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1.
ACS Omega ; 8(37): 34077-34083, 2023 Sep 19.
Article in English | MEDLINE | ID: mdl-37744814

ABSTRACT

The Biginelli reaction provides 3,4-dihydropyrimidin-2(1H)-ones (DHPMs), whereas the Hantzsch reaction leads to 1,4-dihydropyridines (DHPs) by the one-pot, multicomponent, and operationally simple transformations starting from readily available starting materials. DHPMs and DHPs are well-established heterocyclic moieties in the synthetic organic chemistry literature and have pronounced pharmacological activities. This work reports the synthesis of novel DHPMs and DHPs from carbohydrate-derived 5-substituted-2-furaldehydes by employing gluconic acid aqueous solution (GAAS) as an efficient, inexpensive, and eco-friendly catalyst. The use of urea (or thiourea) as the reagent led to DHPMs, whereas ammonium acetate produced DHPs, selectively, keeping the other two starting materials (i.e., furfurals and ethyl acetoacetate) and the reaction parameters unaltered. Using the general synthetic protocol under optimized reaction conditions (60 °C, 3-6 h, 25 mol % GAAS cat.), all the DHPM and DHP derivatives were obtained in good to excellent isolated yields.

2.
Indian J Otolaryngol Head Neck Surg ; 74(Suppl 2): 1768-1772, 2022 Oct.
Article in English | MEDLINE | ID: mdl-36452610

ABSTRACT

Verrucous carcinoma of oral cavity is a highly well differentiated variant of squamous cell carcinoma with a low potential for invasion and metastasis. It is prevalent in the tobacco quid chewing population in our region. In this observational study, we reviewed the medical case records of 58 patients treated for oral verrucous carcinoma staged T2 to T4a. All patients underwent wide excision of tumour which included marginal mandibulectomy in 22 and hemimandibulectomy in 23 patients along with neck dissection saving the accessory nerve and internal jugular vein. 5 patients were found to have bone involvement along the alveolar sockets. 11 patients had other associated premalignant lesions in oral cavity. Only 2 patients had lymph node metastasis without extra nodal spread in submandibular region. With a mean follow up of 6 years and minimum follow up of 1 year, 3 patients had local recurrence. All these 3 patients had bone involvement and 2 of them had lymph node metastasis on histopathological examination. 3 patients who had associated premalignant lesions developed second primary in oral cavity after 3 years. In our experience, verrucous carcinoma has good prognosis when treated by surgery. Bone involvement along alveolar sockets and associated oral premalignant lesions adversely affect the outcome. There was no difference in the outcome between selective and modified radical neck dissection. Therefore selective neck dissection (supraomohyoid) would be adequate in treating these patients. Adjuvant radiotherapy can be reserved for T4a lesions or for positive margins.

3.
Int. arch. otorhinolaryngol. (Impr.) ; 26(4): 683-687, Oct.-Dec. 2022. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1421663

ABSTRACT

Abstract Introduction Choanal polyps are benign lesions arising from the sinonasal mucosa, extending through the choana into the nasopharynx. Though polyps arising from the maxillary sinus and extending to the choana are common, polyps arising from the sphenoid sinus ostium, posterior part of middle turbinate, and inferior and middle meatus are quite uncommon. Objective To document the site of origin of choanal polyps arising from unusual sites; their clinical, radiological, and histopathological characteristics, as well as diagnostic challenges and management. Methods This retrospective, single-center study included 14 patients aged 16 to 75-years-old with choanal polyps. After obtaining informed consent, their clinical, radiological and surgical details and histopathology reports were reviewed. Patients were followed for at least 6 months after surgery. Results The predominant symptoms were unilateral nasal obstruction (n = 9), snoring, rhinorrhea, and epistaxis. Though anterior rhinoscopy was unremarkable, a mass could be visualized during posterior rhinoscopy in the nasopharynx in 11 patients, and a mass could be directly visualized in the oropharynx in 2 patients. After diagnostic by nasal endoscopy, these polyps were noted to arise from the posterior aspect of the middle meatus (n = 6), middle turbinate (n = 3), posterior septum (n = 3), sphenoid sinus ostium (n = 1), and inferior meatus (n = 1). All patients were managed surgically. The histopathological examination revealed inflammatory polyp (n = 12), actinomycosis (n = 1), and rhinosporidiosis (n = 1). Patients were followed up for 6 to 22 months. We observed no complications or recurrence. Conclusion Diagnostic nasal endoscopy should be performed in all patients presenting with nasal obstruction, to rule out choanal polyps arising from unusual sites. Complete polyp removal and appropriate treatment based on histopathology prevents recurrence.

