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1.
Artigo em Inglês | MEDLINE | ID: mdl-31678225

RESUMO

BACKGROUND: Pathologic complete response (pCR) after neoadjuvant chemotherapy (NACT) is associated with improved overall survival (OS) in breast-cancer patients, but it is unclear how post-NACT response influences radiotherapy administration in patients presenting with node-positive disease. We sought to determine whether nodal pCR is associated with likelihood of receiving nodal radiation and whether radiotherapy among patients experiencing nodal pCR is associated with improved OS. METHODS: cN1 female breast cancer patients diagnosed 2010-2015 who were ypN0 (i.e., nodal pCR, n=12,341) or ypN1 (i.e., residual disease, n=13,668) post-NACT were identified in the National Cancer Database. Multivariate logistic regression was used to identify factors associated with receiving radiotherapy. Cox proportional hazards modeling was used to estimate the association between radiotherapy and adjusted OS. RESULTS: 26,009 patients were included. 43.9% (n=5,423) of ypN0 and 55.3% (n=7,556) of ypN1 patients received nodal radiation. Rates of nodal radiation remained the same over time among ypN0 patients (trend test p=0.29) but increased among ypN1 patients from 49% in 2010 to 59% in 2015 (trend test p<0.001). After adjusting for covariates, nodal pCR (vs no stage change) was associated with decreased likelihood of nodal radiation after mastectomy (∼20% decrease) and lumpectomy (∼30% decrease, both p<0.01). After mastectomy, nodal (vs no) radiation conferred no significant survival benefit in ypN0 patients but approached significance for ypN1 patients (hazard ratio [HR] 0.83, 95% CI 0.69-0.99, p=0.04, overall p-value=0.11). After lumpectomy, nodal radiation was associated with improved adjusted OS for ypN0 (HR 0.38, 95% CI 0.22-0.66) and ypN1 patients (HR 0.44, 95% CI 0.30-0.66, both p<0.001), but this improvement was not significantly greater than that associated with breast-only radiation. CONCLUSIONS: ypN0 patients were less likely to receive nodal radiation than ypN1 patients, suggesting that selective omission already occurs and, in the context of limited survival data, could potentially be appropriate for select patients.

2.
Biol Pharm Bull ; 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31666439

RESUMO

Schisandra chinensis is widely used and effective in protecting liver. There are many mechanisms of drug-induced hepatocyte injury, among which endoplasmic reticulum (ER) stress-induced cell injury plays an important role. However, little is known about whether schisandra chinensis can inhibit rifampicin(RFP)-induced hepatocyte injury by affecting ER stress. In our study, firstly, L02 cells were treated with different concentrations of RFP for different time intervals, and the apoptosis, survival rate and endoplasmic reticulum stress gene and protein expressions of GRP78, PERK, ATF4, CHOP, ATF6, ARMET, p-IRE1 and XBP-1 were measured. We found that RFP increased apoptosis of L02 cells, decreased cell survival, and increased the gene and protein expression levels of GRP78, PERK, ATF4, CHOP, ATF6, ARMET, p-IRE1 and XBP-1, suggesting that RFP could induce hepatocyte injury, and the degree of injury was positively correlated with the dose and time of RFP. Next, we treated RFP-damaged hepatocytes with Schizandrin B. We found that schizandrin B increased cell survival rate in dose-dependent and time-dependent manner, decreased cell apoptosis rate, and reduced protein and gene expression levels of GRP78, PERK, ATF4, CHOP, ATF6, ARMET and XBP-1. These results indicate that schizandrin B alleviates RFP-induced injury in L02 cells by inhibiting ER stress.

3.
Nat Genet ; 51(11): 1616-1623, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31676863

RESUMO

Fruit characteristics of sweet watermelon are largely the result of human selection. Here we report an improved watermelon reference genome and whole-genome resequencing of 414 accessions representing all extant species in the Citrullus genus. Population genomic analyses reveal the evolutionary history of Citrullus, suggesting independent evolutions in Citrullus amarus and the lineage containing Citrullus lanatus and Citrullus mucosospermus. Our findings indicate that different loci affecting watermelon fruit size have been under selection during speciation, domestication and improvement. A non-bitter allele, arising in the progenitor of sweet watermelon, is largely fixed in C. lanatus. Selection for flesh sweetness started in the progenitor of C. lanatus and continues through modern breeding on loci controlling raffinose catabolism and sugar transport. Fruit flesh coloration and sugar accumulation might have co-evolved through shared genetic components including a sugar transporter gene. This study provides valuable genomic resources and sheds light on watermelon speciation and breeding history.

