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1.
Food Funct ; 2020 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-32242562

RESUMO

The formation and disappearance of aldehydes during simulated gastrointestinal digestion (SD) of fried clams was investigated in order to shed light on the underlying mechanism. Results from the thiobarbituric acid reactive substance (TBARS) and fluorometric assays using a specific aldehyde probe indicated that the SD (with lipase) of fried clams initially reduced (at the gastric stage), but subsequently increased (mainly at the intestinal stage) the contents of total aldehydes. Meanwhile, eight specific aldehydes including propanal, acrolein, trans-2-pentenal, hexanal, trans,trans-2,4-octadienal, trans,trans-2,4-decadienal, 4-hydroxy-hexenal and 4-hydroxy-nonenal in the digested meal were determined by using a high-performance liquid chromatography-tandem electrospray ionization mass spectrometry (HPLC-ESI-MS/MS) method. Results indicated that the changes in the trend of the contents of the eight aforementioned aldehydes were similar to those of total aldehydes during SD (with lipase) of fried clams. However, a similar SD process without lipase time-dependently reduced the contents of total and individual aldehydes. Moreover, lipid classes and free fatty acids (FFAs) in the digested meal were determined to reveal the degree of hydrolysis of lipids during the SD process. Results indicated that the SD (with lipase) of fried clams significantly hydrolyzed triacylglycerols (TAG) and polar lipids (PL) and produced FFAs, but the SD process without lipase resulted in negligible lipid hydrolysis. Thus, our results demonstrated a positive correlation between lipid hydrolysis and aldehyde generation during the SD of fried clams. Alternatively, unsaturated FFAs instead of TAG and PL could have served as the main precursors for aldehyde generation due to their high oxidative susceptibility.

2.
Stem Cell Reports ; 2020 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-32243844

RESUMO

Yes-associated protein (YAP) is known to promote the stemness of multiple stem cell types, including pluripotent stem cells, while also antagonizing pluripotency during early embryogenesis. How YAP accomplishes these distinct functions remains unclear. Here, we report that, depending on the specific cells in which it is expressed, YAP could exhibit opposing effects on pluripotency induction from mouse somatic cells. Specifically, YAP inhibits pluripotency induction cell-autonomously but promotes it non-cell-autonomously. For its non-cell-autonomous role, YAP alters the expression of many secreted and matricellular proteins, including CYR61. YAP's non-cell-autonomous promoting effect could be recapitulated by recombinant CYR61 and abrogated by CYR61 depletion. Thus, we define a YAP-driven effect on enhancing pluripotency induction largely mediated by CYR61. Our work highlights the importance of considering the distinct contributions from heterologous cell types in deciphering cell fate control mechanisms and calls for careful re-examination of the co-existing bystander cells in complex cultures and tissues.

3.
Crit Care Nurse ; 40(2): 14-23, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32236427

RESUMO

BACKGROUND: Patients with both true and false arrhythmia alarms pose a challenge because true alarms might be buried among a large number of false alarms, leading to missed true events. OBJECTIVE: To determine (1) the frequency of patients with both true and false arrhythmia alarms; (2) patient, clinical, and electrocardiographic characteristics associated with both true and false alarms; and (3) the frequency and types of true and false arrhythmia alarms. METHODS: This was a secondary analysis using data from an alarm study conducted at a tertiary academic medical center. RESULTS: Of 461 intensive care unit patients, 211 (46%) had no arrhythmia alarms, 12 (3%) had only true alarms, 167 (36%) had only false alarms, and 71 (15%) had both true and false alarms. Ventricular pacemaker, altered mental status, mechanical ventilation, and cardiac intensive care unit admission were present more often in patients with both true and false alarms than among other patients (P < .001). Intensive care unit stays were longer in patients with only false alarms (mean [SD], 106 [162] hours) and those with both true and false alarms (mean [SD], 208 [333] hours) than in other patients. Accelerated ventricular rhythm was the most common alarm type (37%). CONCLUSIONS: An awareness of factors associated with arrhythmia alarms might aid in developing solutions to decrease alarm fatigue. To improve detection of true alarms, further research is needed to build and test electrocardiographic algorithms that adjust for clinical and electrocardiographic characteristics associated with false alarms.

