A discrete time feedback control system model based on a multi-router network has been presented. The model can be described by a set of recurrence equations. The numerical examples about the bifurcation of average and instantaneous queue size along with the variety of RED control parameter are shown. The simulate experiments about those of the RED control parameters are also presented. All of these results show that instability in TCP-Reno traffic under RED can be induced by the inherent nonlinear behavior of the network.

Objective To verify the inter-rater reliability,intra-rater reliability and internal reliability of the action research arm test(ARAT)in patients with chronic stroke.Methods 30 people with chronic stroke were tested with the ARAT by two experienced raters.The inter-rater reliability,intra-rater reliability and internal reliability were examined.Results The ARAT showed high inter-rater reliability and intra-rater reliability(ICC=0.992 and 0.987,respectively)and internal consistency(Cronbach's alpha coefficient=0.936).Conclusion The ARAT shows good inter-rater reliability,intra-rater reliability and internal reliability in assessing patients after stroke.

Objective To verify the convergent validity,discriminant validity and concurrent validity of the Action Research Arm Test(ARAT)in patients with chronic stroke.Methods 30 cases with chronic stroke were assessed with ARAT,upper limb section at Fugl-Meyer Assessment and Motor Activity Log(MAL)on the same day.The validity was investigated using Spearman ρ and t test.Results The scores of the ARAT closely correlated with upper limb section at Fugl-Meyer Assessment(ρ=0.906,P<0.001).The upper limb section at Fugl-Meyer scores≥33 group achieved a significantly higher scores of the ARAT than the scores<33 group(t =6.614,P<0.001).The scores of the ARAT closely correlated with the amount of use(AOU)and quality of movement(QOM)of MAL(ρ=0.894 and 0.761,respectively,P<0.001).Conclusion The ARAT has been shown good convergent validity,discriminant validity and concurrent validity in people with stroke.

Background Exposure of adult mice to more than 95％ O2 produces a lethal injury by 72 hours.Nuclear factor kappa B (NF-κB) is a transcriptional factor that plays a key role in the modulation of cytokine networks during hyperoxia-induced acute lung injury (ALl).Osteopontin (OPN) is a phosphorylated glycoprotein produced principally by macrophages.Studies have reported that exogenous OPN can maintain the integrity of the cerebral microvascular basement membrane and reduce brain damage through inhibiting NF-κB activities in the brain after subarachnoid hemorrhage.However,it is not clear whether OPN can reduce lung injury during ALl by inhibiting transcriptional signal pathways of NF-κB and consequent inhibition of infiammatory cytokines.Thus we examined the effects and mechanisms of recombinant OPN (r-OPN) on ALl.Methods Ninety-six mice were randomly divided into phosphate buffered saline (PBS) and r-OPN groups.Mice were put in an oxygen chamber (＞95％ O2) and assessed for lung injury at 24,48,and 72 hours.Expressions of NF-κB,matrix metalloproteinases 2 and 9 (MMP-2 and MMP-9),and tissue inhibitors of MMP-2 and MMP-9 (TIMP-1,TIMP-2) mRNA in lungs were examined with RT-PCR.Expression and distribution of NF-κB protein in lungs were measured with immunohistochemistry.Results Exposure to hyperoxia for 72 hours induced more severe lung injury in the PBS group compared with the r-OPN group.Expression of NF-κB mRNA in the PBS group exposed to hyperoxia for 48 and 72 hours was significantly higher than the r-OPN group (P ＜0.05).With 72-hour exposure,expression of TIMP-1 mRNA in the r-OPN group was significantly higher than that of the PBS group (P ＜0.05).Expression of TIMP-2 mRNA in the r-OPN group at 48 and 72 hours was significantly higher than those in the PBS group (P ＜0.05).After 72-hour exposure,expression of NF-κB protein in airway epithelium in the PBS group was significantly higher than that in the r-OPN group (P ＜0.05).Conclusion r-OPN can inhibit the release and activation of MMPs through inhibition of the expression of NF-κB and promotion of the expression of TIMPs,and alleviate hyperoxia-induced ALl.

