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1.
Food Chem ; 305: 125389, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31520918

RESUMO

A sensitive analytical method for the monitoring 2-methylimidazole and 4-methylimidazole (2-MI and 4-MI) is desirable due to their carcinogenic property. Here, we propose a highly sensitive method basing on the combination of solid-phase extraction and dispersive liquid-liquid microextraction techniques followed by high-performance liquid chromatography to simultaneously determine 2-MI and 4-MI in beverages. Dansyl chloride was used as a derivatizing reagent. Microextraction parameters were optimized by Plackett-Burman design and response surface methodology. Results show that derivatization led to significant improvements in chromatographic behavior for 2-MI and 4-MI due to increased hydrophobicity. The method shows good linearity (R2 ≥ 0.9985), satisfactory precision (%RSD ≤ 8.3%) and low limit of quantification (20 ng/mL), and was successfully applied to determine 2-MI and 4-MI in carbonated drinks, beers and energy drinks, achieving satisfactory recoveries (85-101%). This method provides a potential for routine analysis of 2-MI and 4-MI at the nanogram per milliliter level in beverages.

2.
Artigo em Inglês | MEDLINE | ID: mdl-31672283

RESUMO

Allergic diseases are ubiquitous diseases with detrimental effects on the quality of life of people worldwide. Common allergic diseases include asthma, allergic rhinitis (AR) and allergic dermatitis (AD). Recently, studies have shown that interleukin (IL)-37, a novel cytokine in the IL-1 family, exhibits broad protective properties in various diseases, such as autoimmune diseases and cancer. IL-37 displays its anti-inflammatory effect on diseases by curbing innate and acquired immunity as well as inflammatory reactions. IL-37 functions by forming a complex with IL-18Rα and IL-1R8 extracellularly and can be translocated to the nucleus upon forming a complex with mothers against decapentaplegic homolog 3 (Smad3) intracellularly, thereby affecting gene transcription and signaling pathway activation. In addition, increasing evidence confirms that IL-37 expression is aberrant in asthma, AR and AD, which indicates that IL-37 may also play essential roles in allergic diseases. Furthermore, accumulating data obtained from recombinant IL-37 (rIL-37)-treated mice and from IL-37 transgenic (IL-37tg) mice suggest a protective role for IL-37. This review will detail the role of IL-37 in the occurrence and development of allergic diseases and discuss the potential of IL-37 as a therapeutic target in allergic diseases.

3.
Int J Food Microbiol ; 311: 108333, 2019 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-31669927

RESUMO

Large amounts of tomato fruits and derived products are produced in China and may be contaminated by Alternaria mycotoxins, which may have the potential risks for human health. There is thus an increasing interest in reducing the mycotoxins. In the present study, 26 Alternaria strains isolated from tomato black rots were identified according to morphological and molecular grounds, and their mycotoxigenic abilities for alternariol (AOH), alternariol monomethyl-ether (AME) and tenuazonic acid (TeA) were also investigated. The results showed that A. alternate was the predominant species with incidence values of 65.4% (17/26), followed by A. brassicae (7/26) and A. tenuissima (2/26). A. alternate isolates showed the highest capacity for AOH, AME and TeA production among the studied isolates either in vitro or in vivo, suggested that A. alternata may be the most important mycotoxin-producing species in tomato fruits. Thus, UV-C irradiation was used to reduce the mycotoxin produced by A. alternata in our study. The results showed that low dose of UV-C irradiation (0.25 kJ/m2) could effectively inhibit mycotoxins production and penetration in tomatoes. Upon treatment with UV-C, there was 79.6, 76.4 and 51.4% of reduction in AOH, AME and TeA penetration when compared to untreated fruits. This may be associated with the enhanced phenolics by UV-C irradiation. In fact, the induced phenolics were including p-coumaric, ferulic and pyrocatechuic acids, of which p-coumaric acid (1.0 mM) displayed the highest reduction of TeA with 60.2%, whereas ferulic acid (1.0 mM) showed strong inhibitory effects on the AOH and AME production by 59.4 and 79.1%, respectively. Therefore, the application of UV-C irradiation seems to be a promising method for reducing the potential risk of Alternaria mycotoxins in fruits and also for enhancing phenolics of processing products.

