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1.
Opt Express ; 27(22): 31407-31417, 2019 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-31684375

RESUMO

The electromagnetic field theory for a step-index fiber geometry is developed to sense a surrounding chiral drug via long-period fiber gratings (LPFGs). This theory employs Debye potentials and electromagnetic fields for cladding modes in the LPFGs by introducing constitutive relations for a chiral drug. The fields in the chiral drug are transformed and decomposed into right- and left-hand circularly polarized components to account for the magnetoelectric coupling due to the chirality. The solving process for complex propagation constants is given. Numerical results show that responses of the LPFGs to refractive index and chirality changes are different. The two minimum transmissions of a coated LPFG are very sensitive to the variation of the complex chirality. On the other hand, the two resonance wavelengths keep invariant as real and imaginary parts of the comparatively small chirality change. This work enriches the electromagnetic field theory for better design of LPFGs against the highly sensitive chirality detection.

2.
Int J Med Sci ; 16(10): 1320-1327, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31692996

RESUMO

Porphyromonas gingivalis is a pivotal periodontal pathogen, and the epithelial cells serve as the first physical barrier to defend the host from bacterial attack. Within this host-bacteria interaction, P. gingivalis can modify the host immune reaction and adjust the gene expression, which is associated with periodontitis pathogenesis and developing strategies. Herein, a meta-analysis was made to get the differential gene expression profiles in epithelial cells with or without P. gingivalis infection. The network-based meta-analysis program for gene expression profiling was used. Both the gene ontology analysis and the pathway enrichment analysis of the differentially expressed genes were conducted. Our results determined that 290 genes were consistently up-regulated in P. gingivalis infected epithelial cells. 229 gene ontology biological process terms of up-regulated genes were discovered, including "negative regulation of apoptotic process" and "positive regulation of cell proliferation/migration/angiogenesis". In addition to the well-known inflammatory signaling pathways, the pathway associated with a transcriptional misregulation in cancer has also been increased. Our findings indicated that P. gingivalis benefited from the survival of epithelial cells, and got its success as a colonizer in oral epithelium. The results also suggested that infection of P. gingivalis might contribute to oral cancer through chronic inflammation. Negative regulation of the apoptotic process and transcriptional misregulation in cancer pathway are important contributors to the cellular physiology changes during infection development, which have particular relevance to the pathogenesis and progressions of periodontitis, even to the occurrence of oral cancer.

3.
BMC Biol ; 17(1): 77, 2019 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-31597572

RESUMO

BACKGROUND: Ryanodine receptor (RyR), a calcium-release channel located in the sarcoplasmic reticulum membrane of muscles, is the target of insecticides used against a wide range of agricultural pests. Mammalian RyRs have been shown to be under the regulatory control of several kinases and phosphatases, but little is known about the regulation of insect RyRs by phosphorylation. RESULTS: Here we present the crystal structures of wild-type and phospho-mimetic RyR Repeat34 domain containing PKA phosphorylation sites from diamondback moth (DBM), a major lepidopteran pest of cruciferous vegetables. The structure has unique features, not seen in mammalian RyRs, including an additional α-helix near the phosphorylation loop. Using tandem mass spectrometry, we identify several PKA sites clustering in the phosphorylation loop and the newly identified α-helix. Bioinformatics analysis shows that this α-helix is only present in Lepidoptera, suggesting an insect-specific regulation. Interestingly, the specific phosphorylation pattern is temperature-dependent. The thermal stability of the DBM Repeat34 domain is significantly lower than that of the analogous domain in the three mammalian RyR isoforms, indicating a more dynamic domain structure that can be partially unfolded to facilitate the temperature-dependent phosphorylation. Docking the structure into the cryo-electron microscopy model of full-length RyR reveals that the interface between the Repeat34 and neighboring HD1 domain is more conserved than that of the phosphorylation loop region that might be involved in the interaction with SPRY3 domain. We also identify an insect-specific glycerol-binding pocket that could be potentially targeted by novel insecticides to fight the current resistance crisis. CONCLUSIONS: The crystal structures of the DBM Repeat34 domain reveals insect-specific temperature-dependent phosphorylation sites that may regulate insect ryanodine receptor function. It also reveals insect-specific structural features and a potential ligand-binding site that could be targeted in an effort to develop green pesticides with high species-specificity.

