***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: BACKGROUND Targeting glutamatergic dysfunction provides an exciting opportunity to improve cognitive impairment in schizophrenia . One treatment approach has targeted inadequate antioxidant defenses at glutamatergic synapses . Animal and human data suggest NMDA antagonists worsen executive cognitive controls -- e.g . increase perseverative responses and impair set-shifting . We conducted a preliminary study to test the hypothesis that L-carnosine , an antioxidant and anti-glycation agent which is co-localized and released with glutamate would improve executive dysfunction , a cognitive domain associated with glutamate . METHODS Seventy-five symptomatically stable adults with chronic schizophrenia were r and omly assigned to L-carnosine as adjunctive treatment ( 2 g/day ) or a matched placebo in a double-blind manner for 3 months . Cognitive domains ( executive dysfunction , memory , attention and motor speed ) were assessed using a computerized battery at baseline , 4 and 12 weeks , along with psychopathology ratings and safety parameters . RESULTS The L-carnosine group performed significantly faster on non-reversal condition trials of the set-shifting test compared with placebo but reversal reaction times and errors were not significantly different between treatments . On the strategic target detection test , the L-carnosine group displayed significantly improved strategic efficiency and made fewer perseverative errors compared with placebo . Other cognitive tests showed no significant differences between treatments . Psychopathology scores remained stable . The carnosine group reported more adverse events ( 30 % ) compared with the placebo group ( 14 % ) . Laboratory indices remained within acceptable ranges . CONCLUSIONS These preliminary findings suggest that L-carnosine merits further consideration as adjunctive treatment to improve executive dysfunction in persons with schizophrenia Background Fatigue is a common symptom in modern society . There has been a recent resurgence of interest in traditional remedies for fatigue . Chicken essence , which is rich in anserine and carnosine , has been widely taken in Asian countries as a traditional remedy with various aims , including attenuation of physical and mental fatigue . However , the evidence for its efficacy specifically for mental fatigue remains unclear . We examined the effect of essence of chicken on mental fatigue in humans , using our established fatigue-inducing task and evaluation methods . Material / Methods In this placebo-controlled crossover study , 20 healthy male volunteers were r and omized to receive daily oral administration of essence of chicken or placebo drink provided by Cerebos Pacific Ltd. via Suntory holdings Ltd. for 4 weeks . The participants performed 2-back test trials as a fatigue-inducing mental task and then had a rest session . Just before and after each session , they completed cognitive task trials focusing on selective attention to evaluate the level of mental fatigue . Results After essence of chicken intake for 1 and 4 weeks , the reaction times on the cognitive task trials after the rest session were significantly shorter than those at baseline , and significant changes were not observed with placebo intake . The reaction times before and after the fatigue-inducing session were not altered by either essence of chicken or placebo intake . Conclusions We showed that daily intake of essence of chicken could be effective for the recovery from mental fatigue and is a promising c and i date for use as an anti-fatigue food Background It has long been postulated that the relative abundance of specific nutrients can affect cognitive processes and emotions . Newly described influences of dietary factors on neuronal function and synaptic plasticity have revealed some of the vital mechanisms that could be responsible for the action of diet on brain health and cognitive function . Here , through a double-blind , r and omized , placebo-controlled trial , we asked if the newly discovered chicken meat ingredient-168 ( CMI-168 ) could be beneficial to the cognitive function in healthy adults . Methods Normal , healthy subjects were supplemented with either placebo or CMI-168 for 6 weeks . The subjects were given a series of cognitive tests to examine their levels of cognitive functioning at the beginning and end of supplementation , as well as two weeks after termination of supplementation . The combination of these tests , namely Digit Span Backwards , Letter-Number Sequencing , and the Rey Auditory Verbal Learning Test ( RAVLT ) , was used to assess the subjects ’ attention and working memory . For all comparisons , the probability level of p < 0.05 was taken as statistically significant using repeated measure 2-way ANOVA followed by Bonferroni post-hoc test . Results Overall , subjects supplemented with CMI-168 showed significantly ( p < 0.01 ) better performance in all cognitive tests after 6 weeks ’ supplementation compared to control and such superior performance was maintained even 