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1.
BMC Plant Biol ; 21(1): 453, 2021 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-34615461

RESUMO

BACKGROUND: Appropriate flowering time is very important to the success of modern agriculture. Maize (Zea mays L.) is a major cereal crop, originated in tropical areas, with photoperiod sensitivity. Which is an important obstacle to the utilization of tropical/subtropical germplasm resources in temperate regions. However, the study on the regulation mechanism of photoperiod sensitivity of maize is still in the early stage. Although it has been previously reported that ZmCCT is involved in the photoperiod response and delays maize flowering time under long-day conditions, the underlying mechanism remains unclear. RESULTS: Here, we showed that ZmCCT overexpression delays flowering time and confers maize drought tolerance under LD conditions. Implementing the Gal4-LexA/UAS system identified that ZmCCT has a transcriptional inhibitory activity, while the yeast system showed that ZmCCT has a transcriptional activation activity. DAP-Seq analysis and EMSA indicated that ZmCCT mainly binds to promoters containing the novel motifs CAAAAATC and AAATGGTC. DAP-Seq and RNA-Seq analysis showed that ZmCCT could directly repress the expression of ZmPRR5 and ZmCOL9, and promote the expression of ZmRVE6 to delay flowering under long-day conditions. Moreover, we also demonstrated that ZmCCT directly binds to the promoters of ZmHY5, ZmMPK3, ZmVOZ1 and ZmARR16 and promotes the expression of ZmHY5 and ZmMPK3, but represses ZmVOZ1 and ZmARR16 to enhance stress resistance. Additionally, ZmCCT regulates a set of genes associated with plant development. CONCLUSIONS: ZmCCT has dual functions in regulating maize flowering time and stress response under LD conditions. ZmCCT negatively regulates flowering time and enhances maize drought tolerance under LD conditions. ZmCCT represses most flowering time genes to delay flowering while promotes most stress response genes to enhance stress tolerance. Our data contribute to a comprehensive understanding of the regulatory mechanism of ZmCCT in controlling maize flowering time and stress response.

2.
Bioresour Technol ; 342: 125987, 2021 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-34600317

RESUMO

The achievement and stable maintenance of partial nitrification and partial anammox process for municipal sewage is a challenging research topic at present. In this study, a novel strategy of hydroxylamine (NH2OH) addition under low DO condition was adopted for rapidly achieving simultaneous partial nitrification denitrification and anammox process (SPNDA) to deal with domestic wastewater, the nitrite accumulation ratio (NAR) increased from 1% to 82% in the first 4 days. After the addition of NH2OH was stopped, the PN effect of SPNDA process remained relatively stable within 100 days. During the stable operation period with aerobic HRT of 5 h, the nitrogen removal efficiency was 87.9 ± 4.2%. Moreover, the abundance of denitrifying bacteria and Candidatus Brocadia increased from 1.79% and 0.062% to 22.49% and 0.38% respectively, which promoted nitrogen removal effect. Overall, this study provided a quickly way for achieving the cost-effective SPNDA process to enhance nitrogen removal with NH2OH addition.

3.
Ann Clin Microbiol Antimicrob ; 20(1): 63, 2021 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-34488786

RESUMO

BACKGROUND: Extended-spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae has become a public health concern. This study aimed to compare the clinical outcomes of patients with nonurinary source bacteraemia caused by ESBL-producing Escherichia coli (E. coli) or Klebsiella pneumoniae (ESBL-producing EK) receiving ß-lactam/ß-lactamase inhibitor combinations (BLICs) versus carbapenem treatment and assess the risk factors of mortality with these two drugs. METHODS: We conducted a retrospective single-centre study of adult hospitalised patients with ESBL-producing EK bloodstream infection (BSI) from nonurinary source at our centre over a 4-year period. One hundred and eighty patients who received BLICs or carbapenems were included in the analysis. The outcome variables were 14-day treatment failure and 30-day mortality. For more reliable results, propensity score analysis was performed to compare the efficacy of the two drugs and analyse their risk factors for 30-day mortality. RESULTS: Out of 180 patients, 114 received BLICs, and 66 received carbapenem therapy. Compared to carbapenem-treated patients, those treated with BLICs were older and had higher age-adjusted Charlson comorbidity index, but they had shorter stay in the hospital. Additionally, their Pitt bacteraemia score, SOFA score, rate of leukaemia, and immune compromise were lower. After propensity score matching (PSM), the baseline characteristics of patients in the two treatment groups were balanced. BLICs were associated with a higher 14-day treatment failure rate (20.6%, 13/63) than carbapenems (16.3%, 7/43), although the difference was not significant in either univariate analysis (P = 0.429) or multivariate analysis (P = 0.122). And the 30-day mortality rate in BTG (11.1%, 7/63) and CTG (11.6%, 5/43) did not significantly differ (univariate analysis, P = 0.926; multivariate analysis, P = 0.420). In the multivariate analysis, after PSM, leukaemia was the only independent predictor of mortality in both BTG and CTG. CONCLUSIONS: Our study showed that BLICs had higher 14-day treatment failure rate compared with carbapenems, although there were no statistically significant differences because of the small number of patients, therefore, further evaluation of the efficacy of BLICs is needed.