4.
Hum Cell ; 32(4): 548-556, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31489579

RESUMO

Glioblastoma is a common malignant primary intracranial tumor characterized by rapid invasive growth and a high recurrence rate after surgery. MicroRNAs (miRNAs) are involved in cell proliferation, differentiation, and apoptosis, and abnormal miRNA expression is associated with the occurrence and progression of various tumors, including glioblastomas. The aim of this study was to determine the levels of miR-148a and integrin subunit alpha 9 (ITGA9) in glioblastoma tissues and cells and their involvement in cancer cell proliferation and migration. Glioblastoma tissues from 19 patients and two glioblastoma cell lines (U87 and LN229) were used in this study. The effects of miR-148a on cell viability, proliferation, colony formation, migration, and invasion were assessed. Glioblastomas were xenografted in nude mice to examine the effects of miR-148a overexpression on tumor growth in vivo. Levels of ITGA9 mRNA and protein in glioblastoma tissues were detected by quantitative reverse transcription PCR and western blot analysis, respectively. The interaction between miR-148a and ITGA9 was determined by a dual-luciferase reporter gene assay. We found that the overexpression of miR-148a decreases the proliferation, clustering, migration, and invasiveness of U87 and LN229 cells and inhibits the tumorigenicity of xenografted glioblastomas. We confirmed that ITGA9 is the target of miR-148a. Restoration of ITGA9 expression reversed the decreased viability, migration, and invasiveness of glioblastoma cells induced by miR-148a overexpression. Our findings indicate that miR-148a can suppress the malignant phenotype of glioblastoma by targeting ITGA9 and identify ITGA9 as a potential therapeutic target for glioblastoma.

5.
J Org Chem ; 84(21): 13604-13614, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31547657

RESUMO

A novel palladium-catalyzed protocol for the synthesis of 2-arylquinolines via tandem reaction of 2-aminostyryl nitriles with arylboronic acids has been developed with good functional group tolerance. The presented approach offers a new synthetic pathway toward the core structures of 2-arylquinolines compared to classical condensation reaction of (E)-2-aminostyryl aryl ketones. Moreover, the present synthetic route could be readily scaled up to gram quantity without difficulty. Preliminary mechanistic experiments showed that this transformation involves a nucleophilic addition of aryl palladium species to the nitrile to generate an aryl ketone intermediate followed by an intramolecular cyclization and dehydration to quinoline ring.

6.
J Colloid Interface Sci ; 555: 145-156, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31377640

RESUMO

Resin hemoperfusion is a life-saving treatment for drug intoxication or hepatic failure of patients. However, current resin adsorbents exhibit a limited hemocompatibility or low adsorption efficiency, representing a major roadblock to successful clinical applications. In this work, we developed a hemocompatible and effective hemoadsorbent based on polystyrene resin (H103) microparticles encapsulated in anti-biofouling zwitterionic poly(carboxybetaine) (PCB) hydrogels. Apart from a strong mechanical stability, this PCB-based adsorbent (PCB-H103) exhibited excellent hemocompatibility (hemolysis ratio was ∼0.64%), which was attributed to the anti-biofouling property of PCB hydrogel. In addition, it can efficiently adsorb both small and middle molecular weight molecules in phosphate-buffered saline, and the efficiencies were significantly higher than poly(ethylene glycol) methacrylate-based and poly(2-hydroxyethyl methacrylate)-based adsorbent counterparts, indicating the favorable permeability of PCB hydrogel coating. More importantly, PCB-H103 could effectively remove protein-bound toxins including phenol red and bilirubin in bovine serum albumin solution or even in 100% fetal bovine serum (FBS). In 100% FBS, the adsorption capacity of PCB-H103 towards bilirubin was 8.3 times higher than that of pristine clinical-scale resin beads. Findings in this work may provide a new strategy for the development of modern resin hemoperfusion technology.

