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1.
J Am Chem Soc ; 141(24): 9739-9745, 2019 06 19.
Artículo en Inglés | MEDLINE | ID: mdl-31117673

RESUMEN

Spiro- and bridged bicyclic structures are in demand for their sp3-rich frameworks that offer unique physiochemical properties and precisely positioned substituent groups. In order to rapidly access such molecules in a cross-coupling fashion we describe olefin amine (OLA) reagents for the transformation of aldehydes and ketones into all three topological types of bicyclic N-heterocycles: bridged, spiro-, and fused rings. The OLA reagents are easily prepared and allow the synthesis of complex molecular frameworks under operationally simple conditions that tolerate a wide array of functional groups. Investigations into the Mn or Fe promoted reaction pathway support a metal hydride hydrogen atom transfer (MH-HAT) to generate a C-centered radical that undergoes addition to an unactivated imine, leading to an N-centered radical. A catalytic cycle featuring regeneration of the metal catalyst by O2 and a second HAT to form the unprotected saturated N-heterocycle appears to be operative.

2.
Angew Chem Int Ed Engl ; 55(3): 927-31, 2016 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-26636436

RESUMEN

Highly enantioselective Michael-type addition (MTA) reactions between N-protected alkenyl benzimidazoles and either pyrazoles or indazoles as nitrogen nucleophiles are accomplished for the first time using chiral phosphoric acid catalyst. Theoretical studies elucidated the reaction pathway and the origin of the stereochemical outcomes, where the catalyst substituent and the N-protecting group of benzimidazole contributed to the resulting high enantioselectivity.

3.
Beilstein J Org Chem ; 9: 1559-64, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23946855

RESUMEN

A chiral phosphoric acid-catalyzed selenofunctionalization of tryptamine derivatives provides access to 3a-(phenylselenyl)-1,2,3,3a,8,8a-hexahydropyrrolo[2,3-b]indole derivatives in high yields and with synthetically useful levels of enantioselectivity (up to 89% ee).

4.
Ying Yong Sheng Tai Xue Bao ; 34(1): 221-228, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36799397

RESUMEN

To screen out phosphorus solubilizing strains that can adapt to cold climate in Qinghai Province, Bacillus mucilaginosus, B. megaterium, B. cereus, Streptomyces violovariabilis, S. cinnamofuscus, and S. flavoagglomeratus were screened with solid plate medium as the primary and liquid medium as the secondary screening, with calcium phosphate, lecithin, and phytic acid as the single source of phosphorus. By comprehensively comparing the size of phosphate solubilizing circle in the solid plate medium and the soluble phosphorus content in the liquid medium, three strains of phosphate solubilizing bacteria with good phosphate solubilizing effects were screened, S. violovariabilis, S. cinnamofuscus, and B. mucilaginosus. The three phosphate solubilizing bacteria were made into liquid ino-culants, and the small rapeseed pot experiment was carried out with two soils with different fertilities in a cold climate in September. Compared with the control, plant height, fresh weight, root length, and root weight of rapes in high-fertility cultivated soil increased by 35.5%, 191.0%, 26.2%, and 282.7%, while plant phosphorus absorption, total phosphorus and available phosphorus contents in the rhizosphere soil increased by 968.9%, 5.1%, and 2.1%, respectively. In low-fertility soil, plant height and fresh weight was increased by 45.8% and 61.3%, root length and weight was decreased by 2.6% and 4.4%, while plant phosphorus absorption and the contents of total P and available P in rhizosphere soil were increased by 91.5 %, 29.1%, and 213.7%, respectively. The effect of the other two inoculants treatments was less significant than S. violovariabilis. Therefore, S. violovariabilis was the phosphate solubilizing strain suitable for the cold climate in Qinghai.


