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1.
Echocardiography ; 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-34075626

RESUMO

BACKGROUND: Congenital atrial appendage aneurysm (AAA) is a rare malformation which can coexist with potentially lethal complications. We aimed to summary echocardiographic characteristics and prognosis of fetal AAA. METHODS: We retrospectively analyzed the echocardiographic data of 17 fetuses with AAA,and their outcomes or pathological reports were also collected. RESULTS: Eight fetuses with left AAA (LAAA) and 9 fetuses with right AAA (RAAA) were identified. Five fetuses were diagnosed with other cardiac defects. Two fetuses with RAAA presented with arrhythmias, including atrial premature beats (n = 1) and bradyarrhythmia (n = 1). LAAA could be detected by four-chamber view (50.0%) and short-axis view (100.0%). RAAA could be detected by four-chamber view (100.0%), and view of right ventricular inflow tract (33.3%). There were three cases with mild pericardial effusion. Three cases with complex cardiac defects were selectively terminated, with confirmation of LAAA by autopsy in one case. Fourteen fetuses were born. After following 2 (range, 1-5) years, the AAA disappeared in one case with LAAA and two cases with RAAA. While, 11 cases were still diagnosed with AAA. Atrial premature beats with RAAA, which appeared in prenatal period, still persisted after birth. CONCLUSION: Congenital AAA is a rare abnormality in utero. The short-axis view and the four-chamber view were the most useful views to detect fetal AAA. Fetal AAA may disappear in childhood. Atrial tachyarrhythmias in utero may exist persistently after birth. Patients with AAA should be followed up closely and appropriate intervention should be taken when complications appeared.

2.
BMC Biol ; 19(1): 118, 2021 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-34130700

RESUMO

BACKGROUND: Species domestication is generally characterized by the exploitation of high-impact mutations through processes that involve complex shifting demographics of domesticated species. These include not only inbreeding and artificial selection that may lead to the emergence of evolutionary bottlenecks, but also post-divergence gene flow and introgression. Although domestication potentially affects the occurrence of both desired and undesired mutations, the way wild relatives of domesticated species evolve and how expensive the genetic cost underlying domestication is remain poorly understood. Here, we investigated the demographic history and genetic load of chicken domestication. RESULTS: We analyzed a dataset comprising over 800 whole genomes from both indigenous chickens and wild jungle fowls. We show that despite having a higher genetic diversity than their wild counterparts (average π, 0.00326 vs. 0.00316), the red jungle fowls, the present-day domestic chickens experienced a dramatic population size decline during their early domestication. Our analyses suggest that the concomitant bottleneck induced 2.95% more deleterious mutations across chicken genomes compared with red jungle fowls, supporting the "cost of domestication" hypothesis. Particularly, we find that 62.4% of deleterious SNPs in domestic chickens are maintained in heterozygous states and masked as recessive alleles, challenging the power of modern breeding programs to effectively eliminate these genetic loads. Finally, we suggest that positive selection decreases the incidence but increases the frequency of deleterious SNPs in domestic chicken genomes. CONCLUSION: This study reveals a new landscape of demographic history and genomic changes associated with chicken domestication and provides insight into the evolutionary genomic profiles of domesticated animals managed under modern human selection.