2 weeks after termination of supplementation . Conclusions The present study reveals the cognition-enhancing properties of a recently developed chicken meat ingredient , likely arising from the promotion of attention and prefrontal cortex functions Stress is a common phenomenon . Every individual experiences it . There are many ways of combating stress . Stress is necessary for preparation against challenging situations and danger . It is necessary to have stress before a test so that we are prepared . For instance , stress actually motivates students to prepare for examination but excessive stress can lead to poor performance . This study evaluates the effect of a commercial essence of chicken ( CEC ) on the various parameters related to stress and cognition of human volunteers .  CEC is produced by a hot-water extraction process from chicken meat under high pressure condition . It contains concentrated amounts of proteins , amino acids and peptides such as carnosine compared to homemade traditional chicken soup . Due to the unique extraction process , it has been postulated that readily absorbed amino acids and bioactive peptides are present in CEC . In this experiment , we evaluated the effect of CEC in comparison with a placebo and carageenan on a group of stressed medical students before their examinations . Students were divided into three groups at r and om and given either CEC , placebo or a carageenan drink daily for two weeks . Before and after the two weeks , the students were given a series of tests to assess their mental and physical well-being as well as attention and memory . The tests were the general health question naire ( GHQ ) , SF36 , digit span , construction of figures , 3-min memory test , comprehension and mental arithmetic . The students who ingested essence of chicken fared significantly better than the other two groups of students . The ability of essence of chicken to control anxiety by distraction and promoting attention and memory is discussed About 25 % of 1990 - 1991 Persian Gulf War veterans experience disabling fatigue , widespread pain , and cognitive dysfunction termed Gulf War illness ( GWI ) or Chronic Multisymptom Illness ( CMI ) . A leading theory proposes that wartime exposures initiated prolonged production of reactive oxygen species ( ROS ) and central nervous system injury . The endogenous antioxidant L-carnosine ( β-alanyl-L-histidine ) is a potential treatment since it is a free radical scavenger in nervous tissue . To determine if nutritional supplementation with L-carnosine would significantly improve pain , cognition and fatigue in GWI , a r and omized double blind placebo controlled 12 week dose escalation study involving 25 GWI subjects was employed . L-carnosine was given as 500 , 1000 , and 1500 mg increasing at 4 week intervals . Outcomes included subjective fatigue , pain and psychosocial question naires , and instantaneous fatigue and activity levels recorded by ActiWatch Score devices . Cognitive function was evaluated by WAIS-R digit symbol substitution test . Carnosine had 2 potentially beneficial effects : WAIS-R scores increased significantly , and there was a decrease in diarrhea associated with irritable bowel syndrome . No other significant incremental changes were found . Therefore , 12 weeks of carnosine ( 1500 mg ) may have beneficial cognitive effects in GWI . Fatigue , pain , hyperalgesia , activity and other outcomes were resistant to treatment Folk wisdom suggests that chicken extract is useful for recovery from physical and mental fatigue .  To explore this question , the physiological effect of Br and 's Essence of Chicken ( BEC ) , a popular chicken extract used as a traditional remedy , was assessed during recovering from mental stress . We quantitated the blood levels of stress-related substances , and examined the task performance and subjects ' mood states during mental workloads . Subjects were 20 , healthy male students who have never tasted BEC .  They took two bottles of BEC or a placebo ( 70 ml/bottle ) daily in the morning for 7 days . On the final experimental day , two mental workload tests were performed : ( A ) a mental arithmetic test ( MAT ; 1600 trials of two or three figure-addition or subtraction for 40 min ) . ( B ) a short-term memory test ( SMT ; 20 trials of memorizing 9 digit numbers ) . Blood was collected before and after each workload task . After the mental workload , the recovery of mean cortisol level of subjects who consumed BEC was significantly faster than that for those consuming the placebo . The task performance of subjects performing the MAT and SMT was also improved with BEC consumption compared with placebo . According to the profile of mood state question naire , subjects felt more active and less fatigued during the workload when they took BEC regularly . We conclude that the extract of chicken has the potential to metabolize stress-related substance in blood and to promote recovery from mental fatigue 
    Output:
    
Currently , there is a lack of convincing evidence to show a cognitive enhancing effect of CE