4.
Sci Rep ; 10(1): 5926, 2020 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-32245979

RESUMO

Existing cerebrovascular blood pressure autoregulation metrics have not been translated to clinical care for pediatric cardiac arrest, in part because signal noise causes high index time-variability. We tested whether a wavelet method that uses near-infrared spectroscopy (NIRS) or intracranial pressure (ICP) decreases index variability compared to that of commonly used correlation indices. We also compared whether the methods identify the optimal arterial blood pressure (ABPopt) and lower limit of autoregulation (LLA). 68 piglets were randomized to cardiac arrest or sham procedure with continuous monitoring of cerebral blood flow using laser Doppler, NIRS and ICP. The arterial blood pressure (ABP) was gradually reduced until it dropped to below the LLA. Several autoregulation indices were calculated using correlation and wavelet methods, including the pressure reactivity index (PRx and wPRx), cerebral oximetry index (COx and wCOx), and hemoglobin volume index (HVx and wHVx). Wavelet methodology had less index variability with smaller standard deviations. Both wavelet and correlation methods distinguished functional autoregulation (ABP above LLA) from dysfunctional autoregulation (ABP below the LLA). Both wavelet and correlation methods also identified ABPopt with high agreement. Thus, wavelet methodology using NIRS may offer an accurate vasoreactivity monitoring method with reduced signal noise after pediatric cardiac arrest.

5.
Phys Rev Lett ; 124(7): 070501, 2020 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-32142314

RESUMO

Twin-field (TF) quantum key distribution (QKD) promises high key rates over long distances to beat the rate-distance limit. Here, applying the sending-or-not-sending TF QKD protocol, we experimentally demonstrate a secure key distribution that breaks the absolute key-rate limit of repeaterless QKD over a 509-km-long ultralow loss optical fiber. Two independent lasers are used as sources with remote-frequency-locking technique over the 500-km fiber distance. Practical optical fibers are used as the optical path with appropriate noise filtering; and finite-key effects are considered in the key-rate analysis. The secure key rate obtained at 509 km is more than seven times higher than the relative bound of repeaterless QKD for the same detection loss. The achieved secure key rate is also higher than that of a traditional QKD protocol running with a perfect repeaterless QKD device, even for an infinite number of sent pulses. Our result shows that the protocol and technologies applied in this experiment enable TF QKD to achieve a high secure key rate over a long distribution distance, and is therefore practically useful for field implementation of intercity QKD.

6.
Sci Rep ; 10(1): 4439, 2020 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-32157148

RESUMO

The safety and efficacy of selective antegrade cerebral perfusion (SACP) in children undergoing aortic arch surgery are unclear. In this retrospective analysis, we compared moderate hypothermic circulatory arrest (MHCA; n = 61) plus SACP vs deep hypothermic circulatory arrest (DHCA; n = 53) in children undergoing aortic arch surgery during a period from January 2008 to December 2017. Demographic characteristics and the underlying anomalies were comparable between the two groups. The MHCA + SACP group had shorter cardiopulmonary bypass (CPB) time (146.9 ± 40.6 vs 189.6 ± 41.2 min for DHCA; p < 0.05) and higher nasopharyngeal temperature (26.0 ± 2.1 vs 18.9 ± 1.6 °C; p < 0.01). The MHCA + SACP group had lower rate of neurologic complications (3/61 vs 10/53 for DHCA; p < 0.05) but not complications in other organ systems. The MHCA + SACP group also had less 24-hour chest drainage (median, interquartile rage: 28.9, 12.6-150.0 vs 47.4, 15.2-145.0 ml/kg for DHCA; p < 0.05), shorter duration of postoperative mechanical ventilation (35.0, 15.4-80.3 vs 94.0, 42.0-144.0 h; p < 0.01), and shorter stay in intensive care unit (3.9, 3.0-7.0 vs 7.7, 5.0-15.0 d; p < 0.05). In regression analysis, in-hospital mortality was associated with longer CPB time. In conclusion, MHCA + SACP is associated with better short-term outcomes in children receiving aortic arch surgery under CPB.

