Molecular mechanism

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An electron localization function and catastrophe theory analysis on the molecular mechanism of gas phase identity SN2 reactions

An electron localization function and catastrophe theory analysis on the molecular mechanism of gas phase identity SN2 reactions

considered one of the most studied chemical reactions [19– 47]. Both experimental and theoretical works, over the past decades, are driven primarily by its crucial role in many syn- thetic routes [48]. As a result, these types of chemical rear- rangements have been the focus of many experimental and theoretical studies in the gas phase [29]. Explication of the general molecular mechanism for nucleophilic substitution at carbon atom will help increase the understanding of the nature of these, and many more, biochemical processes. This is best exemplified by gas-phase nucleophilic displacement (S N 2) reactions where a lively interplay between experiment
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Describing the molecular mechanism of organic reactions by using topological analysis of electronic localization function

Describing the molecular mechanism of organic reactions by using topological analysis of electronic localization function

The determination of the ground-state and excited-state PESs and associated stationary electronic states for a molecular system require the choice of a set of internal coordinates for the nuclei, a far from trivial problem, and accurate interpolation procedures to estimate energies at intermediate geometries. Each PES exhibits considerable structure for a polynuclear molecular system and often provides attractive pictures with local minima corresponding to stable species and transition states serving as gateways for the sys- tem to move between such minima, commonly along minimum- energy paths. Molecular structures (reactants, products, and possi- ble intermediates) are associated with the minimum positions in the valleys, while the TS is a saddle point of index one on the PES. In the analysis of PESs, molecular processes are described by means of reaction paths, which are continuous curves on the PES connec- ting two minima through a saddle point (first-order maximum) and usually associated with steepest-descent curves [15]. The energetic aspects of the reaction can be obtained from the energies of these stationary points, that is, the thermodynamic and kinetic parameters can be derived from the relative values of energy between them. Therefore, the standard description of chemical reactivity tends to rely on calculation of the geometries and energies of these stationa- ry points lying on the reaction pathway of a given chemical rea- rrangement. The theoretical construct of a PES is central to accep- ted pictures of chemical structure and bonding.
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Molecular mechanism for pathogenicity of Salmonella sp

Molecular mechanism for pathogenicity of Salmonella sp

Para el desarrollo de una enfermedad bacteriana es ne- cesaria la localización de la bacteria en un ambiente ade- cuado para su establecimiento, replicación y expresión de sus factores de virulencia. Durante el proceso infeccioso se presenta una interacción entre hospedero-microorganismo, la cual cada día se comprende mejor, debido a los avances en el estudio sobre patogénesis molecular, al desarrollar técnicas como la PCR y la secuenciación del ADN entre muchas otras. Dentro de los pasos que se presentan en el proceso infeccioso se pueden mencionar: adhesión, inva- sión, replicación, resistencia a los mecanismos de defensa y daño al hospedero. La bacteria experimenta severos cam- bios ambientales cuando entra al hospedero por vía oral
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Molecular mechanism involved in the mutagenicity induced by Aflatoxin B1Mecanismos moleculares involucrados en la mutagenicidad inducida por aflatoxina B1Mecanismos moleculares envolvidos na mutagenicidade induzida pela aflatoxina B1

Molecular mechanism involved in the mutagenicity induced by Aflatoxin B1Mecanismos moleculares involucrados en la mutagenicidad inducida por aflatoxina B1Mecanismos moleculares envolvidos na mutagenicidade induzida pela aflatoxina B1

subject Aflatoxin B1, Hepatitis B virus, Hepatocellular carcinoma, AFB1 metabolite, AFB1-DNA adducts, DNA repair.. subject aflatoxina B1, HBV, HCC, AFB1 metabolito, AFB1-DNA adutos, repa[r]

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Autophagy – molecular mechanism, apoptosis and cancer 

Autophagy – molecular mechanism, apoptosis and cancer 

Białko JNK1 może również powodować hiperfosforyla- cję Bcl-2, które w takiej postaci odłącza się od białka Bax i w konsekwencji prowadzi to do śmierci komórki w wy- niku apoptozy.. Wspo[r]

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RGS14 (414)-mediated prevention of an episodic memory loss: a study of molecular mechanism

RGS14 (414)-mediated prevention of an episodic memory loss: a study of molecular mechanism