4.
Plant Dis ; 2021 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-34533406

RESUMO

In a field survey from 2017 to 2019, Fusarium stalk rot symptoms including discolored, disintegrated stalk pith tissues and lodged plants were observed in maize hybrid lines Fuyu1611, Jidan66, and Danyu8439 grown in fields in Anshan (40o49'39''N, 122 o34'6''E), Liaoning province. Its incidence ranged from 15% to 20% and caused a yield loss of up to 30%. Infected pieces of stem tissues were dissected and then sterilized with 1% NaOCl for 1 min, 70% ethanol for 1 min, rinsed 3 times with sterilized ddH2O, and dried with filter paper in hood. Three pieces were placed onto Potato dextrose agar (PDA) and incubated at 25 °C for 5 days. The colonies were single-spore subcultured on PDA at 25 °C for 2 weeks (Leslie and Summerell 2006). Morphological features were observed on PDA and carnation leaf agar (CLA). The average mycelial growth rate was 4.5 to 10.3 mm/day at 25 °C on PDA. The colonies produced aerial mycelia, varying from dense white to grayish-rose, and secreted red pigments in the agar (Fig. 1A; 1B). Macroconidia produced on CLA were long and relatively slender, commonly 4- to 7-septate, averaging 85.6 × 5.2 µm, with thick walls and pronounced dorsiventral curvature with a distinctly foot-shaped and elongated basal cell and an apical cell that was whip-like (Fig. 1C). Microconidia were rarely observed on PDA or CLA. Morphological characteristics of the isolates were similar to the features of Fusarium longipes as previously described (Leslie and Summerell 2006). The portions of three phylogenic loci (EF1-α, RPB1, RPB2) were PCR amplified using the primer pairs EF1/EF2 (O'Donnell et al, 1998), lonR1F/lonR1R (5-TTTTCCTCACCAAGGAGCAGATCATG-3 and 5-CCAATGGACTGGGCAGCCAAAACGCC-3) and lonR2F/lonR2R (5-TATACATTTGCCTCCACTCTTTCCCAT-3 and 5-CGGAGCTTGCGTCCGGTGTGGCCGTTG-3) and sequenced. The consensus sequences were submitted to GenBank (MT513215 and MT997083 for TEF, MT513213 and MT997088 for RPB1; MT513214 and MW020572 for RPB2). BLASTn searches indicated that the nucleotide sequences of the three loci of the two isolates shared 94.52% to 99.69% identity with sequences of F. longipes strains deposited in the GenBank, Fusarium-ID and Fusarium MLST databases (Supplementary Table 1, 3, 4). A phylogram inferred via maximum likelihood analysis of the combined EF-1α, RPB1, RPB2 partial sequence data of Fusarium species (Supplementary Table 2) was inferred using the CIPRIES website (https://www.phylo.org). Isolates LNAS-05-A and LNAS-09-A clustered with F. longipes, with 98% bootstrap support (Fig. 2). Pathogenicity tests were conducted on three-leaf-stage seedlings and flowering-stage c.v. Zhengdan958 and B104 plants according to previously described methods (Ye et al., 2013; Zhang et al. 2016) with minor modifications. Three days after the roots of the seedlings were inoculated with 1 × 106 macroconidia solution, the leaves and stems exhibited typical wilt symptoms (Fig. 1D). Twenty flowering-stage maize plants were drilled individually at the second or third node above the soil using an electric drill (Bosch TSR1080-2-Li) to create a hole (8 mm in diameter). An approximately 0.5 mL mycelia plug (125 mL homogenized hyphal mats + 75 mL sterilized ddH2O) was injected into the hole and covered with Vaseline. Sterilized PDA plugs were used as a control. The stalk tissue of the split internodes turned dark brown and the brown area expanded above and below the injection site by 14 dpi. All of the inoculated plants developed characteristic stalk rot symptoms, whereas no symptoms were observed in the controls (Fig. 1E). The pathogen was re-isolated, and its identity was confirmed by sequencing the above mentioned loci. F. longipes was generally regarded as a tropical Fusarium species (Leslie and Summerell 2006). This is the first report that F. cf. longipes can cause stalk rot of maize under filed condition in a temperate, typical corn belt region of China.