7.
Investig Clin Urol ; 61(2): 115-126, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32158962

RESUMO

Purpose: Our aim was to assess the efficacy and safety of miniaturized percutaneous nephrolithotomy (mPCNL) versus standard PCNL (sPCNL) to provide higher-level evidence. Materials and Methods: Eligible randomized controlled trials were identified from electronic databases. The data analysis was performed by the Cochrane Collaboration's software RevMan 5.3. Results: A total of 1,219 patients from 9 articles published between 2004 and 2019 were included. Compared with those who received sPCNL, patients who received mPCNL experienced a higher stone-free rate (SFR) (odds ratio [OR], 1.43; 95% confidence interval [CI], 1.03-1.99; p=0.03), lower transfusion rates (OR, 0.33; 95% CI, 0.17-0.63; p=0.0007), and lower drops in hemoglobin (mean difference [MD], -0.72; 95% CI, -1.04 to -0.40; p<0.00001), but the operative time seemed to be significantly longer (MD, 10.98; 95% CI, 3.64-18.32; p=0.003). Of note, there was no significant difference between the two groups regarding the SFR (p=0.09) for renal calculi ≥2 cm. In addition, the meta-analysis results showed no significant differences between the groups regarding urine leakage (p=0.60), postoperative fever (p=0.71), impaired ventilation (p=0.97), or total complications (p=0.29) with no heterogeneity between trials. These results remain unaffected with regard to renal calculi ≥2 cm. Conclusions: Our findings suggested that mPCNL had a higher SFR than sPCNL and there was no significant difference between the two groups for renal stones ≥2 cm. Besides, mPCNL tended to be associated with significantly less bleeding and a lower transfusion rate, but the duration of the procedure seemed to be significantly longer.

8.
Mar Drugs ; 18(3)2020 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-32164197

RESUMO

In the work, defatted muscle proteins of monkfish (Lophius litulon) were separately hydrolyzed by pepsin, trypsin, and in vitro gastrointestinal (GI) digestion methods, and antioxidant peptides were isolated from proteins hydrolysate of monkfish muscle using ultrafiltration and chromatography processes. The antioxidant activities of isolated peptides were evaluated using radical scavenging and lipid peroxidation assays and H2O2-induced model of HepG2 cells. In which, the cell viability, reactive oxygen species (ROS) content, and antioxidant enzymes and malondialdehyde (MDA) levels were measured for evaluating the protective extent on HepG2 cells damaged by H2O2. The results indicated that the hydrolysate (MPTH) prepared using in vitro GI digestion method showed the highest degree of hydrolysis (27.24 ± 1.57%) and scavenging activity on a 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical (44.54 ± 3.12%) and hydroxyl radical (41.32 ± 2.73%) at the concentration of 5 mg protein/mL among the three hydrolysates. Subsequently, thirteen antioxidant peptides (MMP-1 to MMP-13) were isolated from MPTH. According to their DPPH radical and hydroxyl radical scavenging activity, three peptides with the highest antioxidant activity were selected and identified as EDIVCW (MMP-4), MEPVW (MMP-7), and YWDAW (MMP-12) with molecular weights of 763.82, 660.75, and 739.75 Da, respectively. EDIVCW, MEPVW, and YWDAW showed high scavenging activities on DPPH radical (EC50 0.39, 0.62, and 0.51 mg/mL, respectively), hydroxyl radical (EC50 0.61, 0.38, and 0.32 mg/mL, respectively), and superoxide anion radical (EC50 0.76, 0.94, 0.48 mg/mL, respectively). EDIVCW and YWDAW showed equivalent inhibiting ability on lipid peroxidation with glutathione in the linoleic acid model system. Moreover, EDIVCW, MEPVW, and YWDAW had no cytotoxicity to HepG2 cells at the concentration of 100.0 µM and could concentration-dependently protect HepG2 cells from H2O2-induced oxidative damage through decreasing the levels of reactive oxygen species (ROS) and MDA and activating intracellular antioxidant enzymes of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px). These present results indicated that the protein hydrolysate and isolated antioxidant peptides from monkfish muscle, especially YWDAW could serve as powerful antioxidants applied in the treatment of some liver diseases and healthcare products associated with oxidative stress.