Los niveles proteicos de BDNF se evaluaron mediante la técnica de Western blot. Así, el tejido del área V2 se homogeneizó mediante un homogeneizador (Glas-Col) en 2 ml de tampón Tris-HCl 0,01 M, pH 7,4 (appendix 5.A.1) que incluía un cocktail de inhibidores de proteasas al 1 % (v/v) (Sigma-Aldrich, P8340) y un cocktail de inhibidores de fosfatasas al 1 % (v/v) (Sigma-Aldrich, P0044). Una vez, estimada la concentración total de proteínas mediante el método de Lowry (Lowry et al 1951) (appendix 5.A.2), las muestras se liofilizaron en el SPC1010 SpeedVac System (Thermo Savant) y se resuspendieron en tampón de carga (1X) (Laemmli 1970) (appendix 5.A.3) para obtener una concentración final de 1 µg/µl. Tras desnaturalizar las proteínas por calor a 95 ºC durante 10 min, se cargaron 2,5 y 5 µg de proteína total de cada muestra junto al marcador de peso molecular Precision Plus Protein™ ladder (Bio-Rad, 161-0374) en un gel de poliacrilamida-SDS en gradiente 4-20 % (Bio-Rad, 456-1096). La electroforesis en gel de poliacrilamida en condiciones desnaturalizantes (SDS-PAGE) para separar las proteínas en función del peso molecular se llevó a cabo aplicando un potencial eléctrico de 150 V en el tampón Tris-Glicina-SDS (TGS) (appendix 5.A.4). Tras la separación, las proteínas se transfirieron a una membrana de PVDF (Bio-Rad, 1704156) usando el sistema de transferencia Turbo Trans-Blot (Bio-Rad) al aplicar una corriente de 25 V durante 7 min.
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Molecular Mechanism and Regulation of Autophagy in Saccharomyces cerevisiae

Molecular Mechanism and Regulation of Autophagy in Saccharomyces cerevisiae

Because the Atg41 expression level changed considerably between growing and starvation conditions, we wanted to determine the mechanism involved in the transcriptional regulation of ATG41. High-throughput analysis indicates that Gcn4, the master regulator of gene expression during amino acid starvation, modulates the transcriptional level of multiple ATG genes [29]. Moreover, combining the previous study and an online yeast transcriptional database, Yeastract (www.yeastract.com), indicated that the ATG41 5’ untranslated region (5’UTR) contains 2 putative Gcn4 binding regions [30]. Therefore, we decided to investigate the possible role of Gcn4 in regulating ATG41 expression. We examined the ATG41 mRNA level by RT-qPCR. As we observed previously (Fig. 2.2A), there was a strong increase in ATG41 mRNA in the wild-type strain following autophagy induction by nitrogen starvation. In contrast, there was a significant reduction relative to the wild type in a gcn4Δ strain (Fig. 2.6A). Next, we tagged Atg41 with protein A in the gcn4Δ mutant and monitored the protein level of Atg41-PA by western blot. In agreement with the RT-qPCR results, the protein level of Atg41-PA was reduced by approximately 40% in the
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PSYCHOLOGICAL MECHANISM OF ENGLISH LEARNERS IN READING COMPREHENSION

PSYCHOLOGICAL MECHANISM OF ENGLISH LEARNERS IN READING COMPREHENSION

This paper uses the method of theoretical analysis and practical demonstration to carry out the research: in terms of theoretical research, on the basis of the analysis of the psychological nature and psychological process of English learners' in reading process, this paper puts forward the three-stage teaching model including before, during and after reading and explains the theoretical basis of psycholinguistics, educational psychology, cognitive psychology and schema theory in each stage. As for practical demonstration, three- stage English teaching class is designed and teaching practice is carried out. Through tests before and after class and questionnaire the psychological mechanism of college students in the reading process is further analyzed (Yu & Liu, 2015). Through the study of the three-stage teaching model in the process of English learners' reading comprehension, it provides new ideas and enlightenment for English teaching in China.
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O|R|P|E - A data semantics driven concurrency control mechanism

O|R|P|E - A data semantics driven concurrency control mechanism

The prototype of O|R|P|E is not a full database system. It was implemented using the JAVA programming language and Figure 1 illustrates its architecture. A client API provides access to the data and depending on the operation’s type read or write, the operation is executed by a dedicated pool. Pools’ “reads” and “writes” represent an read- and write-lane. In addition, a pool to handle the termination (commit and abort) has been implemented. Pools’ reads and writes handle all incoming and outgoing operations and the classification has been placed directly into the index. Depending on an item’s classification the corresponding CC mechanism is plugged in. Once an item has been read or written, the additional pools’ “read-callback” and “write-callback” deliver the results back to the clients. Pool WFG (Wait-for-Graph) is used to handle access to the WFG. Deadlocks may occur during the read- phase of a transcation if the transcation accesses data items in class P . Deadlocks can occur in class P during the read-phase, because lock acquisition is not globally ordered.
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Efficient simulation of Mechanism Kinematics Using Bond Graphs.

Efficient simulation of Mechanism Kinematics Using Bond Graphs.

According to the front-loader mechanism using Bond-Graph (Fig. 18), we can start from rest and analyse if the control of the different actuators generates a good movement of the bucket;[r]

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PSYCHOLOGICAL MECHANISM OF THE AUDIENCE OF LEGAL EDUCATION

PSYCHOLOGICAL MECHANISM OF THE AUDIENCE OF LEGAL EDUCATION

The ultimate goal of legal education is to make all the people know, understand and obey the laws, laying the basis for law-based governance. This paper aims to design suitable measures to promote legal education based on the psychology of the audience. To identify the psychological status of the audience in legal education, a questionnaire survey was carried out among urban residents, some of whom have served in the judicial department. Then, the psychological mechanism of the audience was analysed from the aspects of cognitive process, emotional process and will process. The results show that the main problems with legal education lies in the dominance by the government, the lack of systematicity, and the outdated education methods; the problems with the audience are their insufficient psychological needs and passive acceptance. The research findings shed new light on how to improve legal education from the angle of audience psychology.
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Ergonomic adaptable stroller add-on mechanism for running

Ergonomic adaptable stroller add-on mechanism for running

Once we have the future projection of the number of users that could present our product, being a mechanism that is going to adapt to another existing product in the market, it is important to analyze how this market is. Especially what we want to get out of this analysis is a conclusion in reference to the shape of the stroller handlebar. With this information we will be able to design the adaptation mechanism between our mechanism and the stroller. Therefore, the first thing that will have to analyze will be which were the most sold and the best qualified strollers. In this study, it will also be interesting to analyze what is the price of each of these strollers, since it will be a decisive factor in the future when it comes to having a price reference. Below are the strollers that are best considered during the last year.
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Módulo de Diagnóstico Molecular

Módulo de Diagnóstico Molecular

Los retrovirus , al tener una destruir el molécula de ARN , necesitan convertirla en ADN para 90%de replicarse en el hospedero , esto lo hacen gracias a la palmas en ayuda de una enzima [r]

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FISIOLOGÍA MOLECULAR DE PLANTAS

FISIOLOGÍA MOLECULAR DE PLANTAS

En este caso para superar la asignatura, el alumno realizará una prueba escrita y eventualmente una práctica, que incluirá o incluirán los contenidos de los bloques temáticos del progr[r]

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11. Genética molecular

11. Genética molecular

En la transcripción sólo una de las hebras sirve como molde para fabricar ARNm, pero a veces la cadena complementaria también se transcribe produciendo un ARN antisentido. Cuando el AR[r]

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Presentación Estructurador Molecular

Presentación Estructurador Molecular

El equipo PHI  3001 emite frecuencias específicas de energía (nano ondas) que son capaces de alterar la capa orbital del hidrogeno, “puentes de hidrógeno” de las moléculas del [r]

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Tópicos en Biofísica Molecular

Tópicos en Biofísica Molecular

En un laboratorio de biofísica molecular contamos con una numerosa cantidad de soluciones buffer salinas, cada una de las cuales mantiene el pH en un cierto rango. En la Figura 1 se presenta una tabla con algunos de los buffers más utilizados y los rangos de pH de uso de cada uno de ellos (de la compañía Sigma-Aldrich).

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Diagnóstico molecular de tuberculosis

Diagnóstico molecular de tuberculosis

Directo negativo Alta sospecha clínica Prueba molecular (dx presuntivo) Directo negativo Baja sospecha clínica Prueba molecular no recomendada. Interpretación pruebas molecular[r]

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ESPECTROSCOPÍA DE FLUORESCENCIA MOLECULAR

ESPECTROSCOPÍA DE FLUORESCENCIA MOLECULAR

En la figura se ilustra el otro proceso de relajación: la fluorescencia. Se puede observar que las bandas de radiación son producidas cuando las moléculas fluorecen debido a que las moléculas electrónicamente excitadas se pueden relajar a cualquiera estados vibracionales del estado electrónico fundamental. De igual forma que las bandas de absorción molecular, las bandas de fluorescencia molecular están formadas por una multitud de líneas espaciadas tan estrechamente que son muy difíciles de resolver.

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Virologa molecular en Mxico: Implementacin del diagnstico molecular del SARS Coronavirus

Virologa molecular en Mxico: Implementacin del diagnstico molecular del SARS Coronavirus

The etiological agent of SARS, an emerging infectious dis- ease, is the coronavirus named SARS-CoV. Rapid diagnostic test are very important for case recognition and manage- ment of infected people. Because the Polymerase Chain Reaction (PCR) has a high sensitivity and specificity it has been used as a viral diagnosis tool. Several reports demon- strate SARS-CoV detection by PCR from patients during the firs week of hospitalization. The major aim of this work was to standardize and set up in our region the molecular diagnosis of this virus. We performed a cDNA synthesis from SARS CoV-RNA (kindly donated by Bernhard Notch Tropical Institute Hamburg, Germany) and simultaneously we amplified by PCR a fragment of 195 bp in a single tube. In order to increase sensibility and specificity we performed a Nested PCR to amplify a second DNA fragment. Both PCR products were detected by electrophoresis and ethidium bromide staining. Variation in amplification parameters such as, primers concentration, amplification cycles and anneal- ing temperature, we amplified two reproducible fragments of 195 and 110 bp. Based in our results, now we can apply molecular assays, as PCR, in order to perform a highly sen- sitive and specific molecular diagnosis of SARS-CoV in sus- pected patients in our region.
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