5.
ANZ J Surg ; 2019 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-31625246

RESUMO

BACKGROUND: A small amount of bleeding usually occurs during laparoscopic cholecystectomy (LC), but the occurrence of perioperative hidden blood loss (HBL) is ignored. So our objective is to investigate the amount of HBL and find out the influential factors in LC. METHODS: From January 2017 to May 2019, 139 patients scheduled for LC were enrolled in the study. The data of patients' sex, age, height, weight, body mass index (BMI), form of gallbladder bed, gallbladder status, hypertension, diabetes, liver cirrhosis, drainage volume and operation time were recorded. The patients' height, weight and preoperative and postoperative haematocrit and haemoglobin were recorded and applied to the Gross formula to determine the amount of blood loss. The data of sex, age, BMI, hypertension, diabetes, gallbladder status, liver cirrhosis and operation time were analysed by multivariate linear regression analysis. One-way analysis of variance was performed to find out the relative correlation between HBL and the type of gallbladder bed. RESULTS: The HBL was 259.3 ± 188.5 mL. On the basis of multivariate linear regression analysis and analysis of variance, the gallbladder bed, hypertension and the operation time are influential factors of HBL in patients with LC. However, sex, age, BMI, gallbladder status, liver cirrhosis and diabetes are not significantly correlated with HBL. CONCLUSIONS: HBL should not be overlooked during the perioperative period of LC, especially in patients with hypertension, gallbladder bed >50% gallbladder surface or operation time >60 min.

6.
Singapore Med J ; 60(10): 552, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31663103
7.
QJM ; 2019 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-31605493

RESUMO

AIMS: The purpose of study is to evaluate the effect and complication of preoperative short-term daily recombinant human erythropoietin (rhEPO) treatment for blood-saving in patients undergoing unilateral primary total knee arthroplasty (TKA). METHODS: This three-arm randomized clinical trial compared three different rhEPO-based treatment protocols for unilateral primary total knee arthroplasty. Group A: application of daily doses of rhEPO combined with iron supplement starting 3 days before surgery; Group B: application of daily doses of rhEPO combined with iron supplement starting the day of surgery; Group C: iron supplement alone. Perioperative hemoglobin (Hb) level gaps, total perioperative blood loss, reticulocyte levels and treatment-related complications were studied. RESULTS: 102 patients were included (35, 35, and 32 patients in group A, B, and C, respectively). Total blood loss in group A, B, and C was 490.84ml, 806.76ml, and 924.21ml respectively. Patients in group A had a significant lower total blood loss than group B and C (A vs B: P = 0.010; A vs C: P < 0.001). There was no difference as for total blood loss between group B and C (P = 0.377). Group A patients had significant smaller Hb decline than group C on the 3rd and 5th postoperative day (P = 0.049, P = 0.037), as well as than group B on the 5th postoperative day (P = 0.048). There was no difference as for Hb decline between group B and C. No difference was shown in levels of inflammatory biomarkers or blood-saving protocol-related complications among three groups. CONCLUSIONS: Daily dose of rhEPO combined with iron supplement administered 3 days before TKA procedures could significantly decrease perioperative blood loss and improve postoperative Hb levels, without significantly elevating risks of complication, when compared with admission of rhEPO on the day of surgery and iron supplement alone. Preoperative daily rhEPO treatment could be a more effective blood-saving protocol in TKA procedures.

