Ethics of Human Resources Management in the Cameroonian Health System, Medical Nomadism and the Ineffectiveness of the Fight against High Blood Pressure

Context/objectives: The fight against Chronic Non-Communicable Diseases (NCDs) is a long-term undertaking, which requires available, motivated and well-managed human resources (HR). The administrative management of skills on both qualitative and quantitative levels is one of the essential functions of a health system. To better implement policies of fight against High Blood Pressure (HBP) and other chronic diseases, it is important to establish strategies to retain health personnel. This loyalty requires favorable working conditions and consideration of the contribution-reward couple. Good working conditions are likely to reduce the phenomenon of medical nomadism;conversely, poor HR management can contribute to their exodus towards exotic “green pastures”, thus leading to an additional crisis in the Cameroonian health system. The fight against HBP is a complex, multifaceted and multifactorial reality that requires appropriate management model for all types of resources mainly HR. The main objective of this research is to show the impact of poor management of human resources in Cameroon health system on medical nomadism and the ineffectiveness of the fight against High Blood Pressure. Method: A cross-sectional descriptive survey among five hundred (500) health facilities in the center region of Cameroon has been conducted. A stratified probabilistic technique has been used, and the number of health facilities to be surveyed has been determined using the “sample size estimation table” of Depelteau. The physical questionnaires have been printed and then distributed to data collectors. After data collection, the latter were grouped during processing in Excel sheets. The Chi-square test was used for data with a qualitative value and that of Kolmogorov-Sminorf for data with a quantitative value to assess the normality and reliability of data. The Crochach’s Alpha reliability test allowed us to have a summary of the means and variances and then to search for intragroup correlations between variables. Descriptive analysis was possible with the XLSTAT 2016 software. Results: 43.60% of Health Facilities (HF) managers were unqualified. 82.20% of HF managers have staff in a situation of professional insecurity. They are mainly contractual (49.00), decision-making agents (24.40%), casual agents (08.80). The proportion of unstable personnel is average of 22.00% and very unstable, 12.00%.

Stimulating erythropoiesis in inflammatory bowel disease associated anemia

Anemia is a frequent complication in patients with inflammatory bowel disease (IBD), and is associated with decreased quality of life and increased rate of hospitalization. The primary therapeutic targets of IBD- associated anemia are iron deficiency and anemia of chronic disease. An important prognostic parameter of the success or failure of therapy is the outcome of the underlying disease. Iron deficiency should be appropriately managed with iron supplementation. However, the use of oral iron therapy is limited by several problems, the most important being gastrointestinal side effects leading occasionally to disease relapse and poor iron absorption. Intravenous iron preparations are more reliable, with iron sucrose demonstrating the best efficacy and tolerability. Treatment with erythropoietin or darbepoetin has been proven to be effective in patients with anemia, who fail to respond to intravenous iron. Patients with ongoing inflammation have anemia of chronic disease and may require combination therapy comprising of intravenous iron sucrose and erythropoietin. After initiating treatment, careful monitoring of hemoglobin levels and iron parameters is needed in order to avoid recurrence of anemia. In conclusion, anemia in the setting of IBD should be aggressively diagnosed, investigated, and treated. Future studies should define the optimal dose and schedule of intravenous iron supplementation and appropriate erythropoietin therapy in these patients.

The Cloning of Erythropoiesis-related Genes with the Innovated Model System

Most studies of erythropoiesis have been performed either with the virally transformed MEL cells or with the scarce erythroblasts within unhomogeneous cell populations.MEL cells are the Friend virus transformed mouse erythroleukemia cells and have lost the capacity to respond to erythropoietin.Moreover,the research in the field of erythropoiesis has been severely hampered by the paucity of erythroblasts obtained from chick embryos,human,mouse,rat fetal liver,mouse spleen,or the bone marrow.In our paper,the fetal blood from newly slaughtered pregnant sheep meets the needs of studies as abundant staring biological materials at the nucleotide level and also reflects in vivo proliferative and differential status of erythroblasts.Appling the technique of mRNA differential display with minor modification,we directly compared cDNA fragmerts from the fetal blood erythroblasts and adult pregnant sheep leukocytes by PCR on DNA sequencing gels and revealed two differentially expressing bands.One is a novel gene fragment, which has homology with UV-sensitive cone opsin or rhodopsin by examinating the predicted amino acid sequence.Since the blood cells are sensitive to radiation,it can be safely inferred that this fragment participate in the process of cytocidal effect of the radiation.The other fragment is glucose induced gene /elongation factor 2 3′end noncoding region,which was first cloned from glucose induced bovine aortic smooth muscle cells.Using Northern blot hybridization method,authentic specific expression was confirmed.

