This paper introduces the principle and characteristics of the LED constant-current and constant-power drive circuit for instrument's excitation light source.It also analyzes the steady-state and dynamic performances of the drive circuits.At last,it discusses the improving measures of the precision and stability for the drive circuit of LED excitation light source.

Objective To investigate the cause,treatment and prevention of delayed gastric emptying (DGE) after operation for esophageal carcinoma.Methods The clinical data of 13 cases with DGE after operation for esophageal carcinoma were analyzed retrospectively.Results DGE occurred at 10th day after operation.10 cases with functional delayed gastric emptying(FDGE) recovered after conservative treatmeut.3 cases with mechanical delayed gastric emptying(MDGE) were given surgical treatment.Conclusions The anatomical displacement of stomach may be the main cause of DGE.DGE is also related to vagus nerve and postoperative inadequate gastrointestinal decompression.Clinical symptoms,X-ray barium meal radiography and gastroscopy examination are the important diagnostic method.Conservative treatment should be the first choice for FDGE.The use of some gastro-intestinal prokinetic drugs may have a beneficial effect on FDGE.Once the diagnosis of MDGE is established,surgical treatment should be performed as early as possible.The fully preoperative preparation,the precise and concise techniques in operation and postoperative appropriate management may decrease the occurrence of DGE.

Objective To study the test-retest reliability in quantitative measurement of proprioception using Tecnobody rehabilitation system.Methods Nine healthy volunteers [4 males,5 females,averaged age (22.8 ±0.68) years] participated in three consecutive measurements on both feet by using Tecnobody rehabilitation system for computerized proprioceptive assessment.Standard error of measurement(SEM),correlation coefficient and intraclass correlation coefficient(ICC) obtained from the three consecutive measurements were used to analyze the Timeused in each measuring session,and the average track error (ATE) of the measurements.ResultsSEM values of Time in left foot and right foot were 3.07 ～ 3.83 and 6.65 ～ 8.44 respectively.ATE values in left foot and right foot were 1.33 ～ 1.97 and 1.39 ～ 1.91 respectively.The Time and ATE correlation coefficients of left foot / right foot were 0.919/0.6 and 0.808/0.831,respectively.The Time ICC values were 0.893/0.639 for left foot / right foot,respectively ; and the ATE ICC values were 0.716/0.734 for left foot / right foot,respectively. Conclusion The Tecnobody rehabilitation system provided a fairly good reliability in both relative andabsolute values in quantitative evaluation of proprioception in the feet.These data in a larger amount may be useful for setting up variables and the standard values of the local population for reference in proprioceptive rehabilitation.

Objective To study the clinical value of using a four-point method (FP) in measuring joint angles.Method Methods Twenty-five subjects without knee dysfunction were studied.Every knee joint was tested in extension,below 90° of flexion and above 90° of flexion with the traditional three-point method (TP) and the new four-point method.X-rays were taken as a gold standard measurement.The reliability and validity were analyzed using Bland-Altman plots,which can yield 95% limits of agreement (LOA).Results (1) The joint axis centers moved with changes in joint angle.(2) The 95% LOA of inter-tester reliability was (-5.0,2.7) with the FP and (-6.5,4.4) with the TP.The 95% LOAs of intra-tester reliability were (-3.6,4.0) for tester A and (-4.1,4.8) for tester B with the FP,while (-5.0,6.4) for tester A and (-6.1,5.8) for tester B with the TP.(3) The 95% LOAs in the three positions were (3.5,2.6) in extension,(-3.3,3.6) in mild flexion and (-1.9,5.7) in greater flexion with the FP,and ( 6.8,1.1),(-4.0,7.1) and (0,8.5) with the TP.Conclusions The FP gives better reliability and validity than the TP in joint angle measurement.