9.
Sci Rep ; 10(1): 4213, 2020 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-32144315

RESUMO

Peripheral perfusion index (PPI) percentiles for newborns serve as an important observation tool in clinical practice, but research pertaining to reference ranges are lacking. The aim of this study was to establish PPI percentiles for healthy newborns by gestational age and sex at 24-48 hours of life. We conducted an observational study and examined PPI values at 24-48 hours of life in 3814 asymptomatic newborns born between 35 and 41 weeks gestation who did not need medical treatment from June 1, 2016 to May 31, 2017 at two maternity hospitals in Shanghai. Linear regression analysis was carried out on the associations between PPI values and variables such as gestational age, sex, and birthweight. Pre-ductal PPI values linearly increased with gestational age (ß: 0.072; 95% CI: 0.037, 0.107; P = 0.000). Post-ductal PPI values were also mainly related to gestational age (ß: 0.051; 95% CI: 0.018, 0.085; P = 0.003). Smoothed reference curves for pre- and post-ductal PPI values by gestational age and sex were derived from LMS Chart Maker. Our study is the first study to establish PPI percentiles curves for healthy newborns by gestational age and sex at 24-48 hours of life. Further research is required for the implementation of PPI curves into clinical practice.

10.
J Viral Hepat ; 2020 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-32187804

RESUMO

The performances of routine tests such as FIB-4 and APRI in detecting cirrhosis and significant fibrosis in chronic hepatitis B (CHB) have been shown to be discrepant between studies.Novel testssuch asred cell distribution width-platelet ratio (RPR), γ-glutamyl transpeptidase to platelet ratio (GPR) andeasy liver fibrosis test (eLIFT) have also been introduced recently. To evaluate the aminotransferase influence on the performance of theseroutine tests, a total of 1005 CHB patients who underwent liver biopsies and routine tests were retrospectively analyzed.The diagnostic cutoffs referring to likelihood ratio were determined for excluding or including cirrhosis diagnosis, and also for ruling in significant fibrosis diagnosis.Theperformances ofRPR, FIB-4, eLIFT and APRI in detecting cirrhosis seemedimproved athigher ALTlevels, whistGPR was conversely impaired. The likelihood ratios of APRI 2 indiagnosing cirrhosisatALT< 2 upper limit of normal (ULN), APRI 1.5 in determiningsignificant fibrosisatALT ≤5ULN andFIB-4 3.2 in diagnosing ≥Metavir F3 in the total cohort was∝, 14.6 and 20.6, respectively. The optimal cutoffs for cirrhosis diagnosis were increased with higher ALTs by testswhich included aminotransferaselevel, but not for RPR. The proportions of patients classifiedas having cirrhosis or nocirrhosis stratified by ALT level cutoffs were superior.Stepwise applying RPR, GPR and eLIFT would determine 60% of patients as having cirrhosis or nocirrhosis with an accuracy of 93.0%. In conclusion, the performance of aminotransferase comprisingtestsin detectingcirrhosis in CHB were influenced by ALT levels.Thus ALT stratified cutoffs may be a preferred alternative. In resource-limited settings, stepwise applying routine tests could be recommended as a preferred measurement for cirrhosis detection.

11.
J Infect Dis ; 221(Supplement_2): S164-S173, 2020 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-32176783

RESUMO

BACKGROUND: Information on possible donor-derived transmission events in China is limited. We evaluated the impacts of liver transplantation from infected deceased-donors, analyzed possible donor-derived bacterial or fungal infection events in recipients, and evaluated the etiologic agents' characteristics and cases outcomes. METHODS: A single-center observational study was performed from January 2015 to March 2017 to retrospectively collect data from deceased-donors diagnosed with infection. Clinical data were recorded for each culture-positive donor and the matched liver recipient. The microorganisms were isolated and identified, and antibiotic sensitivity testing was performed. The pathogens distribution and incidence of possible donor-derived infection (P-DDI) events were analyzed and evaluated. RESULTS: Information from 211 donors was collected. Of these, 82 donors were infected and classified as the donation after brain death category. Overall, 149 and 138 pathogens were isolated from 82 infected donors and 82 matched liver recipients, respectively. Gram-positive bacteria, Gram-negative bacteria, and fungi accounted for 42.3% (63 of 149), 46.3% (69 of 149), and 11.4% (17 of 149) of pathogens in infected donors. The incidence of multidrug-resistant bacteria was high and Acinetobacter baumannii was the most concerning species. Infections occurred within the first 2 weeks after liver transplantation with an organ from an infected donor. Compared with the noninfection recipient group, the infection recipient group experienced a longer mechanical ventilation time (P = .004) and intensive care unit stay (P = .003), a higher incidence of renal dysfunction (P = .026) and renal replacement therapy (P = .001), and higher hospital mortality (P = .015). Possible donor-derived infection was observed in 14.6% of cases. Recipients with acute-on-chronic liver failure were more prone to have P-DDI than recipients with other diseases (P = .007; odds ratio = 0.114; 95% confidence interval, .025-.529). CONCLUSIONS: When a liver recipient receives a graft from an infected deceased-donor, the postoperative incidence of infection is high and the infection interval is short. In addition, when a possible donor-derived, drug-resistant bacterial infection occurs, recipients may have serious complications and poor outcomes.

