146 research outputs found
Synthesis of Substituted 2-Amino-Cyclobutanones
A series of weakly nucleophilic nitrogen derivatives including carbamates, amides, sulfonamides, and anilines were reacted with 1,2âbis(trimethylsilyloxy)cyclobutene under acidic conditions to afford various substituted 2âaminocyclobutanone derivatives 3aâi in modest to excellent yields
Hazard Assessment for Manufacture of Combustible Cartridge Cases using Picrite
A systematic study of the effect of impact, friction, flame and electric spark sensitivity was carried out on the samples combustible cartridge case (CCC) withdrawn at different stages of manufacture. These are Stage I dried felted CCC; stage II-CCC from stage III Coated with nitrocellulose coating. based on the results obtained from various experiments, the CCC can be classified for handling storage and transportation as Group 3, for safety distance category as UN 1.3 and for fire fighting as class 2. further it is concluded from hazard analysis study that the CCCs are safe to handle but these should be protected from naked flame
CFD Analysis of a Micro-Rotor In Ground Effect
In this work, computational fluid dynamics is used to compare experimental results for a two-bladed small rotor
Out of Ground Effect and In Ground Effect conditions. The paper focuses on the evalutation and prediction of
the performance of the rotor and investigates the outwash generated in ground effect. Time and phase averaged
outflow velocities with two different scaling methods are compared with experiments. The results are also scaled
to a full-size rotor, and compared with the PAXman model of crew operating in close rotor proximity. A particle
pickup model is also used showing the dust cloud generated by the rotor
Patientsâ Perspectives, Experiences, and Concerns With Perianal Fistulae:Insights From Online Targeted-Disease Forums
Background: Perianal fistulae can undermine physical, emotional, and social well-being in patients with Crohnâs disease and are challenging to manage. Social media offers a rich opportunity to gain an in-depth understanding of the impact of perianal fistulae on patientsâ daily lives outside of controlled environments. In this study, we conducted social media analytics to examine patientsâ experiences with perianal fistulae and assessed the impact of perianal fistulae on patientsâ behavior and overall well-being. Methods: We used a mixed-method approach to examine 119 986 publicly available posts collected from 10 Crohnâs disease forums in the United States between January 01, 2010 and January 01, 2020. Discussions related to Crohnâs perianal fistulae were retrieved. We randomly selected 700 posts and qualitatively analyzed them using an inductive thematic approach. We then applied a latent Dirichlet allocation probabilistic topic model to explore themes in an unsupervised manner on the collection of 119 986 posts. Results: In the qualitative analysis, 5 major themes were identified: (1) burden of perianal fistula; (2) challenges associated with treatment; (3) online information seeking and sharing; (4) patient experiences with treatments; and (5) patientsâ apprehension about treatments. In the quantitative analysis, the percentages of posts related to the major themes were (1) 20%, (2) 29%, (3) 66%, and (4) 28%, while the topic model did not identify theme 5. Conclusions: Social media reveals a dynamic range of themes governing patientsâ perspectives and experiences with Crohnâs perianal fistulae. In addition to the biopsychosocial burden, patients frequently express dissatisfaction with current treatments and often struggle to navigate among available management options.</p
Management of difficult airway in intratracheal tumor surgery
BACKGROUND: Tracheal malignancies are usual victim of delay in diagnosis by virtue of their symptoms resembling asthma. Sometimes delayed diagnosis may lead to almost total airway obstruction. For difficult airways, not leaving any possibility of manipulation into neck region or endoscopic intervention, femorofemoral cardiopulmonary bypass can be a promising approach. CASE PRESENTATION: We are presenting a case of tracheal adenoid cystic carcinoma (cylindroma) occupying about 90% of the tracheal lumen. It was successfully managed by surgical excision of mass by sternotomy and tracheotomy under femorofemoral cardiopulmonary bypass (CPB). CONCLUSION: Any patient with recurrent respiratory symptoms should be evaluated by radiological and endoscopic means earlier to avoid delay in diagnosis of such conditions. Femorofemoral cardiopulmonary bypass is a relatively safe way of managing certain airway obstructions
Primary aneurysmal bone cyst of coronoid process
BACKGROUND: Aneurysmal bone cysts are relatively uncommon in the facial skeleton. These usually affect the mandible but origin from the coronoid process is even rarer. To the best of our knowledge, this is the first reported case of a coronoid process aneurysmal bone cyst presenting as temporal fossa swelling. CASE PRESENTATION: A 17 year old boy presented with a progressively increasing swelling in the left temporal region developed over the previous 8 months. An expansile lytic cystic lesion originating from the coronoid process of the left mandible and extending into the infratemporal and temporal fossa regions was found on CT scan. It was removed by a superior approach to the infratemporal fossa. CONCLUSION: Aneurysmal bone cyst of the coronoid process can attain enormous dimensions until the temporal region is also involved. A superior approach to the infratemporal fossa is a reasonable approach for such cases, providing wide exposure and access to all parts of the lesion and ensuring better control and complete excision
CFD Analysis of a Micro-Rotor In Ground Effect
In this work computational ïŹuid dynamics is validated using experimental results for a model rotor In Ground EïŹect. The paper concentrates on the evaluation and prediction of the performance of the rotors and on the outwash generated In Ground EïŹect. Finally, safety considerations in terms of outïŹow forces and particles in the ïŹow ïŹeld are presented, comparing the results with other safety, distance based criteria. Using data of three diïŹerent aircraft, scaling factors have been used to take into account the diïŹerent size of the small-rotor studied and real case scenarios. The results show how heavier helicopters may generate the most dangerous situations, in terms of induced forces and presence of particles in a delimited area
Relationship between mean platelet volume and vitamin D deficiency in gestational diabetes mellitus
Biophilic architecture: a review of the rationale and outcomes
Contemporary cities have high stress levels, mental health issues, high crime levels and ill health, while the built environment shows increasing problems with urban heat island effects and air and water pollution. Emerging from these concerns is a new set of design principles and practices where nature needs to play a bigger part called âbiophilic architectureâ. This design approach asserts that humans have an innate connection with nature that can assist to make buildings and cities more effective human abodes. This paper examines the evidence for this innate human psychological and physiological link to nature and then assesses the emerging research supporting the multiple social, environmental and economic benefits of biophilic architecture
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