MHz cut-off frequency and permeability mechanism of iron-based soft magnetic composites

The lack of soft magnetic composites with high power density in MHz frequency range has become an obstacle in the efficient operation of the electrical and electronic equipments.Here,a promising method to increase the cut-off frequency of iron-based soft magnetic composites to hundreds of MHz is reported.The cut-off frequency is increased from 10 MHz to 1 GHz by modulating the height of the ring,the distribution of particles,and the particle size.The mechanism of cut-off frequency and permeability is the coherent rotation of domain modulated by inhomogeneous field due to the eddy current effect.An empirical formula for the cut-off frequency in a magnetic ring composed of iron-based particles is established from experimental data.This work provides an effective approach to fabricate soft magnetic composites with a cut-off frequency in hundreds of MHz.

Impact of D-dimer on in-hospital mortality following aortic dissection:A systematic review and meta-analysis

BACKGROUND The utility of D-dimer(DD)as a biomarker for acute aortic dissection(AD)is recognized.Yet,its predictive value for in-hospital mortality remains uncertain and subject to conflicting evidence.AIM To conduct a meta-analysis of AD-related in-hospital mortality(ADIM)with elevated DD levels.METHODS We searched PubMed,Scopus,Embase,and Google Scholar for AD and ADIM literature through May 2022.Heterogeneity was assessed using I2 statistics and effect size(hazard or odds ratio)analysis with random-effects models.Sample size,study type,and patients’mean age were used for subgroup analysis.The significance threshold was P<0.05.RESULTS Thirteen studies(3628 patients)were included in our study.The pooled prevalence of ADIM was 20%(95%CI:15%-25%).Despite comparable demographic characteristics and comorbidities,elevated DD values were associated with higher ADIM risk(unadjusted effect size:1.94,95%CI:1.34-2.8;adjusted effect size:1.12,95%CI:1.05-1.19,P<0.01).Studies involving patients with a mean age of<60 years exhibited an increased mortality risk(effect size:1.43,95%CI:1.23-1.67,P<0.01),whereas no significant difference was observed in studies with a mean age>60 years.Prospective and larger sample size studies(n>250)demonstrated a heightened likelihood of ADIM associated with elevated DD levels(effect size:2.57,95%CI:1.30-5.08,P<0.01 vs effect size:1.05,95%CI:1.00-1.11,P=0.05,respectively).CONCLUSION Our meta-analysis shows elevated DD increases in-hospital mortality risk in AD patients,highlighting the need for larger,prospective studies to improve risk prediction models.

Utility of plasma D-dimer for diagnosis of venous thromboembolism after hepatectomy

BACKGROUND Venous thromboembolism(VTE)is a potentially fatal complication of hepatectomy.The use of postoperative prophylactic anticoagulation in patients who have undergone hepatectomy is controversial because of the risk of postoperative bleeding.Therefore,we hypothesized that monitoring plasma D-dimer could be useful in the early diagnosis of VTE after hepatectomy.AIM To evaluate the utility of monitoring plasma D-dimer levels in the early diagnosis of VTE after hepatectomy.METHODS The medical records of patients who underwent hepatectomy at our institution between January 2017 and December 2020 were retrospectively analyzed.Patients were divided into two groups according to whether or not they developed VTE after hepatectomy,as diagnosed by contrast-enhanced computed tomography and/or ultrasonography of the lower extremities.Clinicopathological factors,including demographic data and perioperative D-dimer values,were compared between the two groups.Receiver operating characteristic curve analysis was performed to determine the D-dimer cutoff value.Univariate and multivariate analyses were performed using logistic regression analysis to identify significant predictors.RESULTS In total,234 patients who underwent hepatectomy were,of whom(5.6%)were diagnosed with VTE following hepatectomy.A comparison between the two groups showed significant differences in operative time(529 vs 403 min,P=0.0274)and blood loss(530 vs 138 mL,P=0.0067).The D-dimer levels on postoperative days(POD)1,3,5,7 were significantly higher in the VTE group than in the non-VTE group.In the multivariate analysis,intraoperative blood loss of>275 mL[odds ratio(OR)=5.32,95%confidence interval(CI):1.05-27.0,P=0.044]and plasma D-dimer levels on POD 5≥21μg/mL(OR=10.1,95%CI:2.04-50.1,P=0.0046)were independent risk factors for VTE after hepatectomy.CONCLUSION Monitoring of plasma D-dimer levels after hepatectomy is useful for early diagnosis of VTE and may avoid routine prophylactic anticoagulation in the postoperative period.

