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1.
Sci Rep ; 14(1): 10255, 2024 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-38704410

RESUMO

Our study explores neutrosophic statistics, an extension of classical and fuzzy statistics, to address the challenges of data uncertainty. By leveraging accurate measurements of an auxiliary variable, we can derive precise estimates for the unknown population median. The estimators introduced in this research are particularly useful for analysing unclear, vague data or within the neutrosophic realm. Unlike traditional methods that yield single-valued outcomes, our estimators produce ranges, suggesting where the population parameter is likely to be. We present the suggested generalised estimator's bias and mean square error within a first-order approximation framework. The practicality and efficiency of these proposed neutrosophic estimators are demonstrated through real-world data applications and the simulated data set.

2.
Sci Rep ; 14(1): 7960, 2024 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-38575651

RESUMO

Respiratory sensitivity and pneumonia are possible outcomes of the coronavirus (COVID-19). Surface characteristics like temperature and sunshine affect how long the virus survives. This research article analyzes COVID-19 mathematical model behavior based on symptomatic and non-symptomatic individuals. In the reproductive model, the best result indicates the intensity of the epidemic. Our model remained stable at a certain point under controlled conditions after we evaluated a specific element. This approach is in place of traditional approaches such as Euler's and Runge-Kutta's. An unusual numerical approach known as the non-standard finite difference (NSFD) scheme is used in this article. This numerical approach gives us positivity. A dependable numerical analysis allowed us to evaluate different approaches and verify our theoretical results. Unlike the widely used Euler and RK4 approaches, we investigated the benefits of implementing NSFD schemes. By numerically simulating COVID-19 in a variety of scenarios, we demonstrated how our theoretical concepts work. The simulation findings support the usefulness of both approaches.


Assuntos
COVID-19 , Epidemias , Humanos , COVID-19/epidemiologia , Modelos Teóricos , Simulação por Computador
3.
Sci Rep ; 14(1): 8466, 2024 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-38605097

RESUMO

This paper presents a novel approach to analyzing the dynamics of COVID-19 using nonstandard finite difference (NSFD) schemes. Our model incorporates both asymptomatic and symptomatic infected individuals, allowing for a more comprehensive understanding of the epidemic's spread. We introduce an unconditionally stable NSFD system that eliminates the need for traditional Runge-Kutta methods, ensuring dynamical consistency and numerical accuracy. Through rigorous numerical analysis, we evaluate the performance of different NSFD strategies and validate our analytical findings. Our work demonstrates the benefits of using NSFD schemes for modeling infectious diseases, offering advantages in terms of stability and efficiency. We further illustrate the dynamic behavior of COVID-19 under various conditions using numerical simulations. The results from these simulations demonstrate the effectiveness of the proposed approach in capturing the epidemic's complex dynamics.


Assuntos
COVID-19 , Humanos , COVID-19/epidemiologia
4.
Sci Rep ; 13(1): 15284, 2023 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-37714901

RESUMO

Typhoid fever is a contagious disease that is generally caused by bacteria known as Salmonella typhi. This disease spreads through manure contamination of food or water and infects unprotected people. In this work, our focus is to numerically examine the dynamical behavior of a typhoid fever nonlinear mathematical model. To achieve our objective, we utilize a conditionally stable Runge-Kutta scheme of order 4 (RK-4) and an unconditionally stable non-standard finite difference (NSFD) scheme to better understand the dynamical behavior of the continuous model. The primary advantage of using the NSFD scheme to solve differential equations is its capacity to discretize the continuous model while upholding crucial dynamical properties like the solutions convergence to equilibria and its positivity for all finite step sizes. Additionally, the NSFD scheme does not only address the deficiencies of the RK-4 scheme, but also provides results that are consistent with the continuous system's solutions. Our numerical results demonstrate that RK-4 scheme is dynamically reliable only for lower step size and, consequently cannot exactly retain the important features of the original continuous model. The NSFD scheme, on the other hand, is a strong and efficient method that presents an accurate portrayal of the original model. The purpose of developing the NSFD scheme for differential equations is to make sure that it is dynamically consistent, which means to discretize the continuous model while keeping significant dynamical properties including the convergence of equilibria and positivity of solutions for all step sizes. The numerical simulation also indicates that all the dynamical characteristics of the continuous model are conserved by discrete NSFD scheme. The theoretical and numerical results in the current work can be engaged as a useful tool for tracking the occurrence of typhoid fever disease.


