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1.
Int J Mol Sci ; 21(19)2020 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-33036486

RESUMO

Seed germination is a critical process for completion of the plant life cycle and for global food production. Comparing the germination transcriptomes of barley (Hordeum vulgare) to Arabidopsis thaliana revealed the overall pattern was conserved in terms of functional gene ontology; however, many oppositely responsive orthologous genes were identified. Conserved processes included a set of approximately 6000 genes that peaked early in germination and were enriched in processes associated with RNA metabolism, e.g., pentatricopeptide repeat (PPR)-containing proteins. Comparison of orthologous genes revealed more than 3000 orthogroups containing almost 4000 genes that displayed similar expression patterns including functions associated with mitochondrial tricarboxylic acid (TCA) cycle, carbohydrate and RNA/DNA metabolism, autophagy, protein modifications, and organellar function. Biochemical and proteomic analyses indicated mitochondrial biogenesis occurred early in germination, but detailed analyses revealed the timing involved in mitochondrial biogenesis may vary between species. More than 1800 orthogroups representing 2000 genes displayed opposite patterns in transcript abundance, representing functions of energy (carbohydrate) metabolism, photosynthesis, protein synthesis and degradation, and gene regulation. Differences in expression of basic-leucine zippers (bZIPs) and Apetala 2 (AP2)/ethylene-responsive element binding proteins (EREBPs) point to differences in regulatory processes at a high level, which provide opportunities to modify processes in order to enhance grain quality, germination, and storage as needed for different uses.

2.
J Coll Physicians Surg Pak ; 30(9): 956-960, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33036681

RESUMO

OBJECTIVE: To evaluate the clinical efficacy and safety of early tracheotomy versus delayed tracheotomy for patients with cervical spinal cord injury. STUDY DESIGN: A descriptive study. PLACE AND DURATION OF STUDY: Department of Orthopedic Surgery, The 80th Army Hospital of PLA, Weifang, Shandong, China, from January 2012 to June 2019. METHODOLOGY: Data of 45 patients with cervical spinal cord injury, who underwent tracheotomy and cervical spine internal fixation at the study place, were retrospectively analysed. Twenty-five patients underwent tracheotomy immediately after cervical spine internal fixation (early tracheotomy group) and 20 patients underwent tracheotomy 3-12 days after cervical spine internal fixation (delayed tracheotomy group). Clinical outcomes and tracheotomy complications were compared between the two groups. RESULTS: Compared with the delayed tracheotomy, the early tracheotomy significantly reduced the total duration of mechanical ventilation (p <0.01), duration of mechanical ventilation after tracheotomy (p <0.05), duration of indwelling tracheal tube (p <0.05), and hospital stay (p <0.01). There were no significant differences in pneumonia, mortality, and complications related to tracheotomy between the groups. No incision infection for tracheotomy and cervical spine internal fixation were found in all patients. CONCLUSION: Compared with delayed tracheotomy, early tracheotomy can significantly reduce the duration of mechanical ventilation, duration of indwelling tracheal tube, and hospital stay. Early tracheotomy did not increase the risk of infection of the cervical spine internal fixation. Therefore, early tracheotomy was beneficial and safe for patients. Key Words: Spinal cord injuries, Tracheotomy, Complications.