8.
Chemistry ; 2019 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-31637740

RESUMO

The side-on-end-on coordination of N 2 can be very important to activate and functionalize this very stable molecule while such coordination has been rarely reported. This study reports a gas phase species (a poly-nuclear vanadium nitride cluster anion V 5 N 5 - ) that can capture N 2 efficiently (12%), and the quantum chemistry modelling suggests an unusual side-on-end-on coordination. The cluster anions were generated by laser ablation and the reaction with N 2 has been characterized by mass spectrometry, photoelectron imaging spectroscopy, and density functional theory calculations. The back-donation interaction between the localized d-d bonding orbital on low coordinated dual metal (V) sites and the antibonding π* orbital of N 2 is the driving force to adsorb N 2 with a high binding energy (about 2.0 eV).

9.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi ; 33(11): 1358-1362, 2019 Nov 15.
Artigo em Chinês | MEDLINE | ID: mdl-31650748

RESUMO

Objective: To investigate the safety, feasibility, and effectiveness of modified staging strategy in treatment of type C3 Pilon fractures. Methods: The clinical data of 23 patients with type C3 Pilon fractures treated with modified staging strategy between January 2012 and January 2018 was retrospectively analyzed. There were 14 males and 9 females with an average age of 47.9 years (range, 22-61 years). Twenty-three cases were high-energy injuries, including 11 cases of traffic accidents and 12 cases of falling from height. One case was an open fracture of Gustilo type ⅢA with no obvious sign of infection on the wound after early treatment. The remaining patients were closed fractures. The time from injury to admission was 3-40 hours with an average of 16.4 hours. The preoperative pain visual analogue scale (VAS) score was 7.22±1.17 and American Orthopaedic Foot and Ankle Society (AOFAS) score was 0. The flexion and plantar flexion activities of ankle joint were (1.13±0.26) and (4.79±0.93)°, respectively. Twenty-two patients had a tibiofibular fracture. In the first-stage operation, the posterior approach was used to reduce the posterior column fracture and the external stent was temporarily assisted. After the soft tissue crisis was removed, the final fracture reduction and internal fixation was performed through the anterior approach in the second-stage operation. Results: All 23 patients were followed up 12-84 months with an average of 26.6 months. The waiting time before the first-stage operation was 4-47 hours with an average of 23.4 hours. The interval between the two stage operations was 6-11 days with an average of 7.9 days. The first-stage operation time was 60-90 minutes with an average of 67.8 minutes; the second-stage operation time was 110-160 minutes with an average of 124.1 minutes. The hospital stay was 15-28 days with an average of 23.5 days. One patient (4.35%) had a tourniquet paralysis symptom after the second-stage operation, and two patients (8.7%) had delayed anterior incision healing. The other patients had incision healing without early complications. The radiographic review showed that the quality of articular surface reduction was excellent in 19 cases, good in 2 cases, and poor in 2 cases, with an excellent and good rate of 91.3%. At last follow-up, the fractures healed with no bone nonunion and malunion; the different degrees of osteoarthritis occurred in 7 cases. At last follow-up, the VAS score was 0.89 ±0.88 and the AOFAS score was 81.3±7.8. The flexion and plantar flexion activities of ankle joint were (10.23±5.05) and (20.97±3.92)°, respectively, and the differences between pre- and post-operation were significant ( P<0.05). Conclusion: The midified staging strategy can not only provide a template for articular surface reduction for the second-stage anterior surgery, but also improve the quality of the reduction. It can also reduce the interval between the two operations and the operation time of the second-stage operation through the first-stage posterior fascial decompression, and can obtain satisfactory effectiveness.


Assuntos
Fraturas do Tornozelo , Fraturas da Tíbia , Adulto , Feminino , Fixação Interna de Fraturas , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
10.
Ying Yong Sheng Tai Xue Bao ; 30(9): 3233-3244, 2019 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-31529899

