Search

The development of multi‐stimuli‐responsive (MSR) materials is a tempting yet intriguing challenge due to the absence of a defined design approach. In this study, we designed and synthesised two compounds based on triphenylamine, namely, TPA‐Tz1 and TPA‐Tz2. The photoluminescent investigations reveal the MSR behaviour of both compounds. TPA‐Tz1 shows reversible mechanochromism with a blue‐shifted emission due to changes in intermolecular interactions. Furthermore, both compounds exhibit solvatochromism in solvents of varying polarity. Detailed studies suggest that solvatochromism in TPA‐Tz1 can be attributed to twisted intramolecular charge transfer (TICT), while in TPA‐Tz2, it is due to intramolecular charge transfer (ICT). Additionally, both compounds display acidochromic properties in solution as well as in the solid state due to the protonation of the triazole ring. All changes in emissions are corroborated through theoretical calculations. The results provide insights into the intricate interplay of molecular interactions and structural rearrangements that contribute to the compound's multifaceted responsiveness. [ABSTRACT FROM AUTHOR]

Doping of suitable metal ions in ferroelectric oxides modifies the physical properties and can induce additional functionalities. Here, we present a detailed study on the effects of Sm concentration on the structural, dielectric, ferroelectric, and piezoelectric properties of ((K0.5Na0.5)1−3xSmx)NbO3 (KNSN) (0.00 ≤ x ≤ 0.02) ceramics. X‐ray diffraction and Raman spectroscopic analysis indicate that KNSN ceramics exhibit the single‐phase orthorhombic (Amm2) structure for x = 0.00 and the coexistence of orthorhombic and tetragonal (Amm2 + P4mm) structure for the composition range 0.005 ≤ x ≤ 0.02. The tetragonal phase fraction increases with an increase in Sm concentration. We observed dielectric relaxation behavior in KNSN at orthorhombic to tetragonal (TO–T) phase transition temperature, and its origin can be attributed to the structural heterogeneity at the inter‐ferroelectric phase boundary. Increasing Sm concentration leads to the broadening of the ferroelectric phase transition peaks. Further, the structural heterogeneity of the ceramics was seen from the slope of the dielectric constant versus log frequency and central peak behavior of Raman spectra at room temperature (RT). The study reveals that x = 0.005 shows maximum dielectric constant (Ɛr = 583), remanent polarization (2Pr = 57.02 μC/cm2), and piezoelectric coefficient (d33 = 94 pC/N) at RT and is associated with increased local structural heterogeneity due to Sm doping. [ABSTRACT FROM AUTHOR]

Purpose: Cancer stem cells (CSCs) constitute a distinctive subpopulation of cancer cells that are competent in tumor initiation, invasion, recurrence, and resistance to chemoradiotherapy. CD44, a hyaluronic acid (HA) receptor has been considered as a potential CSC marker in head and neck cancer. The purpose of this study is to evaluate the correlation between CD44 and clinicopathological parameters, treatment response, survival, and recurrence. Methods: The CD44 expression was examined by immunohistochemistry (IHC) in 90 samples of head and neck squamous cell carcinoma (HNSCC) confirmed patients. The expression of CD44 and its association with clinicopathological parameters, treatment response, and survival was determined. Results: In all HNSCC patient samples, CD44 was expressed consistently at different intensities. Tumor size (p < 0.001), stage (p < 0.001), and treatment response (p < 0.001) showed statistically significant association with CD44 expression. Alcohol and CD44 were observed as independent predictors of response to radiotherapy using multivariate ordinal logistic regression analysis. Analysis of 2‐year overall survival (OS) showed that CD44 expression (p = 0.02), tumor size (p = 0.001), lymph node status (p < 0.001), stage (p < 0.001), and grade (p = 0.007) were significantly associated with OS. Using Cox regression analysis, lymph node status (p = 0.001), grade (p < 0.001), recurrence (p < 0.001), and CD44 expression (p = 0.003) were found to be potential independent predictors of OS. Conclusion: Our findings suggest that CD44 contributes to resistance to radiotherapy and poor OS. The results also suggest that except for CD44 there could be other factors such as lymph node metastasis, grade, and alcohol which should be investigated as potential targets for therapy. [ABSTRACT FROM AUTHOR]

