[Enhance the management of cardiac arrest and improve the prognosis of the patients].

Cardiac arrest is one of the major public health problems with sudden onset, high mortality and high disability rate. The prevalence of cardiovascular disease continues to rise and the burden of cardiac arrest is increasing in China. It is of great significance to explore more effective prevention and treatment measures to improve the prognosis of patients with cardiac arrest. This article discusses the relevant progress on the treatment ability of emergency and critical cardiovascular diseases, medicines and technologies for cardiac arrest care, and registry studies of cardiac arrest, to further promote the effective improvement of key capacities at various stages of the prevention and treatment of cardiac arrest in China.

[Predictive value of ultrasound-guided anesthesia injection in arthroscopy for borderline developmental dysplasia of the hip].

Objective: To evaluate the value of ultrasound-guided intra-articular anesthetic injection in predicting postoperative outcomes for borderline developmental hip dysplasia (BDDH). Methods: A follow-up study. The clinical data of 37 BDDH patients who received ultrasound-guided intra-articular anesthetic injection and arthroscopic examination in the Department of Sports Medicine, Senior Department of Orthopedics, the Fourth Medical Center of PLA General Hospital from May 2018 to February 2021 were retrospectively analyzed. Among them, there were 17 males and 20 females with a mean age of (37.9±12.8) years. All patients underwent ultrasound-guided intra-articular anesthetic injection prior to arthroscopy, and were evaluated with hip physical examination before and after injection, as well as before and after arthroscopy, in order to obtain the visual analog score (VAS) of pain for seven assessments. The total VAS score was calculated based on these evaluations. Follow-up was conducted for at least 12 months. The effective rate of injection referred to the ratio of the improvement of VAS score after anesthetic injection to the total VAS score before injection. Pearson correlation analysis and Bland-Altman analysis were used to test the correlation between modified Harris hip score (mHHS) after ultrasound-guided intra-articular anesthetic injection and mHHS score after arthroscopic surgery. A binary logistic regression model was established to analyze the substantial clinical benefit (SCB) for patients. Following the logistic regression analysis, a receiver operating characteristic (ROC) curve was constructed to evaluate the predictive power of ultrasound-guided intra-articular anesthetic injection in achieving SCB in those patients. The optimal cut-off value for injection efficacy was determined based on the ROC curve when SCB was achieved. Results: The follow-up time for all patients was (26.3±7.6) months. After anesthetic injection for 20 minutes, the total VAS score of pain [M(Q1,Q3)] decreased from 13(8,23) points before injection to 1(0,4) points; and the mHHS score [M(Q1,Q3)] increased from 60(46,70) points before arthroscopy to 90(84,96) points after, with statistically significant differences before and after injection and before and after arthroscopy (both P<0.001). Pearson correlation analysis showed that the mHHS score after intra-articular anesthetic injection was positively correlated with the mHHS score after surgery (r=0.961, P<0.001). The area under the ROC curve for predicting SCB after arthroscopy with ultrasound-guided intra-articular anesthetic injection was 0.769 (95%CI: 0.561-0.976), the Youden index was 0.663, the cut-off value was 0.569 2, the sensitivity was 96.3%, and the specificity was 70.0%. Conclusions: The results of ultrasound-guided intra-articular anesthetic injection before arthroscopy can indicate the presence of intra-articular lesions, and the degree of pain relief after injection is proportional to the functional recovery after arthroscopy. Patients with intra-articular anesthetic injection efficacy>56.92% have better results in hip arthroscopy.

[Clinical efficacy of the treatment of bilateral gluteal muscle contracture by inside-out iliotibial band release under arthroscopy in the supine position].