RESUMO

As the link among species, ecological environment, and ecosystem function, functional diversity can help us to better understand the relationship between biodiversity and ecosystem function. We analyzed functional diversity with thirteen functional traits reflecting the characteristics of food acquisition, locomotion, ecological adaptation, reproduction and population dynamics of fish species. The seasonal, interannual and spatial variations of functional diversity of fish communities were examined using functional richness index (FRic), functional evenness index (FEve), functional divergence index (FDiv) and community weighted mean index (CWM) based on the data from the bottom trawl surveys in spring and autumn from 2011 to 2017 (except 2012) in Haizhou Bay. The results showed that functional diversity indices were significantly different in spring and autumn, with FRic was significantly higher in autumn than that in spring and FDiv was significantly higher in spring than that in autumn. Migration might be the main reason for the seasonal change of functional diversity indices. CWM analysis showed that dominant fish species were cold-temperate or warm-temperate species, with higher trophic level, strong motion ability, and relatively high growth coefficient, resilience and vulnerability in spring. In autumn, the dominant species showed the opposite traits. In both spring and autumn, fish species with pelagic eggs dominated the fish communities. Inter-annual variations in functional diversity indices were observed in spring and autumn. The functional diversity indices showed an annual fluctuation during the study period in both spring and autumn, indicating the low stability of fish community in Haizhou Bay. Significant spatial changes in functional diversity of fish assemblages were observed, with FDiv being higher in the offshore coastal waters (>20 m) than that in the shallow waters (<20 m). The functional diversity showed obvious spatio-temporal variation. The ecological niches and resource utilization of fish species varied with season, year and space in Haizhou Bay.


Assuntos
Baías , Biodiversidade , Ecossistema , Peixes , Animais , Dinâmica Populacional
11.
Plant Sci ; 288: 110219, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31521216

RESUMO

The 14-3-3 proteins are a family of highly conserved phosphoserine-binding proteins that participate in the regulation of diverse physiological and developmental processes. In this research, twenty 14-3-3 genes in apples, which contained a highly conserved 14-3-3 domain, were identified and divided into two subgroups. Among them, MdGRF11 was further cloned and investigated. qRT-PCR analyses and GUS staining show that MdGRF11 is expressed in various organs and tissues with the highest expression levels found in the fruit. MdGRF11 was upregulated by polyethylene glycol 6000 (PEG 6000), NaCl, abscisic acid (ABA) and low temperature (4 °C) treatments. MdGRF11-overexpressing transgenic Arabidopsis and apple calli exhibited reduced sensitivity to salt and PEG 6000 treatments. Moreover, the ectopic expression of MdGRF11 improved the tolerance of transgenic tobacco to salt and drought stresses, which grew longer roots, underwent more growth, and presented higher chlorophyll levels than the wild-type control under salt and drought stress conditions. Furthermore, MdGRF11 expression remarkably reduced electrolyte leakage, malondialdehyde content levels, H2O2 and O2- accumulation under salt and drought stress conditions, which relied on the regulation of ROS-scavenging signaling to reduce oxidative damage of cells after salt and drought stress treatment. MdGRF11 also enhanced tolerance to stress by upregulating expression levels of ROS-scavenging and stress-related genes, especially improving responses to drought stress by modifying the water loss rates and stomatal aperture. Moreover, MdGRF11 could interact with MdAREB/ABF transcription factors through yeast two hybrid analyses. In conclusion, our results indicate that MdGRF11 acts as a positive regulator of salt and drought stress responses through regulating ROS scavenging and other signaling systems.

12.
Zhongguo Gu Shang ; 32(8): 765-771, 2019 Aug 25.
Artigo em Chinês | MEDLINE | ID: mdl-31533392

RESUMO

OBJECTIVE: To evaluate efficacy of radiographic and clinical of Chevron osteotomy versus Scarf osteotomy for hallux valgus at moderate and severe degree. METHODS: Randomized controlled trial (RCT) about Chevron and Scarf osteotomy for hallux valgus, in PubMed, Embase, Cochrane Library, CBM, CNKI, Wanfang Data were searched by computer from establishing database to June 2018. According to inclusion and exclusion criteria, two researchers independently screened the literatures, evaluated risk of bias and extracted related observation index, RevMan 5.3.5 software was used to perform Meta-analysis. Postoperative hallux valgus angle (HVA), intermetatarsal angle (IMA), distal metatarsal articular angle (DMAA), AOFAS score, complications and patients' satisfaction degree between Chevron and Scarf osteotomy. RESULTS: Six RCT literatures were included, involving 507 patients, 92.5% patients were at moderate and severe degree, and 261 patients were performed by Chevron osteotomy and 246 patients were performed by Scarf osteotomy. Meta analysis results showed that Chevron osteotomy was better than Scarf osteotomy in correcting HVA [MD=-1.95, 95%CI(-2.64, -1.27), P<0.000 01]. While there were no statistical differences in IMA [MD=-0.42, 95%CI(-1.04, 0.21), P=0.19], DMAA[MD=0.78, 95%CI(-0.72, 2.29), P=0.31], AOFAS score [MD=2.47, 95%CI(-2.38, 7.33), P=0.32], complications [RR=1.09, 95%CI(0.54, 2.20), P=0.82], and patients' satisfaction degree [RR=1.00, 95%CI(0.96, 1.05), P=0.92]. CONCLUSIONS: Chevron osteotomy, which has advantages in simple operation, shorten metatarsal bone, less trauma, was better in correcting HVA of hallux valgus at moderate and severe degree, and had similar effects in IMA, DMAA, AOFAS score, complications and patients' satisfactory degree.