4.
Opt Express ; 27(21): 30931-30940, 2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31684334

RESUMO

Dielectric metasurfaces made from crystalline silicon, titanium dioxide, gallium nitride and silicon nitride have developed rapidly for applications in the visible wavelength regime. High performance metasurfaces typically require the realisation of subwavelength, high aspect ratio nanostructures, the fabrication of which can be challenging. Here, we propose and demonstrate the operation of high performance metasurfaces in ultra-thin (100 nm) crystalline silicon at the wavelength of 532 nm. Using optical beam analysis, we discuss fabrication complexity and show that our approach is more fabrication-tolerant than the nanofin approach, which has so far produced the highest performance metasurfaces, but may be difficult to manufacture, especially when using nanoimprint lithography.

5.
Opt Express ; 27(20): 29415-29424, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31684676

RESUMO

This paper proposes a distributed acoustic sensor (DAS) scheme, which is immune to the fading problem and can overcome the trade-off existing in traditional ϕ-OTDR between spatial resolution and sensing distance. An optical chirped pulse and non-matched filter method are used, and hence the spatial resolution is mainly determined by the bandwidth of the chirped pulse and non-matched ratio, rather than pulse duration. The Rayleigh interference pattern method is adopted here to quantitatively demodulate strain distribution along the whole sensing fiber, so there is no fading problem, which is a serious problem in the Rayleigh phase method. In proof-of-concept experiments, a DAS with 2-m spatial resolution and 10-km distance range is demonstrated. The response bandwidth of strain is 5 kHz, only limited by the fiber length. A nε-scale strain signal is detected at the far end of fiber with a high SNR of 35 dB.

6.
Artigo em Inglês | MEDLINE | ID: mdl-31689074

RESUMO

By adjusting the stretch state of triethylenetetramine (TETA) chain in amine-functionalized porous organic polymer (POP), two adsorbents were designed to study the rational microenvironment for heavy metal ions removal. The quantum calculation eluci-dated the hooped amino-chains in FC-POP-CH2TETA-H exhibited stronger interactions with Pb(II) than the extended one in FC-POP-CH2TETA-E, not only through the metal-ligand chelating, but also the metal-coordination. The high binding energy of -2624 kJ/mol as well as the constructed microenvironment by the hooped amino-chains ensured an extremely high Pb(II) capacity of 1134 mg g-1 on FC-POP-CH2TETA-H. Meanwhile, no more than 5 min to approach adsorption equilibrium revealed its ultra-fast adsorption rate. It also showed excellent broad removal capability for multiple metal ions and non-sensitive to the pH value. Therefore, by controlling the microenvironmental structures with suitable porosity, functional group stretching states, and coordi-nation modes, the removal efficiency of heavy metal ions would be significantly enhanced, which further provided a promising strategy for designing rational microenvironment to improve the task-specific separation properties.

7.
BMC Musculoskelet Disord ; 20(1): 511, 2019 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-31679513

RESUMO

BACKGROUND: Proximal humeral fractures (PHFs) are the third most commonly occurring fractures in elderly patients. Most of these fractures can be treated with conservative methods, but the optimal surgical treatment strategy for unstable fractures in elderly patients remains controversial. This study aimed to compare the radiological and clinical outcomes between locking compression plate (LCP) fixation and LCP fixation with fibular allograft implantation for the treatment of comminuted PHFs. METHODS: We retrospectively reviewed 60 patients (mean age, 72.75 years) with closed 3- or 4-part fractures, and a minimum of 2 years of follow-up. Fracture reduction was quantitatively determined by humeral head height (HHH) and neck-shaft angle (NSA). The clinical outcome was evaluated by Constant-Murley score (CMS) and American Shoulder and Elbow Surgeons (ASES) score. RESULT: The average radiological changes were higher in the LCP group than in the locking plate with fibular allograft group (HHH of 4.16 mm vs 1.18 mm [p < 0.001] and NSA of 9.94° versus 3.12° [p < 0.001]) . The final average outcome scores were lower in the LCP group than in the FA group (CMS of 73.00 vs 78.96 [p = 0.024] and ASES score of 72.80 vs 78.64 [p = 0.022]). The FA group showed better forward elevation (p = 0.010) and abduction (p = 0.002); however, no significant differences were observed for shoulder external rotation or internal rotation. The number of complications was higher in the LCP group (28.57%) than in the FA group (1.2%) (p < 0.001). CONCLUSION: For comminuted PHFs in elderly patients, LCP fixation combined with a fibular allograft is reasonable option to ensure satisfactory radiological and clinical outcomes. TRIAL REGISTRATION: ZDYJLY(2018)New-9 . Name of registry: IEC for clinical Research of Zhongda Hospital, Affiliated to Southeast University. Date of registration: 2018-05-17.