Erythropoiesis-stimulating agents in the management of cancer patients with anemia: a meta-analysis

Background： Erythropoiesis-stimulating agents （ESAs） are widely used in the management of anemia in cancer patients. Despite their apparent effectiveness, recent studies have suggested that ESAs could result in serious adverse events and even higher mortality. The aim of the current study was to evaluate the benefits and risks of ESAs in the management of cancer patients with anemia using a recta-analysis. Methods： The initial literature search covered Medline, PubMed, Embase, and the Cochrane Center Register of Controlled Trials, and identified 1,569 articles. The final meta-analysis included eight randomized controlled trials （n=2,387） in cancer patients with 〈11 g/dL hemoglobin （Hb） at the baseline and target Hb （for stopping ESA treatment） at no more than 13 g/dL. The assessment measures included Hb response, blood transfusion rate and adverse events that included venous thromboemblism （VTE）, hypertension, and on-study mortality. The results are expressed as pooled odds ratio （OR）. Publication bias was assessed using funnel plot analysis. Results： ESAs significantly increased the Hb concentration [OR 7.85, 95% confidence interval （CI）： 5.85 to 10.53, P〈O.O01] and reduced the red blood cell （RBC） transfusion rate （OR 0.52, 95% CI： 0.42 to 0.65, P〈0.001）. ESAs did not increase the accumulated adverse events （OR 0.95, P=0.82）, or the on-study mortality （OR 1.09, P=0.47）. Conclusions： ESAs are not associated with increased frequency of severe adverse events in anemic cancer patients when the target Hb value is no more than 13 g/dL.

Erythropoiesis Stimulating Agents (ESAs) in the Treatment of Cardio-Renal Syndrome Anaemia

Coexistence of chronic kidney disease (CKD) and chronic heart failure (CHF) define a recently recognized clinical entity known as cardio-renal syndrome. Sufficient evidence suggests that the two pathological conditions share common pathogenic etiology which is not yet fully defined. Superimposed anaemia is a common finding among patients suffering from cardio-renal syndrome. The combination of CKD, CHF and anaemia increase the probability of death by 6 times compared to normal individuals. Early attempts to restore anaemia either by iron supplementation, erythropoiesis stimulating agents (ESAs) or combination of the two have reported to improve quality of life, morbidity and mortality especially among patients treated by cardiologists. Recent publications of well controlled epidemiological studies failed to prove convincing beneficial effect of the above mentioned therapy moreover skepticism has raised concerning the safety of restoring anaemia among patients with cardio-renal syndrome as well as used medications. There are still unresolved problems concerning the definition of anaemia, by means of hemoglobin level among these patients, the target hemoglobin level and the therapeutic regimen of ESAs administration and iron supplementation. We need much more evidence in order to define an effective and safe treatment strategy correcting anaemia among patients with cardio-renal syndrome.

Cell cycle.independent roles of p19INK4d in human terminal erythropoiesis

Normally, cyclin interacts with cyclin-dependent kinase (CDK) to form a cyclin-CDK complex, which promotes cell cycle progression, whereas cyclin-dependent kinase inhibitor (CDKI) molecules inhibit the formation of cyclin- CDK complex, arresting cell cycle. Terminal erythropoiesis is closely coordinated with cell cycle exit, which is regulated by cyclins, CDKs, and CDKIs [1]. In the global transcriptome of human terminal erythropoiesis [2], p19INK4d is expressed highly, and its expression is significantly up-regulated during human terminal erythropoiesis. However, the roles of p19INK4d in terminal erythropoiesis are still unknown.

