Sonographic and Cytological Evaluation of Salivary Gland Tumors.

INTRODUCTION: Salivary gland tumours are relatively uncommon, but they have a multifaceted clinical presentation and varied morphological configuration. The investigations required for these tumours remain debatable. We conducted a study to determine the accuracy of various modalities used in salivary gland tumours. METHODS: We enrolled 72 subjects, consisting of 44 females and 28 males, with a mean age of 40.93 ± 16.51 years (range: 15 to 79 years), suffering from various salivary gland tumours. The tumour distribution included 42 parotid gland tumours (58.33%), followed by 21 submandibular gland tumours (29.16%), three sublingual gland tumours (4.16%), and six minor salivary gland tumours (8.33%). These individuals were subjected to clinical examination, sonography, and fine needle aspiration cytology as per indications. The results of each modality were compared to surgical pathology to find sensitivity and accuracy. RESULTS: The clinical examination was found to be least sensitive (83.8%) as compared to FNAC (97.6%), and ultrasound (100%). Ultrasound had the highest diagnostic accuracy (86.2%) as compared to clinical examination (80.6%) and FNAC (82.6%). CONCLUSION: Although sonography was found to have the highest sensitivity and accuracy as compared to fine needle aspiration cytology and clinical examination, the difference was subtle, as both sonography and fine needle aspiration cytology had a statistically significant correlation with histopathology.

Effect of binaural beat music and noise cancelling headphones on intraoperative anxiety in patients undergoing spinal anaesthesia - A randomised controlled study.

Background and Aims: This study aimed to determine the effects of music and active noise cancellation on intraoperative anxiety in patients undergoing lower limb surgeries under spinal anaesthesia. Methods: After obtaining ethical approval, this randomised controlled study was conducted in adult patients (18-50 years of age) of either gender. Patients were randomly allocated to binaural beat music (Group A), noise cancellation (Group B) or no headphones (Group C) group (n = 36 in each group). State-Trait Anxiety Inventory-6 (STAI-6) score and Visual Analogue Score for Satisfaction (VAS-S) were noted preoperatively and at the end of surgery. In addition, Ramsay sedation scores and Likert communication difficulty scores were noted at 30 min intraoperatively. Haemodynamic parameters were noted preoperatively and at different intervals intraoperatively till the end of the surgery. Results: There was a significant decrease in anxiety scores in Group A, Group B and Group C with postoperative STAI-6 scores (mean ± standard deviation) of 7.8 ± 1.7, 11.7 ± 4.2 and 14.7 ± 5.3, respectively. The difference was significant in Groups A and B compared to Group C (P < 0.001). Patient satisfaction scores in Groups A and B were better than in Group C (7.3 ± 1.7 and 6.2 ± 1.6 vs. 5.2 ± 1.3, respectively). Sedation scores and communication difficulty was significantly better in Groups A and B compared to Group C. Systolic blood pressure was significantly better intra- and postoperatively. There were no significant differences in other haemodynamic parameters on most occasions. Conclusion: Music and noise-cancellation headphones can reduce anxiety and improve satisfaction and sedation scores in patients undergoing spinal anaesthesia.

Transient metal-centered states mediate isomerization of a photochromic ruthenium-sulfoxide complex.

Ultrafast isomerization reactions underpin many processes in (bio)chemical systems and molecular materials. Understanding the coupled evolution of atomic and molecular structure during isomerization is paramount for control and rational design in molecular science. Here we report transient X-ray absorption studies of the photo-induced linkage isomerization of a Ru-based photochromic molecule. X-ray spectra reveal the spin and valence charge of the Ru atom and provide experimental evidence that metal-centered excited states mediate isomerization. Complementary X-ray spectra of the functional ligand S atoms probe the nuclear structural rearrangements, highlighting the formation of two metal-centered states with different metal-ligand bonding. These results address an essential open question regarding the relative roles of transient charge-transfer and metal-centered states in mediating photoisomerization. Global temporal and spectral data analysis combined with time-dependent density functional theory reveals a complex mechanism for photoisomerization with atomic details of the transient molecular and electronic structure not accessible by other means.

Hydricity, electrochemistry, and excited-state chemistry of Ir complexes for CO2 reduction.