Objective: To investigate the clinical efficacy of bilateral gluteal muscle contracture treated with inside-out iliotibial band release under arthroscopy in the supine position. Methods: A prospective non-randomized controlled trial. Forty-six patients admitted to the Department of Sports Medicine, Senior Department of Orthopedics, the Fourth Medical Center of PLA General Hospital from April 2021 to August 2022 for bilateral gluteal muscle contracture and proposed surgical treatment were enrolled. The subjects were divided into two groups according to the preferred surgical protocols of the patients: the supine position group was treated with inside-out iliotibial band release under arthroscopy in the supine position, and the operation in lateral position group was carried out with outside-in iliotibial band release under arthroscopy in the lateral position. The total duration of non-surgical operations and the total duration of surgical operations were recorded for all patients. The gluteal muscle contracture disability scale within 3 days before surgery and at least 2 months after surgery were compared between the two groups, and the occurrence of complications between the two groups was compared too. Results: There were 26 cases in the supine position group, 11 males and 15 females with a mean age of (31.8±7.3) years; and there were 20 cases in the lateral position group, 7 males and 13 females with a mean age of (30.6±6.3) years. The differences in gender, age, body mass index (BMI) and postoperative follow-up time between the two groups were not statistically significant (all P>0.05). The total duration of non-surgical operations was shorter in the supine position group than in the lateral position group [(47.9±10.4) min vs (63.9±7.5) min, P<0.001]. There was no statistically significant difference in the total duration of surgical operations between the supine position group and the lateral position group [31.0(27.0, 43.5) min vs 33.0(24.8, 38.0) min, P>0.05]. The postoperative gluteal muscle contracture disability scales were significantly improved in both the supine position and lateral position groups when compared with those before the operation [93.0 (85.0, 98.0) vs 61.0 (50.5, 66.8), P<0.001 and 88.5±6.9 vs 63.6±9.6, P<0.001, respectively]. There was no statistically significant difference in the gluteal muscle contracture disability scale between the supine position and lateral position groups before and 2 months after surgery [59.3±11.9 vs 63.6±9.6 and 93.0 (85.0, 98.0) vs 89.5(84.0, 94.8), both P>0.05, respectively]. Two patients in each group developed subcutaneous hematoma after surgery, and all of them resolved within 2 weeks after surgery, the difference in complication incidence rate was not statistically significant (P>0.05). No postoperative complications such as fat liquefaction in the operated area, infection, decreased hip abductor muscle strength or nerve injury in the lower extremity were observed in both groups. Conclusion: The treatment of bilateral gluteal muscle contracture by inside-out iliotibial band release under arthroscopy in the supine position can effectively improve clinical efficiency, with definite efficacy, and it is an operative program worth promoting.

[Outcomes of fluoroscopy-free hip arthroscopy technique in the treatment of femoroacetabular impingement syndrome].

Objective: To evaluate the effect of fluoroscopy-free technique in the arthroscopic treatment of femoroacetabular impingement syndrome (FAIS). Methods: A retrospective cohort study. Clinical data of FAI patients treated with hip arthroscopy in the No.4 Medical Center, PLA General Hospital from October 2018 to December 2021 were retrospectively analyzed. The patients were divided into two groups according to the surgical procedure: the fluoroscopy group and the fluoroscopy-free group. The operation time and modified Harris hip score (mHHS), international hip outcome tool (iHOT12) and visual analogue scale (VAS) of hip joint pain before and after the operation were observed and compared between the two groups. And the incidence of surgical complications in the two groups were compared too. Results: A total of 460 patients (213 males and 247 females) [aged (32.6±8.3) years (15-67 years)] with valid follow-up were included in this study. There were 275 cases in the fluoroscopy-free group and 185 cases in the fluoroscopy group. The operation time was shorter in the fluoroscopy-free group when compared with that in the fluoroscopy group, and the difference was statistically significant [(93.36±12.54) min vs (115.62±6.03) min, P<0.001]. In both groups, the VAS scores decreased and the mHHS scores and iHOT12 scores improved significantly at the last follow-up when compared with those before the operation (all P<0.001); however, there was no significant difference in the scores between the two groups (all P>0.05). The complication rate in the fluoroscopy-free group was 10.18% (28/275), and it was 10.81%(20/185) in the fluoroscopy group (P=0.829). Conclusion: Fluoroscopy-free hip arthroscopy technique for FAI can avoid radiation and shorten the operation time, but it does not increase the incidence of complications with reliable clinical outcomes.

[Analytical performance verification protocols and performance specifications of platelet-dependent von Willebrand factor activity testing].