3.
Environ Pollut ; 285: 117471, 2021 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-34082372

RESUMO

Tris (1,3-dichloro-2-propyl) phosphate (TDCIPP), an alternative to brominated flame retardants, might pose an exposure risk to humans and wild animals during fetal development. Our recent study suggested that short-term TDCIPP exposure during early development caused sex-dependent behavioral alteration in adults. In the present study, multigenerational neurodevelopmental toxicity upon early-life exposure of parental zebrafish was evaluated, and the possible underlying mechanisms were further explored. Specifically, after embryonic exposure (0-10 days post-fertilization, dpf) to TDCIPP (0, 0.01, 0.10, and 1.00 µM), zebrafish larvae were cultured in clean water until the sexually matured to produce progeny (F1). The results confirmed neurodevelopmental toxicity in F1 larvae characterized by changes of developmental endpoints, reduced thigmotaxis, as well as altered transcription of genes including myelin basic protein a (mbpa), growth associated protein (gap43) and synapsin IIa (syn2a). Sex-specific changes in thyroid hormones (THs) indicated the relationship of abnormal THs levels with previously reported neurotoxicity in adult females after early-life exposure to TDCIPP. Similar changing profiles of TH levels (increased T3 and decreased T4) in adult females and F1 eggs, but not in F1 larvae, suggested that the TH disruptions were primarily inherited from the maternal fish. Further results demonstrated hypermethylation of global DNA and key genes related to TH transport including transthyretin (ttr) and solute carrier family 16 member 2 (slc16a2), which might affect the transport of THs to target tissues, thus at least partially contributing to the neurodevelopmental toxicity in F1 larvae. Overall, our results confirmed that early-life TDCIPP exposure of parental fish could affect the early neurodevelopment of F1 offspring. The underlying mechanism could involve altered TH levels inherited from maternal zebrafish and epigenetic modifications in F1 larvae.

4.
Ann Rheum Dis ; 2021 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-34049857

RESUMO

OBJECTIVE: Identify predictors of treatment failure in patients with giant cell arteritis (GCA) receiving tocilizumab in combination with glucocorticoids and in patients with GCA receiving only glucocorticoids. METHODS: Posthoc analysis of the Giant-Cell Arteritis Actemra trial including 250 patients who received tocilizumab every week plus a 26-week prednisone taper (n=100), tocilizumab every-other-week plus a 26-week prednisone taper (n=49) or placebo plus a 26-week (n=50) or 52-week (n=51) prednisone taper in the intention-to-treat population. Responders for this analysis were patients who maintained remission (no GCA signs/symptoms and no erythrocyte sedimentation rate elevation) through week 52. Treatment failure was defined as inability to achieve remission by week 12 or relapse between weeks 12 and 52. Predictors investigated in univariate and multivariable analyses included patient characteristics, disease-related and treatment-related factors and patient-reported outcomes (PROs). RESULTS: 149 patients received tocilizumab plus prednisone (TCZ/PDN) and 101 received placebo plus prednisone (PBO+PDN). After adjustment for confounders, treatment failure was significantly less likely in the TCZ/PDN group than the PBO/PDN group (OR, 0.2; 95% CI, 0.1 to 0.3; p<0.0001). Risk for treatment failure was significantly higher in women than men in the PBO/PDN group (OR, 5.2; 95% CI, 1.6 to 17.2; p=0.007) but not in the TCZ/PDN group. Predictors of treatment failure in the TCZ/PDN group included lower baseline prednisone doses and worse PROs at baseline. CONCLUSION: The strongest risk factors for treatment failure in GCA are treatment with prednisone alone and female sex. Lower starting prednisone doses and impaired PROs are associated with failure to respond to tocilizumab. TRIAL REGISTRATION NUMBER: NCT01791153.

5.
Sci Rep ; 11(1): 11079, 2021 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-34040137

RESUMO

Environmental pollution with toxic metals can lead to the possible contamination of the marine fish. We investigated the levels of As, Cd, Cr, Hg and Pb in 652 marine fish samples (15 species) collected from coastal areas of Zhejiang, China and estimated their health risk. Mean concentrations of As, Cd, Cr, Hg and Pb were 0.783, 0.009, 0.114, 0.031, 0.043 mg/kg wet weight. The average estimated daily intakes (EDIs) for As, Cd, Cr, Hg and Pb were 1.214, 0.014, 0.177, 0.048 and 0.067 µg/kg bw/day. The risk assessment at mean exposure level showed that there was no health risk associated with these elements through consumption of marine fish. However, potential health risk may exist for high exposure consumers considering the possible contamination of As and Hg. Given that the different levels of certain elements in marine fish in China, this study provides a scientific basis for food safety assessment and suggestions for risk management.