8.
Chin J Nat Med ; 17(10): 746-755, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31703755

RESUMO

To investigate the effect of Yiqi Wenyang (YQWY) decoction on reversing cardiac hypertrophy induced by the transverse aortic constriction (TAC). Wistar rats aged 7-8 weeks were subjected to TAC surgery and then randomly divided into 4 groups (n = 5/group): Sham group, TAC group, low-dose group and high dose group. After 16-week intragastric administration of YQWY decoction, the effect of YQWY decoction on alleviating cardiomyocyte hypertrophy was examined by transthoracic echocardiography (TTE), hematoxylin/eosin (HE), wheat germ agglutinin (WGA) staining, enzyme linked immunosorbent assay (ELISA), Western blot (WB), immunohistochemistry (IHC) and immunofluorescence (IF), respectively. The results showed significant differences in left ventricle volume-diastole/systole (LV Vol d/s), N-terminal pro-B-type brain natriuretic peptide (NT-proBNP) (P < 0.01), Ejection Fraction (EF), LV mass and fractional shortening (FS) (P < 0.05) between YQWY-treated group and TAC group. HE and WGA staining showed that treatment with YQWY decoction dramatically prevented TAC-induced cardiomycyte hypertrophy. Moreover, the results of WB, IHC and IF indicated that administration of YQWY could suppress the expressions of cardiac hypertrophic markers, which included the atrial natriuretic peptide (ANP), BNP and myosin heavy chain 7 (MYH7) (P < 0.05) and inhibit phosphorylation of GATA binding protein 4 (P-GATA4) (P < 0.05), phosphorylation of extracellular signal-regulated kinase (P-ERK) (P < 0.05), phosphorylation of P38 mitogen activated protein kinase (P-P38) (P < 0.05) and phosphorylation of c-Jun N-terminal kinase (P-JNK) (P < 0.05). Thus, we concluded that YQWY decoction suppressed cardiomyocyte hypertrophy and reversed the impaired heart function, and the curative effects of YQWY decoction were associated with the decreased phosphorylation of GATA4 and mitogen activated protein kinases (MAPKs), as well as the reduced expression of the downstream targets of GATA4, including ANP, BNP, and MYH7.

9.
Food Funct ; 2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31696200

RESUMO

OBJECTIVE: To examine the anti-fatigue function of anwulignan from Schisandra and its underlying mechanism. METHODS: After an excessive fatigue mouse model was created, anwulignan was administered to the mice, and its effect on exercise tolerance was studied by the weight-bearing swimming test, rotarod test, grip strength test, and tail suspension test. The biochemical indicators closely related to fatigue, including blood urea nitrogen (BUN), lactic acid (LD), lactate dehydrogenase (LDH), and creatine kinase (CK) in the serum; liver glycogen (LG) in the liver tissue; muscle glycogen (MG); inorganic phosphate (Pi) and Annexin V in the gastrocnemius; superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities; malondialdehyde (MDA), catalase (CAT), and thiobarbituric acid reactive substances (TBARS); and the 8-hydroxy-2-deoxyguanosine (8-OHdG) and reactive oxygen species (ROS) content in both serum and the gastrocnemius were detected. Morphological changes were also observed. The anti-fatigue-related proteins of the NRF2/ARE, Bcl2, and PGC-1α pathways in the gastrocnemius of the mice were detected by western blot. RESULTS: Anwulignan significantly increased the exercise tolerance by decreasing BUN, LD, LDH, CK, Pi, MDA, TBARS, 8-OHdG, ROS, and Annexin V levels and increasing LG, MG, SOD, CAT, and GSH-Px levels, significantly upregulated the expression of NRF2 and Bcl2 proteins, which are anti-oxidation and anti-apoptosis regulators, and also activated the p38MAPK-PGC-1α pathway. CONCLUSION: Anwulignan can increase exercise tolerance and relieve fatigue in an excessive fatigue mouse model. The underlying mechanism may be through its regulatory effect on the NRF2 and PGC-1α signaling pathway. This study will provide scientific data for anwulignan to be developed as a novel and efficient component in anti-oxidant or anti-fatigue health food.