5.
J Healthc Inform Res ; : 1-32, 2021 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-34514291

RESUMO

Purpose: COVID-19 is still showing a tendency of spreading around the world. In order to improve the subsequent control of COVID-19, it is essential to conduct a study on measuring and predicting the scale of the outbreak in the future. Methods: This paper uses rolling mechanism and grid search to find the best fractional order of Fractional Order Accumulation Grey Model (FGM). Buffer level is proposed based on the general form of weakening buffer operator to measure the effect of government control measurements on the epidemic. And the buffer level is associated with the Government Response Stringency index and the Mobility Index. Results: Firstly, the model proposed in this paper dominates the ARIMA model which has been widely used in predicting the confirmed COVID-19 cases. Secondly, in the process of using the buffer level to modify the FGM, this paper finds that government measurements require the active cooperation of the public and often have a time lag when they are effective. Only when government increase its stringency and the public observe the order can the spread of COVID-19 be slowed down. If there is only the controlling measure and the public does not react actively, it will not slow down the epidemic. Thirdly, according to the Mobility Index and Government Response Stringency Index in December, this paper predicts the cumulative confirmed cases of the end of January in different scenarios according to different buffer levels. The study suggests that the world should continue to maintain high vigilance and take corresponding control measures for the outbreak of COVID-19. Conclusions: Government's control measures and public's abidance are both important in this battle with COVID-19. Governments control measures have time-lag effect and the time lag is about 9 days. When the government increases its stringency and the public cooperates with the government, we must consider the weaken buffer operator with proper buffer level in the prediction process. These prediction methods can be considered in the prediction of COVID-19 confirmed cases in the future or the trend of other epidemics.

6.
Org Lett ; 2021 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-34579530

RESUMO

We disclose a direct C(sp)-, C(sp2)-, and C(sp3)-H thiolation reaction using ß-sulfinylesters as the versatile sulfur source. The key step of this protocol is chemoselective C-S bond cleavage of the sulfonium salts that are formed in situ from the corresponding alkenes, alkynes, and 1,3-dicarboxyl compounds with ß-sulfinylesters. The successful capture of the acrylate byproduct supports a retro-Michael reaction mechanism.

7.
Org Lett ; 2021 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-34543038

RESUMO

A lithium-bromide-promoted nucleophilic substitution/annulation cascade reaction between CF3-imidoyl sulfoxonium ylides and 1,3-dicarbonyl compounds has been established, and the corresponding 1,2,3-trisubstituted 5-trifluoromethylpyrroles have been obtained in 27-78% yield. This reaction features a broad substrate scope and generates dimethyl sulfoxide and H2O as byproducts.

9.
Bioresour Technol ; 339: 125515, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34332859

RESUMO

In this study, influence of biochar on nitrification was explored using multi-level (DNA, RNA, protein) and multi-aspect (diversity, structure, key community, co-occurrence pattern and functional modules) analyses (M-LAA) of ammonia-oxidizing microorganisms (AOMs) during cattle manure composting. Biochar addition increased the copy numbers and diversity of AOMs, restricted (36.02%) the amoA gene transcripts of archaea but increased (24.53%) those of bacteria, and reduced (75.86%) ammonooxygenase (AMO) activity. Crenarchaeota and Thaumarcheota mediated NH4+-N, Unclassified_k_norank_d_Archaea and Crenarchaeota regulated AMO activity and potential ammonia oxidation (PAO) rates. Nitrosomonas and Nitrosospira were the predominant microbial taxa influencing NH4+-N variation and PAO rates, respectively. Additionally, both Crenarchaeota and Nitrosospira played crucial roles in mediating NO3--N and NO2--N. Furthermore, biochar altered the network patterns of AOMs community by changing the keystone species and the interactivity among communities. These findings indicated that influence of biochar on nitrification could be better explained using M-LAA of AOMs.