6.
Mol Ther ; 2021 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-33974998

RESUMO

Dysregulated adenosine-to-inosine (A-to-I) RNA editing is implicated in various cancers. However, no available RNA editing inhibitors have so far been developed to inhibit cancer-associated RNA editing events. Here we decipher the RNA secondary structure of antizyme inhibitor 1 (AZIN1), one of the best-studied A-to-I editing targets in cancer, by locating its editing site complementary sequence (ECS) at the 3'end of exon 12. Chemically modified antisense oligonucleotides (ASOs) which target the editing region of AZIN1 caused a substantial exon 11 skipping; while ECS-targeting ASOs effectively abolish AZIN1 editing without affecting splicing and translation. We demonstrate that complete 2'-O-methyl (2'-O-Me) sugar ring modification in combination with partial phosphorothioate (PS) backbone modification may be an optimal chemistry for editing inhibition. ASO3.2, which targets the ECS, specifically inhibits cancer cell viability in vitro and tumor incidence and growth in xenograft models. Our results demonstrate that this AZIN1-targeting, ASO-based therapeutics may be applicable to a wide range of tumor types.

7.
Environ Sci Technol ; 55(10): 6926-6935, 2021 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-33938212

RESUMO

Bis(2-ethylhexyl)-2,3,4,5-tetrabromophthalate (TBPH), a novel brominated flame retardant, can potentially cause lipid metabolism disorder; however, its biological effects on lipid homeostasis remain unknown. We investigated its ability to cause nonalcoholic fatty liver disease (NAFLD) in zebrafish. Female zebrafish were fed a high-fat diet (HFD, 24% crude fat) or normal diet (ND, 6% crude fat), and exposed to TBPH (0.02, 2.0 µM) for 2 weeks. Consequently, HFD-fed fish showed a higher measured concentration of TBPH than ND-fed fish. Further, TBPH-treated fish in the HFD group showed higher hepatic triglyceride levels and steatosis. In comparison to ND-fed fish, treating HFD-fed fish with TBPH led to an increase in the concentration of several proinflammatory markers (e.g., TNF-α, IL-6); TBPH exposure also caused oxidative stress. In addition, the mRNA levels of genes encoding peroxisome proliferator-activated receptors were increased, and the transcription of genes involved in lipid synthesis, transport, and oxidation was upregulated in both ND- and HFD-fed fish. Both the ND and HFD groups also showed demethylation of the peroxisome proliferator-activated receptor-γ coactivator 1-α gene promoter, accompanied by the upregulation of tet1 and tet2 transcription. To summarize, we found that TBPH amplified the disruption of lipid homeostasis in zebrafish, leading to the enhancement of diet-induced NAFLD progression.

8.
Mech Ageing Dev ; 197: 111496, 2021 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-33957218

RESUMO

We have reported that pseudoginsenoside-F11 (PF11) can significantly improve the cognitive impairments in several Alzheimer's disease (AD) models, but the mechanism has not been fully elucidated. In the present study, the effects of PF11 on AD, in particular the underlying mechanisms related with protein phosphatase 2A (PP2A), were investigated in a rat model induced by okadaic acid (OA), a selective inhibitor of PP2A. The results showed that PF11 treatment dose-dependently improved the learning and memory impairments in OA-induced AD rats. PF11 could significantly inhibit OA-induced tau hyperphosphorylation, suppress the activation of glial cells, alleviate neuroinflammation, thus rescue the neuronal and synaptic damage. Further investigation revealed that PF11 could regulate the protein expression of methyl modifying enzymes (leucine carboxyl methyltransferase-1 and protein phosphatase methylesterase-1) in the brain, thus increase methyl-PP2A protein expression and indirectly increase the activity of PP2A. Molecular docking analysis, structural alignment and in vitro results showed that PF11 was similar in the shape and electrostatic field feature to a known activator of PP2A, and could directly bind and activate PP2A. In conclusion, the present data indicate that PF11 can ameliorate OA-induced learning and memory impairment in rats via modulating PP2A.