Assuntos
Hallux Valgus , Articulação Metatarsofalângica , Hallux Valgus/cirurgia , Humanos , Ossos do Metatarso , Osteotomia , Resultado do Tratamento
13.
Analyst ; 144(20): 6004-6010, 2019 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-31538153

RESUMO

Aflatoxin B1 (AFB1) and fumonisin B1 (FB1) are the most common mycotoxins and often coexist in agricultural products, and are known to form a toxic superposition and even have carcinogenic effects on humans. We propose a multiplexed fluorescence resonance energy transfer (FRET) aptasensor for the simultaneous detection of mycotoxins with magnetically controlled graphene oxide (GO)/Fe3O4 as the single energy acceptor. CdTe quantum dots emitting green (GQDs) and red (RQDs) fluorescence were modified by aptamers that are specific for AFB1 and FB1 and used as dual energy donors. Compared with conventional FRET systems based on a GO quencher, GO/Fe3O4, as a single energy acceptor, not only simultaneously quenches the different fluorescence emission peaks of the aptamer-modified GQDs and RQDs but also can be effectively removed by magnetic separation to eliminate background interference. In the absence of the GO/Fe3O4 nanocomposites, the aptamer-modified GQDs and RQDs emit strong fluorescence under ultraviolet radiation. The fluorescence of the GQDs and RQDs is quenched when the GO/Fe3O4 nanocomposites are added to the system owing to the π-π stacking interactions between the GO/Fe3O4 nanocomposites and the GQD- and RQD-labeled aptamers. However, in the presence of AFB1 and FB1, the binding of aptamers to their specific targets will fold their single stranded structures and hinder the contact between the base group in the aptamers and GO/Fe3O4, which will cause the fluorescence recovery of GQDs and RQDs. With the help of a one-step magnetic separation, the supernatants can be collected for fluorescence analysis. After the optimization of detection conditions, the developed method had a wide linear range of 10 pg mL-1-100 ng mL-1 for AFB1 and 50 pg mL-1-300 ng mL-1 for FB1 and showed no cross-reactivity with other closely related mycotoxins. The limit of detection for AFB1 and FB1 were calculated to be 6.7 and 16.2 pg mL-1 based on S/N = 3, respectively. The detection of mycotoxins was successfully realized in peanut samples, indicating the successful application of this new FRET system for various future targets.