Objective: To investigate the analytical performance verification protocols and performance specifications of platelet-dependent von Willebrand factor (VWF) activity testing (VWF:GPIbM) for clinical laboratories. Methods: According to Clinical Laboratory Standards Institute (CLSI) documents and National Health Standard of China, the performance verification of VWF:GPIbM was designed and implemented using Sysmex CS-5100 instrument and its corresponding reagents. (1) Precision verification: Two commercial quality control samples (with normal and low activity levels) and three plasma pools (with activity range from 5.0% to 150.0%) were prepared. Each sample was tested five times daily for five consecutive days. The coefficient of variation (CV) of intra-and inter-run precisions were calculated, and the precision evaluation criterion was set according to package inserts. (2) Trueness verification: The calibrator was diluted to five reference materials with activity values of 5.2%, 31.2%, 62.4%, 104.0% and 138.7%, and each reference material was tested five times daily for five consecutive days. The bias between the measured value and the reference value was calculated, and the trueness evaluation criterion was set according to the total allowable error. (3) Linearity verification: Ten pooled plasmas with theoretical value range from 3.6% to 160.4% were prepared for the linearity verification of two calibration curves set by the manufacturer (i.e. low range and normal range calibration curve). Each pooled plasma was tested three times in a single run. The slope and R2 of linear regression of mean of measured value and theoretical value, as well as bias, were calculated, and the linearity evaluation criterion was set according to National Health Standard of China and package inserts. (4) Limit of quantitation verification: The calibrator was diluted to two reference materials with activity values of 3.3% and 2.7%, and each material was tested twelve times. The limit of quantitation evaluation criterion was set according to CLSI document. Results: The CVs of intra-and inter-run were 1.0%-2.5% and 1.1%-2.6%, respectively. The biases of trueness verification were -0.4%, 1.0%, -2.6%, 0.3% and -2.7%, respectively. The linearity verification results of low range (3.6%-31.8%) and normal range (28.4%-160.4%) showed that the slopes of regression equation were 1.021 7 and 0.996 2, respectively, R2 were 0.993 5 and 0.993 9, respectively, and the biases with 0-1.8% and -10.1%-0 of plasmas met the criterion. The biases ranged from -0.4% to 0.3% of test results in the verification of limit of quantitation met the criterion. Conclusion: The verification results of VWF:GPIbM assay for precision, trueness, linearity and limit of quantification meet the performance requirements indicated in the package inserts and the criteria set in this study, which can be taken as a reference of performance verification for the clinical laboratories.

[Current status of CD34+cell enumeration assay in clinical laboratories and its improvement].

Objective: To investigate the current status and problems of CD34+ cell enumeration in clinical laboratories and provide suggestions for the development of quality improvement programs. Methods: A total of 101 laboratories participating in the national external quality assessment program of CD34+cell enumeration were surveyed. Questionnaires and quality assessment materials were distributed to collect information on assay methodology and testing results. Quality control requirements for CD34+cell enumeration were determined according to the international guidelines, and the compliance of the surveyed laboratories was analyzed. Testing results were analyzed in groups and compared with the College of American Pathologists (CAP) quality assessment data. Results: A total of 97 laboratories returned the questionnaires and 99 laboratories returned the results of quality assessment materials. The questionnaire data showed high compliance rates of quality control requirements such as gating protocols, pipetting methods, and the number of cells acquired (92.8%, 83.9%, and 82.5% respectively). However, these laboratories had relatively low compliance rates such as the use of whole blood quality control materials for internal quality control, selection of erythrocyte lysing reagents, sample processing method, whether to report absolute count results, and quality control of equipment (5.2 %, 28.9%, 39.2%, 46.4%, and 55.7%, respectively). Testing results demonstrated that the coefficient of variation (CV) of percent counts was similar to the CAP quality assessment data, but the CV of absolute counts was greater than the CAP quality assessment data. Conclusions: Clinical laboratories have poor compliance with some quality control requirements and the variability of absolute count results between different laboratories is not satisfactory. Therefore, it is recommended that clinical laboratories should strengthen the training related to the quality control of CD34+cell enumeration, especially the absolute counting.

[The value of soluble thrombomodulin in evaluating endothelial injury in patients with kidney disease].