Assuntos
Febre Tifoide , Humanos , Salmonella typhi , Simulação por Computador , Contaminação de Medicamentos , Modelos Teóricos
5.
Entropy (Basel) ; 24(7)2022 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-35885190

RESUMO

In this paper, on the basis of the Carleman matrix, we explicitly construct a regularized solution of the Cauchy problem for the matrix factorization of Helmholtz's equation in an unbounded two-dimensional domain. The focus of this paper is on regularization formulas for solutions to the Cauchy problem. The question of the existence of a solution to the problem is not considered-it is assumed a priori. At the same time, it should be noted that any regularization formula leads to an approximate solution of the Cauchy problem for all data, even if there is no solution in the usual classical sense. Moreover, for explicit regularization formulas, one can indicate in what sense the approximate solution turns out to be optimal.

6.
J Hazard Mater ; 423(Pt B): 127090, 2022 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-34537646

RESUMO

In this study, spinel CuCo2O4 (CCO) with a hierarchical hollow sphere morphology was encapsulated in V2O5-decorated ultra-wrinkled graphitic carbon-nitride (VO-UCN) for the first time via a facile glycerol-assisted solvothermal method in the interest of developing a novel high-efficiency double Z-type nano-photocatalyst (denoted as VO-UCN@CCO). The remarkable physicochemical features of the as-prepared nano-photocatalysts were verified using diverse characterization techniques including TGA, XRD, FT-IR, FE-SEM, TEM, BET, UV-vis DRS, PL, EIS, and transient photocurrent techniques. Herein, VO-UCN@CCO nanocomposite was employed for the photodisintegration of levofloxacin (LVOF) antibiotic under visible-light irradiation and the impact of certain operative reaction system variables was explored in an effort to optimize the photocatalytic capability. The 40% loading of CCO in VO-UCN@CCO nanocomposite was found to display maximum photocatalytic performance (about 95%) for LVOF photodecomposition, which was 9.3, 6.6, and 13.8 times greater when compared with pristine VO, UCN, and CCO, respectively. A high capability was observed for as-prepared photocatalyst during reusability tests and near 90% degradation efficiency was obtained in the sixth run. The complete mineralization of LVOF was achieved by the VO-UCN@CCO photocatalyst process after 300 min of reaction. An excellent synergy factor towards the degradation of LVOF was obtained for VO-UCN@CCO compared to each of its components alone. This peculiar design is envisaged to provide new inspirations for ameliorating the photocatalytic decontamination of tenacious and non-biodegradable species present in real wastewater.


Assuntos
Levofloxacino , Nanocompostos , Óxido de Alumínio , Catálise , Grafite , Óxido de Magnésio , Compostos de Nitrogênio , Fotólise , Espectroscopia de Infravermelho com Transformada de Fourier
7.
Complement Med Res ; 28(6): 557-570, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33866314

RESUMO

BACKGROUND: Coenzyme Q10 (CoQ10) has been known as ubiquinone or ubidecarenone, which is a kind of lipid-soluble and vitamin-like antioxidant. It has a potent antioxidant effect against oxidation status via various mechanisms, including its ability to regenerate other antioxidants, such as vitamin E and vitamin C, and to increase antioxidant enzymes. Moreover, CoQ10 can quench free radicals and prevent lipid peroxidation. The aim of this systematic review and meta-analysis was to evaluate the effect of CoQ10 on oxidative stress variables. METHODS: A comprehensive electronic database search in Scopus, Web of Science, Embase, Cochrane Library, and Medline was performed to identify eligible randomized clinical trials. A meta-analysis of included studies was performed on selected variables using a random-effects model. Quality assessment was conducted by means of the Cochrane risk of bias assessment tool. RESULTS: To evaluate the effect of CoQ10 supplementation, 17 trials and 972 participants were included for the meta-analysis. The pooled analysis of primary studies showed that CoQ10 increased serum total antioxidant capacity (standardized mean difference [SMD] 0.62 mmol/L, 95% CI 0.18-1.05, I2 = 76.1%, p ˂ 0.001) and superoxide dismutase (SMD 0.40 U/mg, 95% CI 0.12-0.67, I2 = 9.6%, p ˂ 0.345) levels and decreased malondialdehyde (SMD -1.02 mmol/L, 95% CI -1.60 to -0.44, I2 = 88.2%, p ˂ 0.001) level significantly compared to the placebo group. Although the effect of CoQ10 on nitric oxide (SMD 1.01 µmol/L, 95% CI -1.53 to 3.54, p ˂ 0.001, I2 = 97.8%) and glutathione peroxidase (SMD -0.01 mmol/L, 95% CI -0.86 to 0.84, p ˂ 0.001, I2 = 88.6%) was not significant, CoQ10 can be mentioned as an improvement in antioxidant defense status against reactive oxygen species. CONCLUSION: These supplements have positive effects on antioxidant defense against oxidizing agents and elevate antioxidant enzyme levels in the body. However, due to limited research the results should be taken with caution.