3.
Ann Palliat Med ; 2020 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-33040550

RESUMO

BACKGROUND: Endoscopic submucosal dissection (ESD) under general anesthesia in left lateral position may lead to transient impairment of pulmonary function. We used electrical impedance tomography (EIT), an increasingly implied non-invasive instrument for bedside real-time monitoring regional changes in ventilation, to assess the changes of regional lung aeration and ventilation in patients undergoing ESD. METHODS: Twenty-two patients scheduled for elective ESD under mechanical ventilation in left lateral position were studied. We acquired 2-min EIT records at four time points: (M1) baseline, before induction of anesthesia, (M2) after the start of mechanical ventilation and before surgery, (M3) after surgery and before extubation, and (M4) after extubation and before leaving operation room, respectively. To quantify regional changes in lung ventilation, we calculated the ventilation proportion of left and right lung regions. Possible changes in lung aeration were detected by changes in end-expiratory lung impedance (EELI). Global inhomogeneity index (GI) was also analyzed. RESULTS: After tracheal intubation in the left lateral position, left lung showed a lower ventilation proportion (M1, 49.6% vs. M2, 36.2% P<0.05), a reduction in EELI {∆EELI -87 [-809; 253]} and a higher GI index value (M1, 0.29±0.09 vs. M2, 0.41±0.12, P<0.05), while right lung showed a higher ventilation proportion (M1, 50.4% vs. M2, 63.8%, P<0.05) and an increase in EELI {∆EELI 161 [-952; 1,905]}. During ESD operation, no changes in either regional ventilation distribution or GI index were observed. After extubation, the GI values in right and left lung were both returned to the level before anesthesia. CONCLUSIONS: In patients with left lateral position undergoing ESD, left lung was characterized by decreased ventilation and more inhomogeneity while right lung was opposite after intubation. ESD procedure with carbon dioxide insufflation did not lead to significant changes in either regional ventilation or homogeneity. And the change of lung inhomogeneity during ESD procedure is transient.

4.
Front Immunol ; 11: 2058, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33042117

RESUMO

With the ulcerative colitis (UC) incidence increasing worldwide, it is of great importance to prevent and treat UC. However, efficient treatment options for UC are relatively limited. Due to the potentially serious adverse effects of existing drugs, there is an increasing demand for alternative candidate resources derived from natural and functional foods. Astragalin (AG) is a type of anti-inflammatory flavonoid, with Moringa oleifera and Cassia alata being its main sources. In this study, we investigated the therapeutic effects of AG on mice with dextran sulfate sodium (DSS)-induced colitis. Our results suggested that AG treatment reduced weight loss and the disease activity index (DAI), prevented colon shortening and alleviated colonic tissue damage. AG treatment reduced the expression of pro-inflammatory cytokines and related mRNAs (such as TNF-α, IL-6, and IL-1ß), inhibited colonic infiltration by macrophages and neutrophils, ameliorated metabolic endotoxemia, and improved intestinal mucosal barrier function (increased expression levels of mRNAs such as ZO-1, occludin, and Muc2). Western blot analysis revealed that AG downregulated the NF-κB signaling pathway. Moreover, AG treatment partially reversed the alterations in the gut microbiota in colitis mice, mainly by increasing the abundance of potentially beneficial bacteria (such as Ruminococcaceae) and decreasing the abundance of potentially harmful bacteria (such as Escherichia-Shigella). Ruminococcaceae and Enterobacteriaceae (Escherichia-Shigella) were thought to be the key groups affected by AG to improve UC. Therefore, AG might exert a good anti-UC effect through microbiota/LPS/TLR4/NF-kB-related pathways in mice. The results of this study reveal the anti-inflammatory effect and mechanism of AG and provide an important reference for studying the mechanisms of natural flavonoids involved in preventing inflammation-driven diseases.

5.
Theranostics ; 10(24): 11110-11126, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33042273

RESUMO

Rationale: Many external factors can induce the melanogenesis and inflammation of the skin. Salidroside (SAL) is the main active ingredient of Rhodiola, which is a perennial grass plant of the Family Crassulaceae. This study evaluated the effect and molecular mechanism of SAL on skin inflammation and melanin production. It then explored the molecular mechanism of melanin production under ultraviolet (UV) and inflammatory stimulation. Methods: VISIA skin analysis imaging system and DermaLab instruments were used to detect the melanin reduction and skin brightness improvement rate of the volunteers. UV-treated Kunming mice were used to detect the effect of SAL on skin inflammation and melanin production. Molecular docking and Biacore were used to verify the target of SAL. Immunofluorescence, luciferase reporter assay, CO-IP, pull-down, Western blot, proximity ligation assay (PLA), and qPCR were used to investigate the molecular mechanism by which SAL regulates skin inflammation and melanin production. Results: SAL can inhibit the inflammation and melanin production of the volunteers. SAL also exerted a protective effect on the UV-treated Kunming mice. SAL can inhibit the tyrosinase (TYR) activity and TYR mRNA expression in A375 cells. SAL can also regulate the ubiquitination degradation of interferon regulatory factor 1 (IRF1) by targeting prolyl 4-hydroxylase beta polypeptide (P4HB) to mediate inflammation and melanin production. This study also revealed that IRF1 and upstream stimulatory factor 1 (USF1) can form a transcription complex to regulate TYR mRNA expression. IRF1 also mediated inflammatory reaction and TYR expression under UV- and lipopolysaccharide-induced conditions. Moreover, SAL derivative SAL-plus (1-(3,5-dihydroxyphenyl) ethyl-ß-d-glucoside) showed better effect on inflammation and melanin production than SAL. Conclusion: SAL can inhibit the inflammation and melanogenesis of the skin by targeting P4HB and regulating the formation of the IRF1/USF1 transcription complex. In addition, SAL-plus may be a new melanin production and inflammatory inhibitor.