Objective: To evaluate the value of soluble thrombomodulin (sTM) in evaluating endothelial injury in patients with kidney disease. Methods: One hundred and thirty-three patients who first visited the Department of Nephrology of Beijing hospital for various reasons from September 2020 to January 2021 and 130 healthy people were collected and divided into groups according to age, gender, primary disease, complications and so on. The differences of sTM and serum creatinine in patients with different diseases and renal disease stages were analyzed. Results: For patients with chronic kidney disease (CKD), sTM increased significantly with the decrease of renal function. The level of sTM in patients with CKD stage 1-5 was (0.013±0.007), (0.019±0.010), (0.022±0.008), (0.027±0.008), (0.033±0.006)TU/L, respectively (F=21.005,P<0.05). There was no significant difference in the level of sTM between patients with non-CKD urinary tract infection (0.013±0.009) TU/L and patients with stage 1 CKD (t=1.023, P>0.05). No matter whether the patients were complicated with infection or cardiovascular disease, there was no significant difference in sTM level under the condition of serum creatinine matching (all P>0.05). In 4 patients with acute renal injury, serum creatinine returned to normal after active treatment, but sTM did not decrease significantly. Correlation analysis showed that there was a positive correlation between sTM and serum creatinine (r=0.697, P<0.01). Conclusion: sTM can evaluate the renal function damage of patients with CKD more early, and the level of sTM in patients with renal disease is more related to the degree of endothelial damage.

[Clinical application of the simultaneous detection of methotrexate and 7-hydroxymethotrexate in the delayed elimination for pediatric acute lymphoblastic leukemia].

Objective: To discuss the application value of the simultaneous determination of methotrexate (MTX) and 7-hydroxymethotrexate (7-OHMTX) in the delayed elimination of MTX for pediatric acute lymphoblastic leukemia (ALL). Methods: Cross sectional study. A total of 97 children who received 192 high-dose MTX treatments cycles in Lu Daopei Hospital from April to August 2019 were enrolled. The peripheral blood was collected at 0,24,48 h after the end of MTX infusion and analyzed by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). One hundred and ninety-two MTX treatments were divided into a normal MTX elimination group (n=149) and delayed elimination group (n=43) according to the standard of delayed elimination and divided into 0-9 year old group (n=95), 10-14 group (n=50), 15-18 group (n=47) according to age. The comparisons of the C(MTX), C(7-OHMTX) between normal and delayed group was conducted as well as among different age groups. Receiver operator characteristic curve (ROC) of C(MTX-0h) and C(7-OHMTX-0h) was analyzed and the concentration corresponding to the maximum of the Youden index on the ROC was set as the warning value for delayed elimination. Correlation between the delayed elimination after the end of MTX infusion and toxicity was investigated and the percentage of delayed elimination was also analyzed. Results: The concentrations of MTX and 7-OHMTX were significantly higher in the delayed elimination group than the normal group. Immediately after infusion (0 h), a C(7-OHMTX-0h) of >17.8 µmol/L (sensitivity 97.7%, specificity 54.4%) and a C(MTX-0h) of >148.8 µmol/L (sensitivity 72.1%, specificity 84.6%) were found to be warning predictors of delayed elimination under the MTX treatment protocol. MTX delayed elimination was positively correlated with methotrexate-induced toxicities (r=0.58, P<0.01). The percentage of hepatotoxicity and nephrotoxicity was 32.6% and 37.2% in the delayed elimination group, which was significantly higher than normal group of 12.8% and 3.4% (P<0.05). No significant difference was found in other toxicities. There was significant difference in C(MTX) among different age groups but no significant difference in C(7-OHMTX). Conclusion: Simultaneously determination of MTX and 7-OHMTX in plasma by HPLC-MS/MS in childhood ALL patients can provide a reference for clinical individualized medicine and pharmacokinetic research.

[Association study of genetic variations in SLCO1B3 gene with prognosis in breast cancer patients treated with neoadjuvant chemotherapy of TA regimen].

