke. However, the mechanisms regulating ischaemic microglia remain unclear. In the present study, middle cerebral artery occlusion and oxygen and glucose deprivation models were established for in vivo and vitro monitoring of experimental stroke. We applied recombinant human thioredoxin-1 (rhTrx-1) and Necrostatin-1 (Nec-1, inhibitor of RIPK1) to examine the role of receptor-interacting protein kinase 1 (RIPK1) in the development of inflammation in ischaemic microglia via explored the inflammatory responses and the associated mechanisms. Molecular docking results indicated that rhTrx-1 could directly bind to RIPK1. In vivo and vitro data revealed that rhTrx-1 reduced necroptosis, mitochondrial membrane potential damage, reactive oxygen species accumulation and NLR Family, pyrin domain-containing 3 protein (NLRP3) inflammasome activation and regulated the microglial M1/M2 phenotypic changes by inhibiting RIPK1 expression in ischaemic microglia. Consistent with these findings, further in vivo experiments revealed that rhTrx-1 treatment attenuated cerebral ischaemic injury by inhibiting the inflammatory response. Our data demonstrated the role of RIPK1 in microglia-induced neuroinflammation following cerebral ischaemia. Administration of rhTrx-1 provides neuroprotection in ischaemic stroke-induced microglial neuroinflammation by inhibiting RIPK1 expression.

17.
J Am Chem Soc ; 142(39): 16849-16860, 2020 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-32886881

RESUMO

One ring threaded by two other rings to form a non-intertwined ternary ring-in-rings motif is a challenging task in noncovalent synthesis. Constructing multicolor photoluminescence systems with tunable properties is also a fundamental research goal, which can lead to applications in multidimensional biological imaging, visual displays, and encryption materials. Herein, we describe the design and synthesis of binary and ternary ring-in-ring(s) complexes, based on an extended tetracationic cyclophane and cucurbit[8]uril. The formation of these complexes is accompanied by tunable multicolor fluorescence outputs. On mixing equimolar amounts of the cyclophane and cucurbit[8]uril, a 1:1 ring-in-ring complex is formed as a result of hydrophobic interactions associated with a favorable change in entropy. With the addition of another equivalent of cucurbit[8]uril, a 1:2 ring-in-rings complex is formed, facilitated by additional ion-dipole interactions involving the pyridinium units in the cyclophane and the carbonyl groups in cucurbit[8]uril. Because of the narrowing in the energy gaps of the cyclophane within the rigid hydrophobic cavities of cucurbit[8]urils, the binary and ternary ring-in-ring(s) complexes emit green and bright yellow fluorescence, respectively. A series of color-tunable emissions, such as sky blue, cyan, green, and yellow with increased fluorescence lifetimes, can be achieved by simply adding cucurbit[8]uril to an aqueous solution of the cyclophane. Notably, the smaller cyclobis(paraquat-p-phenylene), which contains the same p-xylylene linkers as the extended tetracationic cyclophane, does not form ring-in-ring(s) complexes with cucurbit[8]uril. The encapsulation of this extended tetracationic cyclophane by both one and two cucurbit[8]urils provides an incentive to design and synthesize more advanced supramolecular systems, as well as opening up a feasible approach toward achieving tunable multicolor photoluminescence with single chromophores.

18.
Zhongguo Zhong Yao Za Zhi ; 45(15): 3694-3699, 2020 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-32893560

RESUMO

Forsythiae Fructus is divided into Qingqiao and Laoqiao due to different harvesting periods. So far, the accumulation of heavy metals in the two types of Forsythiae Fructus has not been reported. In this study, the residual levels of copper(Cu), lead(Pb), chromium(Cr), arsenic(As), cadmium(Cd) and mercury(Hg) in 29 batches of Laoqiao and 60 batches of Qingqiao were determined by inductively coupled plasma mass spectrometry(ICP-MS). The samples were collected from Shanxi, Shaanxi, Henan, and Hebei Provinces. In addition, the diversity and correlation of harmful elements in Qingqiao and Laoqiao were analyzed by multivariate statistical method. Furthermore, principal component analysis(PCA) was used to analyze the harmful elements concentrations of Qingqiao and Laoqiao. The results showed that there was a significant difference on the residual levels of heavy metals and harmful elements between Qingqiao and Laoqiao. Among them, the content of Pb in Laoqiao is significantly higher than that in Qingqiao(P<0.01), while the content of Cu is significantly lower than that in Qingqiao. However, the difference in harmful elements among different producing areas of Forsythiae Fructus is not significant. PCA analysis showed that Qingqiao and Laoqiao were successfully grouped into two categories. This study suggests significant difference in the residual levels of heavy metals and harmful elements between Qingqiao and Laoqiao. Besides, Forsythiae Fructus has a certain enrichment of Pb in the fruit ripening stage(Laoqiao). This study provides a reference for the quality classification and safety of Forsythiae Fructus.