7.
ACS Appl Mater Interfaces ; 11(34): 30927-30935, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31379149

RESUMO

Spontaneous electricity generation through water evaporation is becoming a hot research area. However, low power output, limited material availability, and unscalable fabrication largely hinder its wide applications. Here, we report scalable painting and blade coating approaches for the mass production of flexible hydroelectric films (HEFs) based on solid oxides (e.g., Al2O3), which are of tolerance to mechanical deformation and are compatible with three-dimensional diverse configuration. The electricity power is generated continuously and can last for more than 10 days in ambient conditions. A single HEF unit is capable of supplying an output voltage of more than 2.5 V and even up to 4.5 V at specific conditions. The accumulative energy output can be tuned conveniently by means of series/parallel connections or size control to meet the practical needs of commercial electronics. A family of solid oxides has been verified to have the ability for water evaporation-induced electricity generation, which offers considerable room for the development of high-performance energy-supplying devices.

8.
Chem Biodivers ; 16(9): e1900294, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31381811

RESUMO

Bawei Longzuan granule (BLG) is a representative Zhuang medicine preparation. The present work aims to characterize the chemical constituents of BLG and evaluate its anti-arthritic activity. The major chemical constituents of BLG were tentatively identified by ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS), which revealed the presence of some alkaloids (e. g., magnoflorine, sinomenine and nitidine) and flavonoids (e. g., hesperidin, diosmin and sinensetin) that may be partly responsible for the anti-arthritic effect of BLG. In addition, the collagen-induced arthritis (CIA) model in rats was induced by intradermal injection of bovine collagen-II in complete Freund's adjuvant at the base of tail. The CIA rats received oral administration of BLG (1.25, 2.5 and 5 g/kg) for 30 days. Then, various indicators were determined to evaluate its anti-arthritic activity, including paw swelling, arthritic score, body weight, knee joint pathology, thymus index and spleen index. Additionally, the serum levels of tumor necrosis factor (TNF)-α, interferon (IFN)-γ, interleukin (IL)-1ß, IL-6, IL-4 and IL-10 were measured to determine the underlying mechanisms. The results showed that BLG efficiently ameliorated the severity of arthritis in CIA rats by decreasing paw swelling and arthritis score and improving the histological lesions of knee joint. Moreover, the serum levels of several pro-inflammatory cytokines (i. e., IL-1ß, TNF-α, IL-6 and IFN-γ) were downregulated, whereas two anti-inflammatory factors (i. e., IL-4 and IL-10) were upregulated after BLG administration. These results indicated that BLG possessed promising therapeutic effect on collagen-induced arthritis by inhibiting inflammatory responses. BLG can be used as a complementary or alternative traditional medicine to treat rheumatoid arthritis.

9.
Microb Pathog ; 135: 103651, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31398532

RESUMO

Bartonella infection is distributed worldwide with animal and public health. Recent studies have shown that host cells infection by Bartonella has a series of different infection stages, beginning with encounter and adherence to the cells. In this study, we expressed and purified recombinant Bartonella henselae (B. henselae) α-enolase. And we found that B. henselae α-enolase is highly conserved in Bartonella species. The interacting protein partners of B. henselae α-enolase were showed by String-11. The interactions between B. henselae α-enolase and human plasminogen were subsequently confirmed by ELISA, pull down, T7 phage display and molecular docking assays. And the plasminogen-binding sites of B. henselae α-enolase are predicted at 247FYKNGSYFY255. These findings will help elucidate and improve the understanding of the molecular mechanisms of Bartonella infection.

10.
ACS Appl Mater Interfaces ; 11(37): 34330-34337, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31429271

RESUMO

The microdroplets in fog flow have been considered as an important resource for supplying fresh drinking water. Most of the reported works of fog collection focus on the water-collecting ability rather than the environmental reliability of selected materials. In this work, a beetle-inspired hierarchical fog-collecting interface based on the antibacterial needle-array (ABN) and hydrophilic/hydrophobic cooperative structure is displayed. The hydrophilic ABN is coated with zwitterionic carboxybetaine (CB) brushes that endow the fog collector with a long-term cleaning in harsh environment. Due to its strong affinity to water molecules, the tilted needles with a CB coating can facilitate the capture of fog and the rapid delivery of condensed water driven by gravity. After being transported to the connected hydrophobic sheet, the collected droplets can be rapidly detached and stored in the container, achieving a high fog-harvesting rate. Furthermore, CB-patterned channels are integrated on the hydrophobic sheet for the pathway-controlled water delivery. The CB coating is able to efficiently resist bacterial adhesion and contamination during fog harvesting, protecting the device from microbiological corrosion. The current design provides a promising method to incorporate antibacterial ability into fog collectors, which offer great opportunity to develop water harvesters for real-world applications.

