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1.
Planta ; 259(4): 77, 2024 Feb 29.
Artículo en Inglés | MEDLINE | ID: mdl-38421445

RESUMEN

MAIN CONCLUSION: The expression peak of VcAP1.4, VcAP1.6, VcAP3.1, VcAP3.2, VcAG3, VcFLC2, and VcSVP9 coincided with the endo-dormancy release of flower buds. Additionally, GA4+7 not only increased the expression of these genes but also promoted flower bud endo-dormancy release. The MIKCC-type MADS-box gene family is involved in the regulation of flower development. A total of 109 members of the MIKCC-type MADS-box gene family were identified in blueberry. According to the phylogenetic tree, these 109 MIKCC-type MADS-box proteins were divided into 13 subfamilies, which were distributed across 40 Scaffolds. The results of the conserved motif analysis showed that among 20 motifs, motifs 1, 3, and 9 formed the MADS-box structural domain, while motifs 2, 4, and 6 formed the K-box structural domain. The presence of 66 pairs of fragment duplication events in blueberry suggested that gene duplication events contributed to gene expansion and functional differentiation. Additionally, the presence of cis-acting elements revealed that VcFLC2, VcAG3, and VcSVP9 might have significant roles in the endo-dormancy release of flower buds. Meanwhile, under chilling conditions, VcAP3.1 and VcAG7 might facilitate flower bud dormancy release. VcSEP11 might promote flowering following the release of endo-dormancy, while the elevated expression of VcAP1.7 (DAM) could impede the endo-dormancy release of flower buds. The effect of gibberellin (GA4+7) treatment on the expression pattern of MIKCC-type MADS-box genes revealed that VcAP1.4, VcAP1.6, VcAP3.1, VcAG3, and VcFLC2 might promote flower bud endo-dormancy release, while VcAP3.2, VcSEP11, and VcSVP9 might inhibit its endo-dormancy release. These results indicated that VcAP1.4, VcAP1.6, VcAP1.7 (DAM), VcAP3.1, VcAG3, VcAG7, VcFLC2, and VcSVP9 could be selected as key regulatory promoting genes for controlling the endo-dormancy of blueberry flower buds.


Asunto(s)
Arándanos Azules (Planta) , Arándanos Azules (Planta)/genética , Filogenia , Reproducción , Flores/genética , Duplicación de Gen
2.
Lancet Digit Health ; 5(11): e812-e820, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37775472

RESUMEN

BACKGROUND: Endoscopic ultrasonography (EUS) is a key procedure for the diagnosis of biliopancreatic diseases. However, the performance among EUS endoscopists varies greatly and leads to blind spots during the operation, which can impair the health outcomes of patients. We previously developed an artificial intelligence (AI) device that accurately identified EUS standard stations and significantly reduced the difficulty of ultrasonography image interpretation. In this study, we updated the device (named EUS-IREAD) and validated its performance in improving the quality of EUS procedures. METHODS: In this single-centre, randomised, controlled trial, we updated EUS-IREAD so it consisted of five learning models to identify eight EUS stations and 24 anatomical structures. The trial was done at the Renmin Hospital of Wuhan University (Wuhan, China) and included patients aged 18 years or older with suspected biliopancreatic (pancreas and biliopancreatic duct) lesions due to clinical symptoms, radiological findings, or laboratory findings, and with a high risk of pancreatic cancer. Patients were randomly assigned (1:1) by a dedicated research assistant using a computer-generated random number series (with a block size of four) to undergo the EUS procedure with or without the assistance of EUS-IREAD. Endoscopists in the EUS-IREAD-assisted group were required to observe all standard stations and anatomical structures according to the prompts by the AI device. Data collectors, the independent data anaylsis team, and patients were masked to group allocation. The primary outcome was the missed scanning rate of standard stations between the two groups, which was assessed in patients who underwent EUS procedure in accordance with the assigned intervention (per protocol). This trial is registered with ClinicalTrials.gov, NCT05457101. FINDINGS: Between July 9, 2022, and Feb 28, 2023, 290 patients (mean age 55·93 years [SD 14·06], 152 [52%] male, and 138 [48%] female) were randomly assigned and analysed, including 144 in the EUS-IREAD-assisted group and 146 in the control group. The EUS-IREAD-assisted group had a lower missed scanning rate of stations than the control group (4·5% [SD 0·8] vs 14·3% [1·0], -9·8% [95% CI -12·2 to -7·5]; odds ratio 3·6 [95% Cl 2·6 to 4·9]; p<0·0001). No significant adverse event was found during the study. INTERPRETATION: Our study confirms the capability of EUS-IREAD to monitor the blind spots and reduce the missed rate of stations and structures during EUS procedures. The EUS-IREAD has the potential to play an essential part in EUS quality control. FUNDING: Innovation Team Project of Health Commission of Hubei Province and College-enterprise Deepening Reform Project of Wuhan University.