Assuntos
Compostagem , Esterco , Amônia , Animais , Archaea/genética , Bovinos , Carvão Vegetal , Nitrificação , Oxirredução , Filogenia , Microbiologia do Solo
10.
J Exp Bot ; 2021 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-34338753

RESUMO

Flowering time is an important agronomic trait that determines the distribution and adaptation of plants. The accurate prediction of flowering time in elite germplasm is very critical for maize breeding. However, the molecular mechanisms underlying photoperiod response remain elusive in maize. Here we cloned the flowering time controlling gene, ZmNF-YC2, by map-based cloning and confirmed that ZmNF-YC2 is the protein of nuclear transcription factor Y subunit C-2 and a positive regulator of flowering time in maize under long-day conditions. Our results show that ZmNF-YC2 promotes the expression of ZmNF-YA3. ZmNF-YA3 negatively regulates the transcription of ZmAP2. ZmAP2 suppresses the expression of ZMM4 to delay flowering time. Then we developed a gene regulatory model of flowering time in maize using ZmNF-YC2, ZmNF-YA3, ZmAP2, ZMM4 and other key genes. The cascading regulation of ZmNF-YC2 on maize flowering time has not been reported in other species.

11.
Sci Total Environ ; 793: 148581, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34328985

RESUMO

Denitrifying phosphorus removal (DPR) technology is one of the most effective approach to simultaneously realize nitrogen (N) and phosphorus (P) removal from low COD/N ratio wastewater. Identifying the interaction of denitrifying phosphate-accumulating organisms (DPAOs), denitrifying glycogen organisms (DGAOs) and denitrifying ordinary heterotrophic organisms (DOHOs) is critical for optimizing denitrification and anoxic P uptake efficiency in DPR processes. In this study, a novel DPR system of anaerobic anoxic oxic - biological contact oxidation (AAO-BCO) was employed to dispose actual sewage with various influent COD/N ratios (3.5-6.7). High efficiency of TIN (76.5%) and PO43--P (94.4%) removal was observed when COD/N ratio was between 4.4 and 5.9. At the COD/N ratio of 5.7 ± 0.2, prominent DPR performance was verified by the superior DPR efficiency (88.7%) and anoxic phosphorus uptake capacity (PUADPAOs/ΔTIN = 1.84 mg/mg), which was further proved by the preponderance of DPAOs in C, N and P removal pathways. GAOs have a competitive advantage over PAOs for COD utilization at low COD/N ratio of 3.7 ± 0.2, which further limited the N removal efficiency. High proportion of N removal via DOHOs (21.2%) at the COD/N ratio of 6.5 ± 0.2 restrained the DPR performance, which should be attributed to the outcompete of DOHOs for NO3-. The nutrient removal mechanisms were explicated by stoichiometric calculation methodology to quantify the contribution of diverse functional microorganisms, contributing to improving the robustness of AAO-BCO system when facing the fluctuation of influent carbon source concentration.


Assuntos
Desnitrificação , Esgotos , Reatores Biológicos , Nitrogênio , Nutrientes , Fósforo , Eliminação de Resíduos Líquidos
12.
J Org Chem ; 86(15): 10407-10413, 2021 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-34314182

RESUMO

A base-mediated semihydrogenation of ynamides using p-toluenesulfonyl hydrazide as an inexpensive and easy-to-handle hydrogen donor is reported. This transition-metal-free protocol avoids overhydrogenation and reduction of other functional groups, generating the thermodynamically unfavorable Z-enamides exclusively.


Assuntos
Amidas , Elementos de Transição , Catálise , Hidrogenação , Estereoisomerismo
13.
J Glob Antimicrob Resist ; 26: 148-153, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34118479