Iron-Restricted Erythropoiesis in Anaemic Patients with Giant Cell Arteritis and Polymyalgia Rheumatica

The aim of this observational study was to biochemically characterize the anaemia in GCA (giant cell arteritis) and PMR (polymyalgia rheumatica) patients. Values for mean corpuscular volume, mean corpuscular hemoglobin and soluble transferrin receptor were normal, whereas serum iron and total iron binding capacity (TIBC) were subnormal, and mean ferritin was above the upper reference limit. Iron-restricted erythropoiesis (IRE), defined as a bone marrow smear staining positive for iron in combination with transferrin saturation less than 20%, was present in all patients. All patients exhibited clinical and biochemical signs of active inflammation with elevated C-reactive protein and an increased erythrocyte sedimentation rate.

Is ineffective esophageal motility associated with gastropharyngeal reflux disease?

AIM： TO evaluate the association between IEM and gastropharyngeal reflux disease （GPRD） in patients who underwent ambulatory 24-h dual-probe pH monitoring for the evaluation of supraesophageal symptoms. METHODS： A total of 632 patients who underwent endoscopy, esophageal manometry and ambulatory 24-h dual-pH monitoring due to supraesophageal symptoms （e.g. globus, hoarseness, or cough） were enrolled. Of them, we selected the patients who had normal esophageal motility and IEM. The endoscopy and ambulatory pH monitoring findings were compared between the two groups. RESULTS;： A total of 264 patients with normal esophageal motility and 195 patients with the diagnosis of IEM were included in this study. There was no difference in the frequency of reflux esophagitis and hiatal hernia between the two groups. All the variables showing gastroesophageal reflux and gastropharyngeal reflux were not different between the two groups. The frequency of GERD and GPRD, as defined by ambulatory pH monitoring, was not different between the two groups. CONCLUSION： There was no association between IEM and GPRD as well as between IEM and GERD. IEM alone cannot be considered as a definitive marker for reflux disease.

Habitual rapid food intake and ineffective esophageal motility

AIM:To study non-cardiac chest pain(NCCP) in relation to ineffective esophageal motility(IEM) and rapid food intake.METHODS:NCCP patients with a self-reported habit of fast eating underwent esophageal manometry for the diagnosis of IEM.Telephone interviews identified eating habits of additional IEM patients.Comparison of manometric features was done among IEM patients with and without the habit of rapid food intake and healthy controls.A case study investigated the effect of 6-mo gum chewing on restoration of esophageal motility in an IEM patient.The Valsalva maneuver was performed in IEM patients and healthy controls to assess the compliance of the esophagus in response to abdominal pressureincrease.RESULTS:Although most patients diagnosed with NCCP do not exhibit IEM,remarkably,all 12 NCCP patients who were self-reporting fast eaters with a main complaint of chest pain(75.0%) had contraction amplitudes in the mid and distal esophagus that were significantly lower compared with healthy controls [(23.45 mmHg(95%CI:14.06-32.85)vs 58.80 mmHg(95%CI:42.56-75.04),P < 0.01 and 28.29 mmHg(95%CI:21.77-34.81) vs 50.75 mmHg(95%CI:38.44-63.05),P < 0.01,respectively)].In 7 normal-eating IEM patients with a main complaint of sensation of obstruction(42.9%),the mid amplitude was smaller than in the controls [30.09 mmHg(95%CI:19.48-40.70) vs 58.80 mmHg(95%CI:42.56-75.04),P < 0.05].There was no statistically significant difference in manometric features between the fast-eating and normal-eating groups.One NCCP patient who self-reported fast eating and was subsequently diagnosed with IEM did not improve with proton-pump inhibition but restored swallow-induced contractions upon 6-mo gum-chewing.The Valsalva maneuver caused a markedly reduced pressure rise in the mid and proximal esophagus in the IEM patients.CONCLUSION:Habitual rapid food intake may lead to IEM.A prospective study is needed to validate this hypothesis.Gum-chewing might strengthen weakened esophageal muscles.