Associations of serum D-dimer and glycosylated hemoglobin levels with third-trimester fetal growth restriction in gestational diabetes mellitus

BACKGROUND Gestational diabetes mellitus(GDM)is a special type of diabetes that commonly occurs in women during pregnancy and involves impaired glucose tolerance and abnormal glucose metabolism;GDM is diagnosed for the first time during pregnancy and can affect fetal growth and development.AIM To investigate the associations of serum D-dimer(D-D)and glycosylated hemoglobin(HbA1c)levels with third-trimester fetal growth restriction(FGR)in GDM patients.METHODS The clinical data of 164 pregnant women who were diagnosed with GDM and delivered at the Obstetrics and Gynecology Hospital of Fudan University from January 2021 to January 2023 were analyzed retrospectively.Among these women,63 whose fetuses had FGR were included in the FGR group,and 101 women whose fetuses had normal body weights were included in the normal body weight group(normal group).Fasting venous blood samples were collected from the elbow at 28-30 wk gestation and 1-3 d before delivery to measure serum D-D and HbA1c levels for comparative analysis.The diagnostic value of serum D-D and HbA1c levels for FGR was evaluated by receiver operating characteristic analysis,and the influencing factors of third-trimester FGR in GDM patients were analyzed by logistic regression.RESULTS Serum fasting blood glucose,fasting insulin,D-D and HbA1c levels were significantly greater in the FGR group than in the normal group,while the homeostasis model assessment of insulin resistance values were lower(P<0.05).Regarding the diagnosis of FGR based on serum D-D and HbA1c levels,the areas under the curves(AUCs)were 0.826 and 0.848,the cutoff values were 3.04 mg/L and 5.80%,the sensitivities were 81.0%and 79.4%,and the specificities were 88.1%and 87.1%,respectively.The AUC of serum D-D plus HbA1c levels for diagnosing FGR was 0.928,and the sensitivity and specificity were 84.1%and 91.1%,respectively.High D-D and HbA1c levels were risk factors for third-trimester FGR in GDM patients(P<0.05).CONCLUSION D-D and HbA1c levels can indicate the occurrence of FGR in GDM patients in the third trimester of pregnancy to some extent,and their combination can be used as an important index for the early prediction of FGR.

D-Dimer: Predictor of Postpartum Hemorrhage among Pre-Eclampsia at Kilimanjaro Christian Medical Centre

Background: Postpartum hemorrhage (PPH) is the major contributor to maternal mortality and morbidity worldwide as well as in Tanzania. Studies have shown Pre-eclampsia as a risk indicator for Postpartum hemorrhage and D-dimer tends to rise in women with pre-eclampsia. Few studies that have shown the association between D-dimer and PPH have been controversial and differ according to ethnicity and lifestyle. Hence there is no suitable reference interval for D-dimer in predicting Postpartum hemorrhage among women with pre-eclampsia. Broad Objective: This study aimed to assess the association, sensitivity, and specificity of D-dimer as a laboratory predictor of postpartum hemorrhage among women with pre-eclampsia at KCMC hospital. Methodology: This was a hospital-based analytical cross-sectional study conducted at KCMC Hospital in Northern Tanzania from September 2022 to March 2023. A total of 195 women with pre-eclampsia were included in this study. Plasma D-dimer levels were taken from women with pre-eclampsia pre-delivery. Haematocrit was compared before and after delivery, and a fall of 10% was considered as Postpartum hemorrhage together with clinical assessment of the patient. Participants were divided among those who had severe features and those who did not have severe features and were further categorized into those who had PPH and those who did not have PPH. Logistic regression was used to determine the association between D-dimer and PPH adjusting for other factors. The Receiver Operating Curve (ROC) was used to evaluate the predictive value. Results: Higher median D-dimer levels were seen among women who had PPH compared to those who had no PPH. D-dimer was seen to be associated with PPH, thus for every unit increase of µg/ml of D-dimer among women who had pre-eclampsia without severe features there was a 14% significant increase in the odds of having postpartum hemorrhage and a 45% significant increase of having postpartum hemorrhage among those who had pre-eclampsia with severe features. Furthermore, the cut-off point of a D-dimer level of 0.66 µg/ml significantly predicts postpartum hemorrhage with a sensitivity of 75% and specificity of 55%. For those who had no severe features the cut-off point was 0.53 µg/ml with a sensitivity of 95% and specificity of 53%, and for those who had severe features the cut-off point was 3.58 µg/ml with a sensitivity of 50% and specificity of 96%. Conclusion: D-dimer can be used to predict postpartum hemorrhage among pre-eclampsia, especially among those who have severe features. This shows that D-dimer has specificity in predicting PPH in women with pre-eclampsia and can be applied in clinical services to save women from maternal morbidity and mortality. Blood products such as fresh frozen plasma, platelets, and whole blood together with tranexamic acid should be readily available in women with pre-eclampsia especially those with severe features with a D-dimer level of 3.58 µg/ml and above during delivery as they are at high risk of developing PPH.

