***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Purpose This study aim ed to assess the effectiveness of functional electrical stimulation on the swallowing function of irradiated nasopharyngeal carcinoma patients with dysphagia . Material s and methods Twenty nasopharyngeal carcinoma subjects with dysphagia were divided into a functional electrical stimulation ( FES ) and a home rehabilitation program ( HRP ) group . Each subject completed a quality of life question naire on swallowing and a videofluoroscopic study at the commencement and the end of the procedures . The FES group received functional electrical stimulation of the supra-hyoid muscles over 15 sessions . The HRP group performed self-swallowing exercises at home . The evaluation parameters included the quality of life question naire scores , the penetration – aspiration scale ( PAS ) , the movement of the hyoid bone , and the amount of pyriform sinuses stasis . Results Most swallowing outcomes of the FES group improved after FES . The quality of life score ( p = 0.003 ) , the duration of the movement of thin barium through the hyoid ( p = 0.001 ) , the moving speed of paste barium through the hyoid ( p = 0.028 ) , and the pyriform sinus stasis area of the paste barium ( p = 0.026 ) reached significant difference in the FES group . Most swallowing outcomes did not improve in the HRP group . The degree of improvement in the movement speed of the hyoid bone in the thin barium ( p = 0.018 ) and the PAS of the paste barium ( p = 0.016 ) were statistically significantly greater in the FES group than in the HRP group . Conclusion FES will improve the swallowing function of NPC patients with dysphagia and bring about better quality of life Chemical and physical transformations of solid food begin in the mouth , but the oral phase of digestion has rarely been studied . In the present study , twelve healthy volunteers masticated mouthfuls of either bread or spaghetti for a physiologically-determined time , and the levels of particle degradation and starch digestion before swallowing were compared for each food . The amounts of saliva moistening  bread and spaghetti before swallowing were , respectively , 220 ( SEM 12 ) v. 39 ( SEM 6 ) g/kg fresh matter . Particle size reduction also differed since bread particles were highly de grade d , showing a loss of structure , whereas spaghetti retained its physical structure , with rough and incomplete reduction of particle size .  Starch hydrolysis was twice as high for bread as for spaghetti , mainly because of the release of high-molecular-mass alpha-glucans . The production of oligosaccharides was similar after mastication of the two foods , respectively 125 ( SEM 8) and 92 ( SEM 7 ) g/kg total starch . Starch hydrolysis , which clearly began in the mouth , depended on the initial structure of the food , as in the breakdown of solid food . These significant physical and chemical degradations of solid foods during oral digestion may influence the entire digestive process Activity patterns of the swallowing-related muscles were examined in normal subjects at different four body positions during swallowing of foods with different textural properties . Surface electromyograms were recorded from two muscle groups , the anterior tongue and suprahyoid muscles . The T(P ) technique we developed was applied to the electromyograms for quantitative analysis of the activity patterns . Three test foods were prepared by dissolving 2.0 % ( low ) , 5.7 % ( middle ) and 9.1 % ( high concentration ) of a thickening agent into distilled water . Each subject was delivered r and omly , one of the test foods to swallow at one of the four body positions i.e. horizontal supine , 30 degrees inclined , 60 degrees inclined and upright . In this study , T(50 ) values were calculated in activity data of the two muscle groups , and the T(50 ) values were statistically examined analysis of variance with a linear model including four fixed effects of ' concentrations ' , ' body positions ' , ' subjects ' and ' sessions ' . Three major findings obtained were that ( i ) the activity pattern of the anterior tongue was altered from a decrementing discharge pattern to an incrementing discharge pattern by shifting from the upright to the horizontal supine position , ( ii ) the activity pattern of the suprahyoid muscles was altered from a decrementing discharge pattern to an incrementing discharge pattern by shifting from the low concentration food to the higher ones and ( iii ) two subgroups were detected in subjects with the significant effects of ' concentrations ' and ' body positions ' . These findings lead a conclusion that activity patterns of the swallowing-related muscles are affected by food properties and body positions Bolus manipulation is a primary treatment strategy in the management of oral-pharyngeal dysphagia . The use of thickening agents to alter bolus rheology is particularly commonplace ; however , the precise effects of these alterations on swallowing remain uncertain . The purpose of our study , a prospect i ve , double-blind clinical trial ( Level 1b ) , was to investigate the effects of viscosity on aspiration .  