17 research outputs found
CONCEPTUAL DESIGN OF A CARBON NANOTUBE BASED GEARBOX
No full textABSTRACT Gears, bearings, springs, fasteners etc. are some typical machine elements used to build machines and mechanical systems. These elements are used for performing one or more of functions such as, to transmit motion, to support moving members, to store energy, to join two components etc. The continuous miniaturization and the need for mechanical systems having sizes of a few nanometers have led to new but challenging issues in design and manufacturing of these machine elements. Carbon nanotubes have a potential to be used as machine elements in multiple roles for building mechanical systems at a nano level. This paper explores the use of single-walled and multi-walled carbon nanotubes in building a nano-mechanical system such as gearbox. The paper presents a conceptual design of a gearbox completely made of carbon nano tubes and discusses its feasibility and realizability. The paper also discusses future directions of research in building nanomachines and nano-mechanical systems using carbon nanotube based machine element
T cell receptor ζ reconstitution fails to restore responses of T cells rendered hyporesponsive by tumor necrosis factor α
No full text
Endometriose e infertilidade: revisão sistemática da literatura e relato de casos
No full textTrabalho de Conclusão de Curso - Universidade Federal de Santa Catarina. Curso de Medicina. Departamento de Tocoginecologia
Electrochemical Method: A Green Approach for the Synthesis of Organic Compounds
No full textBackground: Heterocyclic compounds have gained attention due to their growing demand against various infectious diseases, but their synthesis with hazardous chemicals, costly catalysts, and costly purification methods encourage researchers to explore alternative sources. The electrochemical method offers a powerful and versatile approach for assembling different heterocyclic structures. Moreover, it gives a highly proficient and green methodology that avoids harmful oxidants and reductants. Objective: In this review, we aim to compile the different types of reactions i.e., Curtin-Hammet, Michael addition, Wittig reaction, Henry, Diels-Alder, Friedel-crafts, Kolbe, Heck, Benzoin condensation reaction taking place in case of electrochemical synthesis in the last 3 years from 2017-2020. So, to the best of our knowledge, after 2017, there is no such report present that can explain the present scenario in the field of electrochemical synthesis. So this encouraged us to write a review on this interesting topic.Result: From this study, we concluded that the electrochemical methods provide a green and proficient methodology for radical intermediate’s age utilizing electrons as traceless reagents, which could avoid the use of harmful oxidants and reductants.No Full Tex
Normal and Abnormal Ca Cycling during Rapid Pacing and the Development of Triggered Waves in Dog Left Atrial Myocytes
No full textSildenafil stimulates human trophoblast invasion through nitric oxide and guanosine 3′,5′-cyclic monophosphate signaling
No full textTriggered intracellular calcium waves in dog and human left atrial myocytes from normal and failing hearts
No full textGlobal Perspectives on Task Shifting and Task Sharing in Neurosurgery
No full textBackground
Neurosurgical task shifting and task sharing (TS/S), delegating clinical care to non-neurosurgeons, is ongoing in many hospital systems in which neurosurgeons are scarce. Although TS/S can increase access to treatment, it remains highly controversial. This survey investigated perceptions of neurosurgical TS/S to elucidate whether it is a permissible temporary solution to the global workforce deficit.
Methods
The survey was distributed to a convenience sample of individuals providing neurosurgical care. A digital survey link was distributed through electronic mailing lists of continental neurosurgical societies and various collectives, conference announcements, and social media platforms (July 2018-January 2019). Data were analyzed by descriptive statistics and univariate regression of Likert Scale scores.
Results
Survey respondents represented 105 of 194 World Health Organization member countries (54.1%; 391 respondents, 162 from high-income countries and 229 from low- and middle-income countries [LMICs]). The most agreed on statement was that task sharing is preferred to task shifting. There was broad consensus that both task shifting and task sharing should require competency-based evaluation, standardized training endorsed by governing organizations, and maintenance of certification. When perspectives were stratified by income class, LMICs were significantly more likely to agree that task shifting is professionally disruptive to traditional training, task sharing should be a priority where human resources are scarce, and to call for additional TS/S regulation, such as certification and formal consultation with a neurosurgeon (in person or electronic/telemedicine).
Conclusions
Both LMIC and high-income countries agreed that task sharing should be prioritized over task shifting and that additional recommendations and regulations could enhance care. These data invite future discussions on policy and training programs