Cut-off value of glycated hemoglobin A1c for detecting diabetic retinopathy in the Chinese population

BACKGROUND Glycated hemoglobin A1c(HbA1c)is considered the most suitable for diabetes mellitus diagnosis due to its accuracy and convenience.However,the effect of HbA1c on diabetic retinopathy(DR)in the Han and Korean populations in Jilin,China,remains inconclusive.AIM To determine the best cut-off of HbA1c for diagnosing DR among the Chinese.METHODS This cross-sectional study included 1933 participants from the Yanbian area of Jilin Province,China.Trained investigators employed a questionnaire-based survey,physical examination,laboratory tests,and fundus photography for the investigation.The best cut-off value for HbA1c was established via the receiver operating characteristic curve.The factors associated with HbA1c-associated risk factors were determined via linear regression.RESULTS The analysis included 887 eligible Chinese Han and Korean participants,591 of whom were assigned randomly to the training set and 296 to the validation set.The prevalence of DR was 3.27% in the total population.HbA1c of 6.2% was the best cut-off value in the training set,while it was 5.9% in the validation set.In both Chinese Han and Korean populations,an HbA1c level of 6.2% was the best cut-off value.The optimal cut-off values of fasting blood glucose(FBG)≥7 mmol/L and<7 mmol/L were 8.1% and 6.2% respectively in Han populations,while those in Korean populations were 6.9%and 5.3%,respectively.Age,body mass index,and FBG were determined as the risk factors impacting HbA1c levels.CONCLUSION HbA1c may serve as a useful diagnostic indicator for DR.An HbA1c level of 6.2% may be an appropriate cut-off value for DR detection in the Chinese population.

Analysis of the Role of D-Dimer,Interleukin-6,and Interleukin-18 in Differential Diagnosis of Pediatric Refractory Mycoplasma pneumoniae Pneumonia

Objective:To analyze the value of D-dimer(D-D),interleukin-6(IL-6),and IL-18 in the differential diagnosis of children with refractory Mycoplasma pneumoniae pneumonia(RMPP).Methods:The medical records of 92 children with Mycoplasma pneumoniae pneumonia(MPP)treated in the hospital were selected for retrospective analysis from January 2023 to January 2024.After comprehensive examinations such as computed tomography examination of the chest,48 children with general Mycoplasma pneumoniae pneumonia(GMPP)were put in the GMPP group and 44 children with RMPP were grouped in the RMPP group.The IL-6,IL-18,and D-D levels were compared between the two groups,and the receiver operating characteristic(ROC)curves were plotted to analyze their value for differential diagnosis of RMPP.Results:The levels of IL-6,IL-18,and D-D in the RMPP group were higher than those in the GMPP group(P<0.05);the ROC curves showed that the specificity of the differential diagnosis of IL-6,IL-18,and D-D was higher,and their diagnostic value was significant.Conclusion:Determination of IL-6,IL-18,and D-D levels in children with MPP can further diagnose the children’s condition,which can help physicians formulate targeted treatment plans,and is of great significance to the improvement of the children’s condition,which is worthy of attention.