11.
Exp Mol Med ; 51(8): 88, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31371698

RESUMO

The number of patients with diabetic nephropathy (DN) is still on the rise worldwide, and this requires the development of new therapeutic strategies. Recent reports have highlighted genetic factors in the treatment of DN. Herein, we aimed to study the roles of long noncoding RNA (lncRNA) plasmacytoma variant translocation 1 (PVT1) and histone 3 lysine 27 trimethylation (H3K27me3) in DN. A model of DN was established by inducing diabetes in mice with streptozotocin. Mouse podocyte clone 5 (MPC5) podocytes and primary podocytes were cultured in normal and high glucose media to observe cell morphology and to quantify PVT1 expression. The roles of PVT1 and enhancer of zeste homolog 2 (EZH2) were validated via loss-of-function and gain-of-function in vitro experiments to identify the interactions among PVT1, EZH2, and forkhead box A1 (FOXA1). The podocyte damage and apoptosis due to PVT1 and FOXA1 were verified with in vivo experiments. PVT1 was highly expressed in MPC5 and primary podocytes in DN patients and in cultures grown in high glucose medium. A large number of CpG (C-phosphate-G) island sites were predicted at the FOXA1 promoter region, where PVT1 recruited EZH2 to promote the recruitment of H3K27me3. The silencing of PVT1 or the overexpression of FOXA1 relieved the damage and inhibited the apoptosis of podocytes in DN, as was evidenced by the upregulated expression of synaptopodin and podocin, higher expression of Bcl-2, and lower expression of Bax and cleaved caspase-3. The key findings of this study collectively indicate that the suppression of lncRNA PVT1 exerts inhibitory effects on podocyte damage and apoptosis via FOXA1 in DN, which is of clinical significance.

12.
Angew Chem Int Ed Engl ; 58(43): 15334-15338, 2019 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-31415119

RESUMO

Although asymmetric phosphine catalysis is a powerful tool for the construction of various chiral carbon centers, its synthetic potential toward an enantioenriched atropisomer has not been explored yet. Reported herein is a phosphine-catalyzed atroposelective (4+2) annulation of δ-acetoxy allenoates and 2-hydroxyquinone derivatives. The reaction provides expedient access to aryl-naphthaquinone atropisomers by the de novo construction of a benzene ring. The two functionalities of the catalyst, a tertiary phosphine (Lewis base) and a tertiary amine (Brønsted base), cooperatively enable this process with high regio- and enantioselectivities.

13.
Arch Oral Biol ; 107: 104513, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31442933

RESUMO

OBJECTIVE: The aim of this study was to explore the role of macrophage migration inhibitory factor (MIF) and intercellular adhesion molecule (ICAM)-1 in rats with periodontitis and atherosclerosis. METHODS: Twenty-four male Sprague-Dawley rats were randomly divided into 4 groups: control group (C), periodontitis group (P), atherosclerosis group (AS), and periodontitis plus atherosclerosis group (P + AS). The levels of MIF and ICAM-1 in serum were detected by an enzyme-linked immunosorbent assay (ELISA). The protein expression of MIF and ICAM-1 in the carotid artery tissues was examined by immunohistochemical staining. RESULTS: The results of the ELISA showed that the serum level of MIF in the P + AS group (59.40 ±â€¯3.92 ng/mL) was significantly higher than that in the C group (42.93 ±â€¯2.63 ng/mL), the P group (45.57 ±â€¯2.59 ng/mL) and the AS group (50.88 ±â€¯4.20 ng/mL) (P < 0.05). Similarly, the ICAM-1 level in the P + AS group (6.77 ±â€¯1.47 ng/mL) was much higher than that in the C (1.33 ±â€¯0.25 ng/mL), P (3.99 ±â€¯0.44 ng/mL) and AS groups (4.19 ±â€¯0.89 ng/mL) (P < 0.05). Furthermore, the expression of MIF, as assessed by immunohistochemical staining, was significantly higher in the artery tissues of the P + AS group than in the tissues of the other three groups (P < 0.05). However, there was no significant difference in the protein level of ICAM-1 between the P + AS and AS groups, where its expression was much stronger than in the C and the P groups. CONCLUSION: Our results indicate that there is a close association between periodontitis and atherosclerosis. MIF and ICAM-1 may play a role in the development of atherosclerosis and periodontitis.