RESUMO

OBJECTIVES: We aimed to determine the clinical impact of inappropriate empirical antibiotic treatment (IEAT) compared with appropriate empirical antibiotic treatment (AEAT) in hospitalised patients with urinary tract infections (UTIs) caused by Escherichia coli (E. coli). METHODS: This retrospective cohort study included adult patients with a primary diagnosis of UTI who were treated with empirical antibiotics at a tertiary hospital in southern China over a 2-year period. Clinical data of patients who received IEAT were compared with those of patients receiving AEAT. We used multivariable logistic regression to identify the predictors for receiving IEAT and the risk factors affecting clinical outcomes. RESULTS: A total of 213 patients were enrolled (median age, 61 years), of whom 103 (48.4%) received IEAT. IEAT was associated with empirical use of fluoroquinolones, male sex and age-adjusted Charlson comorbidity index (aCCI) score >6. Hospital length of stay (LOS) was longer for patients who received IEAT than for those who received AEAT (13.6 ± 8.6 days vs. 10.8 ± 7.9 days; P = 0.008). IEAT was an independent risk factor for longer LOS along with aCCI score ≥2, lung disease and cardiac disease. CONCLUSION: Empirical use of fluoroquinolones for UTIs should be avoided, especially in male patients with aCCI score >6. Improved empirical antimicrobial therapy may have a beneficial impact in reducing bacterial resistance and healthcare costs by decreasing the LOS. Therefore, interventions to promote in-depth antibiotic stewardship programmes in China are needed.

14.
J Immunother Cancer ; 9(6)2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34140315

RESUMO

BACKGROUND: Programmed cell death ligand 1 (PD-L1) expressed on tumor and immune cells are both associated with the response to programmed cell death 1 (PD-1) pathway blockade therapy. Here, we examine the role of CD8+PD-L1+ tumor-infiltrating lymphocyte (Tils) in the tumor microenvironment of non-small cell lung cancer (NSCLC). METHODS: Tumor tissue samples of a total of 378 patients from two NSCLC cohorts were collected retrospectively. Tumor genetic variations were measured by targeted next-generation sequencing of 543 oncogenes. Tils were assessed by multiplex immunohistochemistry assay. Correlations among Tils, tumor genetic variations, and clinicopathological characteristics were analyzed. RESULTS: The levels of CD8+PD-L1+ Tils varied in NSCLC tumor tissues. Tumor samples with high CD8+PD-L1+ Tils had higher levels of CD8+ Tils, CD68+ macrophages, PD-L1+ tumor cells, PD-1+ Tils, and CD163+ M2-type macrophages, and also had a higher tumor mutation burden, all of which collectively constituted a typically hot but immunosuppressive tumor microenvironment. Therefore, in a non-immunotherapy cohort, we observed that the higher the CD8+PD-L1+ Tils level in the tumor tissue, the worse the prognosis (progression-free survival; cohort A, stage I-II tumor; p=0.005). Contrarily, in an immunotherapy cohort, where the immune suppression was blocked by anti-PD-1 treatment, the higher the CD8+PD-L1+ Tils level, the better the response to the anti-PD-1 treatment (complete response/partial response vs stable disease/progressive disease; cohort B; p=0.0337). CONCLUSIONS: CD8+PD-L1+ Tils may be an indicator of the hot but immunosuppressive tumor microenvironment which is related to a high tumor mutation burden. PD-1 pathway blockade therapy can help to mitigate this immunosuppression and obtain better curative effects.

15.
Sci Total Environ ; 783: 147037, 2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34088161

RESUMO

This study aimed to investigate the mechanism of lead (Pb) immobilization by hydroxyapatite (HAP) in a soil-rice system, a pot experiment was conducted using Pb-contaminated soil amended with various rates of HAP and planted with rice (Oryza sativa L.). The Pb species in the soil and rice roots were determined using Pb L3-edge X-ray absorption near edge structure (XANES). Application of HAP increased soil pH and induced the dissolution of phosphate, subsequently promoting the formation of chloropyromorphite, an insoluble Pb species, in the soil. Therefore, the acid soluble and DTPA-extractable Pb concentrations decreased significantly with increasing levels of applied HAP. HAP reduced the retention of Pb in the iron plaque on the root surface at maturity, thereby alleviating Pb uptake by rice roots. The amount of phosphate in roots were increased with increasing rate of application of HAP, but was negatively correlated with Pb in rice stems and leaves. Application of 32 g kg-1 of HAP triggered the precipitation of Pb5PO4Cl in roots, limiting Pb translocation from roots to shoots. In addition, HAP may induce the redistribution of Pb in rice nodes, lowering the transfer factor of Pb from the stem (or leaf) to rice grains. When the rate of application of HAP exceeds 4 g kg-1, the Pb concentration in brown rice could be reduced to less than the Chinese National Standard of 0.2 mg kg-1 (GB2762-2017).

