The Inspiratory Maneuver: A Simple Method to Assess the Superficial Lamina Propria During Endoscopy

We describe a simple means of assessing the condition of the superficial lamina propria during endoscopy, which we use in our practice as an adjunct to careful stroboscopic examination. An intake of breath against partially adducted vocal folds serves to draw the mucosa inferomedially into the glottis, which reveals areas of diminished mobility, the relationship of mucosal lesions to deeper tissues of the vocal folds, and subtle submucosal lesions. This is possible because of the unique geometry of the glottis that renders the vector forces of airflow different at inspiration and expiration. Because the integrity of the superficial lamina propria is essential to healthy phonation, we have found the inspiratory maneuver useful across a wide variety of mucosal pathologic conditions.     

Characterization of chronic vocal fold scarring in a rabbit model

The purpose of the current study was to assess the histologic and rheologic properties of the scarred vocal fold lamina propria during a chronic phase of wound repair in a rabbit model. Eighteen rabbit larynges were scarred using a procedure that involved stripping the vocal fold lamina propria down to the thyroarytenoid muscle, using 3-mm microforceps. The approximate dimension of injury to the vocal fold was 3 x 1.5 x 0.5 mm [length x width x depth]. At 6 months postoperatively, histologic analysis of the scarred and control lamina propria in eight of these rabbits was completed for collagen, procollagen, elastin, and hyaluronic acid. Compared with control samples, scarred tissue samples revealed fragmented and disorganized elastin fibers. Additionally, collagen was significantly increased, organized, and formed thick bundles in the scarred vocal fold lamina propria. Measurements of the viscoelastic shear properties of the scarred and control lamina propria in the remaining 10 rabbits revealed increased elastic shear modulus (G') in 8 of 10 scarred samples and increased dynamic viscosity (eta') in 9 of 10 scarred samples. Although rheologic differences were not statistically significant, they revealed that on average, scarred samples were stiffer and more viscous than the normal controls. Histologic data are interpreted as indicating that by 6 months postinjury, the scarred rabbit vocal fold has reached a mature phase of wound repair, characterized by an increased, organized, and thick bundle collagen matrix. Rheologic data are interpreted as providing support for the potential role of increased, thick bundle collagen, and a disorganized elastin network on shear stiffness and dynamic viscosity in the chronic vocal fold scar. Based on these results, a 6-month postoperative time frame is proposed for future studies of chronic vocal fold scarring using the rabbit animal model.     

Laryngeal Chondroma

Cartilaginous tumors of the larynx represent less than 1% of laryngeal tumors. Chondroma and "low-grade" chondrosarcoma are the most common; 70%-75% of these tumors arise on the endolaryngeal surface of the posterior lamina of the cricoid cartilage. The clinical presentation is varied and directly dependent on the size and location of the tumor; stridor, hoarseness, dyspnea, or a neck mass are common presenting signs. CT scanning in the axial plane is the mainstay of radiographic imaging due to its ability to show size, extent of the tumor, and invasion into surrounding structures. Surgical extirpation is the standard therapy with no role for radiation therapy or chemotherapy. Although significant recurrence rates have been reported, there is not a significant difference between initial conservative therapy followed by salvage therapy versus initial radical therapy.     

The Prevalence of Helicobacter Pylori Infection in Benign Laryngeal Disorders

Helicobacter pylori (HP) is an accepted cause of chronic active gastritis and has a major causative role in peptic ulcers. It is a gastric carcinogen. Its role in nonulcer dyspepsia (NUD) is less clear, yet 50% of patients with NUD are infected with HP, and some recent literature demonstrates long-term improvement of symptoms following eradication. HP has been investigated in several other organ systems, but has not been investigated to any major degree in laryngeal disorders, a region that could be directly exposed to the bacterium from pharyngolaryngeal reflux. This study represents one arm of a larger study designed to investigate such a relationship. Of 101 patients with nonmalignant voice disorders presenting to our voice clinics, 54.5% tested positive for the H. pylori organism. Of the controls, 47.1% tested positive. When striated into age groups of < 45 years, 46–61 years, and > 62 years, and then age-matched with the controls, the likelihood of infection with the H. pylori organism was greater in both the experimental middle group, and in the middle group when combined with the elder group, than in the matched controls, and this difference demonstrated a trend approaching statistical significance. This finding is discussed in the light of other studies on HP and on gastroesophageal reflex (GER).     

Coefficient estimates of negative powers and inverse coefficients for certain starlike functions

For ?1≤B<A≤1, let \(\mathcal {S}^{*}(A,B)\) denote the class of normalized analytic functions \(f(z)= z+{\sum }_{n=2}^{\infty }a_{n} z^{n}\) in |z|<1 which satisfy the subordination relation z f ^′(z)/f(z)?(1 + A z)/(1 + B z) and Σ^?(A,B) be the corresponding class of meromorphic functions in |z|>1. For \(f\in \mathcal {S}^{*}(A,B)\) and λ>0, we shall estimate the absolute value of the Taylor coefficients a _n (?λ,f) of the analytic function (f(z)/z)^?λ . Using this we shall determine the coefficient estimate for inverses of functions in the classes \(\mathcal {S}^{*}(A,B)\) and Σ^?(A,B).     