14.
Biomed Res Int ; 2019: 2587245, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31428630

RESUMO

Background: To improve the efficacy of regenerative treatment for gingival recessions, the autologous platelet concentrates (APCs) combined with coronally advanced flap (CAF) have been investigated. However, few studies systematically assess the complementary effect of APCs in periodontal regeneration. The present study aims to evaluate the additional effect of different types of APCs to CAF in the treatment of gingival recessions. Methods: Electronic databases (EMBASE, MEDLINE, and Cochrane Central Register of Controlled Trails) and relevant journals were searched until May 15, 2019. Only randomized controlled trials (RCTs) in English were included. Outcome variables include root coverage (RC), recession depth (RD), clinical attachment level (CAL), keratinized tissue width (KTW), and gingival thickness (GT). Data were analyzed with Revman5.3. The estimate of effect sizes was expressed as the mean differences and the 95% confidence interval. Results: 8 RCTs involving 170 patients (328 sites) were included. Our meta-analysis indicated RC, RD, CAL, KTW, and GT were better improved in the CAF plus APCs groups than the CAF alone. The subgroup analyses revealed that platelet-rich fibrin (PRF) brought significant improvement in RC, RD, CAL, and GT. Concentrated growth factors (CGF) lead clinic beneficial in CAL, KTW, and GT. No significant effect of platelet-rich plasma (PRP) could be found in any clinical parameters when combined with CAF. Conclusions: PRF could exert additional effect to CAF; the preferred treatment for gingival recessions was considered. Based on the limited studies, it seemed that PRP failed to show any additional effect and it was not suggested for gingival recessions. Given the limited research and high risk of bias, it is still needed to confirm the additional effect of CGF by more high-quality studies.

15.
Int Immunopharmacol ; 74: 105737, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31288152

RESUMO

Influenza A virus usually leads to economic loss to breeding farms and pose a serious threat to human health. Virus infecting tissues directly and influenza virus-induced excessive production of inflammatory factors play the key role in pathogenesis of the disease, but the mechanism is not well clarified. Here, the role of autophagy was investigated in H9N2 influenza virus-triggered inflammation. The results showed that autophagy was induced by H9N2 virus in A549 cells and in mice. Inhibiting autophagy by an autophagy inhibitor (3-methyladenine, 3-MA) or knockdown of Atg5(autophagy-related gene) by Atg5 siRNA significantly suppressed H9N2 virus replication, H9N2 virus-triggered inflammatory cytokines and chemokines, including IL-1ß, TNF-α, IL-8, and CCL5 in vitro and in vivo, and suppressed H9N2 virus-triggered acute lung injury as indicated as accumulative mortality of mice, inflammatory cellular infiltrate and interstitial edema, thickening of the alveolar walls in mice lung tissues, increased inflammatory cytokines and chemokines, increased W/D ratio in mice. Moreover, autophagy mediated inflammatory responses through Akt-mTOR, NF-κB and MAPKs signaling pathways. Our data showed that autophagy was essential in H9N2 influenza virus-triggered inflammatory responses, and autophagy could be target to treat influenza virus-caused lung inflammation.

16.
Adv Mater ; : e1901979, 2019 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-31334581

RESUMO

Graphene-based fibers (GBFs) are macroscopic 1D assemblies formed by using microscopic 2D graphene sheets as building blocks. Their unique structure exhibits the same merits as graphene such as low weight, high specific surface area, excellent mechanical/electrical properties, and ease of functionalization. Furthermore, the fibrous nature of GBFs is intrinsically compatible with existing textile technologies, making them suitable for applications in flexible and wearable electronics. Recently, novel synthetic methods have endowed GBFs with new structures and functions, further improving their mechanical and electrical properties. These improvements have rapidly bridged the gaps between laboratory demonstrations and real-life applications in fiber-shaped batteries, supercapacitors, and electrochemical sensors. Recent advances in the fabrication, optimization, and application of GBFs are systematically reviewed and a perspective on their future development is given.