Objective: To assess the association of single nucleotide polymorphisms (SNPs) in SLCO1B3 gene with prognosis of breast cancer (BC) patients treated with neoadjuvant chemotherapy of TA regimen (taxane and antharcycline drugs). Methods: 439 female BC patients were recruited and treated with neoadjuvant chemotherapy of TA regimen. A blood sample (2 ml) of peripheral blood was collected from each patient before chemotherapy. Tagging SNPs (tag-SNPs) were selected. We investigated the association of tag-SNPs with prognosis, by Sequenom Mass ARRAY system platform, characterizing tag-SNPs. The hazard ratio (HR) and 95% confidence interval (CI) for progression or death were calculated by multivariable-adjusted Cox regression model. Results: Seven tag-SNPs (rs11045689, rs200104106, rs3764006, rs3834935, rs4149117, rs7305323 and rs73241801) were selected for study. Compared with individuals carrying the rs11045689 GG genotype, individuals carrying rs11045689 AA genotype performed worse PFS and OS, with the HR (95% CI) for progression being 1.39 (1.11~1.75) and the HR (95% CI) for death being 1.38 (1.04~1.83). Compared with individuals carrying the rs73241801 CC genotype, individuals carrying rs73241801 TT genotype performed better OS (P=0.041), with the HR (95% CI) for death being 0.65 (0.44~0.94). The number of risk allele was significantly associated with PFS (P=0.012) and OS (P=0.017) of BC patients by accumulation analysis. Compared with individuals carrying one or less than one risk allele, individuals carrying four risk alleles performed worse PFS and OS, with the HR (95% CI) for progression being 1.37 (1.09~1.72) and the HR (95% CI) for death being 1.36 (1.02~1.81). Conclusion: The variations of rs11045689 and rs73241801 in SLCO1B3 gene were significantly associated with prognosis of BC patients treated with neoadjuvant chemotherapy of TA regimen, which might serve as biomarkers for predicting prognosis of BC patients treated with neoadjuvant chemotherapy.

[Study on commutability evaluation of reference materials for fibrinogen].

Objective: To discuss the commutability evaluation method of reference materials for fibrinogen measurement and evaluate the commutability of the Third WHO International Standard Fibrinogen Plasma (WHO 09/264), SSC/ISTH Secondary Coagulation Standard (SSC LOT4) and homemade reference materials (RM01, RM02) in order to provide suggestions on how to determine the suitable method of commutability evaluation and reliable traceability standard. Methods: The comparability of fibrinogen among different measurement systems were evaluated and WHO 09/264 was used to calibrate each system to improve the comparability if the comparability among different systems couldn't be accepted. Forty clinical samples and the reference materials randomly interspersed among the clinical samples were measured on Stago STA-R Evolution, Sysmex CS 5100, IL ACL TOP 700 simultaneously. Measurement results were pairwise analyzed by Deming regression and difference in bias approach according to the Clinical and Laboratory Standards Institute (CLSI) EP14-A3 protocol and the recommendations of the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) working group on commutability, respectively. Results: The comparability of fibrinogen measurement among common systems could not meet the criterion. WHO 09/264 could improve the agreement among different measurement systems. The prediction interval of Deming regression was affected by the comparability of measurement systems, resulting in unreliable results. The difference in bias approach was more suitable because its criterion was related to the medical requirements. WHO 09/264 was commutable between Stago and Sysmex, inconclusive between Stago and IL, Sysmex and IL (The calibration effectiveness of WHO 09/264 showed that it was commutable among the three measurement systems). SSC LOT4 was commutable between Stago and Sysmex, inconclusive between Stago and IL, Sysmex and IL. RM01 and RM02 were commutable between all systems pairs assessed by difference in bias approach. Conclusions: There are differences in the results of two commutability evaluation approaches. The difference in bias approach is recommended for commutability evaluation. WHO International Standard and homemade reference materials can be used as traceability standard for fibrinogen measurement.

[Analysis of internal quality control data of complete blood count from laboratories participating in national external quality assessment].