Asunto(s)
Inteligencia Artificial , Endosonografía , Humanos , Masculino , Femenino , Persona de Mediana Edad , Estudios Prospectivos , China
3.
PeerJ ; 10: e13459, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35637713

RESUMEN

Background: Chenopodium formosanum Koidz. Amaranthaceae-also known as Djulis or red quinoa (RQ)-is a cereal plant indigenous to Taiwan, known for its high nutrient value. However, its bran is considered a waste product and the nutrient value has never been analyzed. Methods: In this study, we examined the proximate composition of RQ bran, specifically its soluble polysaccharide fractions. Results: RQ bran exhibited high contents of protein (16.56%), ash (7.10%), carbohydrate (60.45%), total polyphenolics (1.85%), betaxanthin (9.91 mg/100 g of RQ bran), and indicaxanthin (7.27 mg/100 g of RQ bran). Specifically, it was rich in polyunsaturated fatty acids (PUFAs; 39.24%)-with an n-6/n-3 and PUFA/saturated fatty acid (SFA) ratio of 18.137 and 0.743, respectively. Four soluble polysaccharide fractions were also obtained: CF-1, CF-2, CF-3, and CF-4, with yields of 3.90%, 6.74%, 22.28%, and 0.06%, respectively, and molecular weights of 32.54, 24.93, 72.39, and 55.45 kDa, respectively. CF-1, CF-2, CF-3, and CF-4 had respectively 15.67%, 42.41%, 5.44%, and 14.52% peptide moiety content and 38.92%, 50.70%, 93.76%, and 19.80% carbohydrate moiety. In CF-2, the glucose content was 95.86 mol% and that of leucine was 16.23%, implicating the presence of a typical leucinoglucan. All four polysaccharide fractions lacked glutamic acid and hydroxyproline. The IC50 of CF-1, CF-2, and CF-3 was respectively 12.05, 3.98, and 14.5 mg/mL for DPPH free radical-scavenging ability; 5.77, 4.10, and 7.03 mg/mL for hydrogen peroxide-scavenging capability; 0.26, 0.05, and 0.19 mg/mL for O2 - free radical-scavenging capability; and 100.41, 28.12, and 29.73 mg/mL for Fe2+ chelation. Conclusion: Our results indicated that RQ bran has a large amount of nutrient compounds, and a cost-efficient process for their extraction is needed. Their biomedical application as nutraceuticals also warrants further investigation.