Asunto(s)
Brassica napus , Fósforo Dietético , Fósforo , Fosfatos , Suelo , Microbiología del Suelo
5.
Huan Jing Ke Xue ; 44(12): 6801-6810, 2023 Dec 08.
Artículo en Zh | MEDLINE | ID: mdl-38098405

RESUMEN

Sludge biochar(BC), which was prepared by the pyrolysis of waste-activated sludge at 450℃, was applied for peroxymonosulfate(PMS) activation to construct a BC/PMS system for ciprofloxacin(CIP) degradation. The physical and chemical properties of BC were studied using scanning electron microscopy(SEM), an energy dispersive spectrometer(EDS), a Fourier transform infrared spectrometer(FTIR), X-ray diffraction(XRD), a Zeta potential analyzer, and electron paramagnetic resonance spectroscopy(EPR). The effects of BC dosage, PMS dosage, initial pH value, and inorganic anions on CIP removal in the BC/PMS system were investigated. Further, the degradation mechanism of the BC/PMS system was speculated through the free radical quenching experiment and X-ray photoelectron spectroscopy(XPS) analysis. The results showed that the CIP degradation rate was 49.09% at a BC dosage of 1.0 g·L-1, PMS of 3.0 mmol·L-1, CIP of 20 mg·L-1, and pH of 6.0 in 120 min. SO42- and NO3- had no obvious effect on the removal of CIP in the BC/PMS system, whereas HCO3- and Cl-could inhibit CIP degradation significantly. The CIP removal in the BC/PMS system was attributed to the common function of the radical pathway dominated by ·OH and SO4-· and the non-radical pathway dominated by 1O2. The CIP degradation pathway mainly included piperazine ring opening and hydroxylation reaction.


Asunto(s)
Aguas del Alcantarillado , Contaminantes Químicos del Agua , Ciprofloxacina , Contaminantes Químicos del Agua/análisis , Peróxidos/química
6.
J Am Chem Soc ; 134(15): 6532-5, 2012 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-22471657

RESUMEN

The hybrid Au(I)/Brønsted acid binary catalyst system enables enynes to serve as latent 1,3-silyloxydienes capable of participating in the first cascade hydrosiloxylation of an enynyl silanol/asymmetric Diels-Alder reaction. A variety of polycyclic compounds bearing multistereogenic centers were obtained in high yields and excellent enantioselectivities from the relay catalytic cascade reaction between (2-(but-3-en-1-ynyl)phenyl) silanols and quinones catalyzed by the combined achiral gold complex and chiral N-triflyl phosphoramide.

7.
Hu Li Za Zhi ; 58(1): 48-58, 2011 Feb.
Artículo en Zh | MEDLINE | ID: mdl-21328205

RESUMEN

BACKGROUND: The treatment and care of demented elderly represents a major medical and social issue in Taiwan. Many empirical studies have demonstrated the efficacy of applying multi-sensory environment therapy to improve mood symptoms and reduce disturbed behavior frequencies among this population. While the technique has been widely applied in various clinical settings in the West, a study focusing on the treatment efficacy of multi-sensory environment therapy has yet to be conducted in Taiwan. PURPOSE: The purpose of the current study was to investigate the treatment efficacy of multi-sensory environment therapy on psychological and behavioral symptomatology among elderly patients with dementia. METHODS: This quasi-experimental study recruited 20 study participants from a nursing home in northern Taiwan. Treatment and control groups were arranged to contain 10 cases each. Participants were stratified by Mini-Mental State Examination (MMSE) score before random assignment to one of the two groups. The treatment group received a total of 24 sessions of multi-sensory environment therapy for 12 weeks. The control group received routine nursing home care. Researchers assessed treatment outcomes by comparing Neuropsychiatry Inventory (NPI) scores at baseline, week 6, and week 12, respectively. RESULTS: The experimental group showed a significant improvement over the control group on the NPI item "Motor Disturbance" at week 6. The experimental group scored significantly better than the control group on overall NPI score and on NPI items "Irritability or Liability" and "Motor Disturbance" after completion of the 12-week treatment regimen. CONCLUSIONS: Multi-sensory environment therapy helps improve behavioral and emotional symptoms in elderly patients with dementia. This technique may offer the potential to both improve the life quality of this population and reduce caretaker burdens.