Correlation Analysis Between Changes of D-Dimer Level and Rheumatoid Arthritis Complicated with Interstitial Lung Disease

Objective:To explore the correlation between the change of D-dimer level and rheumatoid arthritis complicated with interstitial lung disease.Methods:From January 2022 to February 2024,20 rheumatoid arthritis patients complicated with interstitial lung disease(interstitial lung disease group),20 rheumatoid arthritis patients without interstitial lung disease(without interstitial lung disease group),and 20 healthy people(control group)in Xijing Hospital were selected for this study.The fasting venous blood of the three groups of subjects was collected and their D-dimer,C-reactive protein(CRP),rheumatoid factor(RF),and erythrocyte sedimentation rate(ESR)were detected.Subsequently,the correlation between each index and rheumatoid arthritis complicated with interstitial lung disease was analyzed.Results:The D-dimer level of the interstitial lung disease group was significantly higher than the other two groups(P<0.05).The D-dimer level of the group without interstitial lung disease was significantly higher than the control group(P<0.05).CRP levels in the interstitial lung disease group and the group without interstitial lung disease were significantly higher than those of the control group(P<0.05).The ESR and RF levels of the interstitial lung disease group were significantly higher than the other two groups(P<0.05).The levels of ESR and RF levels of the group without interstitial lung disease were significantly higher than the control group(P<0.05).Conclusion:D-dimer levels of rheumatoid arthritis patients are higher than those of healthy individuals,and those complicated with interstitial lung disease present even higher levels.This finding shows that there is a correlation between D-dimer levels and rheumatoid arthritis with interstitial lung disease,which may facilitate the evaluation and diagnosis of this disease.

Subseasonal Prediction of Early-summer Northeast Asian Cut-off Lows by BCC-CSM2-HR and GloSea5

Northeast Asian cut-off lows are crucial cyclonic systems that can bring temperature and precipitation extremes over large areas.Skillful subseasonal forecasting of Northeast Asian cut-off lows is of great importance.Using two dynamical forecasting systems,one from the Beijing Climate Center(BCC-CSM2-HR)and the other from the Met Office(GloSea5),this study assesses simulation ability and subseasonal prediction skill for early-summer Northeast Asian cut-off lows.Both models are shown to have good ability in representing the spatial structure of cut-off lows,but they underestimate the intensity.The skillful prediction time scales for cut-off low intensity are about 10.2 days for BCC-CSM2-HR and 11.4 days for GloSea5 in advance.Further examination shows that both models can essentially capture the initial Rossby wave train,rapid growth and decay processes responsible for the evolution of cut-off lows,but the models show weaker amplitudes for the three-stage processes.The underestimated simulated strength of both the Eurasian midlatitude and East Asian subtropical jets may lead to the weaker local eddy-mean flow interaction responsible for the cut-off low evolution.

凝血功能四项、FDP及D-Dimer检测在产后出血诊断中的应用分析

目的分析产后出血诊断中凝血功能四项、D-Dimer、FDP检测的应用。方法将100例于本院分娩产妇依据产后出血发生情况分为发生组和未发生组两组各50例,对所有产妇的TT、PT、APTT、FIB等凝血功能四项水平进行测定并分析,对D-dime、FDP水平进行测定并分析。结果分娩后,发生组的PT、APTT均长于未发生组(P<0.05),FIB水平低于未发生组(P<0.05)。分娩前后发生组的D-Dimer、FDP水平均高于未发生组(P<0.05)。分娩前后发生组的凝血功能四项、D-Dimer、FDP检测正常率均低于未发生组(P<0.05),异常率均高于未发生组(P<0.05)。结论产后出血诊断中凝血功能四项、D-Dimer、FDP检测的应用价值高。

PCT、IL-6与D-Dimer、TAT联合检测评估患者细菌感染程度和发生血栓风险的研究

探讨PCT、IL-6与D-Dimer、TAT联合检测在评估患者细菌感染程度和发生血栓风险的临床应用价值。方法 收集和选用无血栓背景的肺部细菌感染患者样本55例、脓毒血症患者样本66例、无细菌感染的样本10例,总样本量共131例。采用化学发光法(CLIA)检测患者血浆中PCT、IL-6与D-Dimer、TAT的表达水平,比较4中血浆标志物的表达差异。结果 PCT和IL-6联合检测在细菌感染的诊断价值高于PCT和IL-6单项指标的检测价值。D-Dimer和TAT联合检测在血栓形成风险的诊断价值高于D-Dimer和TAT单项指标的检测价值。结论 细菌感染的严重程度与血栓形成的风险呈正相关;采用PCT、IL-6与 D-Dimer、TAT四项联合检测,能同时评估患者细菌感染程度和发生血栓的风险,避免患者因细菌感染而发生血栓,对机体造成更大的伤害,起到早期预警、早期干预、早期治疗的作用。

