Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 37
Filtrar
1.
Zhongguo Zhong Yao Za Zhi ; 45(1): 119-123, 2020 Jan.
Artigo em Zh | MEDLINE | ID: mdl-32237420

RESUMO

Astragali Radix is commonly used as bulk medicinal materials. Chinese Pharmacopoeia contains about 150 compound preparations of Astragali Radix, but the sample preparation method under the determination of Astragali Radix content in Chinese Pharmacopoeia is tedious and time-consuming, not convenient for the test of a large number of samples. Therefore, it is of great significance to simplify the sample preparation method and improve the practicability of the method for the quality control of Astragali Radix and its preparations. In this study, ultrasonic extraction method was used instead of heated reflux extraction, and solid phase extraction method was used to enrich and prepare the samples. A set of practical quality evaluation method was established for Astragali Radix slices and standard decoction, greatly shortening the sample preparation time and improving the accuracy of the method. The results of Astragali Radix standard decoction analysis showed that the transfer rate of calycosin 7-O-ß-D-glucospyranoside,(96.5±28.7)%, had great variation, which was found to be related to the conversion of mulberry isoflavone glucoside into calycosin 7-O-ß-D-glucospyranoside during the preparation of standard decoction. The transfer rates were(59.4±14.4)% and(101.3±12.3)% for calycosin and astragaloside Ⅳ respectively, which were relatively stable. Therefore, it is suggested that Astragali Radix slices and water decoction preparations should be evaluated by using calycosin and astragaloside Ⅳ as the quality evaluation index. The results provide a scientific and practical method for quality control of Astragali Radix slices and its standard decoction, and also provide scientific evidence for quality evaluation of the preparations.


Assuntos
Astrágalo/química , Medicamentos de Ervas Chinesas/análise , Astragalus propinquus , Medicamentos de Ervas Chinesas/normas , Glucosídeos/análise , Raízes de Plantas/química , Controle de Qualidade , Extração em Fase Sólida
2.
Appl Opt ; 57(26): 7579-7583, 2018 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-30461827

RESUMO

A quantum cascade laser emitting at λ∼8.5 µm based on the excited-state injection is presented. The operating voltage is reduced for a low-voltage defect in the excited-state design, compared with the conventional ground-state injection design. The threshold voltage and voltage defect are as low as 6.3 V and 54 mV for a 30-stage active region, respectively. Devices were fabricated through standard buried-heterostructure processing to decrease the heat accumulation. A continuous-wave optical power of 340 mW is obtained at 283 K with a threshold current density of 2.7 kA/cm2. Such a design has the potential to further improve the wall plug efficiency for increased voltage efficiency.

3.
Opt Express ; 25(12): 13807-13815, 2017 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-28788922

RESUMO

We demonstrate a quantum cascade laser with active regions consisting of InAs quantum dots deposited on GaAs buffer layers that are embedded in InGaAs wells confined by InAlAs barriers. Continuous wave room temperature lasing at the wavelength of 7.2 µm has been demonstrated with the threshold current density as low as 1.89 kA/cm2, while in pulsed operational mode lasing at temperatures as high as 110 °C had been observed. A phenomenological theory explaining the improved performance due to weak localization of states had been formulated.

4.
Water Sci Technol ; 67(3): 485-93, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23202551

RESUMO

Recently, it has been found that biological phosphorus removal can be achieved in an aerobic/extended-idle (AEI) process using both glucose and acetate as the sole substrate. However, the microbial consortiums involved in glucose-fed and acetate-fed systems have not yet been characterized. Thus the aims of this paper were to investigate the diversities and dynamics of bacterial communities during the acclimation period, and to quantify polyphosphate-accumulating organisms (PAOs) and glycogen-accumulating organisms (GAOs) in the systems. The phylogenetic analysis showed that the microbial communities were mainly composed of phylum Proteobacteria, Bacteroidetes, Chlorobi and another six kinds of unclassified bacteria. Fluorescence in-situ hybridization (FISH) analysis revealed that PAOs and GAOs accounted for 43 ± 7 and 16 ± 3% of all bacteria in the glucose-fed system, and 19 ± 4 and 35 ± 5% of total bacteria in the acetate-fed system, respectively. The results showed that the conventional PAOs could thrive in the AEI process, and a defined anaerobic zone was not necessarily required for putative PAOs growth.