Objective To investigate factors related to chronic pain in those injured with fractures 27 months after the Sichuan earthquake.The correlation between intensity of pain and quality of life was also analyzed.Methods A total of 705 victims were investigated on site.Their residual pain was categorized using a visual analogue scale (VAS) score as no pain,mild pain,moderate pain or severe pain.The pain-related biological,psychological and social factors were analyzed using the Barthel Index ( BI ),Life Satisfaction Questionaire-11 ( LiSat-11 )and the SF-36 health questionnaire. Rehabilitation and surgical interventions,employment,income and emotional status were also investigated. Results The incidence of chronic pain was 88.5％ in this population,of which mild pain and moderate pain were 35.7％ and 33.3％,respectively.The percentage of the victims who had received fracture surgery was 65.8％ ; the percentage of those who had recovered was 96.9％.BI scores for the victims without pain,with mild,moderate and severe pain were 92.7 + 10.2,92.8 + 8.4,91.2 ± 9.9 and 90.4 + 14.7,respectively ; the differences between these groups were all statistically insignificant.The influence of pain intensity on life satisfaction showed a significant linear trend.The percentages of the victims with restricted occupational ability in the four groups were 38.3％,61.5％,75.7％ and 62.8％ respectively.The median of personal annual income were ￥ 3550,￥ 2500,￥ 2000 and ￥ 2500.The VAS scores were significantly related to abnormal emotions,life satisfaction,employment and annual income.The subjects with different levels of residual pain also showed significant differences in the physical functioning,role-physical,bodily pain,general health,vitality,social functioning,role-emotional and mental health sub-scales of the SF-36.The total SF-36 scores were highest among victims without pain (70.6 + 17.5) and declined significantly in those with mild (61.3 + 14.3 ),moderate (52.7 + 14.3 ) and severe pain (52.3 + 14.7 ).This negative correlation between pain intensity and SF-36 total score was statistically significant. Conclusions Chronic pain remains common among fracture victims 27 months after the earthquake.Its intensity is correlated with psychological and social factors as well as quality of life.

Objective To investigate the episodic memory monitoring in patients with white matter lesions (WML) and explore the relevance of episodic memory disorder and memory monitoring and the possible mechanism.Methods The feeling of knowing-episodic memory (FOK-EM) paradigm was adopted and subsequently administered in 30 WML patients and 30 control participants who were matched in age and educational level.Results Compared with control group (cued recall 4.37 ± 1.59;recognition 8.73 ± 1.05),the episodic memories of WML patients were significantly impaired on the cued recall performance (3.30 ± 1.51,t =2.666,P ＜ 0.05) and recognition performance (7.23 ± 0.77,t =6.306,P ＜ 0.01).Furthermore,the accuracy of FOK judgment (-0.13 ± 0.31),the correct judgment and correct recognition of FOK-EM (23.16％ ±5.96％) and the correct judgment and false recognition of FOK-EM (34.26％ ± 7.65％) in the WML patients group were significantly different compared with the control group (the accuracy of FOK judgment:0.34 ± 0.27,t =6.280,P ＜ 0.01;the correct judgment and correct recognition:35.12％ ± 6.82％,t =7.234,P ＜ 0.01;the correct judgment and false recognition:19.27％ ±6.50％,t =-8.174,P ＜ 0.01).In addition,the correct judgment and false recognition performance were positively correlated with the severity of periventricular lesions and deep white matter lesions in the WMLpatients group (r=0.716,P＜0.01;r=0.598,P＜0.01).Conclusions The WML patients demonstrated an overestimation of their recognition ability of episodic memory.Moreover,this impairment of memory monitoring was correlated with the deficit of executive function caused by the damage of the prefrontal-subcortical circuit,indicating that this mechanism could be an influential factor of episodic memory disorder in WML.

Objective:To investigate frailty status of the elderly patients with leukoaraiosis (LA) and to analyze the correlation between white matter hyperintensities and their frailty status.Methods:From June 2019 to September 2020, a total of 162 patients with leukoaraiosis over 65 years old were screened by cranial MRI.The Fried frailty phenotype was used to evaluate their frailty status.The Fazekas scale scoring method was used to independently assess the periventricular white matter hyperintense (PVH) and deep white matter hyperintense (DWMH) by the cranial MRI images.SPSS 22.0 software was used for statistical analysis.ANOVA test was used to compare normal distribution data between groups, and Kruskal-Wallis H test was used to compare non-normal distribution data between groups.Spearman rank correlation analysis was used to analyze the correlation between PVH and DWMH scores and Fried frailty phenotype score. Results:Among 162 elderly patients with leukoaraiosis, 46 patients (28.40%) were non-frailty, 76 patients (46.91%)were pre-frailty and 40 patients (24.69%) were frailty.There were statistically significant differences in age( F=9.382, P<0.01), number of chronic diseases( H=10.736, P<0.01), number of medication ( H=15.927, P<0.01) and mini-nutritional assessment short form (MNA-SF) scores( F=5.263, P<0.01) among older LA patients with different frailty phenotype.There was statistical difference in PVH scores in elderly LA patients with different frailty phenotype (χ 2=108.537, P<0.01), but no significant difference in DWMH scores (χ 2=4.239, P>0.05). Spearman correlation analysis showed significant positive correlation between PVH score and frailty phenotype score in elderly LA patients ( r=0.718, P<0.001). Conclusion:Elderly LA patients have a high incidence of frailty, which may be related to aging, multi-disease coexistence, multiple medication, nutritional risk and other factors.The occurrence of weakness in elderly LA patients is related to periventricular white matter lesions, and the more serious the white matter damage, the more obvious the degree of frailty.