One hundred patients with dysphagia were prospect ively evaluated with fluoroscopic swallow studies performed across three st and ardized and r and omized conditions : thin liquid barium ( THIN ) , liquid barium thickened with a starch-based agent ( STARCH ) , and liquid barium thickened with a gum-based agent ( GUM ) . Outcome measures included the prevalence of aspiration and score on the Penetration-Aspiration Scale . A total of 23 out of 100 patients exhibited 56 episodes of aspiration . Twenty patients aspirated on THIN , 15 on STARCH , and 11 on GUM bolus conditions ( P<0.05 , thin vs gum ) . There were 28 instances of aspiration on THIN , 16 on STARCH , and 12 on GUM . Mean Penetration-Aspiration Scale score ± st and ard deviation was 2.11 ± 2.22 for THIN , 1.76 ± 1.88 for STARCH , and 1.42 ± 1.47 for GUM conditions , respectively ( P<0.001 , THIN vs GUM ) . A clinical ly significant reduction in the incidence of penetration and aspiration was observed for gum-thickened barium compared with thin liquid barium Abstract . This study was design ed to investigate the ability of normal young adult volunteers to sensorially identify Newtonian fluids of specified viscosities . Twenty subjects , 10 men and 10 women between the ages of 18 and 29 years participated . Seven stimuli , consisting of combinations of corn syrup and water , with viscosities ranging from 2 to 2,240 centipoise ( cP ) were prepared and characterized using a coaxial rotational viscometer . Subjects were presented with two anchor stimuli representing the extremes of the range of viscosities as a basis from which the experimental stimuli were judged . The seven experimental stimuli were r and omly presented to each subject 10 times . The accuracy with which the subjects identified the viscosity of the fluid was significant at p < 0.01 . The pattern of response was not significantly different across subjects nor gender . There were no differences in performance throughout the duration of the study . The repeat presentation of the anchor points did not significantly affect performance . Further research on oral perception of viscosity , and the processes that mediate changes in swallow physiology result ing from changes in viscosity is required The purpose of this study was to determine ( i ) whether or not textural properties of foods and body positions affect the duration s of anterior tongue and suprahyoid muscle activities during swallowing , and ( ii ) if such changes occur , is the ' pre-peak ' or the ' post-peak ' duration of integrated muscle activity responsible . We used two test foods with different properties of hardness and adhesiveness . We recorded  electromyograms ( EMGs )  from the anterior tongue and suprahyoid muscles as well as the laryngeal movement associated with swallowing in normal subjects ( six men and three women ; 21 - 30-years old ) . The subjects swallowed the test foods in four r and omly set postures : upright , two inclined ( 60 degrees and 30 degrees to horizontal ) , and supine . None of the measured duration s for the anterior tongue and suprahyoid EMGs were different among the four positions during swallowing of either food . The ' total ' duration , from the start to the end of the integrated EMG , of anterior tongue activity was significantly ( P<0.001 , anova ) longer during the swallowing of the tougher and more adhesive food than during swallowing of the other food , but the ' total ' duration of suprahyoid activity was unchanged . The ' post-peak ' duration of anterior tongue activity , which stretched from the peak to the end of the integrated EMG , was also significantly longer ( P<0.001 , anova ) during swallowing of the tougher and more adhesive food . The results indicate that tougher and more adhesive foods prolong the duration , especially the ' post-peak ' duration , of anterior tongue activity during swallowing in the upright , inclined and supine positions BACKGROUND Dysphagia is a common complication of stroke and is a potential cause for aspiration and malnutrition and is also associated with poor outcome . Videofluoroscopic Swallowing Study ( VFSS ) is the most objective method for evaluation of swallowing disorders . AIM To investigate the incidence and characteristics of penetration-aspiration in post-stroke patients , and to study the relationship between penetration-aspiration and kinematic parameters of swallow . MATERIAL S AND METHODS We prospect ively studied swallowing function in 105 consecutive post-stroke patients and 100 normal adults by videofluoroscopic swallowing studies .  The severity of airway invasion , penetration-aspiration , was studied quantitatively and kinematic parameters of swallow i.e. oral transit time , pharyngeal transit time ( PTT ) , pharyngeal delay timem ( PDT ) , maximal extent of vertical and anterior movement of larynx and hyoid bone for four kinds of boluses were also studied . Logistic regression was used to analyze the association between aspiration and kinematic parameters of swallow . RESULTS Stroke patients scored significantly higher scores on penetration-aspiration scale than the normal subjects ( P < 0.001 ) during four bolus swallows . Logistic regression analysis showed that PTT , PDT , maximal extent of vertical laryngeal and hyoid movement were statistically associated with the prevalence of aspiration ( P < 0.05 ) . CONCLUSION Penetration-aspiration is common in stroke patients . Several kinematic parameters of swallow are associated with the presence of aspiration on fluoroscopy . These data demonstrate that VFSS may be helpful for objective identification of dysphagia in stroke patients 
    Output:
    
Qualitative synthesis revealed two key trends with respect to the impact of thickening liquids on swallowing : thicker liquids reduce the risk of penetration – aspiration , but also increase the risk of post-swallow residue in the pharynx .
The literature was insufficient to support the delineation of specific viscosity boundaries or other quantifiable material properties related to these clinical outcomes .
With respect to food texture , the literature pointed to properties of hardness , cohesiveness , and slipperiness as being relevant both for physiological behaviors and bolus flow patterns .