A new DRIE cut-off material in SOG MEMS process

The silicon on glasses process is a common preparation method of micro-electro-mechanical system inertial devices,which can realize the processing of thick silicon structures.This paper proposes that indium tin oxides(ITO)film can serve as a deep silicon etching cut-off layer because ITO is less damaged under the attack of fluoride ions.ITO has good electrical conductivity and can absorb fluoride ions for silicon etching and reduce the reflection of fluoride ions,thus reducing the foot effect.The removal and release of ITO use an acidic solution,which does not damage the silicon structure.Therefore,the selection of the sacrificial layer has an excellent effect in maintaining the shape of the MEMS structure.This method is used in the preparation of MEMS accelerometers with a structure thickness of 100μm and a feature size of 4μm.The over-etching of the bottom of the silicon structure caused by the foot effect is negligible.The difference between the simulated value and the designed value of the device characteristic frequency is less than 5%.This indicates that ITO is an excellent deep silicon etch stopper material.

Utility of D-dimer in total joint arthroplasty

As the number of patients receiving total joint replacements continues to rise,considerable attention has been directed towards the early detection and prevention of postoperative complications.While D-dimer has long been studied as a diagnostic tool in venous thromboembolism(VTE),this assay has recently received considerable attention in the diagnosis of periprosthetic joint infection(PJI).D-dimer values are substantially elevated in the acute postoperative period after total joint arthroplasty,with levels often exceeding the standard institutional cutoff for VTE(500µg/L).The utility of D-dimer in detecting VTE after total joint replacement is currently limited,and more research to assess its value in the setting of contemporary prophylaxis protocols is warranted.Recent literature supports D-dimer as a good to excellent biomarker for the diagnosis of chronic PJI,especially when using serum sample technique.Providers should exercise caution when interpreting D-dimer levels in patients with inflammatory and hypercoagulability disorders,as the diagnostic value is decreased.The updated 2018 Musculoskeletal Infection Society criteria,which includes D-dimer levels>860µg/L as a minor criterion,may be the most accurate for diagnosing chronic PJI to date.Larger prospective trials with transparent lab testing protocols are needed to establish best assay practices and optimal cutoff values for D-dimer in the diagnosis of PJI.This review summarizes the most current literature on the value of D-dimer in total joint arthroplasty and elucidates areas for future progress.

Multifractal estimation of NMR T_(2) cut-off value in low-permeability rocks considering spectrum kurtosis: SMOTE-based oversampling integrated with machine learning

The transverse relaxation time (T_(2)) cut-off value plays a crucial role in nuclear magnetic resonance for identifying movable and immovable boundaries, evaluating permeability, and determining fluid saturation in petrophysical characterization of petroleum reservoirs. This study focuses on the systematic analysis of T_(2) spectra and T_(2) cut-off values in low-permeability reservoir rocks. Analysis of 36 low-permeability cores revealed a wide distribution of T_(2) cut-off values, ranging from 7 to 50 ms. Additionally, the T_(2) spectra exhibited multimodal characteristics, predominantly displaying unimodal and bimodal morphologies, with a few trimodal morphologies, which are inherently influenced by different pore types. Fractal characteristics of pore structure in fully water-saturated cores were captured through the T_(2) spectra, which were calculated using generalized fractal and multifractal theories. To augment the limited dataset of 36 cores, the synthetic minority oversampling technique was employed. Models for evaluating the T_(2) cut-off value were separately developed based on the classified T_(2) spectra, considering the number of peaks, and utilizing generalized fractal dimensions at the weight <0 and the singular intensity range. The underlying mechanism is that the singular intensity and generalized fractal dimensions at the weight <0 can detect the T_(2) spectral shift. However, the T_(2) spectral shift has negligible effects on multifractal spectrum function difference and generalized fractal dimensions at the weight >0. The primary objective of this work is to gain insights into the relationship between the kurtosis of the T_(2) spectrum and pore types, as well as to predict the T_(2) cut-off value of low-permeability rocks using machine learning and data augmentation techniques.