6.
Cell Signal ; : 109808, 2020 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-33045317

RESUMO

Breast cancer ranks as the major reason for mortality in women populations, accounting for 23% of all cancer deaths. One in every three Asian women encounters the risk of this cancer in their lifetime. Long intergenic non-coding RNAs (lincRNAs) have emerged as tumor promoters and suppressors. The molecular mechanism of breast cancer remains elusive. Therefore, the current study aimed to explore the role lincRNA LINC00922 plays in the development of breast cancer. Breast cancer tissues and adjacent tissues were obtained from 109 patients with breast cancer. The RNA extraction and quantification and immunohistochemical staining characterized the high expression of LINC00922 and low expression of NKD2 in breast cancer tissues in comparison to its adjacent counterparts. Furthermore, the ectopic expression and knockdown experiments were conducted to figure out the in vivo and in vitro effects of LINC00922 on breast cancer progression. The ectopically expressed LINC00922 activated the Wnt signaling pathway, promoted epithelial-mesenchymal transition, cell proliferative, invasive and migratory capacities, tumor growth and metastasis. Additionally, the RIP and ChIP assay identified that LINC00922 recruited DNMT1, DNMT3A and DNMT3B proteins in the promoter region of NKD2 to promote NKD2 promoter methylation, thus reducing the NKD2 expression. Moreover, the Wnt signaling pathway was activated subsequent to NKD2 silencing, which was reversed by LINC00922 silencing. Lastly, the anti-oncogenic effects of LINC00922 inhibition was antagonized after NKD2 knocked down. The current study provides evidence that LINC00922 acts as a tumor promoter by promoting NKD2 methylation. Hopefully, it provides a novel potential gene target for the treatment of breast cancer.

7.
Schizophr Res ; 2020 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-33046333

RESUMO

In this study, we applied brain grey matter volume and structural covariance methods on T1 weighted images to delineate potential structural brain changes in individuals with high schizotypy, who were defined as healthy individuals scoring in the top tenth percentile of the Schizotypal Personality Questionnaire (SPQ). Eighty-seven college students with high schizotypy and 122 controls were recruited in China. Differences in grey matter volume and volume covariance between the two groups, and correlations of grey matter volume with SPQ scores in the high schizotypy group were examined. We found that individuals with high schizotypy had decreased grey matter volume at the left medial superior frontal gyrus (medsFG) extending towards the superior frontal gyrus, decreased structural covariance within the right medsFG, between the right superior frontal gyrus (sFG), the right superior temporal gyrus and the right anterior insula; and increased structural covariance between the caudate and the right inferior temporal gyrus. Correlation analysis revealed that grey matter volume of the left middle temporal pole and the right sFG correlated positively with the SPQ total scores, volume of the bilateral cerebellum 9 sub-region correlated negatively with the SPQ cognitive-perceptual sub-scale scores, volume of the bilateral striatum correlated positively with the SPQ interpersonal sub-scale scores, and volume of the bilateral superior temporal pole correlated positively with the SPQ disorganization sub-scale scores in the high schizotypy group. These results highlight important grey matter structural changes in the medsFG in individuals with high schizotypy.