Asunto(s)
Síntomas Conductuales/terapia , Demencia/terapia , Sensación , Anciano , Demencia/psicología , Femenino , Humanos , Masculino , Pruebas Neuropsicológicas
8.
Psychophysiology ; 58(3): e13744, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33314155

RESUMEN

When comparing the digits of different physical sizes, the processing of numerical value interacts with the processing of physical size. Given the universal use of Arabic numbers in mathematics and daily life, this study aims to elucidate the cognitive processes involved in the interactions of task-relevant and task-irrelevant features during information processing. We investigated this question by examining event-related potential (ERP) using a modified version of the size congruity comparison, which is a Stroop-like task. Numerical value and physical size were varied independently under task-relevant and task-irrelevant conditions. To better examine how the task-irrelevant features modulated the processing of the task-relevant attributes, a neutral condition was included in both tasks. For the physical task, congruent trials showed a less negative N200 response than neutral trials (indicating a facilitation effect), and incongruent trials elicited a larger N450 and smaller late positive complex (LPC) response than neutral trials (indicating an interference effect). For the numerical task, congruent trials showed a larger LPC response than neutral trials (indicating a facilitation effect). These ERP findings indicate that the sources of the facilitation and interference effects appear in different cognitive processes for each task. We further suggest that language characteristics may be a factor in the superior numerical processing exhibited in this study.


Asunto(s)
Atención/fisiología , Potenciales Evocados/fisiología , Conceptos Matemáticos , Reconocimiento Visual de Modelos/fisiología , Percepción del Tamaño/fisiología , Adulto , Electroencefalografía , Femenino , Humanos , Masculino , Psicolingüística , Test de Stroop , Adulto Joven
9.
J Environ Sci (China) ; 19(7): 776-82, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17966862

RESUMEN

The characteristics of anaerobic phosphorus release and anoxic phosphorus uptake were investigated in sequencing batch reactors using denitrifying phosphorus removing bacteria (DPB) sludge. The lab-scale experiments were accomplished under conditions of various nitrite concentrations (5.5, 9.5, and 15 mg/L) and mixed liquor suspended solids (MLSS) (1844, 3231, and 6730 mg/L). The results obtained confirmed that nitrite, MLSS, and pH were key factors, which had a significant impact on anaerobic phosphorus release and anoxic phosphorus uptake in the biological phosphorous removal process. The nitrites were able to successfully act as electron acceptors for phosphorous uptake at a limited concentration between 5.5 and 9.5 mg/L. The denitrification and dephosphorous were inhibited when the nitrite concentration reached 15 mg/L. This observation indicated that the nitrite would not inhibit phosphorus uptake before it exceeded a threshold concentration. It was assumed that an increase of MLSS concentration from 1844 mg/L to 6730 mg/L led to the increase of denitrification and anoxic P-uptake rate. On the contrary, the average P-uptake/N denitrifying reduced from 2.10 to 1.57 mg PO4(3-)-P/mg NO3(-)-N. Therefore, it could be concluded that increasing MLSS of the DEPHANOX system might shorten the reaction time of phosphorus release and anoxic phosphorus uptake. However, excessive MLSS might reduce the specific denitrifying rate. Meanwhile, a rapid pH increase occurred at the beginning of the anoxic conditions as a result of denitrification and anoxic phosphate uptake. Anaerobic P release rate increased with an increase in pH. Moreover, when pH exceeded a relatively high value of 8.0, the dissolved P concentration decreased in the liquid phase, because of chemical precipitation. This observation suggested that pH should be strictly controlled below 8.0 to avoid chemical precipitation if the biological denitrifying phosphorus removal capability is to be studied accurately.


Asunto(s)
Reactores Biológicos , Nitritos/metabolismo , Fosfatos/metabolismo , Fósforo/metabolismo , Contaminantes Químicos del Agua/metabolismo , Anaerobiosis , Concentración de Iones de Hidrógeno , Nitratos/metabolismo
10.
J Environ Sci (China) ; 17(5): 794-7, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16313005

RESUMEN

The principal aim of this paper is to develop an approach to realize stable biological nitrogen removal via nitrite under normal conditions. Validation of the new method was established on laboratory-scale experiments applying the sequencing batch reactor (SBR) activated sludge process to domestic wastewater with low C/N ratio. The addition of sodium chloride (NaCl) to influent was established to achieve nitrite build-up. The high nitrite accumulation, depending on the salinity in influent and the application duration of salt, was obtained in SBRs treating saline wastewater. The maintenance results indicated that the real-time SBRs can maintain stable nitrite accumulation, but conversion from shorter nitrification-denitrification to full nitrification-denitrification was observed after some operation cycles in the other SBR with fixed-time control. The presented method is valuable to offer a solution to realize and to maintain nitrogen removal via nitrite under normal conditions.