14.
Mol Med Rep ; 20(6): 5032-5040, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31485636

RESUMO

When paraquat (PQ) enters the human body, it increases oxidative stress and inflammation, ultimately resulting in acute lung injury (ALI). Curcumin, a naturally occurring compound, has been reported to ameliorate PQ­induced ALI; however, the underlying molecular mechanisms remain unclear. In the present study, normal lung fibroblasts (WI­38VA13) were treated with 10 µmol/l PQ for 48 h, followed by a further 48 h incubation with 300 µmol/l curcumin. Cells were then harvested to determine their viability. Flow cytometry was performed to analyze the levels of reactive oxygen species (ROS) and the rate of apoptosis. The levels of apoptotic proteins and activation of the thioredoxin interacting protein/NLR pyrin domain containing 3 (TXNIP/NLRP3) axis were measured via reverse transcription­quantitative polymerase chain reaction and western blot analyses. Proinflammatory cytokine levels were examined using enzyme­linked immunosorbent assays. Finally, the expression levels of Notch1, extracellular signal­regulated kinase 1/2 (ERK1/2) and phosphorylated­ERK1/2 were evaluated via western blotting. Following treatment with curcumin, PQ­induced increases in ROS levels and apoptosis were significantly attenuated, and Bcl­2 expression levels were upregulated, whereas those of Bax were downregulated. It was also observed that curcumin treatment downregulated the expression levels of TXNIP, NLRP3, interleukin (IL)­1ß and IL­18, and downstream caspase­1 compared with PQ treatment alone. Curcumin significantly attenuated the upregulation of Notch1 without affecting ERK1/2 phosphorylation. The present findings suggested that the inhibitory effects of curcumin on TXINP1 may inhibit activation of the NLRP3 inflammasome, subsequently suppressing the upregulation of proinflammatory cytokines and ultimately improving PQ­induced ALI.

15.
Plant J ; 2019 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-31529543

RESUMO

To understand sex determination in watermelon (Citrullus lanatus), a spontaneous gynoecious watermelon mutant, XHBGM, was selected from the monoecious wild type XHB. Using map-based cloning, resequencing and fluorescence in situ hybridization analysis, a unique chromosome translocation between chromosome 2 and chromosome 3 was found in XHBGM. Based on the breakpoint location in chromosome 2, a putative C2H2 zinc finger transcription factor gene, ClWIP1 (gene ID Cla008537), an orthologue of the melon gynoecy gene CmWIP1, was disrupted. Using clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated system 9 to edit ClWIP1, we obtained gynoecious watermelon lines. Functional studies showed that ClWIP1 is expressed specifically in carpel primordia and is related to the abortion of carpel primordia in early floral development. To identify the cellular and metabolic processes associated with ClWIP1, we compared the shoot apex transcriptomes of two gynoecious mutants and their corresponding wild types. Transcriptome analysis showed that differentially expressed genes related to the ethylene and cytokinin pathways were upregulated in the gynoecious mutants. This study explores the molecular mechanism of sex determination in watermelon and provides a theoretical and technical basis for breeding elite gynoecious watermelon lines.

16.
Ultrason Sonochem ; 60: 104799, 2019 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-31563793

RESUMO

The cavitation erosion (CE) of most materials in seawater is more serious than in fresh water due to the onset of corrosion; however, in a previous study we reported results that contradict this widely accepted trend. In this research our objective is to provide fundamental insight into the mechanisms that may be responsible for these earlier results. To accomplish this objective, two types of Co-based coatings, prepared by high velocity oxygen fuel (HVOF) spraying system, were used to further investigate the underlying corrosion-mitigating CE mechanism in seawater. Accordingly, the influence of spraying parameters on microstructure, composition and mechanical properties of the coatings was analyzed on the basis of SEM, XRD, Raman spectroscopy, Vicker's hardness and nano-indentation results. Electrochemical corrosion tests were used to evaluate the corrosion behavior of the Co-based coatings. Their CE performances in seawater and deionized water were comparatively studied by a vibratory apparatus. Results demonstrated that a higher flame temperature facilitated the oxides formation with associated improvements in compactness, hardness and toughness of the coatings. The presence of alumina in combination with the oxides formed in-situ facilitated the formation of an oxidation film on surfaces, and effectively enhanced the charge transfer resistance of the coating, thereby significantly improving the corrosion resistance in seawater. Metallic Co was not only more easily oxidized but also more readily corroded than the alloyed Co. Compactness was identified as an important factor affecting CE resistance of coatings in deionized water, because defects facilitate the nucleation and eventual collapse of bubbles. Moreover, bubble collapse produced a transient high temperature spike in excess of 600 °C that also caused Co and Cr elements to oxidize. Because the CE tests were carried out in seawater, additional Co3O4 and Cr2O3 were generated owing to corrosion that more effectively increased the surface compactness and mechanical properties of the coatings. This behavior was particular notable for coatings with metallic Co and Cr, which should be why seawater corrosion could weaken the CE of Co-based coatings.