8.
Ecotoxicol Environ Saf ; 208: 111453, 2020 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-33068984

RESUMO

Trichloroethylene (TCE), an important volatile organic solvent, causes a series of toxic damage to human. Conventional genetic mechanisms cannot fully explain its toxicity and carcinogenicity, indicative of the possible involvement of epigenetic mechanisms. Our study was intended to investigate the epigenetic toxicity and underlying mechanisms of TCE. Data showed that 0.3 mM TCE treatment for 24 h increased the growth of L-02 cells transiently. In contrast, subacute exposure to TCE inhibited cell growth and induced the genomic DNA hypomethylation and histone hyperacetylation. Further studies have revealed the TCE-induced DNA hypomethylation in the promoter regions of tumor-related genes, N-Ras, c-Jun, c-Myc, c-Fos and IGF-II, promoting their protein levels in a time-dependent manner. These results reveal there is a negative relationship existing between DNA hypomethylation and protein expression in tumor-related gene after TCE exposure under specific epigenetic microenvironment, serving as early biomarkers for TCE-associated diseases.

9.
J Hazard Mater ; 404(Pt B): 124149, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-33069996

RESUMO

In this study, the profiles of bacteria/phage-comediated antibiotic resistance genes (b/pARGs) were monitored in water samples collected from 45 pig farm wastewater treatment plants (WWTPs) in seven different regions of China. We found that 8 major types and 112 subtypes of b/pARGs were detected in all the water samples, and the detected number ranged from 53 to 92. The absolute abundances of bARGs and pARGs in the influent were as high as 109 copies/mL and 106 copies/mL, respectively. Anaerobic anoxic/oxic (AAO) and anaerobic short-cut nitrification/denitrification (ASND) treatment plants can effectively reduce the absolute abundance and amount of b/pARGs. Anaerobic treatment plants cannot reduce the absolute abundance of pARGs, and even increase the amount of pARGs. Mobile genetic elements (MGEs), bacterial communities and environmental factors were important factors impacting the b/pARG profile. Among these factors, the bacterial community was the major driver that impacted the bARG profile, while bacterial community and MGEs were the major codrivers impacting the pARG profile. This study was the first to investigate the profiles of b/pARGs in pig farm WWTPs in China on such a large scale, providing a reference for the prevention and control of ARG pollution in agricultural environments.

10.
Ticks Tick Borne Dis ; 12(1): 101588, 2020 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-33075731

RESUMO

Ticks are common vectors of human and animal diseases. Ochrobactrum spp. belong to the Brucellaceae family and have recently been recognized as emerging human pathogens. The ability of Haemaphysalis longicornis ticks to carry Ochrobactrum spp. remains uncertain. During June and July 2018, 686 ticks were collected from 11 sites in Pingdingshan Henan province in central China. We extracted 169 DNA samples for Brucellaceae 16S rRNA nested PCR and sequenced them in order to identify Ochrobactrum spp. The data sequences were aligned with NCBI BLAST program and phylogenetic tree was constructed using Mega 5.0. Twenty samples were sequenced successfully out of a total forty-one positive for Brucellaceae. Thirteen DNA samples were identical to O. intermedium (99.85 %-100.00 %) and 3 were identical to O. cicer (99.85 %-100.00 %) (15 collected from host and one from vegetation). Four DNA samples (3 collected from host and one from vegetation) had 99.83-100 % B. melitensis identity. This study adds to the growing body of evidence that shows Ochrobactrum spp. are present in H. longicornis. Ochrobactrum spp. and Brucella spp. are phenotypically and genetically closely related pathogens. Our finding highlights the importance of gene sequencing and phylogenetic analysis to differentiate between Ochrobactrum spp. and Brucella spp. in the research and potentially clinical setting. Future work is required to investigate the transmission potential of Ochrobactrum spp. by H. longicornis.

11.
IEEE Trans Cybern ; PP2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-33079690

RESUMO

In this article, a novel control algorithm is developed for a class of nonlinear stochastic systems subject to multiple disturbances, including exogenous dynamic disturbance and general non-Gaussian noise. An observer is designed to estimate the exogenous disturbance, and then the disturbance compensation is incorporated into a feedback control strategy for the non-Gaussian system. Considering the ability of entropy in randomness quantification, a performance index is established based on the generalized entropy optimization principle. Furthermore, it is adjusted to be available for the controller solution, which also solves the coupling between two kinds of disturbances. On this basis, the optimal controller is provided in a recursive way, with which the closed-loop stability and good antidisturbance ability can be guaranteed simultaneously. Compared with the existing studies on the non-Gaussian stochastic systems, the proposed control algorithm has merits in multiple disturbances decoupling and enhanced antidisturbance performance. Finally, a simulation example is given to demonstrate the effectiveness of theoretical results.