Objective: To investigate current status and problems of internal quality control (IQC) of complete blood count in China so as to perform IQC normally. Methods: The IQC data of complete blood count for five parameters were collected from laboratories participating in national external quality assessment during 2012-2017 (totally 12 times), including WBC, RBC, Hb, Hct and PLT. After confirmation of all data, data for the 12 times were analyzed as follows.The proportions of using different levels of quality control materials were calculated.The 25th, 50th, 75th, 90th percentiles CV of data collected for the 12 times were calculated respectively and the trends of CV were observed over time.The difference of CV among laboratories running three control levels was compared.The CV of each parameter in 2017 was compared with precision requirements based on biological variation, health standards and German Medical Association Directive; The proportions of laboratories using different control rules were calculated. Results: After invalid data was excluded from those IQC data of laboratories for the 12 times external quality assessment (up to 2 402, as low as 1 449) from 2012 to 2017, the residual data (up to 2 332, as low as 1 431, accounting for 96.0%-99.2%) was used for analysis. 61.9%-66.1%, 18.2%-23.6% and 14.3%-17.3% of laboratories ran one, two and three control levels respectively, and the proportions of laboratories running more than two control levels increased from 33.9% to 38.1%. The decrease trend of the 75th, 90th percentiles CV of WBC, RBC, Hb, Hct for three levels, PLT for normal level and the 90th percentiles CV of PLT low level had statistically significance over time (P<0.05); the decrease trend of the 75th percentiles CV of PLT low level and 75th, 90th percentiles CV of PLT high level had no statistically significance over time. The CV had significant difference between low and normal, low and high control level for WBC and PLT, while there were no difference between normal and high control levels. There were no significant difference of CV among three control levels for RBC, Hb, and Hct. Except for the CV of Hct low, normal level and PLT low level, 85% of laboratories for the other parameters could meet the minimum precision requirements based on biological variation; more than 85% laboratories met the requirements of health standards; except for the CV of PLT low level, more than 80% laboratories met the requirements of German Medical Association Directive. The proportion of laboratories using 1(3s)/2(2s) quality control rules increased from 59.2% to 76.0%. Conclusions: During the past 6 years, the CV for IQC has shown a decrease trend over time. However, the control level and quality control rules used by some laboratories do not meet management requirements. The CV of Hct and PLT in a few laboratories do not meet the minimum requirements of the health standards, and need to implement quality improvements fatherly.

Comparison between a novel human cortical bone screw and bioabsorbable interference screw for graft fixation of ACL reconstruction.

OBJECTIVE: To compare the mechanical behavior of a novel bioabsorbable cortical interference screw (BCIS) with bioabsorbable interference screw (BIS; Polylactate hydroxyapatite) used for anterior cruciate ligament (ACL) reconstruction in femoral and tibial fixation with doubled Achilles tendon graft in vitro. PATIENTS AND METHODS: 30 paired goat knee specimens were harvested from 15 male sheep aged 18 months. All soft tissues were stripped from the bones of 20 paired specimens, and the last 10 paired specimens were stripped all soft tissues besides ACL (femur-ACL-tibia complex). The Achilles tendon was harvested as graft for ACL reconstruction. The specimens were divided into several groups: BCIS femoral fixation (group A, n=10), BIS femoral fixation (group B, n=10), BCIS tibial fixation (group C, n=10), BIS tibial fixation (group D, n=10), Group E is femur-ACL-tibia complex (n=10). Cyclic loading test was performed from 50 to 250 N at 1 Hz for 1000 cycles and followed by a load-to-failure test at 25 mm/sec. A paired t-test was used to compare the biomechanical properties of group A, B, E and group C, D, E. RESULTS: No fixation structures failed during the cyclic phase. Cyclic displacement for group B was superior to group A, and showed statistically significant difference after 30, 100, 500, 1000 cycles. Group E got minimum cyclic displacements compared with group A and group B, and showed statistically significant difference after 500, 1000 cycles compared with group A. Cyclic displacement for group D was superior to group C, and showed statistically significant difference after 100, 500, 1000 cycles. Group E got minimum cyclic displacements compared with group C and group D, and showed statistically significant difference after 500,1000 cycles compared with group C. Regarding MFL, group A was superior to group B (572.10±111.12 N vs. 413.96±34.56 N, p=0.118), group E was superior to group A (599.74±85.45N vs. 572.10±111.12 N, p=0.992), and group C was superior to group D (802.88±240.07 N vs. 415.63±51.9 N, p<0.001), group C was superior to group E (802.88±240.07 N vs. 599.74±85.45 N, p=0.024). Regarding YL, group A was superior to group B (521.57±93.96 N vs. 366.99±44.66 N, p=0.109), group E was superior to group A (565.37±66.05 N vs. 521.57±93.96 N, p=0.952), and group C was superior to group D (735.63±242.91 N vs. 394.49±31.90 N, p<0.001), group C was superior to group E (735.63±242.91 N vs. 565.37±66.05 N, p=0.063). Regarding stiffness, group A was superior to group B (157.36±34.31 N/mm vs. 91.98±25.57 N/mm, p=0.001), group E was superior to group A (181.35±25.42 N vs. 157.36±34.31 N/mm, p=0.529), and group C was superior to group D (175.28±43.19 N/mm vs. 128.24±18.92 N/mm, p=0.032), group E was superior to group C (181.35±25.42 N/mm vs. 175.28±43.19 N/mm, p=0.995). CONCLUSIONS: In vitro, this experimental study suggested the biomechanical properties of novel bioabsorbable cortical interference screw (BCIS) were superior to bioabsorbable interference screw (BIS) used for femoral and tibial anterior cruciate ligament (ACL) reconstruction in a goat knee model.