4.
Int Arch Otorhinolaryngol ; 26(4): e683-e687, 2022 Oct.
Article in English | MEDLINE | ID: mdl-36405473

ABSTRACT

Introduction Choanal polyps are benign lesions arising from the sinonasal mucosa, extending through the choana into the nasopharynx. Though polyps arising from the maxillary sinus and extending to the choana are common, polyps arising from the sphenoid sinus ostium, posterior part of middle turbinate, and inferior and middle meatus are quite uncommon. Objective To document the site of origin of choanal polyps arising from unusual sites; their clinical, radiological, and histopathological characteristics, as well as diagnostic challenges and management. Methods This retrospective, single-center study included 14 patients aged 16 to 75-years-old with choanal polyps. After obtaining informed consent, their clinical, radiological and surgical details and histopathology reports were reviewed. Patients were followed for at least 6 months after surgery. Results The predominant symptoms were unilateral nasal obstruction ( n = 9), snoring, rhinorrhea, and epistaxis. Though anterior rhinoscopy was unremarkable, a mass could be visualized during posterior rhinoscopy in the nasopharynx in 11 patients, and a mass could be directly visualized in the oropharynx in 2 patients. After diagnostic by nasal endoscopy, these polyps were noted to arise from the posterior aspect of the middle meatus ( n = 6), middle turbinate ( n = 3), posterior septum ( n = 3), sphenoid sinus ostium ( n = 1), and inferior meatus ( n = 1). All patients were managed surgically. The histopathological examination revealed inflammatory polyp ( n = 12), actinomycosis ( n = 1), and rhinosporidiosis ( n = 1). Patients were followed up for 6 to 22 months. We observed no complications or recurrence. Conclusion Diagnostic nasal endoscopy should be performed in all patients presenting with nasal obstruction, to rule out choanal polyps arising from unusual sites. Complete polyp removal and appropriate treatment based on histopathology prevents recurrence.

5.
Indian J Otolaryngol Head Neck Surg ; 74(2): 136-141, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35813778

ABSTRACT

Squamous cell carcinoma of oral cavity has a high prevalence in our region. Upper alveolar cancers are uncommon but present with locally advanced disease extending to infra temporal fossa. The outcome of treatment in these tumors is poor. Surgery followed by adjuvant therapy is the mainstay of treatment. We are presenting a retrospective analysis of outcome of treatment in 20 patients with locally advanced (T4b) upper alveolar carcinoma treated by infra-structure maxillectomy with compartment resection of infra-temporal fossa and neck dissection followed by adjuvant radiotherapy or radiotherapy with chemotherapy. Study period was from 2013 to 2018. Minimum follow up was 12 months and mean follow up 30 months. 12 patients are alive and disease free, 6 patients had local recurrence and 2 patients had regional recurrence with one having pulmonary metastasis. We observed that positive or close margins (< 5 mm after formalin fixation) predisposed to early recurrence. Erosion of pterygoid plates was a poor prognostic factor. Cervical lymph node metastasis occurred late in disease, but carried poor prognosis. Compartment resection of infra temporal fossa gave better outcome compared to other studies which reported outcome of treatment in upper alveolar cancers.