Asunto(s)
Chenopodium quinoa , Chenopodium , Chenopodium/química , Antioxidantes/farmacología , Chenopodium quinoa/química , Nutrientes , Semillas/química , Polisacáridos/análisis , Radicales Libres/análisis
4.
J Med Chem ; 65(6): 4767-4782, 2022 03 24.
Artículo en Inglés | MEDLINE | ID: mdl-35234475

RESUMEN

Chemotherapy-induced neurotoxicity is a common adverse effect of cancer treatment. No medication has been shown to be effective in the prevention or treatment of chemotherapy-induced neurotoxicity. Using minoxidil as an initial template for structural modifications in conjunction with an in vitro neurite outgrowth assay, an image-based high-content screening platform, and mouse behavior models, an effective neuroprotective agent CN016 was discovered. Our results showed that CN016 could inhibit paclitaxel-induced inflammatory responses and infiltration of immune cells into sensory neurons significantly. Thus, the suppression of proinflammatory factors elucidates, in part, the mechanism of action of CN016 on alleviating paclitaxel-induced peripheral neuropathy. Based on excellent efficacy in improving behavioral functions, high safety profiles (MTD > 500 mg/kg), and a large therapeutic window (MTD/MED > 50) in mice, CN016 might have great potential to become a peripherally neuroprotective agent to prevent neurotoxicity caused by chemotherapeutics as typified by paclitaxel.


Asunto(s)
Antineoplásicos Fitogénicos , Antineoplásicos , Fármacos Neuroprotectores , Enfermedades del Sistema Nervioso Periférico , Animales , Antineoplásicos/farmacología , Antineoplásicos Fitogénicos/toxicidad , Ganglios Espinales , Ratones , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/uso terapéutico , Paclitaxel/toxicidad , Enfermedades del Sistema Nervioso Periférico/inducido químicamente , Enfermedades del Sistema Nervioso Periférico/tratamiento farmacológico , Enfermedades del Sistema Nervioso Periférico/prevención & control
5.
J Hazard Mater ; 424(Pt C): 127411, 2022 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-34629198

RESUMEN

The excessive use of carbaryl has resulted in the risk of its exposure. In this study, we isolated six nanobodies (Nbs) from a camelid phage display library against the biomarker of carbaryl, 1-naphthol (1-NAP). Owing to its characteristics of easy genetic modifications, we produced a nanobody-alkaline phosphatase (Nb-CC4-ALP) fusion protein with good stability. A dual-emission system based ratiometric fluoroimmunoassay (RFIA) for quick and highly sensitive determination of 1-NAP was developed. Silicon nanoparticles (SiNPs) was used as an internal reference and for aggregation-induced emission enhancement (AIEE) of gold nanoclusters (AuNCs), while AuNCs could be quenched by MnO2 via oxidation. In the presence of ALP, ascorbic acid phosphate (AAP) can be transformed into ascorbic acid (AA), the later can etch MnO2 to recover the fluorescence of the AuNCs. Based on optimal conditions, the proposed assay showed 220-fold sensitivity improvement in comparison with conventional monoclonal antibody-based ELISA. The recovery test of urine samples and the validation by standard HPLC-FLD demonstrated the proposed assay was an ideal tool for screening 1-NAP and provided technical support for the monitoring of carbaryl exposure.


Asunto(s)
Nanopartículas del Metal , Plaguicidas , Fosfatasa Alcalina/genética , Carbaril/toxicidad , Fluoroinmunoensayo , Límite de Detección , Compuestos de Manganeso , Nanopartículas del Metal/toxicidad , Naftoles , Óxidos , Fosfatos
7.
Anal Methods ; 13(16): 1911-1918, 2021 04 28.
Artículo en Inglés | MEDLINE | ID: mdl-33913967

RESUMEN

Diazinon (DAZ) is an organophosphorus pesticide (OP), which is commonly used to prevent and control harmful pests that endanger agricultural products. In this study, we developed a novel heterology coating strategy for the immunoassay of DAZ. The DAZ coating hapten can be directly conjugated to the carrier protein without requiring a spacer arm. This proposed hapten coating strategy is time-saving and significantly improves the sensitivity of the immunoassay due to the lack of a spacer arm. The as-synthesized coating antigen was used to screen the monoclonal antibody (mAb). Finally, the developed indirect competitive enzyme-linked immunoassay (icELISA) showed IC50 and limit of detection (LOD) values of 0.58 ng mL-1 and 8 pg mL-1, respectively. This method exhibited negligible cross-reactivity towards other analogues, and the recoveries of samples (cucumber, cabbage, and lettuce) ranged from 92.6% to 125.4%, with coefficients of variance (CV) below 12%. Good correlation between icELISA and high-performance liquid chromatography mass spectrometry (HPLC-MS/MS) was obtained. The proposed icELISA was an ideal tool for monitoring DAZ residues in food samples.