Causes and Solutions of Administrative Departments＇ Economic Policy Ineffectiveness

Administrative department, as the focus of national political system reform, is associated with optimization and adjustment of state institutions and plays a macro-control role in socialist economic development. Administrative departments, just the ＂government＂, conduct economic control function to promote the sustainable development of social economic causes. The thesis firstly introduces administrative departments＇ era effect and causes of administrative departments＇ economic policy ineffectiveness. And on the basis of these, the thesis comes up with some solutions to solve economic ineffectiveness, hoping that it would be helpful to relevant researches.

Post-transcriptional regulation of erythropoiesis

Erythropoiesis is a complex,precise,and lifelong process that is essential for maintaining normal body functions.Its strict regulation is necessary to prevent a variety of blood diseases.Normal erythropoiesis is precisely regulated by an intricate network that involves transcription levels,signal transduction,and various epigenetic modifications.In recent years,research on posttranscriptional levels in erythropoiesis has expanded significantly.The dynamic regulation of splicing transitions is responsible for changes in protein isoform expression that add new functions beneficial for erythropoiesis.RNA-binding proteins adapt the translation of transcripts to the protein requirements of the cell,yielding mRNA with dynamic translation efficiency.Noncoding RNAs,such as microRNAs and lncRNAs,are indispensable for changing the translational efficiency and/or stability of targeted mRNAs to maintain the normal expression of genes related to erythropoiesis.N6-methyladenosine-dependent regulation of mRNA translation plays an important role in maintaining the expression programs of erythroid-related genes and promoting erythroid lineage determination.This review aims to describe our current understanding of the role of post-transcriptional regulation in erythropoiesis and erythroid-associated diseases,and to shed light on the physiological and pathological implications of the post-transcriptional regulation machinery in erythropoiesis.These may help to further enrich our understanding of the regulatory network of erythropoiesis and provide new strategies for the diagnosis and treatment of erythroid-related diseases.

Comprehensive Characterization and Global Transcriptome Analysis of Human Fetal Liver Terminal Erythropoiesis

The fetal liver(FL)is the key erythropoietic organ during fetal development,but knowledge on human FL erythropoiesis is very limited.In this study,we sorted primary erythroblasts from FL cells and performed RNA sequencing(RNA-seq)analyses.We found that temporal gene expression patterns reflected changes in function during primary human FL terminal erythropoiesis.Notably,the expression of genes enriched in proteolysis and autophagy was up-regulated in orthochromatic erythroblasts(OrthoEs),suggesting the involvement of these pathways in enucleation.We also performed RNA-seq of in vitro cultured erythroblasts derived from FL CD34+cells.Comparison of transcriptomes between the primary and cultured erythroblasts revealed significant differences,indicating impacts of the culture system on gene expression.Notably,the expression of lipid metabolism-related genes was increased in cultured erythroblasts.We further immortalized erythroid cell lines from FL and cord blood(CB)CD34+cells(FL-iEry and CB-iEry,respectively).FL-iEry and CB-iEry were immortalized at the proerythroblast stage and can be induced to differentiate into OrthoEs,but their enucleation ability was very low.Comparison of the transcriptomes between OrthoEs with and without enucleation capability revealed the down-regulation of pathways involved in chromatin organization and mitophagy in OrthoEs without enucleation capacity,indicating that defects in chromatin organization and mitophagy contribute to the inability of OrthoEs to enucleate.Additionally,the expression of HBE1,HBZ,and HBG2 was up-regulated in FL-iEry compared with CB-iEry,and such up-regulation was accompanied by down-regulated expression of BCL11A and up-regulated expression of LIN28B and IGF2BP1.Our study provides new insights into human FL erythropoiesis and rich resources for future studies.