Study of ΛΛ dynamics and ground state structure of low and medium mass double Λ hypernuclei

We critically review the ΛΛ dynamics by examining Λ - Λ and Λ-nucleon phenomenological potentials in the study of the bound state properties of double-Λ hypernuclei _ΛΛ ⁶ He, _ΛΛ ¹⁰ Be, _ΛΛ ¹⁴ C, _ΛΛ ¹⁸ O, _ΛΛ ²² Ne, _ΛΛ ²⁶ Mg, _ΛΛ ³⁰ Si, _ΛΛ ³⁴ S, _ΛΛ ³⁸ Ar, _ΛΛ ⁴² Ca, _ΛΛ ⁴⁶ Ti, _ΛΛ ⁵⁰ Cr, _ΛΛ ⁵⁴ Fe, _ΛΛ ⁵⁸ Ni, _ΛΛ ⁶² Zn, _ΛΛ ⁶⁶ Ge, _ΛΛ ⁷⁰ Se, _ΛΛ ⁷⁴ Kr, _ΛΛ ⁷⁸ Sr, _ΛΛ ⁸² Zr, _ΛΛ ⁸⁶ Mo, _ΛΛ ⁹⁰ Ru, _ΛΛ ⁹⁴ Pd, _ΛΛ ⁹⁸ Cd, _ΛΛ ¹⁰² Sn in the frame work of (core+Λ+Λ) three body model. An effective ΛN potential is obtained by folding the phenomenological ΛN potential into the density distribution of the core nuclei. The former two cases (i.e. _ΛΛ ⁶ He and _ΛΛ ¹⁰ Be) are revisited to justify the correctness of the present potential model. Assuming the same potential model we predicted some of the structural properties of heavier doubly Λ-hypernuclei. The hyperspherical harmonics expansion method, which is an essentially exact method has been employed for the three body system. A convergence in binding energy up to 0.15% for K _max=20 has been achieved. In our calculation we have made no approximation in restricting the allowed l-values of the interacting pairs.     

A tandem synthesis of 3-aroylcoumarinoflavones catalyzed by <Emphasis Type="SmallCaps">l</Emphasis>-proline and their antioxidant activity

A facile, convenient, efficient and high-yielding synthesis of 3-aroylcoumarinoflavones has been developed by the condensation of easily synthesized 7-hydroxy-8-formylflavones and benzoyl acetonitriles in the presence of catalytic amount of l-proline in ethanol reflux. All the synthesized compounds were evaluated for their antioxidant activity. Some of the compounds showed very good activity compared to standard BHT.     

Cyanobiphenyl-based liquid crystal dimers and the twist-bend nematic phase

ABSTRACT

The synthesis and characterisation of several members of the 1,ω-bis(4-cyanobiphenyl-4′-yl) alkane (CBnCB) and the 1-(4-cyanobiphenyl-4′-yloxy)-ω-(4-cyanobiphenyl-4′-yl) alkane (CBnOCB) homologous series are reported. The new odd members described CB5CB, CB13CB, CB4OCB, CB8OCB and CB10OCB all exhibit twist-bend nematic and nematic phases. The members of these series already reported in literature, CB7CB, CB9CB, CB11CB and CB6OCB, were also prepared in order to allow for a direct comparison of their transitional properties. The properties of these dimers are also compared to those of the corresponding members of the 1,ω-bis(4-cyanobiphenyl-4,-yloxy) alkanes (CBOnOCB). For any given total spacer length, for odd members of these series, the nematic–isotropic transition temperatures and associated entropy changes are greatest for the CBOnOCB dimer and lowest for the CBnCB dimer. These trends are understood in terms of molecular shape. For short spacer lengths, the twist-bend nematic–nematic transition temperature (T_NTBN) is higher for the CBnOCB series than for the CBnCB series but this is reversed as the spacer length increases. Of the CBOnOCB dimers, a virtual value of T_NTBN was estimated for CBO3OCB and T_NTBN was measured for CBO5OCB. These values are considerably lower than those observed for the corresponding members of the CBnCB or CBnOCB series. The dependence of T_NTBN on molecular structure is discussed not only in terms of the molecular curvature but also in the ability of the molecules to pack efficiently. As the temperature range of the preceding nematic phase increases, so the twist-bend nematic–nematic transition entropy change decreases and the transition approaches second order for the longer spacers. For comparative purposes, the transitional behaviour of the even-membered dimers CB6CB, CB5OCB and CBO4OCB is reported and differences accounted for in terms of molecular shape.     

Experiment and prediction of a cavity type separated flow

A detail study involving flow visualization, Laser Doppler Velocimeter (LDV) measurements and numerical prediction is presented. The visualization experiments revealed striking results of a pulsatile motion in the separated flow region associated with the formation and passage of large eddy structures. Measurements of mean velocities and turbulence intensity profiles across the separated flow field, provided information about the separated shear layer development and the recirculating flow pattern. The numerical predictions, obtained with a two-layer turbulence model in conjunction with the SIMPLE algorithm, failed to reproduce the coherent eddies and the pulsatile motion, but the mean velocities are reasonably reproduced.