Assuntos
Reatores Biológicos/microbiologia , Consórcios Microbianos , Fósforo/metabolismo , Poluentes Químicos da Água/metabolismo , Eletroforese em Gel de Gradiente Desnaturante , Hibridização in Situ Fluorescente , Fósforo/isolamento & purificação , Filogenia , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Poluentes Químicos da Água/isolamento & purificação
5.
Environ Technol ; 33(7-9): 961-6, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22720421

RESUMO

A novel strain of thermophilic bacteria with a highly efficient sludge dissolution performance was isolated from garden soil at 65 degrees C in this study. The colony morphology, physiological and biochemical characteristics of the strain were investigated. The results showed that the strain was Gram-positive, small rod-shaped, sporulating and secreted extracellular enzymes (protease and amylase). The 16S rDNA analysis demonstrated that this strain had not been previously reported. Therefore, it was labelled Bacillus thermophilic bacteria AT07-1 (registration number: FJ231108). To evaluate its capability for excess sludge solubilization, a pure culture of the strain was used in sludge solubilization tests; an enhanced solubilization process was subsequently obtained. After 36 h digestion, the protease activity in the inoculated system reached 0.37 U/ml, an increase of 0.16 U/ml compared with the non-inoculated system (0.21 U/ml). The solubilization rate for volatile suspended solids reached 46.45% in 48 h after inoculation with Bacillus thermophilic bacteria AT07-1, which was 10.24% higher than the non-inoculated system, and which could meet the standard of sludge stability suggested by the US Environmental Protection Agency.


Assuntos
Bacilos Gram-Positivos Formadores de Endosporo/isolamento & purificação , Esgotos/microbiologia , Bacilos Gram-Positivos Formadores de Endosporo/classificação , Bacilos Gram-Positivos Formadores de Endosporo/metabolismo , RNA Ribossômico 16S/genética
6.
Environ Technol ; 33(10-12): 1307-12, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22856303

RESUMO

A fungi strain named Fusarium sp. was isolated from manganese-electrolysed slag by using a gradient dilution spread plate method, identified by 26S RNA sequence analysis and phylogenetic tree analysis, and explored for the bioleaching capacity to manganese (II) from manganese-electrolysed slag in liquid mineral medium under different environmental conditions, including system temperature, incubator rotation speed and initial pH value. DNA sequence and phylogenetic analysis indicated the name of this fungi strain, that is, Fusarium sp., and higher bioleaching efficiencies (71.6%) of manganese by this fungi were observed when the bioleaching was carried out under the optimized conditions as follows: contact time: 72 h; system temperature: 28 degrees C; inoculums concentration: 2% (v/v); incubator rotation speed: 150 rpm; pH 4.0. Because of its low cost, environment friendliness and better efficiency, the bioleaching technique will have a significant impact on manganese-electrolysed slag pollution mitigation.


Assuntos
Fusarium/química , Manganês/isolamento & purificação , Indústrias Extrativas e de Processamento , Concentração de Íons de Hidrogênio , Temperatura
7.
Huan Jing Ke Xue ; 42(2): 891-899, 2021 Feb 08.
Artigo em Zh | MEDLINE | ID: mdl-33742884

RESUMO

Focusing on low biogas yields in the anaerobic co-digestion of waste activated sludge and food waste, the enhancing effects and mechanisms of microscale zero valent iron (mZVI) on anaerobic co-digestion was investigated. The results indicated that the addition of mZVI enhanced the methanogenesis stage of co-digestion but had no significant effect on the solubilization, hydrolysis, and acidification stages. With a dosage of 10 g·L-1 mZVI, the cumulative methane yield (based on VS) within 15 days reached 238.68 mL·g-1, which was 20.05% higher than the control group. The mechanism analysis showed that mZVI promoted electron transport system (ETS) activity (based on INTF/TS), which increased to 21.50 mg·(g·h)-1 with 10 g·L-1 mZVI compared to 13.43 mg·(g·h)-1 in the control group. Furthermore, mZVI enhanced direct interspecies electron transfer (DIET) between specific bacteria and methanogens. Microbial community analysis demonstrated that the abundance of DIET-related microorganisms, such as Syntrophomonas, Methanosarcina, and Methanobacterium, was higher in presence of mZVI.

