Functional screening of the Arabidopsis 2C protein phosphatases family identifies PP2C15 as a negative regulator of plant immunity by targeting BRI1-associated receptor kinase 1.

Genetic engineering using negative regulators of plant immunity has the potential to provide a huge impetus in agricultural biotechnology to achieve a higher degree of disease resistance without reducing yield. Type 2C protein phosphatases (PP2Cs) represent the largest group of protein phosphatases in plants, with a high potential for negative regulatory functions by blocking the transmission of defence signals through dephosphorylation. Here, we established a PP2C functional protoplast screen using pFRK1::luciferase as a reporter and found that 14 of 56 PP2Cs significantly inhibited the immune response induced by flg22. To verify the reliability of the system, a previously reported MAPK3/4/6-interacting protein phosphatase, PP2C5, was used; it was confirmed to be a negative regulator of PAMP-triggered immunity (PTI). We further identified PP2C15 as an interacting partner of BRI1-associated receptor kinase 1 (BAK1), which is the most well-known co-receptor of plasma membrane-localized pattern recognition receptors (PRRs), and a central component of PTI. PP2C15 dephosphorylates BAK1 and negatively regulates BAK1-mediated PTI responses such as MAPK3/4/6 activation, defence gene expression, reactive oxygen species bursts, stomatal immunity, callose deposition, and pathogen resistance. Although plant growth and 1000-seed weight of pp2c15 mutants were reduced compared to those of wild-type plants, pp2c5 mutants did not show any adverse effects. Thus, our findings strengthen the understanding of the mechanism by which PP2C family members negatively regulate plant immunity at multiple levels and indicate a possible approach to enhance plant resistance by eliminating specific PP2Cs without affecting plant growth and yield.

[Uncalibrated Positioning Method for Puncture Robots Based on Optical Navigation].

Robotic puncture system has been widely used in modern minimally invasive surgery, which usually uses hand-eye calibration to calculate the spatial relationship between the robot and the optical tracking system. However, the hand-eye calibration process is time-consuming and sensitive to environmental changes, which makes it difficult to guarantee the puncture accuracy of the robot. This study proposes an uncalibrated positioning method for puncture robot based on optical navigation. The method divides the target path positioning into two stages, angle positioning and position positioning, and designs angle image features and position image features respectively. The corresponding image Jacobian matrix is constructed based on the image features and updated by online estimation with a cubature Kalman filter to drive the robot to perform target path localization. The target path positioning results show that the method is more accurate than the traditional hand-eye calibration method and saves significant preoperative preparation time by eliminating the need for calibration.

[Research Progress and Prospect Analysis of Vascular Interventional Surgical Robot].

Vascular interventional surgery is an important means to treat cardiovascular and cerebrovascular diseases, but the particularity of its working environment will bring greater radiation threat to doctors. Vascular interventional surgery robots can effectively improve the working environment of doctors and can provide more stable operations, improve the success rate of surgery. This study mainly introduces the current research status, key technologies, and future application of vascular interventional surgical robots.

A fast, accurate and uncalibrated robotic puncture method.

BACKGROUND: Robotic puncture system (RPS) consists of an optical tracking system (OTS) and a robotic arm gripping the puncture needle. Typically, the RPS requires hand-eye calibration before the surgery in order to obtain the relative position between the OTS and the robotic arm. However, if there is any displacement or angular deviation in either the robotic arm or the OTS, the calibration results become invalid, necessitating recalibration. METHODS: We propose an uncalibrated robotic puncture method that does not rely on the hand-eye relationship of the RPS. By constructing angle and position graph jacobian matrices respectively, and employing Square Root Cubature Kalman Filter for online estimation. This enables obtaining control variables for the robot to perform puncture operations. RESULTS: In simulation experiments, our method achieves an average error of 1.3495 mm and an average time consumption of 39.331 s. CONCLUSIONS: Experimental results indicate that our method possesses high accuracy, low time consumption, and strong robustness.

A Novel Approach of Surface Texture Mapping for Cone-beam Computed Tomography in Image-guided Surgical Navigation.

The demand for cone-beam computed tomography (CBCT) imaging in clinics, particularly in dentistry, is rapidly increasing. Preoperative surgical planning is crucial to achieving desired treatment outcomes for imaging-guided surgical navigation. However, the lack of surface texture hinders effective communication between clinicians and patients, and the accuracy of superimposing a textured surface onto CBCT volume is limited by dissimilarity and registration based on facial features. To address these issues, this study presents a CBCT imaging system integrated with a monocular camera for reconstructing the texture surface by mapping it onto a 3D surface model created from CBCT images. The proposed method utilizes a geometric calibration tool for accurate mapping of the camera-visible surface with the mosaic texture. Additionally, a novel approach using 3D-2D feature mapping and surface parameterization technology is proposed for texture surface reconstruction. Experimental results, obtained from both real and simulation data, validate the effectiveness of the proposed approach with an error reduction to 0.32 mm and automated generation of integrated images. These findings demonstrate the robustness and high accuracy of our approach, improving the performance of texture mapping in CBCT imaging.

Arabidopsis Protein Phosphatase PIA1 Impairs Plant Drought Tolerance by Serving as a Common Negative Regulator in ABA Signaling Pathway.

Reversible phosphorylation of proteins is a ubiquitous regulatory mechanism in vivo that can respond to external changes, and plays an extremely important role in cell signal transduction. Protein phosphatase 2C is the largest protein phosphatase family in higher plants. Recently, it has been found that some clade A members can negatively regulate ABA signaling pathways. However, the functions of several subgroups of Arabidopsis PP2C other than clade A have not been reported, and whether other members of the PP2C family also participate in the regulation of ABA signaling pathways remains to be studied. In this study, based on the previous screening and identification work of PP2C involved in the ABA pathway, the clade F member PIA1 encoding a gene of the PP2C family, which was down-regulated after ABA treatment during the screening, was selected as the target. Overexpression of PIA1 significantly down-regulated the expression of ABA marker gene RD29A in Arabidopsis protoplasts, and ABA-responsive elements have been found in the cis-regulatory elements of PIA1 by promoter analysis. When compared to Col-0, transgenic plants overexpressing PIA1 were less sensitive to ABA, whereas pia1 showed the opposite trait in seed germination, root growth, and stomatal opening experiments. Under drought stress, SOD, POD, CAT, and APX activities of PIA1 overexpression lines were lower than Col-0 and pia1, while the content of H2O2 was higher, leading to its lowest survival rate in test plants, which were consistent with the significant inhibition of the expression of ABA-dependent stress-responsive genes RD29B, ABI5, ABF3, and ABF4 in the PIA1 transgenic background after ABA treatment. Using yeast two-hybrid and luciferase complementation assays, PIA1 was found to interact with multiple ABA key signaling elements, including 2 RCARs and 6 SnRK2s. Our results indicate that PIA1 may reduce plant drought tolerance by functioning as a common negative regulator involved in ABA signaling pathway.

Conservation and divergence of flg22, pep1 and nlp20 in activation of immune response and inhibition of root development.

Many pattern-recognition receptors (PRRs) and their corresponding ligands have been identified. However, it is largely unknown how similar and different these ligands are in inducing plant innate immunity and affecting plant development. In this study, we examined three well characterized ligands in Arabidopsis thaliana, namely flagellin 22 (flg22), plant elicitor peptide 1 (pep1) and a conserved 20-amino-acid fragment found in most necrosis and ethylene-inducing peptide 1-like proteins (nlp20). Our quantitative analyses detected the differences in amplitude in the early immune responses of these ligands, with nlp20-induced responses typically being slower than those mediated by flg22 and pep1. RNA sequencing showed the shared differentially expressed genes (DEGs) was mostly enriched in defense response, whereas nlp20-regulated genes represent only a fraction of those genes differentially regulated by flg22 and pep1. The three elicitors all inhibited primary root growth, especially pep1, which inhibited both auxin transport and signaling pathway. In addition, pep1 significantly inhibited the cell division and genes involved in cell cycle. Compared with flg22 and nlp20, pep1 induced much stronger expression of its receptor in roots, suggesting a potential positive feedback regulation in the activation of immune response. Despite PRRs and their co-receptor BAK1 were necessary for both PAMP induced immune response and root growth inhibition, bik1 mutant only showed impaired defense response but relatively normal root growth inhibition, suggesting BIK1 acts differently in these two biological processes.

A New Concept for Primary Reconstruction of Skull Defects with 3D-Molded PEEK Patch Assisted by Navigation Based on Animal Study.

AIM: To perform an accurate primary repair of temporal bone defects. MATERIAL AND METHODS: The temporal bone defect models were performed in beagles. Extended estimated patches of the defects were predesigned by 3D reconstruction software and molded from polyether ether ketone (PEEK) using a lathe. The precise trimming of the extended PEEK patches was established via coordinate transformation of the patches between the navigation system and the reconstruction software, and in real-time tracing via intraoperative navigation. Trimmed PEEK patches were embedded onto the defects. Blood tests and image examinations were conducted postoperatively. RESULTS: The extended PEEK patches were prepared precisely according to the predesign. Real-time tracing of the actual skull defect profile was performed quickly and accurately. Trimmed skull patches perfectly matched the shape of the defects. No signs of infection, absorption, or translocation of the patches occurred postoperatively, and little epidural effusion was found. CONCLUSION: With the assistance of navigation and 3D reconstruction technology, customized molded PEEK patches can be used for accurate primary repair of temporal bone defects.

[Design and Validation of Accuracy Assessment Tools and Algorithms for Optical Positioning System in Surgical Navigation].

The precision of optical positioning system is one of the most important factors which affects the precision of navigation guided surgery. In this study, an efficient and low-cost tool and its algorithm were proposed to evaluate the accuracy of optical positioning system based on the ablation scenario of liver cancer, and two validation experiments were designed. Experimental results show that the tool and its algorithm can evaluate the accuracy of the current positioning system accurately and efficiently.

A robotic puncture system with optical and mechanical feedback under respiratory motion.

Puncture robot can improve the accuracy and efficiency of puncture surgery, such as thoracoabdominal and liver puncture. However, as soft tissue is deformed and shifted under respiratory motion and during the puncture process, the needle is pulled, resulting in the needle's bending and deformation, which increases the risks and sufferings of the patient, a robotic puncture system with optical and mechanical feedback is necessary. Therefore, this paper proposes a multi-information sensing 'guide-clamp' end effector for puncture surgery to accurately detect the posture and force on the puncture needle in real time. And gravity bias method with trajectory planning and the compensational controlling model are also proposed to offset the interference of self-weight and achieve zero force following. This system is evaluated by the experiments of robot controlling and human tissue simulation and the results prove the excellent robustness of the system, which meet the clinical requirement.

[Rapid Reconstruction of Craniotomy Defects Based on Surgical Navigation].

In neurosurgery, skull repair caused by surgical approach is one of the important research contents. In this paper, a rapid reconstruction method of the skull defect with optical navigation system is proposed. This method can automatically reconstruct the structure of skull defect with the intraoperative defect edge points and preoperative medical image data. The head model experiment was used to evaluate the effect of the method, the average error of the reconstruction of the defect in the right orbit was 0.424 mm, while the average error of the reconstruction of the defect in the posterior skull base was 0.377 mm. The experimental results show that the structure of the defect is consistent with the actual defect, and the reconstruction accuracy satisfies the clinical requirements in neurosurgery.

A multiple closed-loops robotic calibration for accurate surgical puncture.

BACKGROUND: Robotic puncture system increasingly demands stringent standard in target location accuracy. The positional and orientational transformation relationships among all components of the system are supposed to be calibrated and identified preoperatively. AIMS: The target location performance is directly determined by the calibration result. Therefore, a multiple closed-loops calibration approach is proposed to achieve high-level calibration accuracy in robotic puncture system. MATERIALS & METHODS: This method takes as input the three-dimensional position information of the retro-reflective markers mounted on the surgical tool, which is detected by the optical tracking system in real time during robotic movement. There is less complicated mathematical derivation and calculation in the presented algorithm by applying the closed-loop principle. RESULTS: Experimental results validate that it can achieve accurate robotic target location with less input data and computation-cost, satisfying the clinical puncture requirements. DISCUSSION: The spatial calibration between robotic arm and optical tracking system efficiently realised by the presented approach present an alternative which can be safely applied to the robotic puncture system for accurate insertion. CONCLUSION: Overall, a multiple closed-loops calibration approach is proposed in this work, which may increase surgical efficiency.

Optimization Model for the Distribution of Fiducial Markers in Liver Intervention.

The distribution of fiducial markers is one of the main factors affected the accuracy of optical navigation system. However, many studies have been focused on improving the fiducial registration accuracy or the target registration accuracy, but few solutions involve optimization model for the distribution of fiducial markers. In this paper, we propose an optimization model for the distribution of fiducial markers to improve the optical navigation accuracy. The strategy of optimization model is reducing the distribution from three dimensional to two dimensional to obtain the 2D optimal distribution by using optimization algorithm in terms of the marker number and the expectation equation of target registration error (TRE), and then extend the 2D optimal distribution in two dimensional to three dimensional to calculate the optimal distribution according to the distance parameter and the expectation equation of TRE. The results of the experiments show that the averaged TRE for the human phantom is approximately 1.00 mm by applying the proposed optimization model, and the averaged TRE for the abdominal phantom is 0.59 mm. The experimental results of liver simulator model and ex-vivo porcine liver model show that the proposed optimization model can be effectively applied in liver intervention.

An Accurate Recognition of Infrared Retro-Reflective Markers in Surgical Navigation.

Marker-based optical tracking systems (OTS) are widely used in clinical image-guided therapy. However, the emergence of ghost markers, which is caused by the mistaken recognition of markers and the incorrect correspondences between marker projections, may lead to tracking failures for these systems. Therefore, this paper proposes a strategy to prevent the emergence of ghost markers by identifying markers based on the features of their projections, finding the correspondences between marker projections based on the geometric information provided by markers, and fast-tracking markers in a 2D image between frames based on the sizes of their projections. Apart from validating its high robustness, the experimental results show that the proposed strategy can accurately recognize markers, correctly identify their correspondences, and meet the requirements of real-time tracking.

Therapeutic targets for the anemia of predialysis chronic kidney disease: a meta-analysis of randomized, controlled trials.

Anemia is one of the major complications in predialysis patients with chronic kidney disease (CKD). A clearer cognition of the prognostic impact of hemoglobin (Hb) or hematocrit (Hct) target on the outcomes of predialysis patients with CKD is significant. This article aims to establish the suitable hemoglobin target to provide clinical guidance. MEDLINE, EmBase, the Cochrane Library and other databases were searched with both MeSH terms and keywords to gather researches that assessed all-cause mortality, stroke, treatment of renal replacement, and transfusion. The meta-analysis was accomplished via Revman 5.3 version. Totally, 13 eligible studies involving 7606 patients were included. There was a significantly lower risk of transfusion (risk ratio (RR) 0.59, 95% CI 0.52 to 0.67; p<0.00001) in the higher hemoglobin group than in the lower one. However, no significant difference was found in all-cause mortality (RR 1.10, 95% CI 0.98 to 1.23; p=0.11), stroke (RR 1.32, 95% CI 0.82 to 2.10; p=0.25) and treatment of renal replacement including hemodialysis, peritoneal dialysis and renal transplant (RR 1.08, 95% CI 0.95 to 1.22; p= 0.23) between the higher hemoglobin group and the lower one. The results favor the higher hemoglobin target. To target the higher hemoglobin when treating predialysis patients with CKD may decrease the risk of transfusion without increasing the risk of death, stoke, and treatment of renal replacement.

Geometric calibration of markerless optical surgical navigation system.

BACKGROUND: Patient-to-image registration is required for image-guided surgical navigation, but marker-based registration is time consuming and is subject to manual error. Markerless registration is an alternative solution to avoid these issues. METHODS: This study designs a calibration board and proposes a geometric calibration method to calibrate the near-infrared tracking and structured light components of the proposed optical surgical navigation system simultaneously. RESULTS: A planar board and a cylinder are used to evaluate the accuracy of calibration. The mean error for the board experiment is 0.035 mm, and the diameter error for the cylinder experiment is 0.119 mm. A calibration board is reconstructed to evaluate the accuracy of the calibration, and the measured mean error is 0.012 mm. A head phantom is reconstructed and tracked by the proposed optical surgical navigation system. The tracking error is less than 0.3 mm. CONCLUSIONS: Experimental results show that the proposed method obtains high accessibility and accuracy and satisfies application requirements.

Effect of gender-related depression on heart rate variability during an autonomic nervous test.

Patients with depression have lower heart rate variability (HRV) compared with controls. However, studies have indicated HRV difference between male and female controls. The gender effect might be interactive with the depression effect on the HRV, resulting in a low accuracy of recognising the patients with depression from the controls. Our study explores the effect of gender-related depression on HRV. Four ANS tests including resting, deep breathing, Valsalva, and orthostatic test are employed as stimuli. HRV were collected from 182 subjects comprising 91 depressive patients (33 females/58 males) and 91 controls (33 females/58 males) in the four tests. Time and frequency domains and nonlinear parameters are employed to quantify HRV. Two-way ANOVA is applied to evaluate the effect of gender-related depression. Most HRV parameters of the patients significantly differ from those of the controls, but some parameters indicate different depression effect between the males and females in the deep breathing and Valsalva test. Some HRV parameters illustrate significant difference between the male and female controls. Therefore, the effect of depression on HRV of each gender should be investigated.

[Automatic Robotic Puncture System for Accurate Liver Cancer Ablation Based on Optical Surgical Navigation].

This paper designed an automatic robotic puncture system for accurate liver cancer ablation based on optical surgical navigation. The near-infrared optical surgical navigation system we constructed for liver ablation was applied to carry out surgical planning and simulation, the near-infrared cameras dynamically tracked the current position of puncture needle relative to the location of the patient's anatomy, then guided the surgery robot to position precisely in three-dimensional space and performed the surgery.

Hemoglobin targets for the anemia in patients with dialysis-dependent chronic kidney disease: a meta-analysis of randomized, controlled trials.

BACKGROUND: Anemia is extremely common among dialysis patients and underlies some of the symptoms associated with reduced kidney function, including fatigue, depression, reduced exercise tolerance, and dyspnea. OBJECTIVES: A clearer cognition of the prognosistic impact of hemoglobin (Hb) or hematocrit (Hct) target for the outcomes of dialysis patients is urgent. This article aims to establish the suitable hemoglobin in order to provide clinical guidance. METHODS: MEDLINE, EmBase, the Cochrane Library and other databases were searched with both MeSH terms and keywords to gather randomized controlled trials that assessed all-cause mortality, cardiovascular events, fistula thrombosis, infectious diseases and transfusion among dialysis-dependent patients using erythropoiesis-stimulating agents. The meta-analysis was accomplished via Revman 5.3 version. FINDINGS: Totally, nine eligible studies were included, with study subjects involving 3228 patients. There was a significantly higher risk of fistula thrombosis without heterogeneity (RR 1.34, 95% CI 1.15-1.55; p < 0.05) in the higher Hb target group than in the lower Hb target group in the fixed effects model. However, no significant difference was found in all-cause mortality in the fixed effects model (RR 1.09, 95% CI 0.93-1.27; p = 0.30), cardiovascular events (RR 0.77, 95% CI 0.31-1.92; p = 0.58), infectious diseases (RR 0.69, 95% CI 0.24-1.96; p = 0.49) and transfusion (RR 0.92, 95% CI 0.42-1.99; p = 0.82) in the random effects model between the higher Hb target group and the lower Hb target group. DISCUSSION: The results favor lower Hb target. To target lower Hb target when treating dialysis patients with anemia may decrease the risk of fistula thrombosis without increasing the risk of death, cardiovascular events, infectious diseases and transfusion.

Depression recognition according to heart rate variability using Bayesian Networks.

BACKGROUND: Doctors mainly use scale tests and subjective judgment in the clinical diagnosis of depression. Researches have demonstrated that depression is associated with the dysfunction of the autonomic nervous system (ANS), where its modulation can be evaluated by heart rate variability (HRV). Depression patients have lower HRV than healthy subjects. Therefore, HRV may be used to distinguish depression patients from healthy people. METHODS: HRV signals were collected from 76 female subjects composed of 38 depression patients and 38 healthy people. Time domain, frequency domain, and non-linear features were extracted from the HRV signals of these subjects, who were subjected to the Ewing test as an ANS stimulus. Then, these multiple features were input into Bayesian networks, served as a classifier, to distinguish depression patients from healthy people. Hence, accuracy, sensitivity, and specificity were calculated to evaluate the performance of the classifier. RESULTS: Recognition results indicate 86.4% accuracy, 89.5% sensitivity, and 84.2% specificity. The individuals subjected to the Ewing test showed better recognition results than those at individual test states (resting state, deep breathing state, Valsalva state, and standing state) of the Ewing test. The root mean square of successive differences (RMSSD) of the HRV exhibits a significant relevance with recognition. CONCLUSION: Bayesian networks can be applied to the recognition of depression patients from healthy people and the recognition results demonstrate the significant association between depression and HRV. The Ewing test is a good ANS stimulus for acquiring the difference of HRV between depression patients and healthy people to recognize depression. The RMSSD of the HRV is important in recognition and may be a significant index in distinguishing depression patients from healthy people.