ObjectiveTo explore the efficacy of constraint-induced movement therapy (CIMT) on motor function of upper extremity of chronic stroke patients.MethodsFifteen chronic stroke patients with hemiparesis (course of diseases more than 13.5 months) were treated by CIMT, involving restriction of movement of the intact upper extremity by placing it in a sling for 90% of waking hours for 12 days and training (by shaping) of the more affected extremity for 6 hours on the 10 workdays during that period. The therapeutic effect was evaluated with upper extremity function test (UEFT) and simple test for evaluating hand function (STEF).ResultsPatients showed a significant and very large degree of improvement after treatment on UEFT and STEF (ES, 0.8 and 0.5, respectively).ConclusionCIMT may be an efficacious method for improvement of the affected arm function of chronic stroke patients.

ObjectiveTo investigate the relationship between strength of the paretic lower limb and motor function, balance, walking speed, ability of daily living (ADL) in hemiparetic stroke patients.Methods85 stroke subjects, who were able to walk in the study, were evaluated in the strength of the paretic lower limb, motor function, balance, walking speed and ADL with Motricity Index, Fugl-Meyer Assessment, Berg Balance Scale, 10 m walking speed test and Functional Independence Measure (FIM). The levels of association between them were examined with Pearson's correlation coefficients and with multiple linear regression analyses by using the stepwise method. ResultsStrengths of the paretic lower limb were significantly positive related to motor function, balance, walking speed and ADL (r=0.592-0.811,P<0.001). The paretic ankle dorsiflexors, knee extensors, hip flexors were important clinical factor to consider in determining motor function(R2=0.377,P<0.001), balance(R2=0.321,P<0.001)and walking speed(R2=0.173,P<0.001), ADL(R2=0.42,P<0.001). ConclusionStrengths of the paretic lower limb of stroke patients may play an important role in their motor function, balance, walking speed and ADL.

ObjectiveTo evaluate the effect of the timed “up and go” test (TUGT) on measuring functional mobility of stroke patients.MethodsNinety hemiparetic stroke patients participated in this study. The balance, gait speed and disability of patients were measured by Berg balance scale (BBS), maximal gait speed and functional independence measure (FIM) to find out the critical value of TUGT.ResultsA good relationship existed among TUGT and the BBS,gait speed and FIM (r=-0.926—-0.674,P<0.001).The percentage of independent walking of stroke patients whose TUGT scores <10s or>20s were 100% and 8.3%. The optimal cut off values of TUGT to predict the independent walking of patients were 15.2s, and in stroke group sensitivity and specificity of TUGT were 89.4% and 79.1%.Conclusion TUGT is a reliable instrument with adequate concurrent validity to measure the functional mobility of stroke patients.

ObjectiveTo determine the efficacy of constraint-induced movement therapy(CIMT) on different severity of the motor deficit of upper extremity after stroke.Methods27 stroke patients who had upper-limb hemiparesis and learned nonuse were allocated either to the moderate group(n=12) or the severe group(n=15) according to severity of initial motor deficit of upper extremity by Upper Extremity Function Test(UEFT).The two group patients were given CIMT,involving restriction of movement of the intact upper extremity by placing it in a sling for 90% of waking hours for 12 days and training(by repetitive practice,shaping) of the more affected extremity for 6 hours on the 10 weekdays during that period.Outcome were measured with UEFT.ResultsThere was no significant difference in treatment gain on the UEFT between the moderate patients and the severe patients(P>0.05).However,the Effect Size for the severe patients(ES=2.2) was larger than for the moderate patients(ES=1.8) at the quality of movement(UEFT).ConclusionCIMT is an effective rehabilitation technique for different severity of the motor deficit of upper extremity after stroke,especially in severe stroke patients.

