Three problems about the concept of validity were discussed here,which is the evolution of concept of validity and its existing problems,a new understanding of validity and how to construct validity.During the development of the concept of validity,content validity,predictive validity,construct validity as well as concurrent validity were prevailing until the emergence of construct validity in which all aspects of validity were involved.To date,the bias we put on the concept of validity were mainly originated from the way by which we have taken concept of validity as a nomological network.Actually,the concept of validity is a ontological claim which is seriously based on reference and causality.We should establish a theory hypothesis,form a test,and confirm the measure attribute,so we could obtain the validity.

Objective:To explore the relationship between social support,well-being source and subjective well-being of city teachers.Methods:168 city teachers were measured by questionnaires of "Teacher's Well-being Source Scale" "Index of General Affect" "Life Satisfaction Scale" and "Teacher's Social Support Scale".Results:①Teacher's well-being source could predict teacher's subjective well-being.②Teacher's well-being source was a mediator factor between social support and subjective well-being.Conclusion:The social support from direct leader affect the subjective well-being with well-being source.

ve To increase the analytical efficacy and the sensitivity of determination of trace chloroform and tetrachloro-methane in water. Methods Headspace solid phase microextraction (HSSPME) analysis was applied to replace the traditional headspace method in determination of trace chloroform and tetrachloro-methane in water. Results The lowest detection limits were 0.05?g/L for chloroform and 0.005?g/L for tetrachloro-methane respec-tively. The precisions and accuracies all accorded with the requirements of determination. Conclusion The method of HSSPME was easy and rapid to operate, revealed reliable and accurate results and good practicability. It also showed higher sensitivity without any organic solvent, compared with that of traditional headspace method.

Leptospirosis is recognized as an important emerging zoonotic disease caused by pathogenic Leptospira spp.and has a serious impact on people′s health and animal husbandry.Therefore, it has attracted more and more attention.With the development of biotechnology, major breakthroughs have been made in the fields of pathogenicity, molecular epidemic features and evolution mechanism of Leptospira.In this review, we summarize progress in evolution and molecular typing of Leptospira at home and abroad in order to provide a reference for further research on molecular epidemiological surveillance and new vaccine development.

Objective To investigate the surgical selection of retinal detachment with myopic macular holes. Methods Management strategies were adopted according to the ocular symptoms of patients with high myopia involved in posterior chorioretinal atrophy, the colour showed by the bottom of macular holes and the shape of posterior staphyloma. Seventy-five eyes of 72 patients fulfilled the study criteria. The patients were followed up in an average of eight-month-observation and were divided into three groups: single 16% C2F6 gas tamponade (26 eyes of 26 patients) as group A,vitrectomy combined with 16% C2F6 gas tamponade (26 eyes of 23 patients) as group B and vitrectomy with silicon oil tamponade (23 eyes of 23 patients) as group C. Results 69.2%(18/26) of the macular holes were closed in group A, 73.1%(19/26)in group B and 87.0% (20/23) in group C after the primary surgery. Comparison of postoperative outcomes,macular hole closure rate was not significantly different among three groups (P= 0.3184). Conclusions It suggests that good anatomic retinal reattachment be achieved using any approach. However, the optimal surgical choice regarding of the personality case offered less surgical burden and more rapid visual rehabilitation to patients.