16.
Sleep Med ; 83: 248-255, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34049044

RESUMO

BACKGROUND: We conducted a meta-analysis and systematic review to identify a reliable estimate of sleep problems prevalence among children in mainland China and to describe its epidemiological characteristics. METHODS: Relevant studies were searched thoroughly via electronic databases included China National Knowledge Infrastructure, Wanfang, Weipu, PubMed, Embase and Medline databases from inception until December 2020. Prevalence estimates were calculated by random-effects models. The sources of heterogeneity were explored using subgroup analyses and Meta-regression analysis, and publication bias was estimated by funnel plots and Egger's Test. RESULTS: Overall, 66 studies were included in this meta-analysis, which revealed that the pooled prevalence of sleep problems was 37.6% (95%CI: 34.3-40.9%) with high heterogeneity (I2 = 99.6%,P < 0.001). The incidence of snoring was 7.7%, choking or gasping was 0.9%, apnea was 1.5%, restless sleep was 11.3%, mouth breathing was 4.7%, hyperhidrosis was 17.2%, leg movements was 2.7%, bruxism was 9.6%, sleep talking was 0.7%, sleep-walking was 0.8%, nightmare was 5.1%, enuresis was 3.4%, night awakening was 6.7% and trouble falling asleep was 11.1%. The prevalence rate of sleep problems among males was higher than females (OR:1.01,95%CI:1.05-1.13). In all age groups, the prevalence rates of sleep problems increased with age, including infancy or early childhood group (33.3%), pre-school group (38.9%), school-age group (43.7%). The prevalence rate in South China (30.4%, 95%CI: 23.9-36.8%) was the lowest, and the highest prevalence rate was in West China (47.4%,95%CI:35.9-58.9%), which than any other region in China. The point estimate for sleep disorders prevalence obtained using the CSHQ criterion was higher than other criteria. Meta-regression indicated that age group could influence prevalence estimation (P = 0.011). CONCLUSIONS: Over the past two decades, the prevalence rate of sleep problems among children in mainland China has increased, significantly affecting two-fifth of the school-age children. The incidence of hyperhidrosis, restless sleep and trouble falling asleep were significantly higher than other sleep prombles. The prevalence rate of sleep problems in west China was significantly higher than in any other area. There is still a lack of guidelines on children's sleep problems in mainland China, so future research should pay special attention to the sleep problems of school-age children and children in economically backward areas.


Assuntos
Transtornos do Sono-Vigília , Criança , Pré-Escolar , China/epidemiologia , Feminino , Humanos , Incidência , Masculino , Prevalência , Sono , Transtornos do Sono-Vigília/epidemiologia
17.
Phys Chem Chem Phys ; 2021 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-33960343

RESUMO

Ni-rich layered oxides, like LiNi0.8Co0.1Mn0.1O2 (NCM811), have been widely investigated as cathodes due to their high energy density. However, gradual structural transformation during cycling can lead to capacity degradation and potential decay of cathode materials. Herein, we doped high-valence transition metal (TM) ions (V5+, Nb5+, and Zr4+) at the Ni site of NCM811 by first principles simulations and explored the mechanism of doping TMs in NCMs for enhancing the electrochemical performance. Analysis of the calculations shows that doping V, Nb and Zr has an efficient influence on alleviating the Ni oxidation, reducing the loss of oxygen, and facilitating Li+ migration. Moreover, V doping can further suppress the lattice distortion due to the radius of V5+ being close to the radius of Mn4+. In particular, compared with the barrier of the pristine NCM in Li divacancy, the barrier of V-doped NCM reaches the lowest. In conclusion, V is the most favorable dopant for NCM811 to improve the electrochemical properties and achieve both high capacity and cycling stability.

18.
Pediatr Pulmonol ; 56(7): 2250-2258, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33856119

RESUMO

BACKGROUND: Pulmonary arterial hypertension (PAH) is a rare disease in children, with significant mortality. Because of the limited research on pediatric PAH, first, systematic review of related drugs is conducted, and then economic evaluation of PAH drug treatment programs is conducted, which to provide a reference for the choice of more cost-effective treatment options. METHODS: The search includes electronic databases such as Pubmed, ScienceDirect, and Embase. Through inclusion and exclusion criteria, screen high-quality randomized controlled trials. We used TreeAge Pro 2011 software to construct the markov model, that to simulate the total medical cost and quality-adjusted life years (QALYs), and to calculate the incremental cost-effectiveness ratio. Sensitivity analysis of transfer probability, utility, and cost was carried out. RESULTS: Incorporate two studies that meet the criteria, one compared the therapeutic effects of bosentan and placebo on pediatric PAH, the other compared therapeutic effects of sildenafil and placebo on pediatric PAH, both articles were of good quality. Compared with the sildenafil group (3.38QALYs and $161,120.14), the QALY of the bosentan treatment group (3.33QALYs and $257,411.29) was reduced by 0.05, and the cost increased by $96,291.15. The estimated improvement to quality of life and reduced costs result in an estimate of economic dominance for sildenafil over bosentan. This dominant result persisted probabilistic analyses. CONCLUSIONS: Based on this model, a more cost-effective treatment drug for PAH in children is sildenafil.