Assuntos
Fatores Etários , Diabetes Mellitus , Suplementos Nutricionais , Estresse Oxidativo , Ubiquinona , Humanos , Ubiquinona/análogos & derivados
8.
J Chromatogr A ; 1621: 461041, 2020 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-32204878

RESUMO

The current study presents for the first time a combination of the gel electromembrane extraction (GEL-EME) and switchable hydrophilicity solvent-based homogeneous liquid-liquid microextraction (SHS-HLLME) methods which can be used as an efficient hyphenated extraction procedure. This coupled method, which was followed by GC-FID, was applied for quantification of antidepressants (desipramine, clozapine, and citalopram) in biological and wastewater samples. The effective parameters of both GEL-EME and SHS-HLLME procedures were optimized. Using an agarose gel membrane, analytes were extracted from 7.0 mL of the sample solution to 500 µL of the aqueous acceptor solution. The maximum extraction of analytes of interest was obtained under the optimized conditions (pH of acceptor solution, 5.0; pH of gel membrane, 5.0; pH of sample solution, 7.0, voltage value, 30 V; and extraction time, 30 min). Then, the acceptor solution was transferred to the extraction cell and the SHS-HLLME procedure was conducted again under the optimized conditions. Dipropylamine (50 µL) was selected as an extraction solvent. The introduced technique exhibited good linearities with coefficients of determinatin (R2) higher than 0.983 and an acceptable linear range of 5.0-1000 ng/mL. Accordingly, the limit of detection was ≤ 1.0 ng/mL (S/N = 3) for all analytes, and the high enrichment factors were obtained in the range of 178.7-194.8. Moreover, the corresponding repeatability was from 4.0 to 8.7% (n = 3). The proposed method was successfully utilized to determine trace levels of the drugs in human serum, wastewater, and breast milk samples.


Assuntos
Antidepressivos/análise , Cromatografia Gasosa , Microextração em Fase Líquida/métodos , Antidepressivos/sangue , Antidepressivos/isolamento & purificação , Géis , Humanos , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Leite Humano/química , Sefarose , Solventes/química , Águas Residuárias/química
9.
Genes Nutr ; 14: 22, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31333806