12.
Nanotechnology ; 2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-33080574

RESUMO

Currently, it is still unclear how and to what extent a change in temperature impacts the relative contributions of coherent and incoherent phonons to thermal transport in superlattices. Some seemingly conflicting computational and experimental observations of the temperature dependence of lattice thermal conductivity make the coherent-incoherent thermal transport behaviors in superlattices even more elusive. In this work, we demonstrate that incoherent phonon contribution to thermal transport in superlattices increases as the temperature increases due to elevated inelastic interfacial transmission. On the other hand, the coherent phonon contribution decreases at higher temperatures due to elevated anharmonic scattering. The competition between these two conflicting mechanisms can lead to different trends of lattice thermal conductivity as temperature increases, i.e., increasing, decreasing, or non-monotonic. Finally, we demonstrate that the neural network-based machine learning model can well capture the coherent-incoherent transition of lattice thermal transport in the superlattice, which can greatly aid the understanding and optimization of thermal transport properties of superlattices.

13.
Artigo em Inglês | MEDLINE | ID: mdl-33082226

RESUMO

Hosts and pathogens are engaged in a continuous evolutionary struggle for physiological dominance. A major site of this struggle is the apoplast. In Phytophthora sojae-soybean interactions, PsXEG1, a pathogen-secreted apoplastic endoglucanase, is a key focal point of this struggle, and the subject of two layers of host defense and pathogen counterdefense. Here, we show that N-glycosylation of PsXEG1 represents an additional layer of this coevolutionary struggle, protecting PsXEG1 against a host apoplastic aspartic protease, GmAP5, that specifically targets PsXEG1. This posttranslational modification also attenuated binding by the previously described host inhibitor, GmGIP1. N-glycosylation of PsXEG1 at N174 and N190 inhibited binding and degradation by GmAP5 and was essential for PsXEG1's full virulence contribution, except in GmAP5-silenced soybeans. Silencing of GmAP5 reduced soybean resistance against WT P. sojae but not against PsXEG1 deletion strains of P. sojae. The crucial role of N-glycosylation within the three layers of defense and counterdefense centered on PsXEG1 highlight the critical importance of this conserved apoplastic effector and its posttranslational modification in Phytophthora-host coevolutionary conflict.

14.
Hortic Res ; 7: 161, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33082968

RESUMO

The carotenoid isomerase gene (BoaCRTISO) of Chinese kale was targeted and edited using the CRISPR/Cas9 system in the present study. The results showed a high mutation rate (81.25%), and 13 crtiso mutants were obtained. Only two types of mutations, insertions and replacements, were found. Both the total and individual carotenoid and chlorophyll concentrations of the biallelic and homozygous mutants were reduced, and the total levels declined by 11.89-36.33%. The color of the biallelic and homozygous mutants changed from green to yellow, likely reflecting a reduction in the color-masking effect of chlorophyll on carotenoids. The expression levels of most carotenoid and chlorophyll biosynthesis-related genes, including CRTISO, were notably lower in the mutants than in the WT plants. In addition, the functional differences between members of this gene family were discussed. In summary, these findings indicate that CRISPR/Cas9 is a promising technique for the quality improvement of Chinese kale and other Brassica vegetables.

