Search

PURPOSE: To establish a machine-learning (ML) model based on coronary computed tomography angiography (CTA) images for evaluating myocardial ischemia in patients diagnosed with coronary atherosclerosis. METHODS: This retrospective analysis includes CTA images acquired from 110 patients. Among them, 58 have myocardial ischemia and 52 have normal myocardial blood supply. The patients are divided into training and test datasets with a ratio 7 : 3. Deep learning model-based CQK software is used to automatically segment myocardium on CTA images and extract texture features. Then, seven ML models are constructed to classify between myocardial ischemia and normal myocardial blood supply cases. Predictive performance and stability of the classifiers are determined by receiver operating characteristic curve with cross validation. The optimal ML model is then validated using an independent test dataset. RESULTS: Accuracy and areas under ROC curves (AUC) obtained from the support vector machine with extreme gradient boosting linear method are 0.821 and 0.777, respectively, while accuracy and AUC achieved by the neural network (NN) method are 0.818 and 0.757, respectively. The naive Bayes model yields the highest sensitivity (0.942), and the random forest model yields the highest specificity (0.85). The k-nearest neighbors model yields the lowest accuracy (0.74). Additionally, NN model demonstrates the lowest relative standard deviations (0.16 for accuracy and 0.08 for AUC) indicating the high stability of this model, and its AUC applying to the independent test dataset is 0.72. CONCLUSION: The NN model demonstrates the best performance in predicting myocardial ischemia using radiomics features computed from CTA images, which suggests that this ML model has promising potential in guiding clinical decision-making.

Pose® Method gait retraining has been claimed to modify running form and prevent injury. This study examined the running biomechanics before and after Pose® Method gait retraining. Fourteen runners underwent a 4-week Pose® Method gait retraining program delivered by a certified coach. Paired t-tests were employed to compare vertical average (VALR) and instantaneous loading rates (VILR), lower limb kinematics, footstrike angle and trunk flexion in the sagittal plane before and after the training. Kinetically, there were no significant differences in the VALR (p= 0.693) and VILR (p= 0.782) before and after the training. Kinematically, participants exhibited greater peak hip flexion (p= 0.008) and knee flexion (p= 0.003) during swing. Footstrikeangle also reduced significantly (p= 0.008), indicating a footstrike pattern switch from rearfoot strike to midfoot strike. There was no significant difference in the trunk flexion in the sagittal plane after training (p= 0.658). After a course of Pose® Method gait retraining, runners demonstrated a footstrike pattern switch and some kinematics changes at the hip and knee joint during swing. However, injury-related biomechanical markers (e.g., VALR and VILR) and the trunk kinematics remained similar after training. Runners may consider other gait retraining programs for impact loading reduction.

Objective To explore the feasibility of detecting cardiac microvessel with hypoglossal microcirculatory imaging system (abbreviated as microvision system), and explore its clinical value in diagnosis, treatment and prognosis evaluation of coronary microcirculation disorder. Methods Normal SD rats were used as research objects to detect the microcirculation of the main coronary artery and its branches with microvision system. Forty SD rats were randomly divided into two groups (20 each): myocardial infarction (MI) group and sham operation (Sham) group. The left anterior descending branch of coronary artery was ligated to make the model of myocardial infarction in MI group, and the sham group received the same treatment as in MI group but no ligation. The microvessel of left anterior descending branch was detected and analyzed in sham group and MI group before operation and 5, 10 and 20 minutes after operation by microvision system. The measured parameters included the total vessel density (TVD), the perfused vessel density (PVD), the proportion of perfused vessels (PPV), the microcirculatory flow index (MFI) and the heterogeneity index (HI). Results In microvision system, the left and right coronary vessels and their branches in the normal rat heart were clearly visible, the blood flow perfusion was continuous, and the blood vessels were dense and evenly distributed. In MI group, the longer the ligation time, the more blurred the vein of the microvessel. Furthermore, the blood flow was interrupted and the vessels were non-uniform distribution. The microcirculation was invisible and blood flow disappeared at 20min time point after infarction. Compared with that at 5min time point, TVD, PVD, PPV and MFI decreased, while HI increased at 10min and 20min time points (P