Zebrafish ELL-associated factors Eaf1/2 modulate erythropoiesis via regulating gata1a expression and WNT signaling to facilitate hypoxia tolerance

EAF1 and EAF2,the eleven-nineteen lysine-rich leukemia(ELL)-associated factors which can assemble to the super elongation complex(AFF1/4,AF9/ENL,ELL,and P-TEFb),are reported to participate in RNA polymeraseⅡto actively regulate a variety of biological processes,including leukemia and embryogenesis,but whether and how EAF1/2 function in hematopoietic system related hypoxia tolerance during embryogenesis remains unclear.Here,we unveiled that deletion of EAF1/2(eaf1^(-/-)and eaf2^(-/-))caused reduction in hypoxia tolerance in zebrafish,leading to reduced erythropoiesis during hematopoietic processes.Meanwhile,eaf1^(-/-)and eaf2^(-/-)mutants showed significant reduc-tion in the expression of key transcriptional regulators scl,lmo2,and gata1a in erythropoiesis at both 24 h post fertilization(hpf)and 72 hpf,with gata1a downregulated while scl and lmo2 upregulated at 14 hpf.Mechanistically,eaf1^(-/-)and eaf2^(-/-)mutants exhibited significant changes in the expression of epigenetic modified histones,with a significant increase in the binding enrichment of modified histone H3K27me3 in gata1a promoter rather than scl and lmo2 promoters.Additionally,eaf1^(-/-)and eaf2^(-/-)mutants exhibited a dynamic expression of canonical WNT/β-catenin signaling during erythropoiesis,with significant reduction in p-β-Catenin level and in the binding enrichment of both scl and lmo2 promoters with the WNT transcriptional factor TCF4 at 24 hpf.These findings demonstrate an important role of Eaf1/2 in erythropoiesis in zebrafish and may have shed some light on regeneration medicine for anemia and related diseases and on molecular basis for fish economic or productive traits,such as growth,disease resistance,hypoxia tolerance,and so on.

Ineffective esophageal motility is associated with acute rejection after lung transplantation independent of gastroesophageal reflux

BACKGROUND Gastroesophageal reflux is associated with poorer outcomes after lung transplant,likely through recurrent aspiration and allograft injury.Although prior studies have demonstrated a relationship between impedance-pH results and transplant outcomes,the role of esophageal manometry in the assessment of lung transplant patients remains debated,and the impact of esophageal dysmotility on transplant outcomes is unclear.Of particular interest is ineffective esophageal motility(IEM)and its associated impact on esophageal clearance.AIM To assess the relationship between pre-transplant IEM diagnosis and acute rejection after lung transplantation.METHODS This was a retrospective cohort study of lung transplant recipients at a tertiary care center between 2007 and 2018.Patients with pre-transplant anti-reflux surgery were excluded.Manometric and reflux diagnoses were recorded from pre-transplant esophageal function testing.Time-to-event analysis using Cox proportional hazards model was applied to evaluate outcome of first episode of acute cellular rejection,defined histologically per International Society of Heart and Lung Transplantation guidelines.Subjects not meeting this endpoint were censored at time of post-transplant anti-reflux surgery,last clinic visit,or death.Fisher’s exact test for binary variables and student’s t-test for continuous variables were performed to assess for differences between groups.RESULTS Of 184 subjects(54%men,mean age:58,follow-up:443 person-years)met criteria for inclusion.Interstitial pulmonary fibrosis represented the predominant pulmonary diagnosis(41%).During the follow-up period,60 subjects(33.5%)developed acute rejection.The all-cause mortality was 16.3%.Time-to-event univariate analyses demonstrated significant association between IEM and acute rejection[hazard ratio(HR):1.984,95%CI:1.03-3.30,P=0.04],confirmed on Kaplan-Meier curve.On multivariable analysis,IEM remained independently associated with acute rejection,even after controlling for potential confounders such as the presence of acid and nonacid reflux(HR:2.20,95%CI:1.18-4.11,P=0.01).Nonacid reflux was also independently associated with acute rejection on both univariate(HR:2.16,95%CI:1.26-3.72,P=0.005)and multivariable analyses(HR:2.10,95%CI:1.21-3.64,P=0.009),adjusting for the presence of IEM.CONCLUSION Pre-transplant IEM was associated with acute rejection after transplantation,even after controlling for acid and nonacid reflux.Esophageal motility testing may be considered in lung transplant to predict outcomes.