15.
J Clin Transl Hepatol ; 8(3): 277-284, 2020 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-33083250

RESUMO

Background and Aims: To evaluate the efficacy of Fuzheng Huayu (FZHY), a Chinese herbal formula, plus entecavir (ETV) in regression of liver fibrosis in chronic hepatitis B (CHB) patients with significant fibrosis/cirrhosis. Methods: The current study was a two-center, randomized, double-blind and placebo-controlled pilot study. Fifty-two currently untreated chronic hepatitis B patients with Ishak fibrosis score ≥3 points were identified and 1:1 randomized into FZHY plus ETV combination and placebo plus ETV groups. The second liver biopsy was performed after 48-week treatment. Necroinflammatory improvement and regression of fibrosis were assessed. Fine changes in different collagen features in paired liver biopsies were evaluated by dual-photon microscopy for both groups. Results: Forty-nine patients completed the full course of treatment; forty-six of them underwent second liver biopsy (for which twenty-two were in the combination group and twenty-four were in the control group). Compared to those in the control group, patients in the combination group had significantly higher rate of fibrosis regression (82% vs. 54%) (p<0.05). Furthermore, the necroinflammatory improvement was greater in the combination group than in the control group (59% vs. 25%, p<0.05). Among the more than 80 collagen parameters in the dual-photon analysis, 5 decreased significantly in the combination group compared to the control group (p<0.05). However, no significant improvement was detected in either biochemical, virologic or serologic responses between these two groups at week 48. Conclusions: The combination therapy of FZHY plus ETV for 48 weeks resulted in a higher rate of necroinflammatory improvement and fibrosis regression than ETV alone in chronic hepatitis B patients with significant fibrosis/cirrhosis. The clinical trial number is ChiCTR-TRC-11001377.

16.
Neuroradiology ; 2020 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-33084936

RESUMO

PURPOSE: This systematic review and meta-analysis summarized the current literature to compare the safety and efficacy between first-pass effect (FPE) and multiple-pass effect (MPE) for thrombectomy in treatment of acute ischemic stroke (AIS). METHODS: Major databases were searched for studies which reported clinical outcomes regarding successful or complete recanalization after first pass of mechanical thrombectomy in AIS. The assessment of bias was performed using different scales. I2 statistic was used to evaluate heterogeneity between reviewers. Subgroup, meta-regression, and sensitivity analyses were conducted to explore the source of heterogeneity. Visualization of funnel plots was used to evaluate publication bias. RESULTS: A total of 9 studies were eligible for final analysis. For successful recanalization (mTICI 2b-3), favorable outcomes were seen in 49.7% (95% confidence interval (CI): 40.5-58.9%) and 34.7% (95% CI: 26.8-42.7%) of FPE and MPE patients, respectively. Mortality at 3 months was 13.8% (95% CI: 10.8-16.9%) and 26.0% (95% CI: 17.7-34.2%), respectively. For complete recanalization (mTICI 2c-3), proportion of favorable outcomes were 62.7% (95% CI: 51.2-74.2%) and 47.7% (95% CI: 37.4-58.0%) in FPE and MPE; mortality was seen in 11.5% (95% CI: 4.9-18.2%) and 17.0% (95% CI: 5.2-28.7%), respectively. For AIS with successful recanalization, FPE had more favorable outcome (odds ratio (OR): 1.85, 95% CI: 1.48-2.30; p < 0.01; I2 = 0%) and lower mortality than MPE (OR: 0.58, 95% CI: 0.42-0.79; p = 0.001; I2 = 61.9%). Similar results were seen in a subgroup analysis of patients with complete recanalization, with FPE having better outcome (OR: 1.79, 95% CI: 1.40-2.28; p < 0.01; I2 = 0%) and lower mortality risk (OR: 0.61, 95% CI: 0.44-0.86; p = 0.005; I2 = 0%) compared to MPE. CONCLUSION: FPE is associated with better outcomes than MPE after achieving successful or complete recanalization.

17.
J Mol Model ; 26(11): 310, 2020 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-33084983

RESUMO

First-principle density functional theory calculations have been performed to investigate the adsorption of C2H2 on Ni(111) and Sn@Ni(111) at different coverages. At low coverage, the C2H2 molecule is strongly adsorbed on Ni(111) and the dissociation of the H atom is not favorable. Furthermore, the more the H atom dissociated, the more unstable the system is. However, the dissociation structure of C2H+H has the largest adsorption energy on Sn@Ni(111), indicating that the dissociation structure is more stable than molecular adsorbed C2H2. At moderate coverage, there is some repulsive interaction between two C2H2 molecules, inducing the decrease in adsorption energy. On Ni(111), the two C2H2 tend to adsorb separately, however, the dimer C4H4 has the largest adsorption energy on Sn@Ni(111). At high coverage, the trimer derivative benzene has the largest adsorption energy on both Ni(111) and Sn@Ni(111) surfaces. The adsorption energies of the formed benzene are very high on the two systems, even larger than those of three individual adsorbed C2H2.