10.
Am J Hum Genet ; 105(5): 974-986, 2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31668702

RESUMO

The advent of inexpensive, clinical exome sequencing (ES) has led to the accumulation of genetic data from thousands of samples from individuals affected with a wide range of diseases, but for whom the underlying genetic and molecular etiology of their clinical phenotype remains unknown. In many cases, detailed phenotypes are unavailable or poorly recorded and there is little family history to guide study. To accelerate discovery, we integrated ES data from 18,696 individuals referred for suspected Mendelian disease, together with relatives, in an Apache Hadoop data lake (Hadoop Architecture Lake of Exomes [HARLEE]) and implemented a genocentric analysis that rapidly identified 154 genes harboring variants suspected to cause Mendelian disorders. The approach did not rely on case-specific phenotypic classifications but was driven by optimization of gene- and variant-level filter parameters utilizing historical Mendelian disease-gene association discovery data. Variants in 19 of the 154 candidate genes were subsequently reported as causative of a Mendelian trait and additional data support the association of all other candidate genes with disease endpoints.

11.
Nature ; 574(7779): 486, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31641264
12.
Chin J Integr Med ; 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31630360

RESUMO

OBJECTIVE: To explore the ultrastructure characteristics of patients with dampness-heat of Pi (Spleen)-Wei (Stomach) syndrome (DHPW) and Pi-qi deficiency syndrome (PQD), both of which are Helicobacter pylori (Hp)-correlated gastric diseases (HPCG), and implicate a helpful hint for the clinical microcosmic syndrome differentiation. METHODS: Fourteen gastric mucosa samples from 6 chronic gastritis (CG) and 6 active peptic ulcer (including 8 DHPW, 4 PQD) as well as 2 healthy volunteers were collected and tested for Hp infection. The ultrastructure of gastric mucosa was observed under the transmission electron microscope (TEM). RESULTS: Among 14 gastric mucosa samples, 8 of them were Hp positive (6 DHPW and 2 PQD), which were all accordance with the results screened by supermicro-pathological method. Under TEM, the normal gastric mucosa, with tidy microvilli and abundant in mucus granules, mitochondria and rough endoplasmic reticulum distributed evenly, and with smooth nucleus membrane. But in those specimens of DHPW with Hp infection, microvilli were presented with burr shape. Especially, those samples from dampness-heat syndrome with predominant heat type (DHSH) patients were more obvious, with microvilli damaged, mitochondria concentrated and distributed in disorder, secretory tubule extended. In dampness-heat syndrome with predominant dampness type (DHSD) patients, mucus granules aggregated obviously, mitochondria swelled and blurred, and rough endoplasmic reticulum crowded. For 2 samples of DHPW without Hp infection, their microvilli were intact, with mitochondria increased and gathered but well-distributed, and secretory tubule extended mildly. In 2 PQD patients with Hp positive, the specimens of microvilli were sparse, and their mucus granules and mitochondria were decreased, with fractured crests and vacuole, secretory tubules extension to nucleus membrane, and rough endoplasmic reticulum extension in a pool-like way, and nucleus condensed. The 2 samples from PQD patients without Hp infection were characterized with intact microvilli, decreased mitochondria, fractured crest and extended rough endoplasmic reticulum in a pool-like way. CONCLUSION: It's obviously different in ultrastructure of DHPW and PQD patients under TEM, which may give a helpful hint for the microcosmic syndrome differentiation of HPCG.

13.
J Immunol ; 2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31653683

RESUMO

Although IL-15 has been implicated in the pathogenic hyperimmune activation that drives progressive HIV and SIV infection, as well as in the generation of HIV/SIV target cells, it also supports NK and T cell homeostasis and effector activity, potentially benefiting the host. To understand the role of IL-15 in SIV infection and pathogenesis, we treated two cohorts of SIVmac239-infected rhesus macaques (RM; Macaca mulatta), one with chronic infection, the other with primary infection, with a rhesusized, IL-15-neutralizing mAb (versus an IgG isotype control) for up to 10 wk (n = 7-9 RM per group). In both cohorts, anti-IL-15 was highly efficient at blocking IL-15 signaling in vivo, causing 1) profound depletion of NK cells in blood and tissues throughout the treatment period; 2) substantial, albeit transient, depletion of CD8+ effector memory T cells (TEM) (but not the naive and central memory subsets); and 3) CD4+ and CD8+ TEM hyperproliferation. In primary infection, reduced frequencies of SIV-specific effector T cells in an extralymphoid tissue site were also observed. Despite these effects, the kinetics and extent of SIV replication, CD4+ T cell depletion, and the onset of AIDS were comparable between anti-IL-15- and control-treated groups in both cohorts. However, RM treated with anti-IL-15 during primary infection manifested accelerated reactivation of RM rhadinovirus. Thus, IL-15 support of NK cell and TEM homeostasis does not play a demonstrable, nonredundant role in SIV replication or CD4+ T cell deletion dynamics but may contribute to immune control of oncogenic γ-herpesviruses.

