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Objective: Combined with the determination of macromolecular protein, amino acid and total protein, a quantitative analysis method for the content of small molecular peptides in infant formula milk powder was established. Methods: The contents of total protein, polymer protein and free amino acid in infant formula milk powder were determined by Kjeldahl nitrogen determination method, gravimetric method and ion exchange chromatography, and then the contents of small molecular protein peptide were calculated. Results: The precision RSD of the macromolecular protein detection (n=6) was 0.74%; The recovery rates of the 17 kinds of amino acids were 91.0%~103.2%, and the relative deviations of the detection results were 0.6%~ 2.5%. The recovery rates of small molecular weight peptides were 95.2%~98.2%. Conclusion: The established method has been validated by methodology, with good precision and recovery rate, and can be used for the determination of small molecular peptides in infant formula milk powder.

Background and aims:Transcranial alternating current stimulation (tACS) offers another method of non-invasive brain stimulation in post-stroke rehabilitation. Because it is not known if tACS over bilateral mastoids (tACSbm) can promote the functional recovery in subacute post-stroke patients, we wish to learn the effect of tACSbmon improving neurological function and intracranial hemodynamics of subacute post-stroke patients. Methods:Sixty subacute post-stroke patients (mean age: 65.4 ± 9.8 years), 15 to 60 days after the onset, were randomly assigned to receiving 15 sessions of usual rehabilitation program without (n = 30) or with tACSbm(20 Hz and < 400 μA for 30-min;n = 30). The outcome measures included the NIH Stroke Scale (NIHSS) and measures of intracranial hemodynamics before and after treatment. Results:At the fifteenth session, when compared with the baseline, the mean NIHSS scores of the patients in the tACSbmgroup had significantly a larger decrease [18.3 ± 2.6 vs. 10.8 ± 2.7;p < 0.001] than that of the control group [19.1 ± 2.7 vs. 13.0 ± 2.4] [F(1,54) = 4.29,p = 0.043]. After both the first and fifteenth sessions, compared with the control group, the mean blood flow velocity (MFVs) of the tACSbmgroup had significantly larger increase in the MCA, ACA, and PCA (p < 0.001), the Gosling pulsatility index (PI) of the tACSbmgroup had also significantly larger decline in the MCA, ACA, and PCA than that of the control group (p < 0.001). The best predictor of the changes in the NIHSS scores was the decline in the pulsatility index in the vascular territory of both lesional and non-lesional MCA measured by the end of the last treatment session. Conclusions:tACSbmappeared to be effective for enhancing patients’ functional recovery and cerebral hemodynamics in the subacute phase. The extent of recovery seems to be associated with the decline of the resistance in vascular bed of the main cerebral arteries. The mechanisms behind this effect should be explored further through research. [ABSTRACT FROM AUTHOR]

Pathological upper-limb synergistic movement is a prevalent symptom of post-stroke motor dysfunction and pose a significant challenge in the rehabilitation of hemiplegia. However, the underlying mechanisms remain elusive, hindering the development of effective therapeutic strategies.This study aims to explore the mechanisms underlying pathological synergic movements post-stroke by examining the interrelationship between motor modules associated with upper limb flexion synergy and the repetitive action of “taking food to the mouth.”Surface electromyography (sEMG) was employed to capture the EMG signals of normal elbow flexion, the act of “taking food to the mouth,” and post-stroke upper limb flexion synergy. Non-negative matrix factorization (NMF) was employed to compare and analyze the corresponding modular and coefficient matrices derived from these three motor tasks.The modular matrix associated with flexion synergy exhibited the most significant correlation with the “taking food to the mouth” task, whereas the coefficient matrix shared the lowest correlation.Upper limb flexion synergy after stroke may be related to the activation of the highly excitatory motor module formed by previously repeated movement of “taking food to mouth”. [ABSTRACT FROM AUTHOR]

Many studies have shown that fibronectin type III domain-containing protein 5 (FDNC5) and brain-derived neurotrophic factor (BDNF) play vital roles in plasticity after brain injury. An enriched environment refers to an environment that provides animals with multi-sensory stimulation and movement opportunities. An enriched environment has been shown to promote the regeneration of nerve cells, synapses, and blood vessels in the animal brain after cerebral ischemia; however, the exact mechanisms have not been clarified. This study aimed to determine whether an enriched environment could improve neurobehavioral functions after the experimental inducement of cerebral ischemia and whether neurobehavioral outcomes were associated with the expression of FDNC5 and BDNF. This study established ischemic mouse models using permanent middle cerebral artery occlusion (pMCAO) on the left side. On postoperative day 1, the mice were randomly assigned to either enriched environment or standard housing condition groups. Mice in the standard housing condition group were housed and fed under standard conditions. Mice in the enriched environment group were housed in a large cage, containing various toys, and fed with a standard diet. Sham-operated mice received the same procedure, but without artery occlusion, and were housed and fed under standard conditions. On postoperative days 7 and 14, a beam-walking test was used to assess coordination, balance, and spatial learning. On postoperative days 16-20, a Morris water maze test was used to assess spatial learning and memory. On postoperative day 15, the expression levels of FDNC5 and BDNF proteins in the ipsilateral cerebral cortex were analyzed by western blot assay. The results showed that compared with the standard housing condition group, the motor balance and coordination functions (based on beam-walking test scores 7 and 14 days after operation), spatial learning abilities (based on the spatial learning scores from the Morris water maze test 16-19 days after operation), and memory abilities (based on the memory scores of the Morris water maze test 20 days after operation) of the enriched environment group improved significantly. In addition, the expression levels of FDNC5 and BDNF proteins in the ipsilateral cerebral cortex increased in the enriched environment group compared with those in the standard housing condition group. Furthermore, the Pearson correlation coefficient showed that neurobehavioral functions were positively associated with the expression levels of FDNC5 and BDNF (r = 0.587 and r = 0.840, respectively). These findings suggest that an enriched environment upregulates FDNC5 protein expression in the ipsilateral cerebral cortex after cerebral ischemia, which then activates BDNF protein expression, improving neurological function. BDNF protein expression was positively correlated with improved neurological function. The experimental protocols were approved by the Institutional Animal Care and Use Committee of Fudan University, China (approval Nos. 20160858A232, 20160860A234) on February 24, 2016., Competing Interests: None