A new numerical approach for modeling a class of flow-structure interaction problems typically encountered in biological systems is presented. In this approach, a previously developed, sharpinterface, immersed-boundary method for incompressible flows is used to model the fluid flow and a new, sharp-interface Cartesian grid, immersed boundary method is devised to solve the equations of linear viscoelasticity that governs the solid. The two solvers are coupled to model flow-structure interaction. This coupled solver has the advantage of simple grid generation and efficient computation on simple, single-block structured grids. The accuracy of the solid-mechanics solver is examined by applying it to a canonical problem. The solution methodology is then applied to the problem of laryngeal aerodynamics and vocal fold vibration during human phonation. This includes a threedimensional eigen analysis for a multi-layered vocal fold prototype as well as two-dimensional, flowinduced vocal fold vibration in a modeled larynx. Several salient features of the aerodynamics as well as vocal-fold dynamics are presented.

The false vocal folds are believed to be components of the acoustic filter that is responsible for shaping the voice. However, the effects of false vocal folds on the vocal fold vibration and the glottal aerodynamic during phonation remain unclear. This effect has implications for computational modeling of phonation as well as for understanding laryngeal pathologies such as glottal incompetence resulting from unilateral vocal fold paralysis. In this study, a high fidelity, two-dimensional computational model, which combines an immersed boundary method for the airflow and a continuum, finite-element method for the vocal folds, is used to examine the effect of the false vocal folds on flow-induced vibration (FIV) of the true vocal folds and the dynamics of the glottal jet. The model is notionally based on a laryngeal CT scan and employs realistic flow conditions and tissue properties. Results show that the false vocal folds potentially have a significant impact on phonation. The false vocal folds reduce the glottal flow impedance and increase the amplitude as well as the mean glottal jet velocity. The false vocal folds also enhance the intensity of the monopole acoustic sources in the glottis. A mechanism for reduction in flow impedance due to the false vocal folds is proposed.

The aim of this study was to determine the efficacy of immunonutrition vs standard nutrition in cancer patients treated with surgery. Cochrane Central Register of Controlled Trials, EMBASE, MEDLINE, EBSCOhost, and Web of Science were searched. Sixty‐one randomized controlled trials were included. Immunonutrition was associated with a significantly reduced risk of postoperative infectious complications (risk ratio [RR] 0.71 [95% CI, 0.64–0.79]), including a reduced risk of wound infection (RR 0.72 [95% CI, 0.60–0.87]), respiratory tract infection (RR 0.70 [95% CI, 0.59–0.84]), and urinary tract infection (RR 0.69 [95% CI, 0.51–0.94]) as well as a decreased risk of anastomotic leakage (RR 0.70 [95% CI, 0.53–0.91]) and a reduced hospital stay (MD −2.12 days [95% CI −2.72 to −1.52]). No differences were found between the 2 groups with regard to sepsis or all‐cause mortality. Subgroup analyses revealed that receiving arginine + nucleotides + ω‐3 fatty acids and receiving enteral immunonutrition reduced the rates of wound infection and respiratory tract infection. The application of immunonutrition at 25–30 kcal/kg/d for 5–7 days reduced the rate of respiratory tract infection. Perioperative immunonutrition reduced the rate of wound infection. For malnourished patients, immunonutrition shortened the hospitalization time. Therefore, immunonutrition reduces postoperative infection complications and shortens hospital stays but does not reduce all‐cause mortality. Patients who are malnourished before surgery who receive arginine + nucleotides + ω‐3 fatty acids (25–30 kcal/kg/d) via the gastrointestinal tract during the perioperative period (5–7 days) may show better clinical efficacy.

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A new flow-structure interaction method is presented which couples a sharp-interface immersed boundary method (IBM) flow solver with a finite element method (FEM) based solid dynamics solver. The coupled method provides robust and high fidelity solution for complex fluid-structure interaction (FSI) problems, such as those involving three-dimensional flow and viscoelastic solids. The FSI solver is used to simulate flow-induced vibrations of the vocal folds during phonation. Both two- and three-dimensional models have been examined and qualitative as well as quantitative comparisons made with established results in order to validate the solver. The solver is use to study the onset of phonation in a two-dimensional laryngeal model and the dynamics of the glottal jet in a three-dimensional model and results from these studies are also presented.