14.
J Sep Sci ; 2019 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-31625256

RESUMO

Schisandra chinensis lignans are the main active components of the traditional Chinese medicine Schisandra chinensis in East Asia. At present, there are more and more medicines and health foods in which the total S. chinensis lignans extracts are considered as the main active components, but little research has been done on the active components of S. chinensis lignans in the blood and main target organs. In this study, the components of S. chinensis lignans in the blood, liver and brain tissues of rats at different time points after the intragastrical administration of S. chinensis lignans were determined by a metabolomic method based on high-performance liquid chromatography with quadrupole time-of-flight tandem mass spectrometry spectrometry. Twelve Schisandra chinensis lignans and 15 metabolites in the blood, liver, and brain of rats were identified. The results showed that the main metabolic ways of S. chinensis lignans in rats were hydroxylation, demethylation, and demethylation-hydroxylation, and some of them might undergo demethylation, dehydrogenation, epoxidation, and elimination reaction. The time-dose characteristics of S. chinensis lignans and their metabolites in the blood and target organs were analyzed, which may be helpful to elucidate the active substances that really exert the pharmacodynamic effects of S. chinensis lignans in organisms.

15.
Clin Neuroradiol ; 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31616958

RESUMO

OBJECTIVE: To evaluate the efficacy and safety of endovascular treatment (ET) of acute ischemic stroke (AIS) caused by intracranial atherosclerotic large vessel occlusion (ICAS-LVO). METHODS: A systemic review and meta-analysis were conducted on studies published between July 2005 and October 2018 on the outcomes of ET in patients with AIS due to ICAS-LVO. The outcomes of the ICAS-LVO and embolic LVO groups were also compared. RESULTS: A total of 17 studies including 1315 subjects with ICAS-LVO were included. In the single-arm meta-analysis, the pooled estimates of successful recanalization rate, favorable outcomes, symptomatic intracranial hemorrhage and mortality were 88% (95% CI (95% confidence interval), 84-92%), 52% (95% CI, 47-56%), 5% (95% CI, 3-7%) and 15% (95% CI, 12-19%) respectively. The preferred primary treatment was stent-retriever thrombectomy (84.1%) and the preferred rescue treatment was stent implantation with or without percutaneous transluminal angioplasty (PTA, 32.7%). In the double-arm meta-analysis, the incidence of symptomatic intracranial hemorrhage was lower in the ICAS-LVO compared to the embolic-LVO group (OR (odds ratio) = 0.60, 95% CI, 0.46-0.77, p < 0.01), whereas the implementation of rescue treatment (OR = 5.94, 95% CI, 3.15-11.19, p < 0.01) and stenting rate (OR = 10.06, 95%CI, 4.43-22.85, p < 0.01) were higher in the ICAS-LVO group. Other parameters were similar in both groups. CONCLUSION: The use of ET is a safe and effective therapeutic option for AIS due to ICAS-LVO. Stent-retriever thrombectomy and stent-implement are the preferred primary and rescue therapies respectively for ICAS-LVO. Less symptomatic intracranial hemorrhage and higher stenting were observed in the ICAS-LVO compared to the embolic-LVO group.

16.
Nat Genet ; 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31570892

RESUMO

The cardiac transcription factor (TF) gene NKX2-5 has been associated with electrocardiographic (EKG) traits through genome-wide association studies (GWASs), but the extent to which differential binding of NKX2-5 at common regulatory variants contributes to these traits has not yet been studied. We analyzed transcriptomic and epigenomic data from induced pluripotent stem cell-derived cardiomyocytes from seven related individuals, and identified ~2,000 single-nucleotide variants associated with allele-specific effects (ASE-SNVs) on NKX2-5 binding. NKX2-5 ASE-SNVs were enriched for altered TF motifs, for heart-specific expression quantitative trait loci and for EKG GWAS signals. Using fine-mapping combined with epigenomic data from induced pluripotent stem cell-derived cardiomyocytes, we prioritized candidate causal variants for EKG traits, many of which were NKX2-5 ASE-SNVs. Experimentally characterizing two NKX2-5 ASE-SNVs (rs3807989 and rs590041) showed that they modulate the expression of target genes via differential protein binding in cardiac cells, indicating that they are functional variants underlying EKG GWAS signals. Our results show that differential NKX2-5 binding at numerous regulatory variants across the genome contributes to EKG phenotypes.