Objective: To discuss the clinical significance of antibacterial peptide LL-37 in the early diagnosis of patients with sepsis in emergency department. Methods: Forty patients diagnosed with sepsis in the emergency department of the Affiliated Hospital of Zunyi Medical College from December 2017 to March 2018 were enrolled as sepsis group. Twenty healthy volunteers were enrolled contemporaneously in our hospital at medical center as healthy control group. Peripheral blood was collected immediately after diagnosis in sepsis group or during physical examination in healthy control group. The expression of antibacterial peptide LL-37 was determined by enzyme-linked immunosorbent assay (ELISA). Meanwhile, serum procalcitonin (PCT) and C-reactive protein (CRP) levels were determined. The differences in antibacterial peptide LL-37, PCT and CRP levels between the two groups were compared. Pearson correlation method was used to analyze the correlation between antibacterial peptide LL-37, PCT and CRP. Receiver operating characteristic (ROC) curve was drawn, and the early individually or jointly diagnostic value of each detected index for sepsis was analyzed. Results: The levels of antimicrobial peptide LL-37, PCT and CRP in peripheral blood of sepsis group were significantly higher than those of healthy control group [LL-37 (μg/L): 1.34±0.69 vs. 0.10±0.06, PCT (μg/L): 46.67±39.51 vs. 0.03±0.02, CRP (mg/L): 129.68±49.83 vs. 3.16±2.85], with statistically significant differences (all P < 0.05). Pearson correlation analysis showed that the expression of antimicrobial peptide LL-37 was positively correlated with PCT and CRP levels (r₁ = 0.835, r₂ = 0.932, both P < 0.01). ROC curve analysis showed that the area under ROC curve (AUC) of LL-37, PCT and CRP for early diagnosis of sepsis was 0.885, 0.963 and 0.983, respectively, and the AUC of combined diagnosis of the three parameters was as high as 0.994, indicating that the value of combined diagnosis of sepsis was greater than that of single diagnosis; when the combined prediction probability of the three parameters was 0.92, the sensitivity was 97.5%, and the specificity was 95.0%. Conclusion Antibacterial peptide LL-37 has certain clinical value in early diagnosis of patients with sepsis, which can be used as early routine monitoring indicators for patients with early sepsis when combined with PCT and CRP.

Objective    To evaluate the data of preoperative aortic root CT angiography (CTA), compare it with two-dimensional transthoracic echocardiography and investigate the correlation of the two measurements with the actual intraoperative measurement data. Methods    Clinical data of 53 patients with aortic valve diseases who underwent aortic valve repair in our hospital from January 2018 to August 2020 were retrospectively analyzed, including 38 males and 15 females with an average age of 42.9±18.3 years ranging from 10 to 77 years. Preoperative two-dimensional transthoracic echocardiography (TTE) and aortic root CTA measurements were collected, including aortic valve annulus (AVA), aortic sinus (Sinus) and sino-tubular junction (STJ). In comparison with the intraoperative measurements during the aortic valve repair surgery, the consistency analysis was performed. Results    Both the preoperative echocardiography AVA measurements and the CT AVA measurements were positively correlated with the intraoperative AVA measurements (P<0.001). Compared with the echocardiography AVA data [correlation coefficient (ρ)=0.74, mean squared error (MSE)=12.78], the CT AVA data were more accurate and consistent with the intraoperative AVA measurements (ρ=0.95, MSE=2.72). CT AVA data had a higher correlation coefficient with the intraoperative measurements, compared to that of  the echocardiography AVA data (P<0.001). Conclusion    In comparison with two-dimensional transthoracic echocardiography, preoperative morphological evaluation of aortic root CTA is more consistent with the actual intraoperative measurements during aortic valve repair surgery.

The unique characteristics of the tumor microenvironment (TME) could be exploited to develop antitumor nanomedicine strategies. However, in many cases, the actual therapeutic effect is far from reaching our expectations due to the notable tumor heterogeneity. Given the amplified characteristics of TME regulated by vascular disrupting agents (VDAs), nanomedicines may achieve unexpected improved efficacy. Herein, we fabricate platelet membrane-fusogenic liposomes (PML/DP&PPa), namely "platesomes", which actively load the hypoxia-activated pro-prodrug DMG-PR104A (DP) and physically encapsulate the photosensitizer pyropheophorbide a (PPa). Considering the different stages of tumor vascular collapse and shutdown induced by a VDA combretastatin-A4 phosphate (CA4P), PML/DP&PPa is injected 3 h after intraperitoneal administration of CA4P. First, CA4P-mediated tumor hemorrhage amplifies the enhanced permeation and retention (EPR) effect, and the platesome-biological targeting further promotes the tumor accumulation of PML/DP&PPa. Besides, CA4P-induced vascular occlusion inhibits oxygen supply, followed by photodynamic therapy-caused acute tumor hypoxia. This prolonged extreme hypoxia contributes to the complete activation of DP and then high inhibitory effect on tumor growth and metastasis. Thus, such a combining strategy of artificially-regulated TME and bio-inspired platesomes pronouncedly improves tumor drug delivery and boosts tumor hypoxia-selective activation, and provides a preferable solution to high-efficiency cancer therapy.