Linear Elastic Fracture Mechanics Characterization of an Anisotropic Shale.

The existence of bedding planes in natural shale formations makes the fracture characterization remarkably complicated. To achieve a further understanding of the anisotropic crack extension behaviors of shale using a linear elastic fracture mechanics approach, four groups of three-point bending tests on Longmaxi shale from southeast Chongqing were conducted in this study with different bedding plane inclination angles. The fracture propagation paths were observed using a scanning electron microscope. The results indicated that cracks initiated along the bedding plane when the bedding plane inclination angle (i.e., the angle between the loading direction and the normal direction of the bedding plane) was relatively large; in contrast, cracks penetrated into the matrix and induced higher fracture toughness in cases with lower bedding plane inclination angle. Brittle fractures occurred in the tested shale, and the fracture strength was strongly dependent on the bedding plane inclination angle. Meanwhile, the stress field around the crack tip was analyzed theoretically. The results indicated that the crack tip stress field of anisotropic shale is not only determined by the stress intensity factor but also related to the elastic constants and bedding plane inclination angle. Furthermore, a criterion for determining whether a crack extends along the bedding plane was developed by distinguishing the differences in the strengths of the shale bedding and the matrix.

[Study and analysis of national current status and problems of anticoagulant proteins assay].

Objective: To investigate current status and problems of anticoagulant proteins assay in domestic laboratories so as to provide suggestions for implementing the standardization and quality improvement. Methods: Two hundred and seventy-four laboratories those had developed or prepared to do anticoagulant proteins assay were selected from one thousand and five hundred participants in the national coagulation screening External Quality Assessment(EQA) program by an internet survey and then a questionnaire and quality control materials were sent to them to carry out a further survey. The questionnaire information was analyzed statistically. The results of quality control materials were grouped by the reagents and the average, median, standard deviation(s), coefficient variation(CV) of each group were calculated. The deviations or percentage deviations were determined by comparing the results of each laboratory to the target defined as the peer-group median after exclusion of outliers, and then the pass rates were calculated based on the criterion of RCPA, DGKL and the allowable total error based on biological variation. Results: Two hundred and thirty-five questionnaires were collected. The number of laboratories testing antithrombin(AT), protein C(PC) and protein S(PS) activity were 194, 63 and 50 respectively. The instruments and reagents were mainly from abroad (more than 96%), the matching rate of which were above 94%. For AT, PC and PS activity testing, there were 30.4%, 33.3%, 34.0% of laboratories did not perform verification assays respectively, and 8.8%, 7.9%, 14.0% of laboratories did not renew calibration curve when the reagent lots were changed. 11.3%, 17.5%, 16.0% of laboratories didn't run internal quality control, and 34.9%, 26.9%, 21.4% of laboratories only performed a single level of quality control. 4.1% of laboratories set the reference intervals of AT activity according to different age groups, and the percentage of that of PC and PS activity were 1.6% and 2.0%. 16.0% of laboratories set the reference interval of PS activity by sex. For normal control materials, the CV of AT, PC and PS activity results were 5.7%-12.9%, 4.2%-7.7% and 18.4%-33.1% while the CV for abnormal level were 13.3%-38.3%, 6.1%-14.4% and 31.5%-34.5% respectively. The pass rate was different when it was judged by different criteria. A suitable criterion for each item should be selected according to the concentration level of quality control materials. Conclusion: The comparability between laboratory results are not satisfactory and in order to promote quality improvement, it is necessary to develop guidelines, organize trainings and establish a national EQA scheme.

Two-year follow-up of a Chinese sample at clinical high risk for psychosis: timeline of symptoms, help-seeking and conversion.