12.
Artigo em Inglês | MEDLINE | ID: mdl-32196306

RESUMO

With the trend of device miniaturization and higher integration, polymer composites with high thermal conductivity are highly desirable for efficient removal of accumulated heat to maintain high performance of electronics. In this work, epoxy composites embedded with three-dimensional hexagonal boron nitride (BN) scaffold were fabricated. The BN-poly(vinylidene difluoride) (PVDF) scaffold was prepared by the salt template method using PVDF as the adhesive, while the corresponding epoxy composite was manufactured with vacuum-assisted impregnation. The epoxy/BN-PVDF composite exhibits high thermal conductivity with low loading of BN. The thermal conductivity of epoxy/BN-PVDF composite achieved 1.227 W/(m K) with 21 wt % BN, contributed by the constructed BN pathway held together by PVDF adhesive. In addition, PVDF could be further converted into carbon by thermal treatment, further enhancing the thermal conductivity of epoxy/BN-C composites through alleviating the phonon scattering at the interfaces, eventually obtaining thermal conductivity of 1.466 W/(m K). This type of epoxy-based composite with high thermal conductivity is promising to be used as thermal management materials in advanced electronic devices.

13.
Zhongguo Dang Dai Er Ke Za Zhi ; 22(3): 199-204, 2020 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-32204753

RESUMO

The epidemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection continues so far. The cases of SARS-CoV-2 infection have been reported in pregnant women and neonates as special groups. Perinatal and neonatal management plan for prevention and control of SARS-CoV-2 infection (2nd Edition) has been worked out by the Editorial Committee of Chinese Journal of Contemporary Pediatrics. This paper presents an interpretation on the 2nd Edition of the management plan, so as to facilitate readers to better understand it.


Assuntos
Infecções por Coronavirus/prevenção & controle , Pneumonia Viral/prevenção & controle , Betacoronavirus , Feminino , Humanos , Recém-Nascido , Assistência Perinatal , Gravidez
14.
Nat Commun ; 11(1): 1531, 2020 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-32210233

RESUMO

Vesicle associated membrane protein 2 (VAMP2/synaptobrevin2), a core SNARE protein residing on synaptic vesicles (SVs), forms helix bundles with syntaxin-1 and SNAP25 for the SNARE assembly. Prior to the SNARE assembly, the structure of VAMP2 is unclear. Here, by using in-cell NMR spectroscopy, we describe the dynamic membrane association of VAMP2 SNARE motif in mammalian cells, and the structural change of VAMP2 upon the change of intracellular lipid environment. We analyze the lipid compositions of the SV membrane by mass-spectrometry-based lipidomic profiling, and further reveal that VAMP2 forms distinctive conformations in different membrane regions. In contrast to the non-raft region, the membrane region of cholesterol-rich lipid raft markedly weakens the membrane association of VAMP2 SNARE motif, which releases the SNARE motif and facilitates the SNARE assembly. Our work reveals the regulation of different membrane regions on VAMP2 structure and sheds light on the spatial regulation of SNARE assembly.

15.
Curr Med Sci ; 2020 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-32219626

RESUMO

Based on the New Diagnosis and Treatment Scheme for Novel Coronavirus Infected Pneumonia (Trial Edition 5), combined with our current clinical treatment experience, we recently proposed a revision of the first edition of "Guidance for maternal and fetal management during pneumonia epidemics of novel coronavirus infection in the Wuhan Tongji Hospital". This article focused on the issues of greatest concern of pregnant women including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection diagnostic criteria, inspection precautions, drug treatment options, indications and methods of termination of pregnancy, postpartum fever, breastfeeding considerations, mode of mother-to-child transmission, neonatal isolation and advice on neonatal nursing, to provide valuable experience for better management of SARS-CoV-2 infection in pregnant women and newborns.