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The Spike protein that mediates coronavirus entry into host cells is a major target for COVID-19 vaccines and antibody therapeutics. However, multiple variants of SARS-CoV-2 have emerged, which may potentially compromise vaccine effectiveness. Using a pseudovirus-based assay, we evaluated SARS-CoV-2 cell entry mediated by the viral Spike B.1.617 and B.1.1.7 variants. We also compared the neutralization ability of monoclonal antibodies from convalescent sera and neutralizing antibodies (NAbs) elicited by CoronaVac (inactivated vaccine) and ZF2001 (RBD-subunit vaccine) against B.1.617 and B.1.1.7 variants. Our results showed that, compared to D614G and B.1.1.7 variants, B.1.617 shows enhanced viral entry and membrane fusion, as well as more resistant to antibody neutralization. These findings have important implications for understanding viral infectivity and for immunization policy against SARS-CoV-2 variants.

Objective MicroRNA-122 (miR-122) has been identified as a biomarker of liver diseases. However, the miR-122 detection accuracy in patients with hepatocellular carcinoma (HCC) associated with hepatitis C virus (HCV) is inconclusive. Methods We conducted a systematic literature search of Web of Science, Cochrane Library, PubMed, and Embase to identify studies related to the diagnostic value of miR-122 in HCV-related HCC. We analyzed the results and validated them using data from the Cancer Genome Atlas (TCGA). Results Six articles were included in this meta-analysis, comprising 354 cases and 420 controls. The pooled specificity, sensitivity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and area under the curve were 0.87, 0.83, 5.1, 0.16, 32, and 0.92, respectively. Additional sub-group analyses showed that results for plasma were more sensitive than those for serum. In addition, miR-122 was better at distinguishing between HCV-associated HCC and healthy people or those with HCV than between those with HCV-associated HCC and HCV-related cirrhosis. Small samples (≤100) had better diagnostic odds ratios than larger samples (>100). Analysis of data from TCGA confirmed that miRNA-122 had a high diagnostic value. Conclusion This meta-analysis demonstrates that miR-122 may be a useful diagnostic biomarker for HCV-associated HCC.

Running-related injuries among trail runners are very common and footwear selection may modulate the injury risk. However, most previous studies were conducted in a laboratory environment. The objective of this study was to examine the effects of two contrasting footwear designs, minimalist (MIN) and maximalist shoes (MAX), on the running biomechanics of trail runners during running on a natural trail. Eighteen habitual rearfoot strike trail runners completed level, uphill and downhill running at their preferred speeds in both shod conditions. Peak tibial acceleration, strike index and footstrike pattern were compared between the two footwear and slopes. Interactions of footwear and slope were not detected for all the selected variables. There was no significant effect from footwear (

To detect the effects and mechanism of asprosin (Asp) and spartin on the injury of mice cardiac microvascular endothelial cells (CMECs) induced by high glucose.The cultured CMECs were divided into 2 groups, one group is normal group (5.5 mmol/L glucose in the medium) and another is HG group (30 mmol/L glucose in the medium). Real-time PCR (qRT-PCR) and Western blot were respectively used to detect the mRNA level of spastic paraplegia 20 (SPG20) and protein expression of spartin in CMECs. Upregulation or downregulation of the expression of spartin was achieved via transfection with adenovirus (Ad) or small interfering RNA (siRNA) respectively. CMECs with downregulation of spartin expression were firstly treated with anti-oxidant N-acetylcysteine (NAC) or Asp respectively for 48 h, and then were interfered with 30 mmol/L glucose for 24 h afterward. The apoptosis of cell was detected by flow cytometry. Nitric oxide (NO) production was detected by NO probe and ELISA kit. The intracellular reactive oxygen species (ROS) levels were tested by DHE staining and ELISA kit. Type 2 diabetic model mice were established and then divided into T2DM group and T2DM+Asp group. After the model mice were established successfully (random blood glucose was more than 16.7 mmol/L), Asp (1 μg/g) was intraperitoneally injected once a day. After 2 weeks, mice echocardiography was performed to test cardiac diastolic function. The integrity of the microvascular endothelium was observed by scanning electron microscopy.Compared with the normal group, the mRNA level ofAsp can inhibit oxidative stress in mice CMECs through upregulating spartin signaling pathway, thereby alleviating the damage of microvascular endothelium in diabetic heart.