Lipoprotein (a) Cut-Off in Chronic Kidney Disease Patients with a History of Cardiovascular Disease in Center Hospital University Souro SANOU, Burkina Faso

Patients living with chronic kidney disease (CKD) are at high risk of cardiovascular events. Our aim in this study was to assess the cut-off value for lipoprotein (a) (Lp(a)) in CKD patients with a history of cardiovascular disease (CVD). This was a cross-sectional study. Variables including age, sex, history of CVD, body mass index and CKD stage, were collected during CKD patient’s first admission in the nephrology dialysis department. Blood samples were collected for quantitative determination of Lp(a) by immunoturbidimetric method. They were divided into two groups: CKD patients without history of CVD and CKD patients with history of CVD. Fisher’s exact test was used to assess associations with a significance level of 0.05%. Area under the curve (AUC) and new cut-off value for Lp(a) were identified by drawing Receiver Operating Characteristic (ROC) curve. A total of seventy CKD patients with median age of 43 years [minimum-maximum = 15 - 78 years] were included. Patients with history of CVD were 65.71% (46/70). New Lp(a) cut-off point in CKD patients with history of CVD was 66.50 nmol/L [sensitivity, 87.00%;specificity, 58.30%;AUC = 0.727;p = 0.000]. ROC curve demonstrated good performance of Lp(a) to screen CKD patients with history of CVD. Further research is needed to determine an LPA gene polymorphism’s contribution to increasing risk for CVD at each kidney disease stage.

D-Dimer对原发膜性肾病患者预后评价的研究

探讨D-Dimer对原发膜性肾病患者预后评价。方法 收集2022年3月~2023年3月于我院肾内科住院接受肾活检的明确原发性膜性肾病患者50例作为研究对象,观察其年龄(Age)、性别(Sex)、D-二聚体(D-Dimer)、24小时尿蛋白定量(24hUTP)、尿白蛋白/肌酐比值(ACR)、尿红细胞数(RBC)、纤维蛋白原降解产物(FDP)等数据,并选择正常体检者50例作为对照组,收集上述数据进行对比。经免疫治疗后对观察组患者进行预后随访(包括磷脂酶A2受体抗体(PLA2RAb)、D-Dimer、24hUTP、ACR、RBC、FDP等),进行统计分析。结果 与观察组比较,对照组D-Dimer、24hUTP、ACR、RBC、FDP水平较低,差异有统计学意义(P<0.05)。与治疗后比较,治疗前观察组血清PLA2RAb表达、D-Dimer、24hUTP、ACR、RBC、FDP水平较高,差异有统计学意义(P<0.05)。结论 D-Dimer水平检测有助于原发膜性肾病的诊断,具有检测成本低、方便快速等更好的应用价值。

不同检测系统D-二聚体内源性干扰物最大抗干扰能力分析

目的对不同检测系统的D-二聚体检测时可接受的最大干扰物浓度进行分析、比较。方法随机收集50份患者样本,利用SYSMEX干扰物检测试剂盒4种干扰物胆红素F、胆红素C、溶血血红蛋白、乳糜分别与患者血浆按一定比例稀释,稀释后血浆所含干扰物质浓度与两种检测系统试剂说明书中抗干扰物最大浓度接近,分别在两种检测系统上机检测。结果当干扰物胆红素F浓度达到D-dimer HS及AcuSTAR D-dimer两种检测系统抗干扰Max浓度时,相对偏差<10%的结果占比分别为26%、46%;当干扰物胆红素C浓度达到D-dimer HS及AcuSTAR D-dimer两种检测系统抗干扰Max浓度时,相对偏差<10%的结果占比分别为18%、86%;当干扰物溶血血红蛋白浓度达到D-dimer HS及AcuSTAR D-dimer两种检测系统抗干扰Max浓度时,相对偏差<10%的结果占比分别为44%、88%;当干扰物乳糜浓度达到D-dimer HS及AcuSTAR D-dimer两种检测系统抗干扰Max浓度时,相对偏差<10%的结果占比分别为30%、58%。结论在检测D-二聚体时化学发光法抵抗高浓度内源性干扰物质能力优于免疫比浊法。