We prepared electron-rich derivatives of [Ir(tpy)(ppy)Cl]+ with modification of the bidentate (ppy) or tridentate (tpy) ligands in an attempt to increase the reactivity for CO2 reduction and the ability to transfer hydrides (hydricity). Density functional theory (DFT) calculations reveal that complexes with dimethyl-substituted ppy have similar hydricities to the non-substituted parent complex, and photocatalytic CO2 reduction studies show selective CO formation. Substitution of tpy by bis(benzimidazole)-phenyl or -pyridine (L3 and L4, respectively) induces changes in the physical properties that are much more pronounced than from the addition of methyl groups to ppy. Theoretical data predict [Ir(L3)(ppy)(H)] as the strongest hydride donor among complexes studied in this work, but [Ir(L3)(ppy)(NCCH3)]+ cannot be reduced photochemically because the excited state reduction potential is only 0.52 V due to the negative ground state potential of -1.91 V. The excited state of [Ir(L4)(ppy)(NCCH3)]2+ is the strongest oxidant among complexes studied in this work and the singly-reduced species is formed readily upon photolysis in the presence of tertiary amines. Both [Ir(L3)(ppy)(NCCH3)]+ and [Ir(L4)(ppy)(NCCH3)]2+ exhibit electrocatalytic current for CO2 reduction. While a significantly greater overpotential is needed for the L3 complex, a small amount of formate (5-10%) generation in addition to CO was observed as predicted by the DFT calculations.

Striking Differences in Properties of Geometric Isomers of [Ir(tpy)(ppy)H](+): Experimental and Computational Studies of their Hydricities, Interaction with CO2, and Photochemistry.

We prepared two geometric isomers of [Ir(tpy)(ppy)H](+), previously proposed as a key intermediate in the photochemical reduction of CO2 to CO, and characterized their notably different ground- and excited-state interactions with CO2 and their hydricities using experimental and computational methods. Only one isomer, C-trans-[Ir(tpy)(ppy)H](+), reacts with CO2 to generate the formato complex in the ground state, consistent with its calculated hydricity. Under photocatalytic conditions in CH3CN/TEOA, a common reactive C-trans-[Ir(tpy)(ppy)](0) species, irrespective of the starting isomer or monodentate ligand (such as hydride or Cl), reacts with CO2 and produces CO with the same catalytic efficiency.

One photon yields two isomerizations: large atomic displacements during electronic excited-state dynamics in ruthenium sulfoxide complexes.

Photochromic compounds efficiently transduce photonic energy to potential energy for excited-state bond-breaking and bond-forming reactions. A critical feature of this reaction is the nature of the electronic excited-state potential energy surface and how this surface facilitates large nuclear displacements and rearrangements. We have prepared two photochromic ruthenium sulfoxide complexes that feature two isomerization reactions following absorption of a single photon. We show by femtosecond transient absorption spectroscopy that this reaction is complete within a few hundred picoseconds and suggest that isomerization occurs along a conical intersection seam formed by the ground-state and excited-state potential energy surfaces.

Tuning excited state isomerization dynamics through ground state structural changes in analogous ruthenium and osmium sulfoxide complexes.

The complexes [Ru(bpy)2(pyESO)](PF6)2 and [Os(bpy)2(pyESO)](PF6)2, in which bpy is 2,2'-bipyridine and pyESO is 2-((isopropylsulfinyl)ethyl)pyridine, were prepared and studied by (1)H NMR, UV-visible and ultrafast transient absorption spectroscopy, as well as by electrochemical methods. Crystals suitable for X-ray structural analysis were grown for [Ru(bpy)2(pyESO)](PF6)2. Cyclic voltammograms of both complexes provide evidence for S→O and O→S isomerization as these voltammograms are described by an ECEC (electrochemical-chemical electrochemical-chemical) mechanism in which isomerization follows Ru(2+) oxidation and Ru(3+) reduction. The S- and O-bonded Ru(3+/2+) couples appear at 1.30 and 0.76 V versus Ag/AgCl in propylene carbonate. For [Os(bpy)2(pyESO)](PF6)2, these couples appear at 0.97 and 0.32 V versus Ag/AgCl in acetonitrile, respectively. Charge-transfer excitation of [Ru(bpy)2(pyESO)](PF6)2 results in a significant change in the absorption spectrum. The S-bonded isomer of [Ru(bpy)2(pyESO)](2+) features a lowest energy absorption maximum at 390 nm and the O-bonded isomer absorbs at 480 nm. The quantum yield of isomerization in [Ru(bpy)2(pyESO)](2+) was found to be 0.58 in propylene carbonate and 0.86 in dichloroethane solution. Femtosecond transient absorption spectroscopic measurements were collected for both complexes, revealing time constants of isomerizations of 81 ps (propylene carbonate) and 47 ps (dichloroethane) in [Ru(bpy)2(pyESO)](2+). These data and a model for the isomerizing complex are presented. A striking conclusion from this analysis is that expansion of the chelate ring by a single methylene leads to an increase in the isomerization time constant by nearly two orders of magnitude.