Cell lysis, where cellular material is released, is the basis for the separation and purification of cell contents, biochemical analysis, and other related experiments. It is also a key step in molecular, real-time, and cancer diagnoses as well as in the drug screening of pathogens. The current methods of lysing cells have several limitations, such as damage to the activity of cellular components, the need for a large number of cell samples, time-consuming processes, and the danger of high voltage. Therefore, a simple, fast, and efficient method for the manipulation of micro-volume cells or for single cell lysis is significant for further scientific research and practical application. In this study, a new low-voltage controllable method for cell lysis was established, and a corresponding microfluidic chip was developed. Simple, efficient and rapid micro-volume cells and single cell lysis were successfully achieved under a low-voltage alternating current with a voltage of 16 Vp-p and frequency of 10 kHz. The lysis process was investigated in detail by separately labelling the whole cell, cytoplasm, and nucleus using fluorescent proteins, which indicated that the whole cell was completely lysed. Analysis of voltage and frequency effects revealed that a higher voltage and optimized frequency enhanced the cell lysis efficiency. The presented study provides a new strategy for the lysis of micro-volume cells or a single cell, which is valuable for on-chip real-time diagnostics and point of care (POC) applications.

The cleaning vehicle is a special equipment for real-time detection and cleaning of the track. To ensure normal operation of the cleaning vehicle, we need to establish a remote monitoring system to collect all the state parameters of the entire cleaning vehicle through sensors to monitor them in real time. According to the parameters collected by sensors, we can evaluate the state of the vehicle's working condition and give corresponding treatment suggestions. The system collects various status parameters of the cleaning vehicle through STM32. After storing the data into the database, it uses VC++ to establish man-machine interface and give corresponding processing recommendations, making the vehicle more reliable and more intelligent.

Due to the narrow rail web and uneven rail surface, there are flaw misjudgment of rail web and rail base, clutter appearing and low detection accuracy in the process of flaw detection for slot track. To solve these problems, this paper analyze and design the parameters of 0 ° probe crystal, 0 ° + 37 ° combination probe plexiglass wedge and the skew offset angle and the incident point of oblique 70 ° probe based on the principle of ultrasonic non-destructive testing. By doing the flaw detection experiment on the damage block of slot track, it is verified that the new slot track ultrasonic probe has a good flaw detection effect, which provides theoretical and technical support for slot track ultrasonic flaw detector.

This paper focuses on biofilms of Lactobacillus spp. - a type of normal flora isolated from healthy human vaginas of women of childbearing age; thereupon, it broadens the research scope of investigation of vaginal normal flora. The static slide culture method was adopted to foster biofilms, marked by specific fluorescence staining. Laser scanning confocal and scanning electron microscopy were used to observe the microstructure of the biofilms. Photographs taken from the microstructure were analysed to calculate the density of the biofilms. The body of Lactobacillus spp., though red, turned yellow when interacting with the green extracellular polysaccharides. The structure of the biofilm and aquaporin within the biofilm were imaged. Lactobacillus density increases over time. This study provides convincing evidence that Lactobacillus can form biofilms and grow over time in vitro. This finding establishes an important and necessary condition for selecting proper strains for the pharmaceutics of vaginal ecology.