18.
Mol Genet Genomics ; 2020 Oct 10.
Artigo em Inglês | MEDLINE | ID: covidwho-846592

RESUMO

To better understand the interaction between SARS-CoV-2 and human host and find potential ways to block the pandemic, one of the unresolved questions is that how the virus economically utilizes the resources of the hosts. Particularly, the tRNA pool has been adapted to the host genes. If the virus intends to translate its own RNA, then it has to compete with the abundant host mRNAs for the tRNA molecules. Translation initiation is the rate-limiting step during protein synthesis. The tRNAs carrying the initiation Methionine (iMet) recognize the start codon termed initiation ATG (iATG). Other normal Met-carrying tRNAs recognize the internal ATGs. The tAI of virus genes is significantly lower than the tAI of human genes. This disadvantage in translation elongation of viral RNAs must be compensated by more efficient initiation rates. In the human genome, the abundance of iMet-tRNAs to Met-tRNAs is five times higher than the iATG to ATG ratio. However, when SARS-CoV-2 infects human cells, the iMet has an 8.5-time enrichment to iATG. We collected 58 virus species and found that the enrichment of iMet is higher in all viruses compared to human. Our study indicates that the genome sequences of viruses like SARS-CoV-2 have the advantage of competing for the iMet-tRNAs with host mRNAs. The capture of iMet-tRNAs allows the fast translation initiation and the reproduction of virus itself, which compensates the lower tAI of viral genes. This might explain why the virus could rapidly translate its own RNA and reproduce itself from the sea of host mRNAs. Meanwhile, our study reminds the researchers not to ignore the mutations related to ATGs.

19.
J Biomech ; 112: 110055, 2020 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-33039923

RESUMO

Assessing the biomechanical properties of the cornea in vivo is important for predicting the outcome of refractive surgery, and for controlling the risk of postoperative complications. In this study, we examined the impact of corneal mechanical properties (nonlinearity and anisotropy) on the inverse solution of corneal material parameters based on the non-contact tonometry ("air puff") test. Finite element models with different constitutive models (linear-elastic, isotropic hyperelastic, and fiber-dependent) were established to simulate the non-contact tonometry test. The results showed that the corneal nonlinear mechanical property and fiber distribution had significant effects on the corneal deflection profile. These findings may help in constructing an appropriate inverse solution strategy when using the inverse finite element method and in identifying individual differences in the corneal matrix shear modulus and fiber stiffness.

20.
Eur J Pharmacol ; 889: 173634, 2020 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-33031797

RESUMO

Repurposing of approved antiviral drugs against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a promising strategy to treat Coronavirus disease 2019 (COVID-19) patients. Previously we reported our hypothesis that the antiviral drugs with high lung distributions might benefit COVID-19 patients by reducing viral loads. So far, chloroquine, lopinavir, hydroxychloroquine, azithromycin, favipiravir, ribavirin, darunavir, remdesivir, and umifenovir have been tested in COVID-19 clinical trials. Here we validated our hypothesis by comparing the pharmacokinetics profiles of these drugs and their capabilities of reducing viral load in clinical trials. According to bulk RNA and single cell RNA sequencing analysis, we found that high expression of both angiotensin converting enzyme 2 (ACE2) and transmembrane Serine Protease 2 (TMPRSS2) makes the lung and intestine vulnerable to SARS-CoV-2. Hydroxychloroquine, chloroquine, and favipiravir, which were highly distributed to the lung, were reported to reduce viral loads in respiratory tract of COVID-19 patients. Conversely, drugs with poor lung distributions, including lopinavir/ritonavir, umifenovir and remdesivir, were insufficient to inhibit viral replication. Lopinavir/ritonavir might inhibit SARS-CoV-2 in the GI tract according to their distribution profiles. We concluded here that the antiviral drugs should be distributed straight to the lung tissue for reducing viral loads in respiratory tract of COVID-19 patients. Additionally, to better evaluate antiviral effects of drugs that target the intestine, the stool samples should also be collected for viral RNA test in the future.

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