Objective: An attempt is made to analyze the molecular behavior of juvenile nasopharyngeal angiofibroma (JNA).Study Design: Case Series METHODS: Quantification of mRNAs expression was undertaken through real-time polymerase chain reaction in JNA (9-24) samples for VEGF-A, basic fibroblast growth factor (b-FGF), platelet-derived growth factor PDGF-A, KIT proto-oncogene receptor tyrosine kinase (c-Kit), Avian myelomatosis viral oncogene homolog (c-Myc), Harvey rat sarcoma viral oncogene homolog (H-Ras), tumor suppressor gene TP53, and androgen receptor and interleukin 6 (IL-6). The β-catenin expression was evaluated by western blot in 16 samples. Nasal polyp was taken as control.Results: A significantly increased (P < 0.01) expression of c-myc, VEGFA, bFGF, PDGFA, c-kit, and TP53 was seen, along with enhanced expression of β-catenin. A massive enhancement of H-Ras expression was seen for the first time. Androgen receptor expression was no different, whereas IL-6 despite showing upregulation trend was not significant.Conclusion: The enhanced expressions of various markers suggest their potential role in JNA. Although the biological significance of c-kit, c-myc, and one of the novel markers H-Ras has yet to be defined, their significant expression may have a therapeutic importance.Level Of Evidence: NA. Laryngoscope, 127:E100-E106, 2017. [ABSTRACT FROM AUTHOR]

Background Despite the generally favorable prognosis of patients with papillary thyroid cancers, 10-year recurrence rates for patients with stage I to III disease is greater than 20%, with central compartment recurrences common among these recurrent sites. Methods This study is a retrospective analysis of consecutive patients treated by a single surgeon over an 18-month period of time terminating in 2003. Results Sixty-three patients underwent a comprehensive dissection of levels VI and VII for papillary thyroid carcinoma during this period. There was a female predominance of 2:1, with 48% of patients being greater than 45 years of age. The median number of lymph nodes identified was 16 (range, 3–52), with 7 (1–20) lymph nodes pathologically involved. Permanent hypoparathyroidism was present on presentation in 13% of patients and developed in an additional 5% following surgery. Although recurrent laryngeal paralysis was present on presentation among 8 (13%) of patients, no patients experienced paralysis of documented functioning recurrent laryngeal nerves or necessitated tracheotomy. Postoperative thyroglobulin levels were reduced to nondetectable in 71% of the informative cases. Over 60% of patients were discharged on their first postoperative day. Conclusion Bilateral paratracheal and superior mediastinal dissection is an oncologically safe procedure exhibiting minimal morbidity when performed among experienced individuals despite multiple prior surgical procedures or existing vocal cord paralysis. © 2009 Wiley Periodicals, Inc. Head Neck, 2009 [ABSTRACT FROM AUTHOR]

Background. Cervical lymphadenectomy is frequently performed in patients with lateral cervical lymph node metastases to improve regional control of disease. However, there is no consensus regarding the appropriate levels of the neck that need to be dissected. Treatment options that have been advocated include the modified radical neck dissection, limited neck dissections, and selective nodal excisions. In particular, the routine dissection of level V remains controversial due to the attendant morbidity to the spinal accessory nerve. To identify clinical and pathological predictors of cervical node metastases to level V in differentiated thyroid carcinoma, we reviewed our experience at The University of Texas M. D. Anderson Cancer Center for the management of metastatic well-differentiated thyroid cancer. Methods. We retrospectively analyzed 70 patients who underwent thyroidectomy and neck dissection for well-differentiated thyroid cancer at M. D. Anderson Cancer Center. Results. In our series, 53% of neck specimens harbored metastatic thyroid carcinoma at level V. Additionally, 13 level V contralateral neck dissections were performed, and 57% were found positive for metastases. The presence of ipsilateral level V metastases was significantly associated with multifocal disease (p <.05), ipsilateral level II (p <.05), III (p <.05), or IV (p <.01) metastases. Furthermore, ipsilateral involvement of level V was associated with contralateral lymph node metastases (p <.05). Age, sex, and size of primary tumor were not found to be associated with level V metastases. Additionally, preoperative imaging was not sensitive for detecting the presence of level V metastases. Conclusion. In our series, cervical metastases from differentiated thyroid carcinoma were commonly present at level V. Patients with multifocal cancer within the thyroid gland, and cervical metastases in the ipsilateral jugular nodes have a higher risk of harboring metastatic disease at level V. We believe that routine dissection of the level V lymph nodes should be performed in the setting of a comprehensive neck dissection for patients with lateral neck metastasis from well-differentiated thyroid cancer. © 2008 Wiley Periodicals, Inc. Head Neck, 2008 [ABSTRACT FROM AUTHOR]