To study the genetic stability of Panax quinquefolium after introduced into China for 30 years, the samples of P. quinquefolium from 14 regions of China were studied. RAPD molecular marker technology was applied in this research, and POPGEN32 data analysis and NTSYS2. 10 cluster diagram were used to analyze the data. The results showed that there are abundant genetic diversity in the ginseng samples. There were 81 polymorphic bands based on the 13 random primers. The polymorphism was 83.51%, the effective number of alleles (N(e)) was 1.456 7; Nei's gene diversity index (H) was 0.274 8; Shannon's diversity index (H(o)) was 0.419 4. The clustering analyses indicated that P. quinquefolium and P. ginseng were classified into two obvious groups, especially, it was also found that the P. quinquefolium could be divided into two obvious groups based on whether the P. ginseng was cultivated in the same region or not, but it was thought that there was not genetically a qualitative difference. Thus it suggests that a good breeding field should be established in Jilin Province of China for the germplasm purification.

The qacA/B genes are found in Staphylococcus aureus and confer resistance to various antiseptics and disinfectants. Herein, the prevalence of the qacA/B genes in methicillin-resistant S. aureus (MRSA) and methicillin-sensitive S. aureus (MSSA) was investigated. Molecular typing systems were used to analyse the relatedness of these qacA/B-positive strains. 176 six strains of clinically isolated S. aureus were collected between July, 2008 and June, 2010. The strains carrying the qacA/B genes were characterised by pulse-field gel electrophoresis (PFGE) typing, Staphylococcus protein A (spa) typing, Panton-Valentine leucocidin (pvl) polymerase chain reaction (PCR) detection, staphylococcal chromosomal cassette (SCC) mec typing, and antimicrobial resistance profiles. Strains carrying the qacA/B genes composed 9.1% of the strains isolated, but the incidence of qacA/B genes in MRSA strains was significantly higher than that in MSSA strains (14.6 versus 4.3%, p < 0.05). Additionally, two predominant PFGE (B and A) and spa types (t037 and t042) were identified along with two major antimicrobial resistance profiles. All of these qacA/B-positive strains strains were pvl-negative by PCR. The qacA/B-positive MRSA strains all contained the group III SCCmec element. These strains were obtained mainly from patients in surgical wards; therefore, the neurosurgical ward and ICU may be considered as a source of MRSA strains carrying the qacA/B genes. Finally, the strain identified as spa type t037 is likely to be an epidemiological clone. The presence of the antiseptic resistance genes qacA/B by MRSA could potentially lead to MRSA strain prevalence. Thus, the optimal usage of antiseptics and disinfectants is warranted. A policy of molecular typing needs to be implemented to track the possible dissemination of these resistance genes. Key words : Staphylococcus aureus, mecA, qacA/B and pvl genes, methicillin-resistant, Staphylococcus aureus (MRSA), methicillin-sensitive Staphylococcus aureus (MSSA).

To explore whether PreS2 can change the percentage of T lymphocyte subgroups and the ration of CD4+/CD8+ in hepatocellular carcinoma (HCC) caused by HBV.The P120-146 region composed by the way of Merrifield, which was the most intensive antigen in PreS2 peptides, served as the antigen after dissolved in 0.01 mol/L PBS. 12 patients were chosed as the subjects, who were pathologically diagnosed as HCC after operation, were HBsAg-, HBeAg-, anti-HBc, and HBV DNA positive in serum, and expressed HBsAg in HCC tissue. The monocytes were isolated and cultured in 96 microplate with 1x 10(6) cells in every well, then the PreS2 synthetic peptides was added in at the doses of 1microg, 5microg, and 10microg, also IL-2 with 500 U was added in. Seven days later, the percentage of CD3+, CD4+, CD8+, and the ratio of CD4+/CD8+ were detected.It was found that the percentage of CD4+ increased significantly (t = 3.508, P0.01), and the ratio of CD4+/CD8+ decreasedly obviously (t = 2.235, P0.05) in the 5microg PreS2 synthetic peptides group, compared with those in the control group. The percentage of CD3+ rised markedly in the IL-2 group, compared with that in the control group.With proper doses, PreS2 is capable of changing the expression of T lymphocyte subgroups in HCC tissue, increasing the percentage of CD4+ obviously and changing the motionless state of CD8+, to make the carcinoma cell killed through the action of CD4+ and CD8+.