19.
Brain ; 2021 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-33876820

RESUMO

The unc-13 homolog B (UNC13B) gene encodes a presynaptic protein, mammalian uncoordinated 13-2 (Munc13-2), that is highly expressed in the brain-predominantly in the cerebral cortex-and plays an essential role in synaptic vesicle priming and fusion, potentially affecting neuronal excitability. However, the functional significance of UNC13B mutation in human disease is not known. In this study we screened for novel genetic variants in a cohort of 446 unrelated cases (families) with partial epilepsy without acquired causes by trio-based whole-exome sequencing. UNC13B variants were identified in 12 individuals affected by partial epilepsy and/or febrile seizures from eight unrelated families. The eight probands all had focal seizures and focal discharges in EEG recordings, including two patients who experienced frequent daily seizures and one who showed abnormalities in the hippocampus by brain MRI; however, all of the patients showed favorable outcome without intellectual or developmental abnormalities. The identified UNC13B variants included one nonsense variant, two variants at or around a splice site, one compound heterozygous missense variant, and four missense variants that cosegregated in the families. The frequency of UNC13B variants identified in the present study was significantly higher than that in a control cohort of Han Chinese and controls of the East Asian and all populations in the Genome Aggregation Database. Computational modeling, including hydrogen bond and docking analyses, suggested that the variants lead to functional impairment. In Drosophila, seizure rate and duration were increased by Unc13b knockdown compared to wild-type flies, but these effects were less pronounced than in sodium voltage-gated channel alpha subunit 1 (Scn1a) knockdown Drosophila. Electrophysiologic recordings showed that excitatory neurons in Unc13b-deficient flies exhibited increased excitability. These results suggest that UNC13B is potentially associated with epilepsy. The frequent daily seizures and hippocampal abnormalities but ultimately favorable outcome under antiepileptic therapy in our patients indicate that partial epilepsy caused by UNC13B variant is a clinically manageable condition.

20.
Cornea ; 40(11): 1426-1432, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-33734163

RESUMO

PURPOSE: To analyze the agreement of corrected intraocular pressure (IOP) values between Corvis ST (ΔIOP1) and Pentacam (ΔIOP2) in patients with keratoconus (KC), subclinical KC (sub-KC), and normal cornea. METHODS: In total, 235 eyes were divided into KC, sub-KC, and control groups. Differences in ΔIOP1 (biomechanically corrected IOP minus uncorrected IOP) and ΔIOP2 (central corneal thickness-corrected amounts of IOP) were analyzed within and among groups. Topographical and biomechanical differences were compared among the 3 groups. Factors affecting differences between ΔIOP1 and ΔIOP2 were analyzed. Agreement analysis of ΔIOP2 and ΔIOP1 was performed by Bland-Altman plots for all 3 groups. RESULTS: Mean ΔIOP1 was highest in the KC group (1.23 ± 0.84 mm Hg), followed by sub-KC and control groups (all P < 0.05). Deformation amplitude ratio at 2 mm (DA-2 mm), integrated radius, stiffness parameter at first applanation, and Corvis biomechanical index values significantly differed between sub-KC and control groups. The differences between ΔIOP1 and ΔIOP2 were affected by stiffness parameter at first applanation, after adjusting for central corneal thickness and age, in all 3 groups. The lowest agreement between ΔIOP2 and ΔIOP1 was observed in the KC group (mean difference: 1.90 mm Hg; 95% limit of agreement ranged from -0.2 to 3.9 mm Hg). CONCLUSIONS: Among the 3 groups in this study, the KC group exhibited the worst consistency between ΔIOP2 and ΔIOP1. For the sub-KC and control groups, corrected IOP values derived by Pentacam were similar to Corvis ST. Ophthalmologists should carefully consider the mechanical properties of eyes with KC during IOP management.

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