Asunto(s)
Reactores Biológicos , Nitritos/metabolismo , Nitrógeno/metabolismo , Aguas del Alcantarillado/microbiología , Eliminación de Residuos Líquidos/métodos , Purificación del Agua/métodos , China , Cloruro de Sodio/química , Factores de Tiempo , Eliminación de Residuos Líquidos/instrumentación , Purificación del Agua/instrumentación
11.
J Environ Sci (China) ; 16(4): 548-52, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15495953

RESUMEN

Effect of added carbon source and nitrate concentration on the denitrifying phosphorus removal by DPB sludge was systematically studied using batch experiments, at the same time the variation of ORP was investigated. Results showed that the denitrifying and phosphorus uptake rate in anoxic phase increased with the high initial anaerobic carbon source addition. However once the initial COD concentration reached a certain level, which was in excess to the PHB saturation of poly-P bacteria, residual COD carried over to anoxic phase inhibited the subsequent denitrifying phosphorus uptake. Simultaneously, phosphate uptake continued until all nitrate was removed, following a slow endogenous release of phosphate. High nitrate concentration in anoxic phase increased the initial denitrifying phosphorus rate. Once the nitrate was exhausted, phosphate uptake changed to release. Moreover, the time of this turning point occurred later with the higher nitrate addition. On the other hand, through on-line monitoring the variation of the ORP with different initial COD concentration, it was found ORP could be used as a control parameter for phosphorus release, but it is impossible to utilize ORP for controlling the denitrificaion and anoxic phosphorus uptake operations.


Asunto(s)
Carbono/metabolismo , Nitratos/metabolismo , Fósforo/aislamiento & purificación , Fósforo/metabolismo , Bacterias Anaerobias/fisiología , Reactores Biológicos , Aguas del Alcantarillado/química , Aguas del Alcantarillado/microbiología , Eliminación de Residuos Líquidos
12.
Huan Jing Ke Xue ; 29(6): 1526-32, 2008 Jun.
Artículo en Zh | MEDLINE | ID: mdl-18763495

RESUMEN

The characteristics of denitrifying phosphorus removal in a lab-scale two-sludge anaerobic-anoxic/nitrification SBR (A2 NSBR) system were studied fed with domestic wastewater. The influence of some key operation parameters, like C/P, C/N, and HRT, were examined using parallel tests, pH, dissolved oxygen (DO) and redox potential (ORP) were monitored on line to validate whether they could be used as the control parameters for this denitrifying phosphorus removal process. Results indicated that P removal efficiency showed an increased trend on the whole with the increase of the C/P. When the influent C/P was greater than 19.39, good phosphorus removal efficiency was achieved. However, the phosphorus removal efficiency deteriorated once the influent C/P decreased less than 15.36. On the other hand, relatively good phosphorus removal efficiency could be maintained in the A2 NSBR system even at a low C/N ratio, though the denitrification efficiency decrease instead. It is also found that increasing the influent C/N increased the PHB amount stored by polyphosphate accumulating organisms (PAO) and therefore the ultimate denitrification and phosphorus removal efficiency were both improved. For an excessively high C/N, the incompletely reacted COD will be residual to anoxic stage. Thus, the pure denitrification reaction, which preferentially supports OHOs, becomes the dominant reaction. This decreases the amount of available electron acceptors for denitrifying polyphosphate accumulating organisms (DNPAOs) at the anoxic stage which eventually impacts the anoxic phosphorus removal capacity. In addition, since A2 NSBR has two completely independent SBR systems, it benefits to establish a process control system in terms of the parameters DO, ORP, and pH.