三叉神经痛微球囊压迫术后无效或短期内复发机制及处理方法的研究进展

三叉神经痛(TN)是临床常见的疼痛性疾病,而经皮微球囊压迫术(PMC)是TN最有效的治疗方法。但PMC仍存在无效或复发的可能,且复发后病情也更加复杂。同时影响PMC治疗后无效或复发的因素也较多。因此,对于PMC治疗无效或复发的患者,治疗无效或复发的病因、患者的身体状况、治疗的安全性等均是制订PMC治疗无效或复发后干预策略需要考虑的因素。目前关于PMC的治疗尚处于探索阶段,未来深入研究TN经PMC治疗后无效或复发的机制,可以为疾病的治疗提供新思路。

罗沙司他胶囊与红细胞生成刺激剂治疗慢性维持性血液透析合并肾性贫血的临床观察

目的观察口服罗沙司他胶囊与红细胞生成刺激剂(ESAs)对成人慢性维持性血液透析(MHD)合并肾性贫血(RA)患者的临床治疗效果和安全性。方法纳入2023年6月至2024年6月河北唐山982医院和北京京信医院收治的40例MHD合并RA患者,随机分为观察组(n=20)和对照组(n=20)。观察组给予罗沙司他胶囊口服,对照组给予重组人促红素(huEPO)联合静脉铁剂,治疗时长均为12周。比较两组患者总有效率,血液学指标如血红蛋白(Hb)、红细胞计数(RBC)、血细胞比容(HCT),铁代谢指标如血清铁蛋白(SF)、转铁蛋白饱和度(TAST)及不良反应发生率的变化。结果与对照组相比,观察组在治疗12周后的总有效率显著提高(95%比70%,P<0.05);观察组患者的Hb[(104.76±11.73)g/L比(87.58±6.71)g/L]、Hct[(29.37±3.83)%比(25.88±1.96)%]、RBC[(3.36±0.15)×10^(12)L比(2.93±0.24)×10^(12)/L]、SF[(265.45±21.97)Hg/L比(210.59±11.90)Hg/L]、TSAT[(32.66±3.87)%比(28.27±2.27)%]水平均高于对照组,差异有统计学意义(P均<0.05);不良反应发生率无显著差异(15%比20%,P>0.05)。结论口服罗沙司他胶囊较静注huEPO联合静脉铁剂治疗MH合并RA患者疗效更加显著,能有效提高患者的RBC、Hb、HCT、SF、TSAT等指标水平,改善贫血指标,纠正铁代谢紊乱,减少不良反应的发生。

In vivo bioassay to determine the potency of a new erythropoiesis stimulating protein

A simple in vivo bioassay suitable for the routine quality control testing of a new erythropoiesis stimulating protein was developed.Subcutaneous administration of the new erythropoiesis stimulating protein to Balb/c mice in a single dose resulted in a dose-dependent increase in the number of circulating reticulocytes.Within the erythropoiesis stimulating protein dose range of 3.125 to 200 ng per mouse,there is a strong linear relationship between the dose and reticulocyte counts in the treated mice.This linear relationship allows us to determine the biological potency of the testing erythropoiesis stimulating protein preparation relative to a reference standard using parallel line assay.Accuracy,precision,dose variation and blood collection time of this method were analyzed in order to choose doses in the linear range that are suitable for setting up a useful,precise,and economical bioassay.

文学翻译修辞意识断与续及其阐释

作为人类意识的活跃成分,修辞意识被认为是对修辞现象和本质存在及修辞形势的认识和觉知。语言文化等诸多因素导致译者对原文内容和文体,包括对修辞现象和本质存在理解和觉知不到位,引发翻译中修辞意识中断进而导致阐释问题。译者、原作者、读者作为不同主体的认知差异是导致文学翻译修辞意识中断及阐释失效的主要原因。充分认识到接受心理是以继时态发挥即时作用显得尤为重要,真正有效的修辞话语并不会因为历时变迁而不再有接受者,而是可以被有效阐释。文学翻译实践表明,译者通过努力让修辞意识在译文中得以接续不失为关注作品文学性的有效之举,其旨在引发读者共鸣,促进翻译接受。