9.
Emerg Microbes Infect ; 10(1): 1097-1111, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33944697

RESUMO

Monoclonal antibodies (mAbs) encoded by IGHV3-53 (VH3-53) targeting the spike receptor-binding domain (RBD) have been isolated from different COVID-19 patients. However, the existence and prevalence of shared VH3-53-encoded antibodies in the antibody repertoires is not clear. Using antibody repertoire sequencing, we found that the usage of VH3-53 increased after SARS-CoV-2 infection. A highly shared VH3-53-J6 clonotype was identified in 9 out of 13 COVID-19 patients. This clonotype was derived from convergent gene rearrangements with few somatic hypermutations and was evolutionary conserved. We synthesized 34 repertoire-deduced novel VH3-53-J6 heavy chains and paired with a common IGKV1-9 light chain to produce recombinant mAbs. Most of these recombinant mAbs (23/34) possess RBD binding and virus-neutralizing activities, and recognize ACE2 binding site via the same molecular interface. Our computational analysis, validated by laboratory experiments, revealed that VH3-53 antibodies targeting RBD are commonly present in COVID-19 patients' antibody repertoires, indicating many people have germline-like precursor sequences to rapidly generate SARS-CoV-2 neutralizing antibodies. Moreover, antigen-specific mAbs can be digitally obtained through antibody repertoire sequencing and computational analysis.


Assuntos
Anticorpos Monoclonais/sangue , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , COVID-19/imunologia , SARS-CoV-2/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais/imunologia , Sequência de Bases , COVID-19/sangue , Estudos de Casos e Controles , Epitopos de Linfócito B , Feminino , Células HEK293 , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Moleculares , Filogenia , Conformação Proteica , Receptores de Antígenos de Linfócitos B/genética
10.
Zool Res ; 42(3): 350-353, 2021 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-33998182

RESUMO

Coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus (SARS-CoV-2), has become an unprecedented global health emergency. At present, SARS-CoV-2-infected nonhuman primates are considered the gold standard animal model for COVID-19 research. Here, we showed that northern pig-tailed macaques ( Macaca leonina, NPMs) supported SARS-CoV-2 replication. Furthermore, compared with rhesus macaques, NPMs showed rapid viral clearance in lung tissues, nose swabs, throat swabs, and rectal swabs, which may be due to higher expression of interferon (IFN)-α in lung tissue. However, the rapid viral clearance was not associated with good outcome. In the second week post infection, NPMs developed persistent or even more severe inflammation and body injury compared with rhesus macaques. These results suggest that viral clearance may have no relationship with COVID-19 progression and SARS-CoV-2-infected NPMs could be considered as a critically ill animal model in COVID-19 research.


Assuntos
COVID-19/imunologia , COVID-19/virologia , Macaca nemestrina , SARS-CoV-2/imunologia , Animais , Modelos Animais de Doenças , Interferon-alfa/análise , Interleucina-1beta/análise , Interleucina-6/análise , Pulmão/imunologia , Pulmão/virologia , Nariz/virologia , Faringe/virologia , RNA Viral/análise , Reto/virologia , SARS-CoV-2/genética
11.
Anim Biotechnol ; : 1-4, 2021 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-34009087

RESUMO

Wild yak (Bos mutus) is a vulnerable bovine species on the Qinghai-Tibetan Plateau. So far, most studies on the molecular genetic diversity of wild yak have focused on autosomal and mtDNA variations based on the small number of samples. In this study, we analyzed 84 D-loop and 24 whole mitogenome sequences of wild yak to further comprehensively explore its maternal genetic diversity and lineage composition. Meanwhile, using six yak Y-specific polymorphic markers (i.e., SRY4, USP9Y, UTY19, AMELY3, OFD1Y10 and INRA189), we assessed the paternal genetic diversity and lineage composition based on eight wild yak. Our results showed that wild yak exhibited abundant maternal genetic diversity with haplotype diversities of 0.9621 ± 0.0078 and 0.9928 ± 0.0144 in the D-loop and whole mitogenome sequences, respectively. Maternal phylogenetic analysis of wild yak uncovered three defined lineages (mt-I, mt-II and mt-III). Similarly, profuse paternal genetic diversity was observed in wild yak with Y-haplotype diversity at 0.8214 ± 0.1007. Two Y-haplogroups (Y1 and Y2) and four Y-haplotypes (yH1-yH4) were identified in paternal phylogenetic analysis, indicating wild yak to be of two paternal lineages. The present study of genetic diversity and lineage composition of wild yak would provide useful information for the genetic resource conservation and utilization of this vulnerable wild species.