RESUMO

BACKGROUND: High protein intake may promote angiogenesis giving support to the development of metastasis according to the experimental data. However, nutritional epidemiologic evidence is inconsistent with metastasis. Therefore, we aimed to study the association between dietary intake of protein and tumoral expression levels of Ras homologous gene family member A (RhoA), vascular endothelial growth factor-A (VEGF-A), and VEGF receptor-2 (VEGFR2) in primary breast cancer (BC) patients. METHODS: Over this consecutive case series, 177 women primary diagnosed with histopathologically confirmed BC in Tabriz (Iran) were enrolled between May 2011 and November 2016. A validated food frequency questionnaire was completed for eligible participants. Fold change in gene expression was measured using quantitative real-time PCR. Principal component factor analysis (PCA) was used to express dietary groups of proteins. RESULTS: Total protein intake was associated with the expression level of VEGF-A in progesterone receptor-positive (PR+: ß = 0.296, p < 0.01) and VEGFR2 in patients with involvement of axillary lymph node metastasis (ALNM+: ß = 0.295, p < 0.01) when covariates were adjusted. High animal protein intake was correlated with overexpression of RhoA in tumors with estrogen receptor-positive (ER+: ß = 0.230, p < 0.05), ALNM+ (ß = 0.238, p < 0.05), and vascular invasion (VI+: ß = 0.313, p < 0.01). Animal protein intake was correlated with the overexpression of VEGFR2 when tumors were positive for hormonal receptors (ER+: ß = 0.299, p < 0.01; PR+: ß = 0.296, p < 0.01). Based on the PCA outputs, protein provided by whole meat (white and red meat) was associated inversely with RhoA expression in ALNM+ (ß = - 0.253, p < 0.05) and premenopausal women (ß = - 0.285, p < 0.01) in adjusted models. Whole meat was correlated with VEGFR2 overexpression in VI+ (ß = 0.288, p < 0.05) and premenopausal status (ß = 0.300, p < 0.05) in adjusted models. A group composed of dairy products and legumes was correlated with the overexpression of RhoA (ß = 0.249, p < 0.05) and VEGF-A (ß = 0.297, p < 0.05) in VI+. CONCLUSIONS: Based on the multivariate findings, the dietary protein could associate with the overexpression of RhoA and VEGF-VEGFR2 in favor of lymphatic and vascular metastasis in BC patients.

10.
Talanta ; 199: 329-335, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30952267

RESUMO

Nowadays, developing new methods for the effective extraction/separation of drugs (present at trace levels) from complicated matrices (as biological fluids) is certainly a great challenge for many operators. In this regard, green-based agarose gel electromembrane extraction (G-EME) was for the first time combined with dispersive liquid-liquid microextraction (DLLME) toward G-EME/DLLME methodology (i.e., tandem extraction approach). Two basic drugs such as trimipramine (TRI) and clomipramine (CLO) extracted from the urine samples, were used as model compounds. Regarding method workflow, analytes were extracted from the 5 mL sample, through a synthesized agarose gel membrane, to the 700 µL aqueous acceptor phase under the optimized conditions (pH of acceptor phase: 2.0; pH of gel membrane: 2.0; pH of donor phase: 4.0, voltage value: 30 V, and extraction time: 25 min). In the next step, acceptor solution was poured to a conic vial and mixed with 100 µL alkaline solution (NaOH, 1 M). Afterwards, DLLME procedure took place again at optimal conditions, i.e., extraction solvent was carbon tetrachloride (10 µL), and dispersive solvent was acetone (100 µL). Ultimately, gas chromatography (GC) was applied for the detection and quantification of drugs. Such G-EME/DLLME configuration has brought two main advantages. Firstly, interferences such as proteins and other large biological molecules were eliminated from biological fluids via G-EME. Further, high enrichment factors (EFs of 260-370 refer to extraction recoveries of 52-74%) were obtained using DLLME with acceptable detection limits (1.0-3.0 ng mL-1). Finally, the suggested approach was successfully utilized to determine drugs at trace levels in urine samples.


Assuntos
Clomipramina/urina , Microextração em Fase Líquida/métodos , Sefarose , Trimipramina/urina , Cromatografia Gasosa , Géis/síntese química , Géis/química , Humanos , Concentração de Íons de Hidrogênio , Sefarose/síntese química , Sefarose/química
11.
J Chromatogr A ; 1563: 20-27, 2018 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-29880217

RESUMO

As a well-known extraction procedure, electromembrane extraction (EME) was combined with electro-assisted liquid-liquid microextraction (EA-LLME) in the present work, which resulted in a promising method. This hyphenated sample preparation method, named EME-EA-LLME, was followed by GC for the determination of two model analytes (clomipramine and imipramine). The effective parameters of both EME and EA-LLME (such as organic solvent, pH of acceptor and sample solutions, voltage and extraction time) were optimized. The proposed EME-EA-LLME procedure demonstrated good linearity with coefficients of determination, R2 ≥ 0.998 over the concentration range of 0.5-750 ng/mL. Limit of detection for both analytes was 0.15 ng/mL. The corresponding repeatability ranged from 6.9 to 12.2% (n = 3). The high enrichment factors were obtained as 770.3 and 561.4 for imipramine and clomipramine, respectively. The advantages of this tandem sample preparation method were low detection limits, simplicity, low cost, and short analysis time (<10 min). Finally, the optimized method was used to extract and determine the analytes in urine and wastewater samples. Overall, the results revealed that the developed EME-EA-LLME procedure had better extraction efficiency in comparison with EME and EA-LLME alone.