Assuntos
Arsênico , Medicamentos de Ervas Chinesas , Metais Pesados , Cobre
19.
Zhongguo Zhong Yao Za Zhi ; 45(16): 3900-3907, 2020 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-32893587

RESUMO

A highly sensitive monoclonal antibody against aflatoxin B_1(AFB_1) was prepared and an indirect competition enzyme-linked immunosorbent assay(ic-ELISA) was established based on the antibody which was used for high-throughput and rapid screening of AFB_1 contamination in Chinese herbal medicines to ensure the safety of medication. In this study, the structure of AFB_1 was modified by improved oxime method, and the carrier protein was coupled by EDC-NHS method to obtain the complete antigen of AFB_1, which was more convenient and environmental friendly. The Balb/c female mice were immunized using increasing the immunization dose and various ways of injection, and finally the AFB_1 monoclonal antibody was prepared. The AFB_1 monoclonal antibody belongs to IgG_(2 b) immunoglobulin by identifying its immunological characteristics, and its sensitivity(IC_(50)) can reach 0.15 µg·L~(-1), and the affi-nity is 2.81×10~8 L·mol~(-1). The cross-reaction rates of AFB_2, AFG_1, and AFG_2 were 35.07%, 8.75%, and 1.15%, respectively, and there was almost no cross-reactivity with other mycotoxins. Based on the high sensitivity and specificity of the antibody, an ic-ELISA method was established and applied to the determination of AFB_1 contamination in Ziziphi Spinosae Semen. According to the matrix matching standard curve, the linear concentration range for AFB_1 was 0.05-0.58 µg·L~(-1)(R~2=0.992), the recoveries were 88.00%-119.0%, and the detection limit was 1.69 µg·kg~(-1). The AFB_1 in 33 batches of Ziziphi Spinosae Semen samples was determined by ic-ELISA, and the contamination level was 3.62-206.58 µg·kg~(-1). The linear correlation coefficient between the detection results of ic-ELISA and UHPLC-MS/MS was 0.996, and there were no false positive and false negative cases. It indicates that the established ic-ELISA is accurate and reliable, and could provide a simple and effective technique for fast screening of AFB_1 contamination in Ziziphi Spinosae Semen, and also could be considered as the reference for the detection and monitoring of AFB_1 contamination in other Chinese herbal medicines.


Assuntos
Aflatoxina B1/análise , Sêmen/química , Animais , Anticorpos Monoclonais , Contaminação de Medicamentos , Ensaio de Imunoadsorção Enzimática , Feminino , Camundongos , Espectrometria de Massas em Tandem
20.
Chin J Nat Med ; 18(9): 666-676, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32928510

RESUMO

This study engineered ß-carotene ketolase CrtW and ß-carotene hydroxylase CrtZ to improve biosynthesis of astaxanthin in Escherichia coli. Firstly, crtW was randomly mutated to increase CrtW activities on conversion from ß-carotene to astaxanthin. A crtW* mutant with A6T, T105A and L239M mutations has improved 5.35-fold astaxanthin production compared with the wild-type control. Secondly, the expression levels of crtW* and crtZ on chromosomal were balanced by simultaneous modulation RBS regions of their genes using RBS library. The strain RBS54 selected from RBS library, directed the pathway exclusively towards the desired product astaxanthin as predominant carotenoid (99%). Lastly, the number of chromosomal copies of the balanced crtW-crtZ cassette from RBS54 was increased using a Cre-loxP based technique, and a strain with 30 copies of the crtW*-crtZ cassette was selected. This final strain DL-A008 had a 9.8-fold increase of astaxanthin production compared with the wild-type control. Fed-batch fermentation showed that DL-A008 produced astaxanthin as predominant carotenoid (99%) with a specific titer of 0.88 g·L-1 without addition of inducer. In conclusion, through constructing crtW mutation, balancing the expression levels between crtW* and crtZ, and increasing the copy number of the balanced crtW*-crtZ cassette, the activities of ß-carotene ketolase and ß-carotene hydroxylase were improved for conversion of ß-carotene to astaxanthin with higher efficiency. The series of conventional and novel metabolic engineering strategies were designed and applied to construct the astaxanthin hetero-producer strain of E. coli, possibly offering a general approach for the construction of stable hetero-producer strains for other natural products.

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