12.
Protein Expr Purif ; 185: 105898, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33962003

RESUMO

Nutraceuticals containing modified starch with increased content of slowly-digestible starch (SDS) may reduce the prevalence of obesity, diabetes and cardiovascular diseases due to its slow digestion rate. Enzymatic methods for the preparation of modified starch have attracted increasing attention because of their low environmental impact, safety and specificity. In this study, the efficient glucan branching enzyme McGBE from Microvirga sp. MC18 was identified, and its relevant properties as well as its potential for industrial starch modification were evaluated. The purified McGBE exhibited the highest specificity for potato starch, with a maximal specific activity of 791.21 U/mg. A time-dependent increase in the content of α-1,6 linkages from 3.0 to 6.0% was observed in McGBE-modified potato starch. The proportion of shorter chains (degree of polymerization, DP < 13) increased from 29.2 to 63.29% after McGBE treatment, accompanied by a reduction of the medium length chains (DP 13-24) from 52.30 to 35.99% and longer chains (DP > 25) from 18.51 to 0.72%. The reduction of the storage modulus (G') and retrogradation enthalpy (ΔHr) of potato starch with increasing treatment time demonstrated that McGBE could inhibit the short- and long-term retrogradation of starch. Under the optimal conditions, the SDS content of McGBE-modified potato starch increased by 65.8% compared to native potato starch. These results suggest that McGBE has great application potential for the preparation of modified starch with higher SDS content that is resistant to retrogradation.

13.
Mol Immunol ; 135: 36-44, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33857817

RESUMO

BACKGROUND: Rheumatoid arthritis (RA) is an autoimmune disease for which there are currently no effective therapies. Although mesenchymal stem cells (MSCs) can prevent arthritis through immunomodulatory mechanisms, there are several associated risks. Alternatively, MSC-derived small extracellular vesicles (sEVs) can mimic the effects of MSCs, while reducing the risk of adverse events. However, few studies have examined sEVs in the context of RA. Here, we evaluate the immunomodulatory effects of human umbilical cord MSC (hUCMSC)-derived sEVs on T lymphocytes in a collagen-induced arthritis (CIA) rat model to elucidate the possible mechanism of sEVs in RA treatment. We then compare these mechanisms to those of MSCs and methotrexate (MTX). METHODS: The arthritis index and synovial pathology were assessed. T lymphocyte proliferation and apoptosis, Th17 and Treg proportions, and interleukin (IL)-17, IL-10, and transforming growth factor (TGF)-ß expression were detected using flow cytometry. Retinoic acid receptor-related orphan receptor gamma t (RORγt) and forkhead box P3 (FOXP3), which are master transcriptional regulators of Th17 and Treg differentiation, were also assessed using immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: sEV treatment ameliorated arthritis and inhibited synovial hyperplasia in a dose-dependent manner. These effects were mediated by inhibiting T lymphocyte proliferation and promoting their apoptosis, while decreasing Th17 cell proportion and increasing that of Treg cells in the spleen, resulting in decreased serum IL-17, and enhanced IL-10 and TGF-ß expression. Transcriptionally, sEVs decreased RORγt and increased FOXP3 expression in the spleen, and decreased RORγt and FOXP3 expression in the joints. In some aspects sEVs were more effective than MSCs and MTX in treating CIA. CONCLUSIONS: hUCMSC-derived sEVs ameliorate CIA via immunomodulatory T lymphocytes, and might serve as a new therapy for RA.