8周高原训练对赛艇运动员红细胞生成、铁代谢和有氧运动能力的影响

以28名男子赛艇运动员作为研究对象,分为高原组和平原组,旨在探讨持续8周的高原训练对男子赛艇运动员红细胞生成、铁代谢和有氧运动能力的影响.8周训练期间两组运动员均执行相同的训练计划,训练负荷基本保持一致.分别测量8周训练前后的最大摄氧量(VO_(2peak))和循环血红细胞计数(RBC)、网织红细胞(RET)%、血红蛋白(Hgb)浓度等红细胞参数,以及红铁酮(ERFE)、铁蛋白(FER)、可溶性转铁蛋白受体(sTfR)水平.研究结果发现:①与训练前相比,8周训练后高原组的VO_(2peak)、RVO_(2peak)(相对体重最大摄氧量)显著升高,平原组均无显著变化,两组间VO_(2peak)、RVO_(2peak)的变化均存在显著差异(+9.41%vs+3.03%,p<0.05;+12.83%vs+0.80%,p<0.01).②8周训练后,高原组的RBC、Hgb、HCT(红细胞压积)均显著升高,平原组略微下降.两组间Hgb、HCT的变化存在显著差异(+4.95%vs–3.21%,p<0.01;+6.48%vs–1.57%,p<0.01),RBC存在显著差异的趋势(+3.19%vs–3.61%,p=0.061);高原组和平原组的RET%、RET-He(网织红细胞血红蛋白含量)均未发生显著改变;但高原组的LFR(低荧光强度网织红细胞)、RPI(网织红细胞生成指数)显著升高,MFR(中荧光强度网织红细胞)、IRF(幼稚网织红细胞比率)均显著下降;两组间RPI的变化存在显著差异(+30.60%vs–4.52%,p<0.05).③8周训练后,高原组的FER显著下降,sTfR、sTfR/lg(FER)显著升高,ERFE无显著变化;平原组的ERFE显著升高,FER、sTfR、sTfR/lg(FER)均未发生显著改变;两组间FER、ERFE、sTfR、sTfR/lg(FER)的变化存在显著差异(+17.99%vs+121.31%,p<0.05;–36.16%vs–2.96%,p<0.05;+82.77%vs–8.87%,p<0.05;+108.40%vs–6.96%,p<0.05).④8周训练后,VO_(2peak)的变化幅度仅与循环血sTfR、sTfR/lg(FER)的变化幅度呈显著正相关.由此得出结论:持续8周的高原训练有助于提高赛艇运动员有氧运动能力和循环血的氧转运能力.8周高原训练后期,红细胞生物合成依然较为活跃.sTfR在有氧能力的改善中可能发挥着重要作用.

A Novel Single Phase Grounding Fault Protection Scheme Without Threshold Setting for Neutral Ineffectively Earthed Power Systems

The setting values of thresholds for fault feature parameters are critical in all kinds of protection schemes.When the detected feature parameter value exceeds the setting value,the protection will trip.However,the setting value based conventional protection schemes sometimes cannot satisfy the protection requirements of neutral ineffectively earthed power systems(NIEPS)due to wide variations in operating conditions and the complexities of fault cases.In this paper,a novel single phase grounding fault protection scheme without threshold setting is proposed.The fault detection is achieved based on operating states rather than setting values.A fuzzy c-means algorithm is used to divide the operating state of the protected feeder into non-fault states and fault states.The cluster center of each state is then obtained by classifying the historical feature samples of the protected feeder extracted under various operating conditions into their corresponding states in a constructed multi-dimensional fault feature space.The distances between the detected feature samples and the cluster centers of the non-fault and the fault states are calculated.If the distance to the fault state is shorter than that to the non-fault state,a fault is detected.Otherwise,the feeder is considered normal.A PSCAD/EMTDC simulator is used to simulate a 35 kV NIEPS under various operating conditions,non-linear loads,and complex fault cases.Results show that the proposed single phase grounding fault protection scheme without threshold setting can protect the system correctly under all kinds of faults.