17.
Org Biomol Chem ; 17(41): 9217-9225, 2019 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-31595928

RESUMO

An asymmetric catalytic multicomponent reaction of malononitrile, benzaldehyde, and α-arylidene pyrazolinones to produce spiropyrazolones has been reported. The [1 + 2 + 3] multicomponent reaction was catalyzed by chiral cinchona alkaloids to provide spiropyrazolones in high yields, with excellent enantioselectivities and good diastereoselectivities. We also performed control experiments and proposed a plausible catalytic cycle based on the observed experimental results to explain the reaction process and stereoselectivity of the asymmetric multicomponent reaction.

18.
J Ultrasound Med ; 2019 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-31626344

RESUMO

OBJECTIVES: The aim of this study was to determine whether cervical elastographic parameters in addition to cervical length (CL) during the 3 trimesters of pregnancy would be predictive of spontaneous preterm birth (sPTB) among low-risk women. METHODS: This work was a prospective nested case-control study evaluating cervical elastographic parameters and CL in low-risk women during the 3 trimesters of pregnancy. A binary logistic regression analysis was used to calculate significant covariates for prediction of sPTB. The area under the curve of the prediction model was calculated by using a receiver operating characteristic curve. RESULTS: There were 286 women (26 cases and 260 controls) included in the analysis. The parameters of cervical elasticity became softened and heterogeneous during the 3 trimesters of pregnancy in both women with and without sPTB. The differences in the mean strain value at the internal os of the cervix (IOS), ratio (strain ratio of the internal os to the external os) during the second trimester and the IOS during the third trimester between the groups had statistical significance (P < .01; P = .01; P < .01, respectively). The CL had no association with sPTB during the 3 trimesters. The IOS during the second trimester was a better predictor of sPTB, with an area under the curve of 0.730, and sensitivity was 72.73%. CONCLUSIONS: We observed multiple elastographic parameters and demonstrated the physiologic changes in the cervix during the 3 trimesters of pregnancy. Furthermore, we found that the IOS during the second trimester can be helpful in predicting sPTB. However, the CL had no association with sPTB during the 3 trimesters of pregnancy.

19.
Org Lett ; 21(21): 8563-8567, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31617727

RESUMO

A rhodium-catalyzed oxidative [3 + 2] annulation of 2-acetyl-1-phenylhydrazines with maleimides was accomplished using AgNTf2 and Ag2CO3 as additive and oxidant, respectively. A variety of 2-acetyl-1-phenylhydrazines with maleimides were converted into pyrrolo[3,4-b]indole-1,3-diones in satisfactory to excellent yields. Synthetically useful functional groups, such as halogen atoms (F, Cl, Br, and I), ester, cyano, and nitro, remained intact during tandem C-H activation and annulation reactions.

20.
J Food Biochem ; 43(10): e12858, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31608466

RESUMO

In this study, conditions for solid-phase microextraction coupled to gas chromatography-mass spectrometry to extract and analyze volatile compounds from fresh tomatoes (Solanum lycopersicum cv. Fendi) were optimized. Four main experimental parameters were optimized, including internal standard, fiber material coating, extraction temperature, and salt concentration. The optimal extraction conditions were 85 µm Carboxen/Polydimethylsiloxane fiber, 60°C extraction temperature, 1-heptanol as an internal standard, and without adding sodium chloride in the tomato sample. Analysis of tomato fruit samples using these optimized conditions allowed us to identify 37 volatile compounds that could be grouped into seven categories: aldehydes (11), hydrocarbons (7), alcohols (7), ketones (5), oxygen-containing heterocyclic compounds (3), esters (3), sulfur-and nitrogen-containing heterocyclic compounds (1). PRACTICAL APPLICATIONS: In this study, we optimized a method to extract tomato flavor compounds. In recent years, many consumers complained that tomatoes have poor flavor. A method to extract flavor compounds will assist in characterizing the compounds that contribute to tomato flavor and could be used in the development of tomatoes that have enhanced flavor.

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