16.
Hum Reprod ; 35(3): 494-503, 2020 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-32142584

RESUMO

STUDY QUESTION: Does lysine 2-hydroxyisobutyrylation, a newly identified protein posttranslational modification (PTM), occur in human sperm and affect human sperm function? SUMMARY ANSWER: Lysine 2-hydroxyisobutyrylation mainly occurs in human sperm tail proteins, and excessive lysine 2-hydroxyisobutyrylation affects human sperm motility. WHAT IS KNOWN ALREADY: PTM is regarded as an important pathway in regulating sperm function since mature sperm are almost transcriptionally silent. However, only phosphorylation was extensively studied in mature sperm to date. Lysine 2-hydroxyisobutyrylation, a newly characterised PTM, is broadly conserved in both eukaryotic and prokaryotic cells. Although histone lysine 2-hydroxyisobutyrylation has been shown to be associated with active gene expression in spermatogenic cells, the presence, regulatory elements and function of lysine 2-hydroxyisobutyrylation have not been characterised in mature sperm. STUDY DESIGN, SIZE, DURATION: Sperm samples were obtained from normozoospermic men and asthenozoospermic men who visited the reproductive medical centre at Jiangxi Provincial Maternal and Child Health Hospital, Nanchang, Jiangxi, China, between May 2017 and November 2018. In total, 58 normozoospermic men and 65 asthenozoospermic men were recruited to participate in this study. PARTICIPANTS/MATERIALS, SETTING, METHODS: Lysine 2-hydroxyisobutyrylation was examined using immunoblotting and immunofluorescence assays using a previously qualified pan anti-lysine 2-hydroxyisobutyrylation antibody. The immunofluorescence assay was imaged using super-resolution structured illumination microscopy. Sperm viability was examined by using the eosin staining method, and sperm motility parameters were assessed by computer-assisted sperm analysis. Sperm penetration ability was determined by evaluating the ability of the sperm to penetrate a 1% (w/v) methylcellulose solution. The level of intracellular adenosine triphosphate (ATP) was detected using a rapid bioluminescent ATP assay kit. MAIN RESULTS AND THE ROLE OF CHANCE: Lysine 2-hydroxyisobutyrylation was present in several proteins (20-100 kDa) mainly located in the tail of human sperm. Sperm lysine 2-hydroxyisobutyrylation was derived from 2-hydroxyisobutyrate (2-Hib) and was regulated by acyltransferase P300 and nicotinamide adenine dinucleotide-dependent lysine deacylase sirtuins. Elevation of sperm lysine 2-hydroxyisobutyrylation by 2-Hib decreased total motility, progressive motility, penetration ability and ATP level of human sperm. Interestingly, the level of sperm lysine 2-hydroxyisobutyrylation was higher in asthenozoospermic men than that in normozoospermic men and was negatively correlated with the progressive motility of human sperm. Furthermore, high levels of lysine 2-hydroxyisobutyrylation in asthenozoospermic men accompanied decreased ATP levels. LIMITATIONS, REASONS FOR CAUTION: Although the present study indicated the involvement of sperm lysine 2-hydroxyisobutyrylation in regulating human sperm motility, the underlying mechanism needs to be further illustrated. WIDER IMPLICATIONS OF THE FINDINGS: The findings of this study provide insight into the novel role of lysine 2-hydroxyisobutyrylation in human sperm and suggest that abnormality of sperm lysine 2-hydroxyisobutyrylation may be one of the causes for asthenozoospermia. STUDY FUNDING/COMPETING INTEREST(S): National Natural Science Foundation of China (81771644 to T.L. and 81871207 to H.C.); Natural Science Foundation of Jiangxi province (20171ACB21006). The authors have no conflicts of interest to declare.

17.
Nano Lett ; 2020 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-32202803

RESUMO

We report on the thermal conductivities of two-dimensional metal halide perovskite films measured by time domain thermoreflectance. Depending on the molecular substructure of ammonium cations and owing to the weaker interactions in the layered structures, the thermal conductivities of our two-dimensional hybrid perovskites range from 0.10 to 0.19 W m-1 K-1, which is drastically lower than that of their three-dimensional counterparts. We use molecular dynamics simulations to show that the organic component induces a reduction of the stiffness and sound velocities along with giving rise to vibrational modes in the 5-15 THz range that are absent in the three-dimensional counterparts. By systematically studying eight different two-dimensional hybrid perovskites, we show that the thermal conductivities of our hybrid films do not depend on the thicknesses of the organic layers and instead are highly dependent on the relative orientation of the organic chains sandwiched between the inorganic constituents.