BACKGROUND: Chinese psychiatrists have gradually started to focus on those who are deemed to be at 'clinical high-risk (CHR)' for psychosis; however, it is still unknown how often those individuals identified as CHR from a different country background than previously studied would transition to psychosis. The objectives of this study are to examine baseline characteristics and the timing of symptom onset, help-seeking, or transition to psychosis over a 2-year period in China. METHOD: The presence of CHR was determined with the Structured Interview for Prodromal Syndromes (SIPS) at the participants' first visit to the mental health services. A total of 86 (of 117) CHR participants completed the clinical follow-up of at least 2 years (73.5%). Conversion was determined using the criteria of presence of psychotic symptoms (in SIPS). Analyses examined baseline demographic and clinical predictors of psychosis and trajectory of symptoms over time. Survival analysis (Kaplan-Meier) methods along with Log-rank tests were performed to illustrate the relationship of baseline data to either conversion or non-conversion over time. Cox regression was performed to identify baseline predictors of conversion by the 2-year follow-up. RESULTS: In total 25 (29.1%) of 86 completers transitioned to a psychotic disorder over the course of follow-up. Among the CHR sample, the mean time between attenuated symptom onset and professional help-seeking was about 4 months on average, and converters developed fully psychotic symptoms about 12 months after symptom onset. Compared with those CHR participants whose risk syndromes remitted over the course of the study, converters had significantly longer delays (p = 0.029) for their first visit to a professional in search of help. At baseline assessment, the conversion subgroup was younger, had poorer functioning, higher total SIPS positive symptom scores, longer duration of untreated prodromal symptoms, and were more often given psychosis-related diagnoses and subsequently prescribed antipsychotics in the clinic. CONCLUSIONS: Chinese CHR identified primarily by a novel clinical screening approach had a 2-year transition rate comparable with those of specialised help-seeking samples world-wide. Early clinical intervention with this functionally deteriorating clinical population who are suffering from attenuated psychotic symptoms, is a next step in applying the CHR construct in China.

[The effects and related risk factors on cataract surgery in Shandong province].

Objective: To explore the efficacy and related risk factors on cataract surgery in Shandong province. Methods: A total of 108 190 cataract surgeries which were reported from 17 cities of Shandong province during January 2013 to December were reviewed. The demographic information, preoperative examination, surgery related information (including date of surgery, surgical methods, and intraoperative complications), and postoperative situations (naked eye visual acuity, curative efficacy after three days, and postoperative complications) were reviewed. Wilcoxon signed-ranks, univariate and orderly multivariate Logistic regression analysis were used according to nature of the data. Results: There were 64 852 female patients (59.9 %) and 43 338 male patients (40.1%) in all 108 190 cases. About 36.5% patients (39 496 cases), the highest proportion, were 71 to 80 years of age, 31.26% patients (33 711 cases) were 61 to 70 years old and 13.6% patients (14 720 cases) were over 81 years old. Visual acuity increased significantly after surgery (Z=165.24, P<0.01). Simple factor Logistic regression analysis showed that preoperative corrected visual acuity less than 0.1 (OR=2.30 95%CI: 0.59 to 1.07), complications (OR=8.50,95% CI: 1.34 to 2.94), congenital cataract (OR=1.69, 95%CI: 0.22 to 0.83), extracapsular cataract extraction (OR=1.99, 95% CI:0.57 to 0.81), postoperative complications in three days (OR=7.46, 95% CI:1.77 to 2.25) were predictors of worse outcome after cataract surgery. Multivariate logistic regression analysis showed that the efficacy of cataract surgery were influenced by history of diabetes (OR=1.79, 95% CI: 0.46 to 0.71), history of hypertension (OR=3.49, 95% CI: 1.07-1.43), postoperative complications in three days (OR=3.91, 95% CI: 1.53 to 1.20) and extracapsular cataract extraction (OR=1.54, 95% CI: 0.20 to 0.66). Young male patients (OR=0.82, 95% CI:-0.28 to -0.12), normal preoperative intraocular pressure (OR=0.79, 95%CI: -0.38 to -0.10) and pupil (OR=0.42, 95% CI:-1.17 to -0.57) were predictors of better outcome. Conclusions: Visual acuity improved significantly after cataract surgery in Shandong province. The efficacy of cataract surgery was influenced by many factors. It is important to control systemic diseases and to choose modern operation method. (Chin J Ophthalmol, 2016, 52: 929-935).