Objective:To describe the characteristics and change trends of incidence, mortality and disease burden of acute myocardial infarction (AMI) in Qingdao from 2014 to 2020.Methods:We analyzed the incidence data of AMI retrieved from Qingdao Chronic Diseases Surveillance System. The average annual percent change (AAPC) of morbidity and mortality of AMI were evaluated by using Joinpoint log-linear regression model. Disability adjusted life year (DALY) was used to estimate disease burden of AMI in Qingdao.Results:A total of 70 491 AMI cases and 50 832 deaths of AMI occurred in Qingdao from 2014 to 2020. The age-standardized morbidity and mortality were 54.71/100 000 and 36.55/100 000, respectively. During 2014-2020, the AAPC of age-standardized morbidity was 2.86% (95% CI: 0.42%-5.35%), and 4.30% (95% CI: 1.24%-7.45%) in men and 0.78% (95% CI: -0.89%-2.47%) in women, respectively. The log-linear regression model showed that age-standardized morbidity in age groups 30-39, 40-49 years increased rapidly, with the AAPCs of 8.92% (95% CI: 2.23%-16.06%) and 6.32% (95% CI: 3.30%-9.44%), respectively. The trend was also observed in age groups 30-39, 40-49 and 50-59 years in men, with the AAPCs of 11.25% (95% CI: 3.54%-19.54%), 6.73% (95% CI: 2.63%-10.99%) and 6.72% (95% CI: 2.98%-10.60%), respectively. There was no significant change in age-standardized mortality. The DALY rate increased from 7.49/1 000 in 2014 to 8.61/1 000 in 2020, with the AAPC of 1.97% (95% CI: 0.36%-3.60%). Conclusions:The age-standardized morbidity of AMI in men increased in Qingdao, especially in those aged 30-49 years, while age-standardized mortality rate of AMI was relatively stable from 2014 to 2020. The burden of disease of AMI increased in both men and women.

BACKGROUNDExposure of adult mice to more than 95% O2 produces a lethal injury by 72 hours. Nuclear factor kappa B (NF-κB) is a transcriptional factor that plays a key role in the modulation of cytokine networks during hyperoxia-induced acute lung injury (ALI). Osteopontin (OPN) is a phosphorylated glycoprotein produced principally by macrophages. Studies have reported that exogenous OPN can maintain the integrity of the cerebral microvascular basement membrane and reduce brain damage through inhibiting NF-κB activities in the brain after subarachnoid hemorrhage. However, it is not clear whether OPN can reduce lung injury during ALI by inhibiting transcriptional signal pathways of NF-κB and consequent inhibition of inflammatory cytokines. Thus we examined the effects and mechanisms of recombinant OPN (r-OPN) on ALI.

METHODSNinety-six mice were randomly divided into phosphate buffered saline (PBS) and r-OPN groups. Mice were put in an oxygen chamber (>95% O2) and assessed for lung injury at 24, 48, and 72 hours. Expressions of NF-κB, matrix metalloproteinases 2 and 9 (MMP-2 and MMP-9), and tissue inhibitors of MMP-2 and MMP-9 (TIMP-1, TIMP-2) mRNA in lungs were examined with RT-PCR. Expression and distribution of NF-κB protein in lungs were measured with immunohistochemistry.

RESULTSExposure to hyperoxia for 72 hours induced more severe lung injury in the PBS group compared with the r-OPN group. Expression of NF-κB mRNA in the PBS group exposed to hyperoxia for 48 and 72 hours was significantly higher than the r-OPN group (P < 0.05). With 72-hour exposure, expression of TIMP-1 mRNA in the r-OPN group was significantly higher than that of the PBS group (P < 0.05). Expression of TIMP-2 mRNA in the r-OPN group at 48 and 72 hours was significantly higher than those in the PBS group (P < 0.05). After 72-hour exposure, expression of NF-κB protein in airway epithelium in the PBS group was significantly higher than that in the r-OPN group (P < 0.05).

CONCLUSIONr-OPN can inhibit the release and activation of MMPs through inhibition of the expression of NF-κB and promotion of the expression of TIMPs, and alleviate hyperoxia-induced ALI.

Acute Lung Injury ; genetics ; metabolism ; Animals ; Hyperoxia ; metabolism ; physiopathology ; Matrix Metalloproteinase 2 ; genetics ; metabolism ; Matrix Metalloproteinase 9 ; genetics ; metabolism ; Mice ; NF-kappa B ; genetics ; metabolism ; Osteopontin ; genetics ; metabolism ; Tissue Inhibitor of Metalloproteinase-1 ; genetics ; metabolism ; Tissue Inhibitor of Metalloproteinase-2 ; genetics ; metabolism