8.
Biochem Pharmacol ; 188: 114523, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33741331

RESUMO

Triple-negative breast cancer (TNBC) shares the molecular features facilitating epithelial-to-mesenchymal transition (EMT), which contributed to tumor invasion and metastasis. A platinum(IV) conjugate ketoplatin deriving from FDA-approved drugs cisplatin and ketoprofen was designed and prepared to enhance antitumor activity and suppress EMT in TNBC via positive impact on inflammatory microenvironment by modulating COX-2 signal. As a prodrug, ketoplatin afforded 50.26-fold higher cytotoxicity than cisplatin against TNBC mesenchymal-stem cell-like MDA-MB-231 cells, partly attributing to its dramatic increase of cellular uptake and DNA damage. More importantly, EMT progress in MDA-MB-231 was markedly restrained by ketoplatin, resulting from the suppression of vimentin and N-cadherin mediated by down-regulated COX-2. Further in vivo investigation exhibited that ketoplatin effectively inhibited tumor growth and reduced systemic toxicity compared to cisplatin. Overall, ketoplatin possessed high antitumor activity and low toxicity against TNBC MDA-MB-231 in vitro and in vivo.


Assuntos
Antineoplásicos/administração & dosagem , Cisplatino/análogos & derivados , Cetoprofeno/administração & dosagem , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/metabolismo , Microambiente Tumoral/efeitos dos fármacos , Células A549 , Animais , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/química , Antineoplásicos/química , Cisplatino/administração & dosagem , Cisplatino/química , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Transição Epitelial-Mesenquimal/fisiologia , Feminino , Células HeLa , Humanos , Mediadores da Inflamação/antagonistas & inibidores , Mediadores da Inflamação/metabolismo , Cetoprofeno/análogos & derivados , Células MCF-7 , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Resultado do Tratamento , Neoplasias de Mama Triplo Negativas/patologia , Microambiente Tumoral/fisiologia , Ensaios Antitumorais Modelo de Xenoenxerto/métodos
9.
Water Sci Technol ; 62(4): 947-55, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20729600

RESUMO

The performance of a fluidized bed reactor using immobilized Phanerochaete chrysosporium to remove 2,4-dichlorophenol (2,4-DCP) from aqueous solution was investigated. The contribution of lignin peroxidase (LiP) and manganese peroxidase (MnP) secreted by Phanerochaete chrysosporium to the 2,4-DCP degradation was examined. Results showed that Lip and Mnp were not essential to 2,4-DCP degradation while their presence enhanced the degradation process and reaction rate. In sequential batch experiment, the bioactivity of immobilized cells was recovered and improved during the culture and the maximum degradation rate constant of 13.95 mg (Ld)⁻¹ could be reached. In continuous bioreactor test, the kinetic behavior of the Phanerochaete chrysosporium immobilized on loofa sponge was found to follow the Monod equation. The maximum reaction rate was 7.002 mg (Lh)⁻¹, and the saturation constant was 26.045 mg L⁻¹.


Assuntos
Reatores Biológicos , Células Imobilizadas/metabolismo , Clorofenóis/metabolismo , Phanerochaete/enzimologia , Biotransformação , Clorofenóis/isolamento & purificação , Clorofenóis/farmacologia , Meios de Cultura , Proteínas Fúngicas/metabolismo , Peroxidases/metabolismo , Phanerochaete/efeitos dos fármacos , Phanerochaete/crescimento & desenvolvimento
10.
Water Sci Technol ; 62(1): 15-20, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20595748

RESUMO

This study aims at coupling coal cinder filter with biological process to improve pharmaceutical wastewater quality and reduce the disposal cost. In the coal cinder filter, the removal efficiencies of COD, BOD(5), SS and color were 90+/-2%, 72+/-2%, 95+/-2% and 80+/-2%, respectively. The results attribute to the big specific surface area and strong adsorption ability. Coal cinder filter removes a large portion of the pollutants in the influent wastewater, which would strongly stable the effluent waste water quality, and reduce the load of follow-up biological treatment process. The average removal efficiencies for COD, BOD(5), SS and color of the combined process were about 99.7+/-3%, 98.2+/-4%, 98.5+/-3% and 96.3+/-2%, respectively, with the average effluent quality of COD 16+/-1 mg/L, BOD(5) 11+/-1 mg/L, SS 10+/-0.6 mg/L and color 22+/-1 (multiple), which are consistent with the national requirements of the waste pollutants for pharmaceutical industry of chinese traditional medicine discharge standard (GB 21906-2008). The results indicated that the combined procedure could offer an attractive solution for pharmaceutical wastewater treatment with considerable low cost.