Asunto(s)
Anticuerpos Monoclonales , Verduras , Diazinón , Ensayo de Inmunoadsorción Enzimática , Espectrometría de Masas en Tándem
8.
J Hazard Mater ; 412: 125241, 2021 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-33550127

RESUMEN

Carbamate pesticides (CPs) are the most used pesticides in agricultural production and pest control. In this study, carbofuran, isoprocarb and carbaryl were employed as models, and a general hapten strategy based on carbamate moiety recognition was proposed. Molecular modeling of the three-dimensional (3D) structure and surface electrostatic potential of the CPs indicated that the amide group formed by conjugation significantly influenced recognition by antibodies. The proposed strategy was used to obtain three sensitive and specific monoclonal antibodies (mAbs) with IC50 values of 1.4 ng/mL, 8.4 ng/mL and 13.8 ng/mL for carbofuran, isoprocarb and carbaryl, respectively. Negligible cross-reactivity (%) with analogs was observed, except for fenobucarb (84.6%) for isoprocarb. The obtained antibodies were used to develop an immunochromatographic assay (ICA) to simultaneously and quantitatively detect the three CPs. A strip reader was used to determine the limits of quantitation (LOQs) as 0.05 ng/mL (carbofuran), 31.3 ng/mL (isoprocarb) and 31.3 ng/mL (carbaryl). The recoveries of cucumber and Chinese cabbage samples ranged from 76% to 111%, with CVs from 1.3% to 10.6%, indicating good potential for the rapid simultaneous detection of multiple pesticide residues in a large batch of samples.


Asunto(s)
Carbofurano , Residuos de Plaguicidas , Plaguicidas , Carbamatos/análisis , Haptenos , Inmunoensayo , Residuos de Plaguicidas/análisis , Plaguicidas/análisis
10.
Iran J Public Health ; 48(9): 1732-1734, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31700830

RESUMEN

Chromosome aberration is associated with infertility and isochromosome is a rare chromosomal abnormality potentially associated with infertility or multiple miscarriages. Here we report a man of 29-yr-old diagnosed of infertility from China with rare isochromosome. Peripheral blood lymphocytes were obtained for chromosome G banding karyotyping. Hormones and other tests were performed. The semen analysis revealed Azoospermia. Complementary isochromosome of 46, XY, i(5)(p10),i(5)(q10) was identified. This is the first report of Complementary isochromosome of 46, XY, i(5)(p10),i(5)(q10).

11.
Aesthetic Plast Surg ; 42(6): 1664-1671, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30206648

RESUMEN

OBJECTIVE: To evaluate aesthetic outcomes in patients with bilateral trapezius hypertrophy treated by botulinum toxin type A (BTxA) injection for aesthetic reconstruction of the upper trapezius. METHODS: From May 2015 to May 2016, 30 women with a short neck shape resulting from bilateral trapezius hypertrophy were treated with botulinum toxin type A (BTxA) injection at the most affected area of the upper trapezius. Pre- and postoperative values of SACDF (irregularly shaped area of the four points A, C, D, and F) and SACDE (irregularly shaped area of the four points A, C, D, and E), responses to patients' and doctors' Global Aesthetic Improvement Scale (GAIS) questionnaires for neck aesthetic assessment, as well as reported adverse events, were recorded and analyzed. RESULTS: Duration of follow-up ranged from 4 to 12 months. Subjects experienced non-severe adverse events and complete recovery after a single BTxA injection. In patients' GAIS questionnaires, "very much improved" accounted for 53%, "much improved" accounted for 13%, and "improved" accounted for 27%. In doctors' GAIS questionnaires, "very much improved" accounted for 27%, "much improved" accounted for 33%, "improved" accounted for 33%, and "no change" accounted for 7%. The overall degree of improvement was high. Statistically significant differences were observed with respect to the "very much improved" response to GAIS questionnaires between patients and doctors (P = 0.035). CONCLUSION: A single injection of BTxA for aesthetic reconstruction of the upper trapezius is safe and effective in patients with bilateral trapezius hypertrophy. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .


Asunto(s)
Toxinas Botulínicas Tipo A/administración & dosificación , Hipertrofia/tratamiento farmacológico , Satisfacción del Paciente/estadística & datos numéricos , Músculos Superficiales de la Espalda/efectos de los fármacos , Músculos Superficiales de la Espalda/patología , Encuestas y Cuestionarios , Adulto , Estudios de Cohortes , Estética , Femenino , Estudios de Seguimiento , Humanos , Hipertrofia/patología , Inyecciones Intralesiones , Persona de Mediana Edad , Relajación Muscular/efectos de los fármacos , Estudios Retrospectivos , Estadísticas no Paramétricas , Resultado del Tratamiento
12.
Medicine (Baltimore) ; 97(38): e12326, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30235686

RESUMEN

This study aimed to analyze the clinical manifestations of patients with pyogenic liver abscess and characteristics of pathogenic that caused their infections, in order to provide guidance for the identification of the pathogens that cause liver abscess and selection of antibiotics for treatment of this disease.In the present study, the clinical characteristics, laboratory results, as well as the species and drug resistance of pathogens in patients with bacterial liver abscesses admitted to our hospital from January 2013 to December 2015 were retrospectively analyzed. The patients were treated by ultrasound or CT-guided percutaneous portal vein catheterization and drainage combined with intravenous infusion of antibiotics (the third-generation cephalosporins, the coformulation of carbapenem and dehydropeptidase-I inhibitors, or the coformulation of tazobactam and piperacillin).A total of 178 patients were diagnosed with liver abscess by B ultrasound or CT. The abscesses mostly occurred in elderly male patients and patients with diabetes mellitus. The major clinical and hematological features were fever (163/178, 91.2%), single focal abscess (146/178, 82.0%), elevated white blood cell count, and percentage of neutrophils (136/178, 76.4%). A total of 102 nonrepetitive strains of bacteria were isolated, including Klebsiella pneumoniae (82 strains, 80.3%), Escherichia coli (8 strains), Pseudomonas aeruginosa (2 strains), Acinetobacter baumannii (1 strain), and Gram-positive cocci (9 strains). Susceptibility to antimicrobial drugs was determined by analyzing the minimum inhibitory concentration, and among the 8 cultured E coli strains, 5 strains that could produce extended-spectrum ß-lactamase (ESBLs) were among the most commonly seen nosocomial infections. In the present study, bacterial liver abscesses were mostly community-acquired, and K pneumoniae was highly susceptive to the commonly used antibiotics. Five patients had poor outcomes due to infectious shock or the accompanying liver cancer. In other patients, after treatment, the body temperature and the inflammatory indices, such as the total white blood cell count and C-reactive protein, returned to normal levels, and the area of abscess decreased.Most of the bacterial liver abscesses were caused by K pneumoniae, in which only a few strains exhibited resistance to the commonly used antibiotics. The use of ultrasound- or CT-guided percutaneous drainage combined with antibiotics was an appropriate way to treat the liver abscesses of these patients.


