Experimental study of the optimum puncture pattern of robot-assisted needle insertion into hyperelastic materials.

The robot-assisted insertion surgery plays a crucial role in biopsy and therapy. This study focuses on determining the optimum puncture pattern for robot-assisted insertion, aiming at the matching problem of needle insertion parameters, thereby to reduce the pain for patients and to improve the reachability to the lesion point. First, a 6-degrees of freedom (DOFs) Computed Tomography (CT)-guided surgical robotic system for minimally invasive percutaneous lung is developed and used to perform puncture experiments. The effects of four main insertion factors on the robotic puncture are verified by designing the orthogonal test, where the inserting object is the artificial skin-like specimen with high transparent property and a digital image processing method is used to analyze the needle tip deflection. Next, the various phases of puncture process are divided and analyzed in detail in view of the tissue deformation and puncture force. Then, short discussion on the comparison of puncture force with different effect factors for the same beveled needle is presented. The same pattern can be observed for all of the cases. Finally, based on the experimental data, the formulations of the puncture force and needle deflection which depends on Gauge size, insertion velocity, insertion angle, and insertion depth are developed using the multiple regression method, which can be used to get an optimum puncture pattern under the constrains of minimum peak force and minimum needle tip deflection. The developed models have the effectiveness and applicability on determining the optimum puncture pattern for one puncture event, and which can also provide insights useful for the setting of insertion parameters in clinical practice.

[Mechanism of astragaloside â £ alleviating PC12 cell injury by activating PI3K/AKT signaling pathway: based on network pharmacology and in vitro experiments].

In this study, the molecular mechanism of astragaloside Ⅳ(AS-Ⅳ) in the treatment of Parkinson's disease(PD) was explored based on network pharmacology, and the potential value of AS-Ⅳ in alleviating neuronal injury in PD by activating the PI3 K/AKT signaling pathway was verified through molecular docking and in vitro experiments. Such databases as SwissTargetPrediction, BTMAN-TAM, and GeneCards were used to predict the targets of AS-Ⅳ for the treatment of PD. The Search Tool for the Retrieval of Interacting Genes/Proteins(STRING) was employed to analyze protein-protein interaction(PPI) and construct a PPI network, and the Database for Annotation, Visualization and Integrated Discovery(DAVID) was used for Gene Ontology(GO) term enrichment and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment analysis. Based on the results of GO enrichment analysis and KEGG pathway analysis, the PI3 K/AKT signaling pathway was selected for further molecular docking and in vitro experiments in this study. The in vitro cell model of PD was established by MPP~+. The cell viability was measured by MTT assay and effect of AS-Ⅳ on the expression of the PI3 K/AKT signaling pathway-related genes and proteins by real-time polymerase chain reaction(RT-PCR) and Western blot. Network pharmacology revealed totally 122 targets of AS-Ⅳ for the treatment of PD, and GO enrichment analysis yielded 504 GO terms, most of which were biological processes and molecular functions. Totally 20 related signaling pathways were screened out by KEGG pathway analysis, including neuroactive ligand-receptor interaction, PI3 K/AKT signaling pathway, GABAergic synapse, and calcium signaling pathway. Molecular docking demonstrated high affinity of AS-Ⅳ to serine/threonine-protein kinases(AKT1, AKT2), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit gamma(PIK3 CG), and phosphoinositide-3-kinase, catalytic, alpha polypeptide(PIK3 CA) on the PI3 K/AKT signaling pathway. In vitro experiments showed that AS-Ⅳ could effectively inhibit the decrease of the viability of PC12 induced by MPP~+ and up-regulate the mRNA expression levels of AKT1 and PI3 K as well as the phosphorylation levels of AKT and PI3 K. As an active component of Astragali Radix, AS-Ⅳ acts on PD through multiple targets and pathways. Furthermore, it inhibits neuronal apoptosis and protects neurons by activating the PI3 K/AKT signaling pathway, thereby providing reliable theoretical and experimental supports for the treatment of PD with AS-Ⅳ.

Assessing risk factors for SARS-CoV-2 infection in patients presenting with symptoms in Shanghai, China: a multicentre, observational cohort study.