Asunto(s)
Reactores Biológicos , Nitrógeno/aislamiento & purificación , Fósforo/aislamiento & purificación , Aguas del Alcantarillado/química , Eliminación de Residuos Líquidos/métodos , Bacterias Anaerobias/metabolismo , Biodegradación Ambiental , Nitrógeno/química , Nitrógeno/metabolismo , Fósforo/química , Fósforo/metabolismo , Aguas del Alcantarillado/microbiología
13.
Huan Jing Ke Xue ; 27(12): 2472-6, 2006 Dec.
Artículo en Zh | MEDLINE | ID: mdl-17304843

RESUMEN

It was realized nitrite accumulation in a pilot-scale pre-denitrification process at normal temperature. The influence factors, temperature, pH, FA and DO, for nitrite accumulation were analyzed. The nitrite was accumulated in the beginning time with the DO kept at 0.5 mg/L, however the phenomenon of nitrite accumulation was vanished when the DO increased to 1.5 mg/L. At last the nitrite accumulation was resumed when DO reduced to 0.5 mg/L. So it could be obtained that DO was the main factor to realize nitrite accumulation in the study. It was found that it was possible to keep stable and high nitrite accumulation effectively control DO at 0.5 mg/L.


Asunto(s)
Reactores Biológicos , Nitritos/metabolismo , Nitrógeno/metabolismo , Eliminación de Residuos Líquidos/métodos , Aerobiosis , Nitratos/química , Nitratos/metabolismo , Nitritos/química , Nitrógeno/aislamiento & purificación , Purificación del Agua/métodos
14.
Artículo en Inglés | MEDLINE | ID: mdl-15055936

RESUMEN

The Anaerobic-Anoxic/Nitrification (A2N) system is a continuous-flow, two-sludge process in which Poly-p bacteria are capable of taking up phosphate under anoxic conditions using nitrate as an electron acceptor. The process is very efficient because it maximizes the utilization of organic substrate for phosphorus and nitrogen removal. Further, the process solves the competition for organic substrate among Poly-p organisms and denitrifies as well as the problem of overgrowing of slow nitrifiers by fast organotrophs. An experimental lab-scale A2N system fed with domestic sewage was tested over a period of 260 days. The purpose of the experiment was to examine phosphorus removal capacity of a modified A2N two-sludge system. Factors affecting phosphorus and nitrogen removal by the A2N system were investigated. These factors were the influent COD TN ratio. Sludge Retention Time (SRT), Bypass Sludgy Flow rate (BSF), and Return Sludge Flow rate (RSF). Results indicated that optimum conditions for phosphorus and nitrogen removal were the influent COD/TN ratio around 6.49, the SRT of 14 days, and the BSF and RSF were fixed about 26%-33% of inffuent flow rate.


Asunto(s)
Nitrógeno/metabolismo , Fósforo/metabolismo , Aguas del Alcantarillado/química , Purificación del Agua/métodos , Bacterias/metabolismo , Reactores Biológicos , Humanos , Aguas del Alcantarillado/microbiología , Microbiología del Agua
15.
Huan Jing Ke Xue ; 25(4): 54-8, 2004 Jul.
Artículo en Zh | MEDLINE | ID: mdl-15515936

RESUMEN

Effect of added carbon source and nitrate concentration on the denitrifying phosphorus removal by SBR process was systematicaly studied, at the same time the variation of oxidation reductiun potential (ORP) was investigated. The results showed the phosphate release rate and the denitrifying and dephosphorus uptake rate in anoxic phase increased with the high carbon source concentration under anaerobic condition (100-300mg/L). However when the carbon source added in anaerobic phase was high to 300mg/L, the residual COD inhibited the succeed denitrifying dephosphorus uptake. High nitrate concentration (5, 15, 40mg/L) in anoxic phase increased the initial denitrifying dephosphorus rate. Once the nitrate depletes, phosphate uptake changed to phosphate release. Moreover, the time of the turning point occurred later with the higher nitrate addition. ORP can be used as a control parameter of phosphorus release, and it can also indicate the denitrificaiton react degree during the anoxic phosphorus removal but can't be used as control parameter of phosphorus uptake.


Asunto(s)
Carbono/metabolismo , Nitratos/metabolismo , Fósforo/metabolismo , Contaminantes Químicos del Agua/metabolismo , Purificación del Agua/métodos , Bacterias Anaerobias/metabolismo , Nitritos/química , Nitritos/metabolismo , Nitrógeno/metabolismo , Oxidación-Reducción , Oxígeno/metabolismo , Fosfatos/metabolismo , Fósforo/aislamiento & purificación , Contaminantes Químicos del Agua/aislamiento & purificación
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