17.
Traffic ; 20(11): 829-840, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31513326

RESUMO

Export of mRNA from the nucleus to the cytoplasm is a critical process for all eukaryotic gene expression. As mRNA is synthesized, it is packaged with a myriad of RNA-binding proteins to form ribonucleoprotein particles (mRNPs). For each step in the processes of maturation and export, mRNPs must have the correct complement of proteins. Much of the mRNA export pathway revolves around the heterodimeric export receptor yeast Mex67•Mtr2/human NXF1•NXT1, which is recruited to signal the completion of nuclear mRNP assembly, mediates mRNP targeting/translocation through the nuclear pore complex (NPC), and is displaced at the cytoplasmic side of the NPC to release the mRNP into the cytoplasm. Directionality of the transport is governed by at least two DEAD-box ATPases, yeast Sub2/human UAP56 in the nucleus and yeast Dbp5/human DDX19 at the cytoplasmic side of the NPC, which respectively mediate the association and dissociation of Mex67•Mtr2/NXF1•NXT1 onto the mRNP. Here we review recent progress from structural studies of key constituents in different steps of nuclear mRNA export. These findings have laid the foundation for further studies to obtain a comprehensive mechanistic view of the mRNA export pathway.

18.
Anal Chem ; 91(20): 12688-12695, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31538775

RESUMO

Glyoxal (GLY) acts as a key contributor to tropospheric ozone production and secondary organic aerosol (SOA) formation on local to regional scales. The detection of GLY provides useful indicators of fast photochemistry occurring in the lower troposphere. The fast and sensitive detection of GLY is thus important, while traditional chemical ionization such as the proton-transfer reaction (PTR) is extremely limited by the poor detection limit and extensive fragmentation. To address these limitations, electron attachment reaction (EAR) ionization was applied to detect GLY. The generation of parent anions (GLY-) without fragmentation was observed, and cryogenic photoelectron imaging spectroscopy further characterized the structure of GLY-. The detection limit was estimated to be as low as (52 ± 1) pptv (parts per trillion by volume) with 1 min measurements. Other components in ambient air, such as water, carbon dioxide, and trace gases (acetone, propanal, etc.) have no effect on the detection of GLY. The EAR ionization is more promising than PTR ionization in detecting GLY. The detection of GLY in ambient air by the EAR ionization has been demonstrated.

19.
Artigo em Inglês | MEDLINE | ID: mdl-31553114

RESUMO

Direct conversion of methane with carbon dioxide to value-added chemicals is attractive but extremely challenging because of the thermodynamic stability and kinetic inertness of both molecules. Herein, the first dinuclear cluster species, RhVO3 - , has been designed to mediate the co-conversion of CH4 and CO2 to oxygenated products, CH3 OH and CH2 O, in the temperature range of 393-600 K. The resulting cluster ions RhVO3 CO- after CH3 OH formation can further desorb the [CO] unit to regenerate the RhVO3 - cluster, leading to the successful establishment of a catalytic cycle for methanol production from CH4 and CO2 (CH4 +CO2 →CH3 OH+CO). The exceptional activity of Rh-V dinuclear oxide cluster (RhVO3 - ) identified herein provides a new mechanism for co-conversion of two very stable molecules CH4 and CO2 .

20.
Ying Yong Sheng Tai Xue Bao ; 30(8): 2829-2836, 2019 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-31418209

RESUMO

Based on the bottom trawl surveys in spring (May) and in autumn (September to October) from 2011 to 2017 (except 2012) in Haizhou Bay, variations in the mean trophic levels (MTL) and large fish index (LFI) of fish community were examined to understand the changes of fish community structure in Haizhou Bay. The results showed that the dominant fish species were Hexagrammos otakii, Enedrias fangi, Syngnathus acus, Pseudosciaena polyactis and Saurida elongata, which had obvious seasonal variation. The mean trophic level of fish community varied significantly among different years and seasons. Generally, MTL in autumn was higher than that in spring, and the variation of which in autumn always lagged behind that in spring. The result of LFI calculation showed that the large fish resources declined and fish community structure in Haizhou Bay showed an obvious tendency of miniaturization in recent years.


Assuntos
Baías , Peixes/fisiologia , Animais , China , Peixes/classificação , Perciformes , Estações do Ano
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