Assuntos
Técnicas de Química Analítica/métodos , Técnicas Eletroquímicas , Microextração em Fase Líquida , Antidepressivos/análise , Antidepressivos/isolamento & purificação , Antidepressivos/urina , Cromatografia Gasosa , Clomipramina/análise , Clomipramina/isolamento & purificação , Clomipramina/urina , Humanos , Concentração de Íons de Hidrogênio , Imipramina/análise , Imipramina/isolamento & purificação , Imipramina/urina , Limite de Detecção , Membranas Artificiais , Solventes/química , Águas Residuárias/análise
12.
Auto Immun Highlights ; 9(1): 1, 2017 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-29280010

RESUMO

Vitamin D is one of the main groups of sterols; playing an important role in phospho-calcic metabolism. The conversion of 7-dehydrocholesterol to pre- vitamin D3 in the skin, through solar ultraviolet B radiation, is the main source of vitamin D. Since lupus patients are usually photosensitive, the risk of developing vitamin D deficiency in is high in this population. Although evidences showed the connotation between systemic lupus erythematosus (SLE) and vitamin D through which SLE can lead to lower vitamin D levels, it is also important to consider the possibility that vitamin D deficiency may have a causative role in SLE etiology. This paper analyzes existing data from various studies to highlight the role of vitamin D deficiency in SLE occurrence and aggravation and the probable efficacy of vitamin D supplementation on SLE patients. We searched "Science Direct" and "Pub Med" using "Vitamin D" and "SLE" for finding the studies focusing on the association between vitamin D deficiency and SLE incidence and consequences. Evidences show that vitamin D plays an important role in the pathogenesis and progression of SLE and vitamin D supplementation seems to ameliorate inflammatory and hemostatic markers; so, can improve clinical subsequent.

13.
J Environ Manage ; 199: 7-12, 2017 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-28521210

RESUMO

This study investigates, verifies and determines the optimal parameters for the selective thermal transformation of problematic electronic waste (e-waste) to produce value-added copper-tin (Cu-Sn) based alloys; thereby demonstrating a novel new pathway for the cost-effective recovery of resources from one of the world's fastest growing and most challenging waste streams. Using outdated computer printed circuit boards (PCBs), a ubiquitous component of e-waste, we investigated transformations across a range of temperatures and time frames. Results indicate a two-step heat treatment process, using a low temperature step followed by a high temperature step, can be used to produce and separate off, first, a lead (Pb) based alloy and, subsequently, a Cu-Sn based alloy. We also found a single-step heat treatment process at a moderate temperature of 900 °C can be used to directly transform old PCBs to produce a Cu-Sn based alloy, while capturing the Pb and antimony (Sb) as alloying elements to prevent the emission of these low melting point elements. These results demonstrate old computer PCBs, large volumes of which are already within global waste stockpiles, can be considered a potential source of value-added metal alloys, opening up a new opportunity for utilizing e-waste to produce metal alloys in local micro-factories.


Assuntos
Cobre , Resíduo Eletrônico , Reciclagem , Estanho , Ligas , Computadores , Temperatura
14.
Anim Sci J ; 88(2): 306-313, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27255566

RESUMO

This study was performed to investigate the effect of dietary supplementation with Aloe vera (AV) powder and synbiotic as growth promoter agents on performance, gut morphology, immune responses, hematology and serum biochemistry in broilers. A total of 240-day-old male broiler chicks (Ross 308) were randomly assigned to six treatments with four replicates. Birds were offered either a corn-soybean meal basal diet (control) or the basal diet supplemented with 200 mg/kg virginiamycin (VM), 1 g/kg synbiotic (Syn), 2.5 g/kg AV (AV1), 5.0 g/kg AV (AV2) or 7.5 g/kg AV (AV3). Chickens fed any of the diets, except diet AV1, exhibited better feed conversion ratios at the 14-28 day period and higher average daily gain and duodenal villus height/crypt depth ratio at 42 days than those fed the control diet. Synbiotic supplementation caused a marked increase in the serum antibody titer against infectious bursal disease and infectious bronchitis vaccines. Feeding diet AV3 significantly increased red blood cell count and hemoglobin concentration, and decreased serum triglyceride level compared to the control group. The results suggested that dietary inclusion of 5 and 7.5 g/kg AV, similar with synbiotic supplementation, can be applied as effective alternatives to in-feed antibiotics for broiler diets.


