Articles Related to Mechanism

Matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) has become a widely used technique for the rapid, accurate, durable, economical, and trustworthy method for identification of bacteria, mycobacteria and fungal pathogens in the microbiology laboratory.

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Formaldehyde (HCHO) pollution was eliminated by catalyst effectively. The CexZr1-xOy catalyst was prepared by coprecipitate method, and its performance of HCHO removal was investigated. The results showed that the HCHO removal rate decreased from 100% to 60.88% when the reaction time was from 24h to 48h.In order to study the deactivation mechanism of the CexZr1-xOy catalyst,N2 adsorption and desorption, SEM, EDS, FT-IR, XRD and XPS were used to characterize CexZr1-xOy after different reaction times. Characterization results showed that the pore structure of CexZr1-xOy did not change significantly with the extension of reaction time, and C6H9CeO6 and Ce(CO3)2 increased gradually, while the active component Ce4+ decreased sharply. Therefore, the production and deposition of products are the main reasons for the deactivation of the CexZr1-xOy catalyst. The catalytic performance of regenerated CexZr1-xOy catalyst was tested for 24h, and the results showed that it almost recovered to fresh CexZr1-xOy catalyst. This provides a reference for the preparation of efficient catalyst for formaldehyde removal.

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Brain physiology critically depends on constant oxygen supply to the neurons to ensure various energy–dependent functions of the central nervous system. A volume of latest experimental data on oxygen metabolism obtained with high temporal and spatial resolution, with both invasive and non-invasive methods, and the use of technologies of various degrees of sophistication, strongly suggests arteriole involvement in brain oxygenation. This new approach challenges the traditional views on brain oxygenation according to which oxygen supply to the brain tissues occurs by diffusion at the capillary level.

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Glucose and oxygen are obligatory energy substrates for the brain and their continuous supply to the neurons, as well as the elimination of the end product – carbon dioxide, is of paramount importance for brain physiology and survival. Transport of these substrates from the brain capillaries to the neurons presents a challenging issue.

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Targeting mutant proteins and associated signaling pathways of driver oncogenes by small molecule kinase inhibitors (KIs) are a promising strategy of cancer therapy. However, despite the initial success of treatment, KIs often become ineffective as intrinsic and acquired resistance. This article reviews the English-language literature to explore the underlying mechanisms of drug resistance and to present a challenge for developing drugs to overcome resistance. Mechanisms of acquired resistance include 1) the selection of pre-existing subclones with other mutations, 2) the emergence of secondary mutations in the target kinase domain, 3) upregulation of kinases both within the same kinase family and their related kinase families, as well as activation of alternative bypass pathways, 4) epithelial-mesenchymal transition, 5) overexpression of pro-survival Bcl-2 family proteins and 6) drug efflux mechanisms. Currently available methods are to obtain tumor biopsy samples at recurrence or progression if the tumor lesion is accessible to a biopsy and to use the second- and third-generation KIs based on the individual need of each patient. Furthermore, recent computational challenges provide design principles to prevent the development of drug resistance. In conclusion, we provide an overview of the postulated resistance mechanisms and highlight the future direction of computational structure-based design of new potent KIs.

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A new mechanism of the nanoindentation process based on the consideration of the decrease the energy of the chemical bonds as a result of the pressure of the indenter on the material is proposed. This leads to an increase the mobility of the atoms, which in the beginning creates point defects and as the external force increases, melting and material destruction occurs.

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The prevalence of overweight and obesity among US adults is well-documented and lifestyle intervention remains the foundation for all overweight and obesity treatment interventions, even when bariatric surgery is offered. Unfortunately, lifestyle intervention, though clearly a vital part of any obesity treatment, including bariatric surgery, has not been found to be as effective in achieving health benefits as hoped for.

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This article summarizes the advantages of orally disintegrating tablets (ODTs) as well as critical issues during evaluation of ODTs such as bioequivalence and challenges and limitations of ODTs and finally present and the future of ODTs. ODTs have received everincreasing demand and the field has become a rapidly growing area in the pharmaceutical industry.

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Ovarian cancer constitutes the second most common gynecological cancer with a five-year survival rate of 40%. Among the various histotypes associated with hereditary ovarian cancer, high-grade serous epithelial ovarian carcinoma (HGSEOC) is the most predominant and women with inherited mutations in BRCA1 have a lifetime risk of 40-60%. HGSEOC is a challenge for clinical oncologists, due to late presentation of patient, diagnosis and high rate of relapse. Ovarian tumors have a wide range of clinical presentations including development of ascites as a result of deregulated endothelial function thereby causing increased vascular permeability of peritoneal vessels.

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This retrospective review of 17 patients suggests an increased risk of adverse events including premature death with opiate discontinuation long after withdrawal stage. The results are consistent with previously reported yet not fully understood – opiate associated neuro protective mechanism – against premature death for some vulnerable subgroups.

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Present trend of the crimes in India reveals that a wide variety of firearms including factory /country made are illegally used in crimes like murder, armed robbery, riot, poaching etc. Out of the total firearms received in Tripura State Forensic Science Laboratory, Agartala for the last ten years, about 30% of the firearms are observed to be belonging to country made pistol/pipe guns.

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The DNA mismatch repair (MMR) system is necessary for the maintenance of genomic stability. The MMR system promotes genomic fidelity by repairing base-base mismatches, insertion-deletion loops (IDLs) and heterologies generated during DNA replication and recombination.

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Salmonella is a causative agent for a wide variety of pathological diseases in humans, cattle, poultry and other farm animals and hence Salmonella infections are a major cause of concern to humans, veterinary animals and to food industry.

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