Objective To analyze the prevalence status and the genetic characterizations of influenza B viruses isolated in Hunan Province after pandemic influenza A (H1N1) 2009,and to explore possible reasons for the prevalence.MethodsThroat swabs were collected from outpatients with influenza-like illness in 23 sentinel hospitals of Hunan Province in 2010.Influenza viruses were isolated with Madin-Darby canine kidney (MDCK) cells and identified by haemagglutination inhibition test.The genomes of 10 selected influenza B viruses were sequenced and analyzed for phylogenetic and molecular characterization.ResultsWith the reduction of isolation of pandemic influenza A (H1N1)2009 viruses,influenza B virus became the predominant isolated strain in the first half of 2010.Epidemic viruses mainly belonged to the B/Victoria lineage,and both two lineages co-circulated.Seven out of 11 influenza outbreaks caused by type B.Ten strains were filled into 2 branches of BV and BY which were classified by their lineage types in polymerase (PB2,PB1,PA),hemagglutinin (HA),neuraminidase (NA),NB,membrane protein (M1),influenza B virus membrane protein M2 (BM2),and non-structural protein (NS1,NS2) phylogenetic trees except the NP phylogenetic tree in which 10 strains were all in the BY branch.Compared with World Health Organization (WHO) vaccine strains,the amino acid identity of 11 proteins of the 10 strains was high (97.2％-100.0％).However,some amino acid point mutations were found.No mutation was found in drug resistance mutation sites.Some mutations in NA,NB,PB1,PB2 and NS2 molecules were found in 2 strains isolated from outbreaks compared with strains from sentinel surveillance.Conclusions The point mutations,insertions and genetic reassortment indicate viruses sustaining evolution,which is probably the reason for predominant influenza B viruses after pandemic influenza A (H1N1) 2009 in Hunan Province.

Objective To analyze the effect of quality of life (QOL) on the prognosis of long-term survivors with nasopharyngeal carcinoma (NPC). Methods A total of 192 NPC patients treated between 1999 and 2000 and with tumor-free survival before July 2003 were enrolled in this study. All patients received QOL measurement between July and August in 2003. Measurement scales included Chinese SF-36 questionnaire and a checklist consisting of fourteen items about self-rating symptoms. The median follow-up time was 7.9S years (range 2.67-9.55 years). The effects of QOL, social demographic and clinical factors on prognosis were analyzed. Results Univariate analysis showed that QOL affected the tumor-free survival and overall survival. Multivariate analysis showed that hypomnesia was an independent prognostic factor of tumor-free survival, while trismus, headache and age were independent prognostic factors of overall survival. The younger and the better QOL had better prognosis. The other sociodemographic and clinical factors had no prognostic value. Conclusion QOL is an important factor affecting the prognosis of long-term survivors with NPC, and it should be routinely evaluated during the follow-up.

Objective To evaluate the reliability, validity and feasibility of the Chinese version of SF-36 health survey questionaire in long-term survivors of nasopharyngeal carcinoma (NPC). Methods A total of 85 long-term NPC survivors completed the Chinese version of SF-36 by either telephone or mail survey. Correlation analysis, reliability analysis and factor analysis were performed to evaluate the reliability and validity of the scale. Results The Chinese version of SF-36 was easy to complete. The split-half reliability was 0. 92 and the Cronbach's α coefficient among domains were all above 0. 70, which showed good reliability and discrimination capacity among domains. All the correlation coefficients between each item and its domain achieved or approached 0. 5, which were greater than those between the item and other domains. These results demonstrated that the Chinese version of SF-36 had good content validity and discriminatory validity. Six principal components were extracted from the scale, which could basically represent eight domains. The cumulative variance was 71.4%. Two common factors were extracted from the eight domains, which accounted for 73.3% of the variance. The Chinese version of SF-36 was able to detect differences in the quality of life between NPC patients and healthy populations. Conclusions The Chinese version of SF-36 has good feasibility, reliability and validity in evaluating the quality of life in long-term NPC survivors.