14.
BMC Public Health ; 21(1): 647, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33794836

RESUMO

BACKGROUND: In view of the ongoing coronavirus disease (COVID-19) pandemic, it remains unclear whether the severity of illness and time interval from symptom onset to release from quarantine differ between cases that originated from clusters and cases reported in other areas. This study aimed to assess epidemiological and intergenerational clinical characteristics of COVID-19 patients associated with cluster outbreaks to provide valuable data for the prevention and control of COVID-19. METHODS: We identified the first employee with COVID-19 at a supermarket and screened the close contacts of this index patient. Confirmed cases were divided into two groups according to the generation (first generation comprising supermarket employees [group A] and second or third generations comprising family members or friends of the supermarket employees [group B]). The epidemiological and clinical characteristics of the two groups were retrospectively compared. RESULTS: A total of 8437 people were screened, and 24 COVID-19 patients were identified. Seven patients (29.2%) were asymptomatic; three patients were responsible for six symptomatic cases. The interval from the confirmation of the first case to symptom onset in symptomatic patients was 5-11 days. The clinical manifestations of symptomatic patients upon admission were non-specific. All patients (including the seven asymptomatic patients) were admitted based on chest computed tomography features indicative of pneumonia. There were 11 cases in group A (first generation) and 13 cases in group B (second generation, 11 cases; third generation, 2 cases), with no significant differences in clinical and epidemiological characteristics between the two groups, except for sex, duration from symptom onset to hospitalization, and underlying disease (P > 0.05). CONCLUSIONS: For cluster outbreaks, it is important to comprehensively screen close the contacts of the index patient. Special attention should be paid to asymptomatic cases. The clinical management of cluster patients is similar to that of other COVID-19 patients.


Assuntos
COVID-19/diagnóstico , COVID-19/transmissão , Busca de Comunicante , SARS-CoV-2 , Supermercados , COVID-19/epidemiologia , China , Feminino , Humanos , Masculino , Estudos Retrospectivos
15.
J Phys Chem A ; 125(17): 3589-3599, 2021 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-33900754

RESUMO

Molecular symmetry is vital to the selection rule of vibrationally resolved electronic transition, particularly when the nuclear dependence of electronic wave function is explicitly treated by including Franck-Condon (FC) factor, Franck-Condon/Herzberg-Teller (FC/HT) interference, and Herzberg-Teller (HT) coupling. Our present study investigated the light absorption spectra of highly symmetric tetracene, pentacene, and hexacene molecules of point-group D2h, as well as their monobrominated derivatives with a lower Cs symmetry. It was found that the symmetry-breaking monobromination allows more vibrational normal modes and their pairs to contribute to FC/HT interference and HT coupling, respectively. Through a projection of a molecule's vibrational normal modes to its irreducible representations, a linear relationship between the FC/HT intensity to the polyacene's size was deduced alongside a quadratic dependence of the HT intensity. Both theoretically derived correlations were well justified by our numerical simulations, which also demonstrated an approximately 20% improvement on the agreement with experimental line shape if the HT theory is adopted to replace the FC approximation. Moreover, for these low-symmetry monobrominated polyacenes, the FC intensity was even weaker than its FC/HT and HT counterparts at some excitation energies, making the HT theory imperative to decipher vibronic coupling, a fundamental driving force behind numerous chemical, biological, and photophysical processes.

16.
Bioresour Technol ; 333: 125157, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33878501

RESUMO

Xylonic acid (XA), as a bio-based platform chemical, is of considerable interest for xylose bioconversion. The whole-cell catalysis of Gluconobacter oxydans presents a promising application potential, while the hard works of cell culture still severely hinder XA business from the crude toxics-containing lignocellulosic hydrolysate. Hence, the bacterial cells should be recycled to reduce commercial production cost. The implementation of diatomite detoxification not only absorbs most of the degraded inhibitors in hydrolysate, but also confines the sugar contents loss with 10% and allows the bacterial cells to maintain 90% bioconversion performance during cell-recycling operation. Additionally, a scale-up of XA bioproduction was achieved in a sealed oxygen supply fermenter. Finally, 210 g XA was produced from 1000 g corncob originated hydrolysate within 24 h of whole-cell catalysis. Diatomite treatment provides an efficient and cost-practical approach for the commercial bioproduction of biochemicals like XA from lignocellulosic biomass.