18.
Artigo em Inglês | MEDLINE | ID: mdl-32133747

RESUMO

Nanospaces are ubiquitous in the realm of biological systems and are of significant interest among supramolecular chemists. Understanding chemical behavior within nanospaces offers new perspectives on biological phenomena in Nature and opens the way to highly unusual and selective forms of catalysis. Supramolecular chemistry exploits weak, yet effective, intermolecular interactions such as hydrogen bonding, metal-ligand coordination, and the hydrophobic effect to assemble nano-sized molecular architectures, providing reactions with remarkable rate acceleration, substrate specificity, and product selectivity. In this minireview, we will focus on the strategies that supramolecular chemists use to emulate the efficiency of biological processes, and elucidate how chemical reactivity is efficiently controlled within well-defined nanospaces. Approaches such as orientation and proximity of substrate, transition state stabilization, and active site incorporation will be discussed.

19.
Breastfeed Med ; 2020 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-32129666

RESUMO

Background: To evaluate the efficacy of a multidisciplinary quality improvement intervention to promote mother's own milk feeding and reduce necrotizing enterocolitis (NEC) in very low-birth-weight infants. Materials and Methods: We conducted a pre (January 2014 to March 2015)-post (April 2015 to June 2016), nonrandomized, interventional cohort study of infants born at <1,500 g birth weight and admitted to the Fudan University Children's Hospital level III neonatal intensive care unit in Shanghai. The intervention included establishing a breast milk promotion team and breast milk pumping room, educating staff and parents, and distributing teaching materials. The primary outcome was breast milk feeding rate. Secondary outcomes included incidences of NEC, NEC needing surgery, mortality, and time to full enteral feeds. Results: A total of 488 infants (210 baseline, 278 intervention) <1,500 g were enrolled. The intervention group had significantly increased feeding rates for any mother's milk (34.76% vs. 80.58%; p < 0.01) and high-volume mother's milk (≥50% of feeds; 22.86% vs. 61.15%; p < 0.01), and decreased incidence of NEC needing surgery (7.62% vs. 3.24%; adjusted odds ratio [OR] 0.32, 95% confidence interval [CI] 0.14-0.76). There were no significant differences in rates of mortality (0.5% vs. 1.49%; adjusted OR 2.10, 95% CI 0.22-19.6), NEC (10.00% vs. 7.55%; adjusted OR 0.59, 95% CI 0.31-1.14), and time to full enteral feeds (20.18 ± 1.67 days vs. 24.15 ± 1.65 days; adjusted OR = 1.09, 95% CI 0.99-1.21). Conclusions: Our quality improvement initiative increased the consumption of mother's own milk and reduced the severity of NEC in very low-birth-weight infants.

20.
J Colloid Interface Sci ; 570: 72-79, 2020 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-32145653

RESUMO

It is desirable to unravel the correlation between the geometric and electronic structures and the activity and further prepare high-performance electrocatalysts. Here in this paper, trimetallic Ru@Au-Pt core-shell nanoparticles were prepared by sequential ethanol reduction method, and further subject to characterization of X-ray diffraction, high angle annular dark field transmission electron microscopy, X-ray photoelectron spectroscopy and electrochemical CO stripping. Further analysis based on Williamson-Hall method revealed that the Au/Pt atomic ratio and shell thickness result in apparent variation of micro-strain and CO binding energy of Ru@AuPt nanoparticles, where the CO oxidation peak potential showed an inverted volcano-shape dependence on the microstrain of the metal nanoparticles while the catalytic activity towards electrooxidation of formic acid is linearly dependent on the micro-strain. The best Ru@Au-Pt catalyst delivers a specific activity of 4.14 mA cm-2, which is 52 times that of Pt/C, respectively. This study indicated that the microstrain and stacking fault of metal nanoparticles might be a good descriptor for the catalytic activity and may shed light the rational design, synthesis and surface engineering towards the high-performance electrocatalyst.

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