Assuntos
Aloe , Ração Animal , Fenômenos Fisiológicos da Nutrição Animal/fisiologia , Anticorpos/sangue , Galinhas/crescimento & desenvolvimento , Galinhas/imunologia , Dieta/veterinária , Suplementos Nutricionais , Duodeno/anatomia & histologia , Simbióticos/administração & dosagem , Virginiamicina/administração & dosagem , Animais , Galinhas/anatomia & histologia , Galinhas/sangue , Contagem de Eritrócitos , Hemoglobinas , Masculino , Pós , Glycine max , Triglicerídeos/sangue , Aumento de Peso , Zea mays
15.
Mater Sci Eng C Mater Biol Appl ; 46: 394-9, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25492003

RESUMO

Nanoparticles of high-Z elements exhibit stronger photoelectric effects than soft tissues under gamma irradiation. Hence, they can be used as effective radiosensitizers for increasing the efficiency of current radiotherapy. In this work, superparamagnetic zinc ferrite spinel (ZnFe2O4) nanoparticles were synthesized by a hydrothermal reaction method and used as radiosensitizers in cancer therapy. The magnetic nanoparticles showed fast separation from solutions (e.g., ~1 min for 2 mg mL(-1) of the nanoparticles in ethanol) by applying an external magnetic field (~1T). The ZnFe2O4 nanoparticles were applied in an in vitro radiotherapy of lymph node carcinoma of prostate cells (as high radioresistant cells) under gamma irradiation of (60)Co source. The nanoparticles exhibited no significant effects on the cancer cells up to the high concentration of 100 µg mL(-1), in the absence of gamma irradiation. The gamma irradiation alone (2Gy dose) also showed no significant effects on the cells. However, gamma irradiation in the presence of 100 µg mL(-1) ZnFe2O4 nanoparticles resulted in ~53% inactivation of the cells (~17 times higher than the inactivation that occurred under gamma irradiation alone) after 24h. The higher cell inactivation was assigned to interaction of gamma radiation with nanoparticles (photoelectric effect), resulting in a high level electron release in the media of the radioresistant cells. Our results indicated that ZnFe2O4 nanoparticles not only can be applied in increasing the efficiency of radiotherapy, but also can be easily separated from the cell environment by using an external magnetic field after the radiotherapy.


Assuntos
Nanopartículas Metálicas , Neoplasias da Próstata/radioterapia , Radiossensibilizantes/uso terapêutico , Humanos , Masculino , Microscopia Eletrônica de Varredura
16.
J Med Chem ; 48(4): 1229-36, 2005 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-15715489

RESUMO

In pursuit of an apparent literature anomaly, S- and R-6-methyl-6,7-dihydro-2H-benzo[a]quinolizin-2-one-3-carboxylic acids (12 and 22) were synthesized by an unambiguous route from optically active norephedrines, and their antibacterial potencies were measured. Against Gram-negative microorganisms and DNA gyrase a preference for S-absolute configuration was found whereas R-absolute stereochemistry was more active against Gram-positives. These results are in partial conflict with an earlier report. In an attempt to enhance potency, racemic 10-fluoro-9-piperazinyl (35) and related analogues were synthesized by a novel route. The latter analogues were surprisingly unimproved in potency. The implications of these findings are briefly discussed.


Assuntos
Antibacterianos/síntese química , DNA Girase/química , Piperazinas/síntese química , Quinolizinas/síntese química , Inibidores da Topoisomerase II , Antibacterianos/química , Antibacterianos/farmacologia , Sítios de Ligação , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Piperazinas/química , Piperazinas/farmacologia , Quinolizinas/química , Quinolizinas/farmacologia , Estereoisomerismo , Relação Estrutura-Atividade
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