血栓前状态标志物F1+2、TAT、AT-Ⅲ、D-Dimer对早期复发性流产的预测价值

【目的】探讨血栓前状态分子标志物:凝血酶原片段F1+2(F1+2)、凝血酶-抗凝血酶Ⅲ复合物(TAT)、抗凝血酶Ⅲ(AT-Ⅲ)、D-二聚体(D-Dimer)与早期复发性流产(RSA)的关系,及各分子标志物对血栓前状态(PTS)引起的RSA的诊断价值。【方法】比较103例RSA已孕者(AEP组)、103例有RSA病史现未孕者(ANP组)及40例正常早孕者(NEP组)及40例健康未孕者(NNP组)血清中F1+2、TAT、AT-Ⅲ、D-Dimer水平;并以ROC曲线方法判断PTS引起的RSA发生时以上各个指标的最佳临界值。【结果】1.ANP组血浆F1+2、D-Dimer水平显著高于NNP组,两者间差异有显著性(P<0.008);而且流产3次者较2次者指标水平高,差别有统计学意义(P<0.0167)。F1+2与D-Dimer判断RSA未孕患者存在血栓前状态的最佳筛查界值分别为55.11nmol/L(AUC=0.767)及233.50μg/L(AUC=0.636)。2.ANP组血浆TAT水平高于NNP组,AT-Ⅲ水平低于NNP组,但其差别无统计学意义(P>0.008)。AEP组血浆F1+2、TAT、D-Dimer水平高于NEP组,AT-Ⅲ水平低于NEP组,但其差别无统计学意义(P>0.008)。【结论】RSA与PTS存在相关性;RSA患者在孕前已经表现为PTS,PTS的标志物F1+2、D-Dimer可用于RSA未孕人群流产原因的筛查,其水平越高,流产可能性越大。

D-dimer、C反应蛋白和脑钠肽在肺栓塞患者的临床诊断价值及灵敏度、特异度和准确度对比研究

目的探讨D-Dimer、C-反应蛋白和脑钠肽在肺栓塞患者的临床诊断价值以及灵敏度、特异度和准确度对比研究。方法随机选取2013年5月~2014年5月间收治的大面积肺栓塞患者45例,小面积肺栓塞患者45例,并选取同期体检的健康者45例作为对照组。检测并比较治疗前后各组血浆D-Dimer、CRP和BNP水平。采用Logistic分析患者血浆D-Dimer、CRP和BNP水平与肺栓塞发生的相关性。以肺栓塞检验金标准(肺动脉造影)分别与D-dimer检验、CRP检验和BNP检验法做配对卡方检验,计算Ddimer检验、CRP检验和BNP检验3种检测方法的灵敏度、特异度和准确度,并比较其差异。结果治疗前,大面积组和小面积组肺栓塞D-Dimer、CRP和BNP水平均显著高于对照组(P<0.05);大面积组D-Dimer、CRP和BNP水平也明显高于小面积组(P<0.05)。治疗后,大面积组和小面积患者血浆D-Dimer、CRP和BNP水平明显下降(P<0.05),且与正常对照组比较,差异无统计学意义。Logistic分析结果表明,血浆D-Dimer、CRP和BNP水平与肺栓塞的发生呈正相关性(r=3.11,P<0.05;r=4.36,P<0.05;r=2.86,P<0.05)。D-Dimer检测、CRP检测和BNP检测方法在检测灵敏度、特异度和准确度方面差异无统计学意义。结论 D-dimer、C-反应蛋白和脑钠肽水平与肺栓塞的发生呈正相关性,是评估患者病情的重要指标,具有十分重要临床指导价值。

D-dimer与纤维蛋白原比值在静脉血栓栓塞诊断中的应用价值

目的探讨D-dimer、纤维蛋白原(Fg)、D-dimer与Fg比值(D/F)以及C反应蛋白(CRP)在静脉血栓栓塞(VTE)中的临床诊断价值。方法对民航总医院就诊的221例急诊与住院疑似VTE患者D-dimer、Fg及CRP进行检测,并计算D/F,采用胸部CT、病理诊断等对疑似患者明确诊断。结果 VTE人群的Fg水平低于非VTE人群(t=6.421,P<0.01),而D-dimer、D/F、CRP均显著增高;在VTE诊断灵敏度达到100%时,D/F特异度与阳性预测值(PPV)(73.2%,56.4%)优于使用单独使用D-dimer(47.0%,39.6%);ROC曲线分析表明上述指标在VTE诊断中的准确性顺序为D/F>D-dimer>CRP。结论采用D/F可提高VTE临床诊断的特异性,可作为一项有益的指标应用于VTE辅助诊断。