Asunto(s)
Absceso Piógeno Hepático/microbiología , Absceso Piógeno Hepático/fisiopatología , Administración Intravenosa , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Antibacterianos/uso terapéutico , Cateterismo Periférico , Infecciones Comunitarias Adquiridas/microbiología , Infecciones Comunitarias Adquiridas/fisiopatología , Infección Hospitalaria/microbiología , Infección Hospitalaria/fisiopatología , Diabetes Mellitus/epidemiología , Farmacorresistencia Bacteriana , Femenino , Humanos , Recuento de Leucocitos , Absceso Piógeno Hepático/diagnóstico , Absceso Piógeno Hepático/tratamiento farmacológico , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Vena Porta , Estudios Retrospectivos , Factores Sexuales , Adulto Joven
13.
Oncol Lett ; 15(3): 3814-3819, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29467898

RESUMEN

The present study aimed to investigate the role of microRNA-96 (miR-96) in the proliferation, invasion and apoptosis of bladder cancer cell lines, and the associated mechanisms. The expression of miR-96 and human ether-à-go-go-related (HERG1) potassium channel in the normal uroepithelium SV-HUC-1 cell line, and bladder cancer T24 and 5637 cell lines were examined using reverse transcription-polymerase chain reaction or/and western blotting. Transfection with miR-96 inhibitor or scrambled control (SC) was used to study the biological activities of miR-96 in bladder cancer cell lines. MTT, flow cytometric and Transwell assays were applied to detect cell viability, apoptosis and invasion, respectively. A dual-luciferase reporter assay was applied to determine the association between miR-96 and HERG1 expression. As demonstrated, miR-96 was highly expressed in the two bladder cancer cell lines, particularly in T24 cells. Following transfection with miR-96 inhibitor, miR-96 expression was significantly reduced in the T24 cell line, compared with SC. The miR-96 inhibitor suppressed cell proliferation and invasion, promoted apoptosis and arrested the cell cycle at the G1 phase. Consistently, HERG1 was also highly expressed in the two bladder cancer cell lines at the mRNA and protein level, but not in the normal uroepithelium cell line. The miR-96 inhibitor also significantly decreased HERG1 expression compared with SC. The results of the dual-luciferase reporter assay indicated that miR-96 directly targeted wild-type HERG1. In conclusion, miR-96 inhibitor exhibited anticancer effects on bladder cancer cells by inhibiting proliferation and invasion of cells, and promoting their apoptosis. HERG1 was an important target of miR-96. These results provided experimental evidence supporting miR-96 as a therapeutic target for patients with bladder cancer.

14.
Chem Sci ; 8(3): 1977-1980, 2017 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-28451313

RESUMEN

We developed neutral iridium catalysts with chiral spiro phosphine-carboxy ligands (SpiroCAP) for asymmetric hydrogenation of unsaturated carboxylic acids. Different from the cationic Crabtree-type catalysts, the iridium catalysts with chiral spiro phosphine-carboxy ligands are neutral and do not require the use of a tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (BArF-) counterion, which is necessary for stabilizing cationic Crabtree-type catalysts. Another advantage of the neutral iridium catalysts is that they have high stability and have a long lifetime in air. The new iridium catalysts with chiral spiro phosphine-carboxy ligands exhibit unprecedented high enantioselectivity (up to 99.4% ee) in the asymmetric hydrogenations of various unsaturated carboxylic acids, particularly for 3-alkyl-3-methylenepropionic acids, which are challenging substrates for other chiral catalysts.

15.
Mil Med Res ; 4: 11, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28361006

RESUMEN

Vascular leakage, or increased vascular permeability, is a common but important pathological process for various critical diseases, including severe trauma, shock, sepsis, and multiple organ dysfunction syndrome (MODS), and has become one of the most important causes of death for intensive care units (ICU) patients. Currently, although there has been some progress in knowledge of the pathogenesis of these vascular disorders, the detailed mechanisms remain unclear, and effective prophylaxis and treatment are still lacking. In this study, we aimed to provide a review of the literature regarding the regulatory mechanisms and prophylaxis as well as the treatment of vascular leakage in critical diseases such as severe trauma and shock, which could be beneficial for the overall clinical treatment of vascular leakage disorders.