6.
Indian J Otolaryngol Head Neck Surg ; 73(4): 413-418, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34692453

ABSTRACT

Treatment of locally advanced laryngeal and hypopharyngeal cancers often requires total laryngectomy with partial pharyngectomy and adjuvant radiotherapy. Dysphagia is common after such aggressive treatment which is often under reported, but adversely affects the quality of life in these patients. The cause for this dysphagia is loss of pharyngeal mucosa, fibrosis, disruption of constrictors and loss of skeletal support to soft tissues. In this study 32 patients treated by laryngectomy with partial pharyngectomy and adjuvant radiotherapy underwent fibreoptic endoscopic evaluation of swallowing at 6 and 12 weeks after completion of treatment. Majority of them had delayed transit of bolus, dryness and edema and 6 of them had pharyngeal stenosis, 2 had fibrotic band and 2 had adynamic pharyngeal segments. These findings were the cause of dysphagia. The frequency of occurrence of the above findings and their association with extent of resection of pharyngeal mucosa and adjuvant treatment have been documented. Bilateral neck dissection, post operative chemotherapy with radiotherapy and use of myocutaneous flap for the reconstruction of neopharynx were found to cause severe dysphagia in our series. Some of these patients benefitted by swallowing therapy, diet modifications and nasogastric feeding. Therefore early identification of cause of dysphagia in these patients and timely intervention to facilitate rehabilitation can improve the quality of life and reduce the long term morbidity in these patients.

7.
J Chem Phys ; 154(14): 144305, 2021 Apr 14.
Article in English | MEDLINE | ID: mdl-33858156

ABSTRACT

We have used the FERMI free-electron laser to perform time-resolved photoelectron imaging experiments on a complex group of resonances near 15.38 eV in the absorption spectrum of molecular nitrogen, N2, under jet-cooled conditions. The new data complement and extend the earlier work of Fushitani et al. [Opt. Express 27, 19702-19711 (2019)], who recorded time-resolved photoelectron spectra for this same group of resonances. Time-dependent oscillations are observed in both the photoelectron yields and the photoelectron angular distributions, providing insight into the interactions among the resonant intermediate states. In addition, for most states, we observe an exponential decay of the photoelectron yield that depends on the ionic final state. This observation can be rationalized by the different lifetimes for the intermediate states contributing to a particular ionization channel. Although there are nine resonances within the group, we show that by detecting individual photoelectron final states and their angular dependence, we can identify and differentiate quantum pathways within this complex system.

8.
Indian J Otolaryngol Head Neck Surg ; 71(Suppl 3): 2140-2142, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31763310

ABSTRACT

Lethal midline granuloma is a rare disease, characterised by progressive unrelenting necrosis and mutilation of nose, midline facial tissues and other respiratory passages. This particular type of disease is heterogeneous in its pathogenesis, non-specificity of symptoms obscures timely and correct diagnosis and is responsible for delay in of treatment which can be detrimental as this disease calls for immediate intervention. We present a case report of 60 year old female who gave short one-month history of clinical symptoms.

9.
Opt Lett ; 40(4): 491-4, 2015 Feb 15.
Article in English | MEDLINE | ID: mdl-25680132

ABSTRACT

Single crystals of lithium niobate (LiNbO3), possessing high birefringence and anisotropic properties have been explored, for a long time, to harness their excellent electro-optic properties. However, their nanoforms are comparatively less explored. In this context, dielectric constant and polarization (P) versus electric-field (E) characteristics of LiNbO3 nanomaterials have been studied. A nonideal P-E loop and a dielectric constant of 20 at the onset of 1 kHz were seen. The electro-optic sensitivity was found to be 4 times as compared to the bulk LiNbO3 crystals. The results are attributed to oxygen vacancies, antisite defects, and grain boundary effects in an already congruent structural matrix of LiNbO3.

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