Assuntos
Gluconobacter oxydans , Catálise , Fermentação , Lignina , Xilose/análogos & derivados
17.
Materials (Basel) ; 14(4)2021 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-33670127

RESUMO

Methyl methacrylate (MMA)-based repair material for concrete has the characteristics of low viscosity, excellent mechanical properties, and good durability. However, its application is limited due to its large shrinkage. Existing studies have shown that adding perchloroethylene can reduce the shrinkage. On this basis, other properties of modified MMA-based repair materials were tested and analyzed in the present study. The results revealed that the addition of perchloroethylene (PCE) can hinder the polymerization reaction of the system. When CaCO3 with a mass fraction of 30% was added, the viscosity of the material was within the range of 450-500 mPa·s, and the shrinkage decreased to approximately 10%. The bending strength of MMA, and MMA modified by PCE, repair materials at 28 days could reach up to 28.38 MPa and 29.15 MPa, respectively. After the addition of HS-770 light stabilizer with a mass fraction of 0.4%, the retention ratios of the bending strength of materials with ratios of P0 and P3 could reach 91.11% and 89.94%, respectively, after 1440 h of ultraviolet radiation. The retention ratio of the bending strength of the material could reach more than 95% after immersion in different ionic solutions for 90 days.

18.
Artigo em Inglês | MEDLINE | ID: mdl-33783328

RESUMO

Mislabelling is a significant manifestation of food fraud. Traditional Sanger sequencing technology is the gold standard for seafood species identification. However, this method is not suitable for analysing processed samples that may contain more than one species. This study tested the feasibility of next-generation sequencing in identifying mixed salmon products. Salmon samples containing up to eight species were amplified using 16S rRNA mini-barcode primers, and sequenced on an Illumina HiSeq2500 platform. All species were accurately identified, and mixtures as low as 1% (w/w) could be detected. Furthermore, this study conducted a market survey of 32 products labelled as salmon. For pure and mixed fish products, Sanger and next-generation sequencing techniques were respectively used for species identification, and for NGS results, we also used real-time PCR method to cross-validate the mixed products to further verify the accuracy of the DNA metabarcoding technology established in this study. DNA barcoding and metabarcoding of commercial salmon food products revealed the presence of mislabelling in 16 of 32 (50%) samples. The developed DNA barcoding and metabarcoding methods are useful for the identification of salmon species in food and can be used for quality control of various types of salmon products.

19.
Science ; 371(6533): 1050-1056, 2021 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-33674493

RESUMO

Polar topological texture has become an emerging research field for exotic phenomena and potential applications in reconfigurable electronic devices. We report toroidal topological texture self-organized in a ferroelectric polymer, poly(vinylidene fluoride-ran-trifluoroethylene) [P(VDF-TrFE)], that exhibits concentric topology with anticoupled chiral domains. The interplay among the elastic, electric, and gradient energies results in continuous rotation and toroidal assembly of the polarization perpendicular to polymer chains, whereas relaxor behavior is induced along polymer chains. Such toroidal polar topology gives rise to periodic absorption of polarized far-infrared (FIR) waves, enabling the manipulation of the terahertz wave on a mesoscopic scale. Our observations should inform design principles for flexible ferroic materials toward complex topologies and provide opportunities for multistimuli conversions in flexible electronics.

20.
Nat Commun ; 12(1): 1346, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33649323

RESUMO

SARS-CoV-2 is the underlying cause for the COVID-19 pandemic. Like most enveloped RNA viruses, SARS-CoV-2 uses a homotrimeric surface antigen to gain entry into host cells. Here we describe S-Trimer, a native-like trimeric subunit vaccine candidate for COVID-19 based on Trimer-Tag technology. Immunization of S-Trimer with either AS03 (oil-in-water emulsion) or CpG 1018 (TLR9 agonist) plus alum adjuvants induced high-level of neutralizing antibodies and Th1-biased cellular immune responses in animal models. Moreover, rhesus macaques immunized with adjuvanted S-Trimer were protected from SARS-CoV-2 challenge compared to vehicle controls, based on clinical observations and reduction of viral loads in lungs. Trimer-Tag may be an important platform technology for scalable production and rapid development of safe and effective subunit vaccines against current and future emerging RNA viruses.


Assuntos
Vacinas contra COVID-19/uso terapêutico , COVID-19/imunologia , COVID-19/prevenção & controle , SARS-CoV-2/patogenicidade , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Western Blotting , COVID-19/terapia , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Imunidade Celular/fisiologia , Imunização Passiva , Imuno-Histoquímica , Macaca mulatta , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Eletrônica , SARS-CoV-2/imunologia
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