Asunto(s)
Síndrome de Fuga Capilar/etiología , Heridas y Lesiones/complicaciones , Heridas y Lesiones/terapia , Acuaporinas/metabolismo , Síndrome de Fuga Capilar/diagnóstico , Síndrome de Fuga Capilar/terapia , Humanos , Unidades de Cuidados Intensivos/organización & administración , Unidades de Cuidados Intensivos/estadística & datos numéricos , Proteínas de la Membrana/metabolismo , Nucleósido-Fosfato Quinasa/metabolismo , Permeabilidad , Sepsis/etiología , Sepsis/terapia , Choque/complicaciones , Choque/terapia , Transcitosis/fisiología , Proteína de la Zonula Occludens-1/metabolismo , Proteína de la Zonula Occludens-2/metabolismo
16.
J Am Chem Soc ; 139(1): 541-547, 2017 01 11.
Artículo en Inglés | MEDLINE | ID: mdl-27936658

RESUMEN

The Ir-catalyzed asymmetric hydrogenation of olefins is widely used for production of value-added bulk and fine chemicals. The iridium catalysts with chiral spiro phosphine-oxazoline ligands developed in our group show high activity and high enantioselectivity in the hydrogenation of olefins bearing a coordinative carboxyl group, such as α,ß-unsaturated carboxylic acids, ß,γ-unsaturated carboxylic acids, and γ,δ-unsaturated carboxylic acids. Here we conducted detailed mechanistic studies on these Ir-catalyzed asymmetric hydrogenation reactions by using (E)-2-methyl-3-phenylacrylic acid as a model substrate. We isolated and characterized several key intermediates having Ir-H bonds under the real hydrogenation conditions. Particularly, an Ir(III) migratory insertion intermediate was first isolated in an asymmetric hydrogenation reaction promoted by chiral Ir catalysts. That this intermediate cannot undergo reductive elimination in the absence of hydrogen strongly supports the involvement of an Ir(III)/Ir(V) cycle in the hydrogenation. On the basis of the structure of the Ir(III) intermediate, variable-temperature NMR spectroscopy, and density functional theory calculations, we elucidated the mechanistic details of the Ir-catalyzed hydrogenation of unsaturated carboxylic acids and explained the enantioselectivity of the reactions. These findings experimentally and computationally elucidate the mechanism of Ir-catalyzed asymmetric hydrogenation of olefins with a strong coordinative carboxyl group and will likely inspire further catalyst design.

17.
Angew Chem Int Ed Engl ; 54(30): 8791-4, 2015 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-26062032

RESUMEN

The chiral tridentate spiro P-N-S ligands (SpiroSAP) were developed, and their iridium complexes were prepared. Introduction of a 1,3-dithiane moiety into the ligand resulted in a highly efficient chiral iridium catalyst for asymmetric hydrogenation of ß-alkyl-ß-ketoesters, producing chiral ß-alkyl-ß-hydroxyesters with excellent enantioselectivities (95-99.9% ee) and turnover numbers of up to 355,000.

18.
Artículo en Inglés | MEDLINE | ID: mdl-30613233

RESUMEN

Recognizing the potential of online student question-generation to engage language learners in communicative activities and use the target language in a personally meaningful way for language and learning motivation development, an experimental study examining the English learning effects of this approach, in comparison to an online drill-and-practice strategy, was conducted. A quasi-experimental research design was adopted. Four sixth-grade classes (N = 106) participated in this study and were randomly assigned to different treatment groups. An online learning system supporting the various learning activities was adopted. The results of analysis of covariance (ANCOVAs) showed that students in the online student question-generation group performed significantly better in English assessments and exhibited higher learning motivation than those in the contrast group. The significance of this study and suggestions for instructional implementation and future works are also presented.