Assuntos
Filtração/métodos , Resíduos Industriais , Preparações Farmacêuticas/química , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/química , Óxido de Alumínio/química , Hidrólise , Oxirredução , Preparações Farmacêuticas/metabolismo , Dióxido de Silício/química , Poluentes Químicos da Água/metabolismo
11.
Water Sci Technol ; 62(5): 1183-9, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20818063

RESUMO

The aim of this study was to isolate a mould from the surface of manganese slag which had strong resistance and high adsorption of Mn(2 + ), and to determine the effects of initial Mn(2 + ) concentration, incubation temperature, rotation speed and inoculation amount on adsorption of Mn(2 + ) from manganese waste water solution. The result showed that a mould (A5) which was isolated from manganese slag had the adsorption rate of Mn(2 + ) to 97.5% at the initial pH value 6, inoculation amount 2%, rotation speed 150 r/min, a concentration of Mn(2 + ) 500 mg/L, and a temperature of 28 degrees C cultivated for 50 h. As there is no research on adsorption of Mn(2 + ) from manganese waste water by fungi before, this research showed a theoretical guidance on this field.


Assuntos
Fungos/metabolismo , Manganês/química , Eliminação de Resíduos Líquidos/métodos , Biodegradação Ambiental , Queixo , Resíduos Industriais , Mineração , Fatores de Tempo
12.
Water Sci Technol ; 61(11): 2881-8, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20489261

RESUMO

Intermittent sand filters (ISFs) are effective and economical in treating wastewater, but they are easy to clog up. To explore a feasible and simple method to alleviate clogging, two pilot-scale ISFs were constructed, one of which contained earthworms and the other did not. During the operation, the effects of earthworms on the hydraulic behaviour of ISFs were investigated. The results showed that both ISFs exhibited good performance in wastewater treatment. However, they showed different hydraulic characteristics although operated at the same organic loading rate (approximately 300 g m(-2) d(-1)). The ISF without earthworms clogged only after 53 d operation, and was partially recovered after 7 d resting, but after that, clogging occurred again, and more rapidly than the initial clogging event (40 d). However, water on the medium surface of the ISF with earthworms was not observed during the whole experiments. In addition, 11-13% of effective porosity and 0.015-0.026 cm s(-1) of infiltration rate were measured in the upper 20 cm of the ISF at the end of the experiments. The facts demonstrated that earthworms played a positive role in alleviating clogging and earthworms fed filter could alleviate surface clogging effectively.


Assuntos
Filtração , Oligoquetos , Dióxido de Silício , Animais , Monitoramento Ambiental
13.
Water Sci Technol ; 59(3): 573-82, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19214013

RESUMO

It was occasionally found that a significant nitrogen loss in solution under neutral pH value in a sequencing batch reactor with a single-stage oxic process using synthetic wastewater, and then further studies were to verify the phenomenon of nitrogen loss and to investigate the pathway of nitrogen removal. The result showed that good performance of nitrogen removal was obtained in system. 0-7.28 mg L(-1) ammonia, 0.08-0.38 mg L(-1) nitrite and 0.94-2.12 mg L(-1) nitrate were determined in effluent, respectively, when 29.85-35.65 mg L(-1) ammonia was feeding as the sole nitrogen source in influent. Furthermore, a substantial nitrogen loss in solution (95% of nitrogen influent) coupled with a little gaseous nitrogen increase in off-gas (7% of nitrogen influent) was determined during a typical aerobic phase. In addition, about 322 mg nitrogen accumulation (84% of nitrogen influent) was detected in activated sludge. Based on nitrogen mass balance calculation, the unaccounted nitrogen fraction and the ratio of nitrogen accumulation in sludge/nitrogen loss in solution were 14.6 mg (3.7% of nitrogen influent) and 0.89, respectively. The facts indicated that the essential pathway of nitrogen loss in solution in this study was excess nitrogen accumulation in activated sludge.