Background: The outbreak of COVID-19 has led to international concern. We aimed to establish an effective screening strategy in Shanghai, China, to aid early identification of patients with COVID-19. Methods: We did a multicentre, observational cohort study in fever clinics of 25 hospitals in 16 districts of Shanghai. All patients visiting the clinics within the study period were included. A strategy for COVID-19 screening was presented and then suspected cases were monitored and analysed until they were confirmed as cases or excluded. Logistic regression was used to determine the risk factors of COVID-19. Findings: We enrolled patients visiting fever clinics from Jan 17 to Feb 16, 2020. Among 53 617 patients visiting fever clinics, 1004 (1·9%) were considered as suspected cases, with 188 (0·4% of all patients, 18·7% of suspected cases) eventually diagnosed as confirmed cases. 154 patients with missing data were excluded from the analysis. Exposure history (odds ratio [OR] 4·16, 95% CI 2·74-6·33; p<0·0001), fatigue (OR 1·56, 1·01-2·41; p=0·043), white blood cell count less than 4 × 109 per L (OR 2·44, 1·28-4·64; p=0·0066), lymphocyte count less than 0·8 × 109 per L (OR 1·82, 1·00-3·31; p=0·049), ground glass opacity (OR 1·95, 1·32-2·89; p=0·0009), and having both lungs affected (OR 1·54, 1·04-2·28; p=0·032) were independent risk factors for confirmed COVID-19. Interpretation: The screening strategy was effective for confirming or excluding COVID-19 during the spread of this contagious disease. Relevant independent risk factors identified in this study might be helpful for early recognition of the disease. Funding: National Natural Science Foundation of China.

Lesion positioning method of a CT-guided surgical robotic system for minimally invasive percutaneous lung.

BACKGROUND: Robot-assisted puncture has gradually attracted more attention and practical clinical application. The lesion positioning and the needle positioning are the basis to ensure the accuracy of puncture and the key techniques in insertion operation. METHODS: A lesion positioning method is established which is realized only by the robot-CT system without using external positioning system, and an omnidirectional needle positioning method is also developed and realized by using VRCM, in order to make the puncture needle always keep pointing to the lesion point. A CT-guided surgical robotic system used for minimally invasive percutaneous lung is designed and the physical prototype is manufactured, to perform in-vitro experiments, thereby to validate the effectiveness of the lesion positioning method and the feasibility of omnidirectional needle positioning method. RESULTS: The accuracy of established lesion positioning method based on three non-collinear markers is within 3 mm, which is similar to that of the least squares method based on the five non-coplanar markers, but the positioning efficiency can be improved by about 40%, and the non-collinearity of markers is easier to be satisfied than non-coplanarity in practical applications. The average calculation error of the established positioning method is 0.997 mm. Moreover, the omnidirectional positioning of the puncture needle under the designed surgical robot is feasible. CONCLUSIONS: The designed surgical robot has good control accuracy and it can satisfy the requirements for use. The established lesion positioning method can provide a good precision basis for robot-assisted puncture surgery. The suitable insertion point and insertion posture can be determined by the developed omnidirectional needle positioning method. This study can provide theoretical reference for further study of path planning or autonomous positioning.

Efficacy of acupuncture for chronic asthma: study protocol for a randomized controlled trial.

BACKGROUND: Although asthma symptoms can be temporarily controlled, it is recommended to use effective low-risk, non-drug strategies to constitute a significant advance in asthma management. Acupuncture has been traditionally used to treat asthma; however, the evidence for the efficacy of this treatment is still lacking. Previous clinical trials of acupuncture in treating asthma were limited by methodological defects; therefore, high-quality research is required. METHODS/DESIGN: This trial is designed as a multi-center, randomized, double-blind, parallel-group controlled trial. Patients with mild to moderate asthma will be randomly allocated to either a verum acupuncture plus as-needed salbutamol aerosol and/or prednisone tablets group or a sham acupuncture plus as-needed salbutamol aerosol and/or prednisone tablets group. Acupoints used in the verum acupuncture group are GV14 (Da Zhui), BL12 (Feng Men), BL13 (Fei Shu) and acupoints used in the sham acupuncture group are DU08 (Jin Suo), BL18 (Gan Shu), BL19 (Dan Shu). After a baseline period of 1 week, the patients in both groups will receive verum/sham acupuncture once every other day with a total of 20 treatment sessions in 6 weeks and a 3-month follow-up. The primary outcome will be measured by using the asthma control test and the secondary outcomes will be measured by using the percentage of symptom-free days, the average dosage of salbutamol aerosol and/or prednisone tablets, lung functions, daily asthma symptom scores, asthma quality of life questionnaire, and so on. DISCUSSION: This trial will assess the effect of acupuncture on asthma and aims to provide reliable clinical evidence for the efficacy of acupuncture in treating asthma. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01931696 , registered on 26 August 2013.

Characteristic features of pulmonary function test, CT volume analysis and MR perfusion imaging in COPD patients with different HRCT phenotypes.

INTRODUCTION: Computed tomography (CT) and magnetic resonance imaging (MRI) can provide detailed anatomic structures and quantitative function information for chronic obstructive pulmonary disease (COPD). OBJECTIVES: To prospectively clarify characteristics of pulmonary function test (PFT), CT volume parameters and magnetic resonance (MR) perfusion imaging in COPD patients with different high-resolution computed tomography (HRCT) phenotypes. METHODS: Sixty-two patients performed PFT, CT and MR perfusion imaging. COPD was classified into three phenotypes according to HRCT quantitative findings: A, E and M phenotype. Total lung volume (TLV), total emphysema volume (TEV) and emphysema index (EI) were quantitated by HRCT. In cases of perfusion defects (PDs), the shape and size were evaluated. The contrast between the normal lung and PDs was quantified by calculating their signal intensity ratio (RSI = SIPD /SInormal ). The correlation was performed between PFT, CT and MR perfusion. RESULTS: There were 42 A phenotype, 9 E phenotype and 11 M phenotype. There was significant difference in forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) between A and M phenotype (P < 0.05). TEV and EI of A phenotype (0.4 ± 0.4 L and 8.0% ± 4.3%) were lower than those of E (1.0 ± 0.3 L and 18.6% ± 3.2%) or M phenotype (0.9 ± 0.2 L and 17.5% ± 1.7%). MR perfusion images showed circumscribed or diffuse patchy PDs. RSI of A phenotype was higher than that of E phenotype (20.3% ± 8.5% vs 11.8% ± 5.4%; P = 0.006). TEV and EI were moderate negatively correlated with diffusion function parameters. RSI was strongly correlated with FEV1% (A) and FEV1/FVC (M). FEV1/FVC was strongly correlated with TEV or EI (E). CONCLUSION: There were different features and correlations between PFT, CT volume and MR perfusion in different phenotype, indicating each phenotype may have novel imaging method guiding clinical management.

Capability of differentiating smokers with normal pulmonary function from COPD patients: a comparison of CT pulmonary volume analysis and MR perfusion imaging.

OBJECTIVE: To compare CT volume analysis with MR perfusion imaging in differentiating smokers with normal pulmonary function (controls) from COPD patients. METHODS: Sixty-two COPD patients and 17 controls were included. The total lung volume (TLV), total emphysema volume (TEV) and emphysema index (EI) were quantified by CT. MR perfusion evaluated positive enhancement integral (PEI), maximum slope of increase (MSI), maximum slope of decrease (MSD), signal enhancement ratio (SER) and signal intensity ratio (RSI) of perfusion defects to normal lung. RESULTS: There were 19 class I, 17 class II, 14 class III and 12 class IV COPD patients. No differences were observed in TLV, TEV and EI between control and class I COPD. The control was different from class II, III and IV COPD in TEV and EI. The control was different from each class of COPD in RSI, MSI, PEI and MSD. Differences were found in RSI between class I and III, I and IV, and II and IV COPD. Amongst controls, MR detected perfusion defects more frequently than CT detected emphysema. CONCLUSIONS: Compared with CT, MR perfusion imaging shows higher potential to distinguish controls from mild COPD and appears more sensitive in identifying abnormalities amongst smokers with normal pulmonary function (controls). KEY POINTS: • Detailed information is needed to diagnose chronic obstructive pulmonary disease. • High-resolution CT provides detailed anatomical and quantitative information. • Magnetic resonance imaging is demonstrating increasing potential in pulmonary function imaging. • MR perfusion can distinguish mild COPD patients from controls. • MRI appears more sensitive than CT in identifying early abnormalities amongst controls.

MiRNA synergistic network construction and enrichment analysis for common target genes in small-cell lung cancer.

BACKGROUND: Small-cell lung cancer (also known as SCLC) is an aggressive form and untreated patients generally die within about 3 months. To obtain further insight into mechanism underlying malignancy with this cancer, an miRNA synergistic regulatory network was constructed and analyzed in the present study. METHOD: A miRNA microarray dataset was downloaded from the NCBI GEO database (GSE27435). A total of 546 miRNAs were identified to be expressed in SCLC cells. Then a miRNA synergistic network was constructed, and the included miRNAs mapped to the network. Topology analysis was also performed to analyze the properties of the synergistic network. Consequently, we could identified constitutive modules. Further, common target genes of each module were identified with CFinder. Finally, enrichment analysis was performed for target genes. RESULTS: In this study, a miRNA synergistic network with 464 miRNAs and 2981 edges was constructed. According to the topology analysis, the topological properties between the networks constructed by LC related miRNAs and LC unrelated miRNAs were significantly different. Moreover, a module cilque0 could be identified in our network using CFinder. The module included three miRNAs (hsa-let-7c, hsa-let-7b and hsa-let-7d). In addition, several genes were found which were predicted to be common targets of cilque0. The enrichment analysis demonstrated that these target genes were enriched in MAPK signaling pathways. CONCLUSIONS: Although limitations exist in the current data, the results uncovered here are important for understanding the key roles of miRNAs in SCLC. However, further validation is required since our results were based on microarray data derived from a small sample size.