17.
Org Lett ; 21(14): 5742-5746, 2019 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-31283243

RESUMO

A palladium-catalyzed cyclizative phosphorylation reaction of (Z)-1-iodo-1,6-diene with diethyl H-phosphonate is developed, which provides facile access to unsaturated six-membered heterocycles bearing an alkylphosphonate group. The key step of this process is the efficient capture of the involved alkyl-Pd(II) species by H-phosphonate with the help of CsF, followed by reductive elimination of alkyl-Pd(II)-P(O)(OEt)2. Moreover, this reaction is successfully extended to H-thionophosphonate.

18.
Artigo em Inglês | MEDLINE | ID: mdl-31286435

RESUMO

This study examined whether Lactobacillus rhamnosus GG (LGG) and Bifidobacterium bifidum TMC3115 (TMC3115) could morphologically or physiologically influence hippocampal neuronal development in vitro. Hippocampal neurons cultured in vitro were exposed to live or heat-inactivated LGG or TMC3115 for either 6 or 24 h. Neuronal morphological changes and drebrin (DRB) and synaptophysin (SYP) protein levels were monitored using immunofluorescence. And the levels of DRB, SYP, and brain-derived neurotrophic factor (BDNF), and cAMP-response element binding protein (CREB) mRNA were detected using RT-PCR. The BDNF, CREB, and phosphorylated-CREB (P-CREB) protein levels were detected by extraction-enzyme-linked immunosorbent assay (ELISA) or Western blot assays. Heat-inactivated LGG and TMC3115 could enhance neuron viability, DRB and SYP protein levels, and BDNF mRNA level were significantly altered after exposure to the tested bacteria with 6 h or 24 h. There were no significant differences in neuronal morphology or DRB, SYP, or CREB mRNA levels among the groups following bacterial exposure. However, following exposure of live TMC3115 for 24 h, the neuronal BDNF and P-CREB protein levels were both significantly up-regulated as detected by western blot assays. These results demonstrated that LGG and TMC3115 could affect neuronal viability, along with hippocampal synaptic and functional development, in a strain-dependent manner, which may also be closely associated with the physiological and culture conditions of each strain. Up-regulated P-CREB may be one of the underlying mechanisms by which the bacteria, especially neurons following exposure of live TMC3115 for 24 h, are able to regulate neuronal BDNF protein production.

19.
Food Chem ; 295: 475-483, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31174784

RESUMO

By inspecting starch hierarchical structural evolutions, this work explores how microwave cooking with storage tailors the slowly digestible features of indica (IRS) and waxy (WRS) rice starches. Particularly, relative to conventional cooking-storage, the microwave treatment especially at high powers (8 and 10 W/g) increased the molecular orders (crystallites) and periodic amorphous-crystalline structures. Such changes facilitated the formation of domains with intermediately-densely packed starch chains, being modestly accessible to the diffusion, absorption and catalysis of enzymes and dominantly showing slowly digestible features. Consistently, the microwave processed starches showed a higher SDS (slowly digestible starch) level and a lower digestion rate. This microwave-enhanced SDS generation became more prominent for IRS, and the treated IRS at 10 W/g showed the highest SDS content (ca. 54%). This is related to the enhanced reassembly of glucan chains into ordered/semicrystalline structures and the formation of slowly digestible domains as induced by the increase of amylose molecules.


Assuntos
Culinária/métodos , Armazenamento de Alimentos/métodos , Micro-Ondas , Oryza/química , Amido/química , Digestão , Amido/farmacocinética , Difração de Raios X
20.
Org Lett ; 21(13): 5368-5372, 2019 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-31247755

RESUMO

A Pd(II)-catalyzed intramolecular and highly selective acetxoylative (3 + 2) annulation of propargylic alcohol and alkene is reported. Mechanistically, a hydroxy-guided regioselective alkyne acetoxypalladation is followed by 6-exo-trig alkene insertion to form an alkyl-Pd(II) intermediate. After oxidation, the resulting cyclometalated alkoxy-Pd(IV)-alkyl undergoes direct reductive elimination to afford a polycyclic oxa-heterocycle. When an additional coordinating site or ligand accessible by palladium is present, an SN2-type C-C reductive elimination of alkyl-Pd(IV) instead occurs along with hydroxy acetylation, affording 3-bicyclo[4.1.0]heptan-5-one products.

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