Assuntos
Reatores Biológicos , Nitrogênio/metabolismo , Esgotos , Aerobiose , Oxirredução , Oxigênio/análise , Soluções , Fatores de Tempo , Volatilização , Eliminação de Resíduos Líquidos
14.
Water Sci Technol ; 60(3): 761-70, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19657172

RESUMO

Three oxidation processes for amoxicillin wastewater pretreatment such as Electro-Fe(3+)(EDTA)/H2O2 (EDTA: ethylenediaminetetraacetic acid), Fe(3+)(EDTA)/H2O2 and Electro-Fe(3+)/H2O2 were simultaneously discussed at pH of 7.0 (+/-0.1). It was found that the above processes could achieve 78%, 64%, 33% chemical oxygen demand (COD(cr)) removal, and 86%, 70%, 47% amoxicillin degradation respectively. Moreover, the results of biodegradability (biological oxygen demand (BOD(5))/COD(cr) ratio) showed that the Electro-Fe(3+)(EDTA)/H2O2 process was a promising way to pretreat antibiotic wastewater due to the biodegradability of the effluent improved to 0.48 compared with the cases of Fe(3+)(EDTA)/H2O2 (0.40) and Electro-Fe(3+)/H2O2 process (0.12). Therefore, it was reasonable to note that EDTA and electricity showed synergetic effect on the oxidation process. Additionally, infrared spectra (IR) were applied to concisely propose a potential degradation way of amoxicillin. The characteristic changes of H2O2 and EDTA in the oxidation process were also investigated in detail.


Assuntos
Amoxicilina/química , Ácido Edético/química , Eletricidade , Peróxido de Hidrogênio/química , Ferro/química , Amoxicilina/isolamento & purificação , Biodegradação Ambiental , Catálise , Concentração de Íons de Hidrogênio , Oxirredução , Oxigênio/isolamento & purificação , Espectrofotometria Ultravioleta , Eliminação de Resíduos Líquidos
15.
Eur J Med Chem ; 167: 377-387, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30784875

RESUMO

The great interest in epithelial-to-mesenchymal transition (EMT) programme lies in its association with process of metastasis and invasion, which is a crucial cause of cancer-related death. Herein, we designed and reported three new NSAID-Pt(IV) prodrugs, taking Non-Steroid Anti-Inflammatory Drugs (NSAIDs) to disrupt EMT programme and assist genotoxic platinum-based drugs as a cytotoxicity booster, to offer a class of potential anticarcinogens with a multi-functional action mechanism. The NSAID-Pt(IV) prodrugs, especially Eto-Pt(IV), highly enhanced cellular uptake with amount up to 42-fold at 3 h compared with CDDP, and greatly increased DNA damage and cell apoptosis, showing much higher cytotoxicity than cisplatin in the tested cancer cells even in A549/cis cells. Among of them, Eto-Pt(IV) and Car-Pt(IV) exhibited more excellent activity than Sul-Pt(IV), arising from their reduction-labile and favorable lipophilicity. Most strikingly, Eto-Pt(IV) markedly inhibited metastasis and invasion of MCF-7 cells, owing to its COX-2 suppression that down-regulated active MMP-2, vimentin protein and up-regulated E-cadherin. In vivo, Eto-Pt(IV) displayed potent antitumor activity and no observable toxicity in BALB/c nude mice bearing MCF-7 tumors.


Assuntos
Anti-Inflamatórios não Esteroides/química , Antineoplásicos/química , Desenho de Fármacos , Compostos de Platina/química , Pró-Fármacos/química , Animais , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Dano ao DNA/efeitos dos fármacos , Xenoenxertos , Humanos , Camundongos , Invasividade Neoplásica , Metástase Neoplásica/tratamento farmacológico , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Pró-Fármacos/farmacologia
16.
Nanoscale Res Lett ; 14(1): 123, 2019 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-30945027

RESUMO

High-power, low-threshold stable single-mode operation buried distributed feedback quantum cascade laser by incorporating sampled grating emitting at λ ~ 4.87 µm is demonstrated. The high continuous wave (CW) output power of 948 mW and 649 mW for a 6-mm and 4-mm cavity length is obtained at 20 °C, respectively, which benefits from the optimized optical field distribution of sampled grating. The single-mode yields of the devices are obviously enhanced by controlling cleaved positions of the two end facets precisely. As a result, stable single-mode emission and mode tuning linearly without any mode hopping of devices are obtained under the different heat sink temperatures or high injection currents.

17.
Nanoscale Res Lett ; 14(1): 331, 2019 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-31641875

RESUMO

In this paper, an anomalous spectral data of distributed Bragg reflector (DBR) quantum cascade lasers (QCLs) emitting around 7.6 µm is presented. The two-section DBR lasers, consisting of a gain section and an unpumped Bragg reflector, display an output power above 0.6 W in continuous wave (CW) mode at room temperature. The anomalous spectral data is defined as a longitudinal mode which moves toward shorter wavelengths with increasing temperature or injection current, which is unexpected. Although the longer wavelength modes are expected to start lasing when raising device temperature or injection current, occasional mode hops to a shorter wavelength are seen. These anomalous mode transitions are explained by means of modal analysis. The thermal-induced change of the refractive index implied by an increase in the temperature or injection current yields nearly periodic transitions between cavity modes.