Background. We report a rare case of endodermal sinus tumor (EST) of the paranasal sinus in a 59-year-old man with a 6-week history of nasal obstruction. Methods and Results. High-resolution MRI showed a right nasoethmoid mass with obstructive changes in the sphenoid, frontal, and right maxillary sinuses and orbital and intracranial extension. Histologic analysis showed 2 distinct histologic features: poorly differentiated carcinoma and EST. Immunohistochemical studies showed strong keratin staining in both components and restricted positivity of α-fetoprotein in the endodermal sinus-like component. The patient underwent 3 cycles of neoadjuvant chemotherapy consisting of ifosfamide, paclitaxel, and cisplatin, which resulted in significant regression of the tumor, but after the fourth cycle, the mass showed a slight increase in size. The tumor was excised with clear margins through an anterior craniofacial approach to the skull base. Histologic examination of the resected specimen showed extensive fibrosis with residual areas of viable tumor composed mainly of the poorly differentiated component with only residual microscopic foci of EST. Adjuvant postoperative intensity-modulated radiation therapy was administered. At 1-year follow-up, the patient was tumor free, with normal α-fetoprotein levels. Conclusion. Because of the rarity of this entity, no standardized treatment protocol has been defined. The involvement of the anterior skull base in our case necessitated a radical craniofacial resection, despite a partial response to chemotherapy. © 2007 Wiley Periodicals, Inc. Head Neck, 2008 [ABSTRACT FROM AUTHOR]

The sense of smell has been largely ignored by otorhinolaryngologists, even though 1) its medical stewardship falls within their specialty's purview, 2) olfactory dysfunction is not uncommon in the general population, and 3) disorders of olfaction have significant quality of life, nutritional, and safety consequences. This report provides a succinct overview of the major intranasal neural systems present in humans (namely, cranial nerves O, I, and V, and the nonfunctional accessory [vomeronasal] organ system), along with a summary of notable findings resulting from the application of modern olfactory tests to patient populations, emphasizing diseases of the nose. Such tests have led to the discovery of significant influences of age, gender, smoking, toxic exposure, and genetics on the ability to smell. Within the field of otorhinolaryngology, they have revealed that 1) surgical and medical interventions in patients with rhinosinusitis do not, on average, lead to complete recovery of olfactory function, despite common beliefs to the contrary, and 2) associations are generally lacking between measures of airway patency and olfactory function in such cases. These findings have thrown into question the dogma that olfactory loss in rhinosinusitis is attributable primarily to blockage of airflow to the receptors and have led to histopathological studies demonstrating significant olfactory epithelial compromise in sinonasal syndromes. [ABSTRACT FROM AUTHOR]

Doping of suitable metal ions in ferroelectric oxides modifies the physical properties and can induce additional functionalities. Here, we present a detailed study on the effects of Sm concentration on the structural, dielectric, ferroelectric, and piezoelectric properties of ((K0.5Na0.5)1−3xSmx)NbO3 (KNSN) (0.00 ≤ x ≤ 0.02) ceramics. X‐ray diffraction and Raman spectroscopic analysis indicate that KNSN ceramics exhibit the single‐phase orthorhombic (Amm2) structure for x = 0.00 and the coexistence of orthorhombic and tetragonal (Amm2 + P4mm) structure for the composition range 0.005 ≤ x ≤ 0.02. The tetragonal phase fraction increases with an increase in Sm concentration. We observed dielectric relaxation behavior in KNSN at orthorhombic to tetragonal (TO–T) phase transition temperature, and its origin can be attributed to the structural heterogeneity at the inter‐ferroelectric phase boundary. Increasing Sm concentration leads to the broadening of the ferroelectric phase transition peaks. Further, the structural heterogeneity of the ceramics was seen from the slope of the dielectric constant versus log frequency and central peak behavior of Raman spectra at room temperature (RT). The study reveals that x = 0.005 shows maximum dielectric constant (Ɛr = 583), remanent polarization (2Pr = 57.02 μC/cm2), and piezoelectric coefficient (d33 = 94 pC/N) at RT and is associated with increased local structural heterogeneity due to Sm doping. [ABSTRACT FROM AUTHOR]