19.
Neurourol Urodyn ; 32(3): 281-6, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22847293

RESUMEN

OBJECTIVE: To explore the myoblast formation around the urethra and increase in urethral resistance of bone marrow mesenchymal stem cells or muscle-like cells/calcium alginate composite gel injection therapy and effect on LPP in SUI rat model. METHODS: Isolation, cultivation, and identification of SD rat bone marrow mesenchymal stem cell were performed. 5-Azacytidine was introduced to induce muscle-like cells. SUI was produced in 72 6-week-old female Sprague-Dawley rats, which were divided into four groups: stem cell-gel group, muscle-like cell-gel group, Gel group, and mock control group. One, 4, and 8 weeks after injection, the leak point pressure (LPP) was measured. HE staining of Desmin and α-skeletal muscle actin (α-SMA) were performed. RESULTS: At 4 and 8 weeks after injection in stem cell-gel group and muscle-like cell-gel group, growth of blood vessels gradually increased at gel edge, BMSC, and muscle-like cells gathered around the new blood vessels observed by fluorescence tracer, muscle-like cells grew into elongated spindle-like cells, Desmin, and α-SMA staining were obviously positive expression. LPP determinations of the mock control group compared with the Gel groups were significantly different. CONCLUSIONS: Compound of BMSC, muscle-like cells, and calcium alginate composite gel has the potential to differentiate into muscle cells in the microenvironment of SUI rat model. It is found by LPP measurement that the correlation between the increase in urethral resistance and the volume effect of calcium alginate gel is high.


Asunto(s)
Alginatos/química , Trasplante de Células Madre Mesenquimatosas , Mioblastos/trasplante , Regeneración , Ingeniería de Tejidos , Andamios del Tejido , Uretra/fisiopatología , Incontinencia Urinaria de Esfuerzo/cirugía , Actinas/metabolismo , Animales , Animales Recién Nacidos , Biomarcadores/metabolismo , Diferenciación Celular , Células Cultivadas , Desmina/metabolismo , Modelos Animales de Enfermedad , Femenino , Geles , Ácido Glucurónico/química , Ácidos Hexurónicos/química , Inmunohistoquímica , Mioblastos/metabolismo , Mioblastos/patología , Fenotipo , Presión , Ratas , Ratas Sprague-Dawley , Nicho de Células Madre , Factores de Tiempo , Ingeniería de Tejidos/métodos , Uretra/metabolismo , Uretra/patología , Incontinencia Urinaria de Esfuerzo/metabolismo , Incontinencia Urinaria de Esfuerzo/patología , Incontinencia Urinaria de Esfuerzo/fisiopatología , Urodinámica
20.
DNA Cell Biol ; 31(6): 1125-30, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22335768

RESUMEN

Interleukin-8 (IL-8) belongs to the superfamily of CXC chemokines, contributing to human cancer progression through potential mitogenic, angiogenic, and motogenic functions. We hypothesize that the functional polymorphism of IL-8 may influence the inflammatory process during pathological stage from hepatitis to hepatocellular carcinoma (HCC). Two polymorphisms in the IL-8 gene (-251A/T and +781C/T) were examined in 160 cases of chronic hepatitis B, 80 cases of hepatitis B virus (HBV)-related liver cirrhosis (LC), 150 cases of HBV-related HCC, and 150 healthy controls using polymerase chain reaction-restriction fragment length polymorphism method and DNA sequencing. In the LC group, the AA genotypes were associated with a significantly decreased risk of LC compared with the TT genotype (OR=0.14, 95% CI 0.02-0.87, p=0.035). The data also revealed that subjects with the A allele appeared to have lower susceptibility to LC than those with the T allele (OR=0.48, 95% CI 0.25-0.92, p=0.027). The +781C/T polymorphism of IL-8 was not found relevant to the liver diseases. This study indicated that the IL-8 gene -251 AA genotype might be a protect factor for LC.


Asunto(s)
Predisposición Genética a la Enfermedad/genética , Virus de la Hepatitis B/patogenicidad , Interleucina-8/genética , Hepatopatías/genética , Hepatopatías/virología , Polimorfismo de Nucleótido Simple , Adulto , Secuencia de Bases , Estudios de Casos y Controles , Femenino , Frecuencia de los Genes/genética , Haplotipos/genética , Hospitales , Humanos , Masculino , Persona de Mediana Edad
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