18.
Bioresour Technol ; 99(13): 5466-73, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18082396

RESUMO

The performance of biological phosphorus removal (BPR) in a sequencing batch reactor (SBR) with single-stage oxic process was investigated using simulated municipal wastewater. The experimental results showed that BPR could be achieved in a SBR without anaerobic phase, which was conventionally considered as a key phase for BPR. Phosphorus (P) concentration 0.22-1.79 mg L(-1) in effluent can be obtained after 4h aeration when P concentration in influent was about 15-20 mg L(-1), the dissolved oxygen (DO) was controlled at 3+/-0.2 mg L(-1) during aerobic phase and pH was maintained 7+/-0.1, which indicated the efficiencies of P removal were achieved 90% above. Experimental results also showed that P was mainly stored in the form of intracellular storage of polyphosphate (poly-P), and about 207.235 mg phosphates have been removed by the discharge of rich-phosphorus sludge for each SBR cycle. However, the energy storage poly-beta-hydroxyalkanoates (PHA) was almost kept constant at a low level (5-6 mg L(-1)) during the process. Those results showed that phosphate could be transformed to poly-P with single-stage oxic process without PHA accumulation, and BPR could be realized in net phosphate removal.


Assuntos
Fosfatos/isolamento & purificação , Fósforo/isolamento & purificação , Polifosfatos/isolamento & purificação , Esgotos , Acetobacter , Aerobiose , Anaerobiose , Reatores Biológicos , Ciclo do Ácido Cítrico , Polimetil Metacrilato
19.
Eur J Med Chem ; 157: 1292-1299, 2018 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-30195239

RESUMO

Modification of platinum (II) into lipophilic platinum (IV) compounds by introducing biologically active molecules were widely employed to develop new platinum-based prodrugs in the past decade. In this paper, two chlorambucil platinum (IV) complexes, CLB-Pt and CLB-Pt-CLB, were synthesized and displayed very potent antiproliferative activity against all the tested cancer cell lines, such as A549, HeLa and MCF-7, especially to treat the well-known refractory triple-negative breast cancer. CLB-Pt-CLB significantly improved cell-killing effect in triple-negative subtype MDA-MB-231 cells, and showed much stronger cytotoxicity than either monotherapy or combination of cisplatin and chlorambucil. CLB-Pt-CLB prodrug entered cells in dramatically increased amount compared with cisplatin and enhanced DNA damage, inducing cancer cell apoptosis. It exhibited high anticancer activity and no observable toxicity in BALB/c nude mice bearing MDA-MB-231 tumors. The chlorambucil moiety not only greatly assisted the passive diffusion of CLB-Pt-CLB into cells, but also produced the synergism with cisplatin in targeting DNA.


Assuntos
Antineoplásicos/farmacologia , Clorambucila/farmacologia , Compostos Organoplatínicos/farmacologia , Pró-Fármacos/farmacologia , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Clorambucila/química , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Humanos , Camundongos , Camundongos Nus , Estrutura Molecular , Compostos Organoplatínicos/síntese química , Compostos Organoplatínicos/química , Pró-Fármacos/síntese química , Pró-Fármacos/química , Relação Estrutura-Atividade , Neoplasias de Mama Triplo Negativas/patologia , Cicatrização/efeitos dos fármacos
20.
Nanoscale Res Lett ; 13(1): 205, 2018 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-29987613

RESUMO

Power scaling in broad area quantum cascade laser (QCL) usually leads to the deterioration of the beam quality with an emission of multiple lobes far-field pattern. In this letter, we demonstrate a tapered QCL array integrated with Talbot cavity at one side of the array. Fundamental supermode operation is achieved in the arrays with taper straight-end connected to the Talbot cavity. Lateral far-field of the fundamental supermode shows a near diffraction limited beam divergence of 2.7°. The output power of a five-element array is about three times as high as a single-ridge laser with an emission wavelength of around 4.8 µm. However, arrays with the taper-end connected to the Talbot cavity always show a high-order supermode operation whatever Talbot cavity length is.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA