Needle Tip Research Articles

Needle tracking in low-resolution ultrasound volumes using deep learning

PurposeClinical needle insertion into tissue, commonly assisted by 2D ultrasound imaging for real-time navigation, faces the challenge of precise needle and probe alignment to reduce out-of-plane movement. Recent studies investigate 3D ultrasound imaging together with deep learning to overcome this problem, focusing on acquiring high-resolution images to create optimal conditions for needle tip detection. However, high-resolution also requires a lot of time for image acquisition and processing, which limits the real-time capability. Therefore, we aim to maximize the US volume rate with the trade-off of low image resolution. We propose a deep learning approach to directly extract the 3D needle tip position from sparsely sampled US volumes.MethodsWe design an experimental setup with a robot inserting a needle into water and chicken liver tissue. In contrast to manual annotation, we assess the needle tip position from the known robot pose. During insertion, we acquire a large data set of low-resolution volumes using a 16 ×\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ imes $$\\end{document} 16 element matrix transducer with a volume rate of 4 Hz. We compare the performance of our deep learning approach with conventional needle segmentation.ResultsOur experiments in water and liver show that deep learning outperforms the conventional approach while achieving sub-millimeter accuracy. We achieve mean position errors of 0.54 mm in water and 1.54 mm in liver for deep learning.ConclusionOur study underlines the strengths of deep learning to predict the 3D needle positions from low-resolution ultrasound volumes. This is an important milestone for real-time needle navigation, simplifying the alignment of needle and ultrasound probe and enabling a 3D motion analysis.

Effects of Shugan Tiaoshen intradermal needling intervention on attentional networks in subthreshold depression: a randomized controlled trial

To analyze the effects of Shugan Tiaoshen (regulating liver and harmonizing spirit) intradermal needling protocol on the attentional networks of patients with subthreshold depression using the attention network test (ANT). Eighty patients with subthreshold depression were randomly divided into an intradermal needling group (40 cases) and a sham needling group (40 cases, 2 cases dropped out), with an additional 43 healthy subjects as a normal group. The intradermal needling group received intradermal needling treatment, while the sham needling group received sham intradermal needling, with the needle tip not penetrating the skin. The bilateral Xinshu (BL 15), Ganshu (BL 18), Shentang (BL 44) as well as auricular points Xin (CO15) and Gan (CO12) were selected alternately. Treatments were administered twice a week for a total of 6 weeks in the two groups. The patient health questionnaire-9 (PHQ-9) and generalized anxiety disorder (GAD-7) scores were observed before treatment, after 3 weeks of treatment, after treatment, and at 1 month after the end of treatment (follow-up), and the ANT of the two groups of patients with subthreshold depression before and after treatment as well as the normal group of healthy subjects was compared. The PHQ-9 and GAD-7 scores of the patients with subthreshold depression were decreased after 3 weeks of treatment, after treatment, and in follow-up in the two groups (P<0.05), the differences in PHQ-9 and GAD-7 scores before and after treatment were greater in the intradermal needling group than those in the sham needling group (P<0.01). Before treatment, the executive control network reaction time of the subthreshold depression group (the intradermal needling group and the sham needling group) was higher than that of the normal group (P<0.05). Compared before treatment, the executive control network reaction time of the patients in the intradermal needling group and the sham needling group was decreased after treatment (P<0.05), and the alerting network reaction time of the intradermal needling group was increased after treatment (P<0.05); the difference in alerting network reaction time before and after treatment was greater in the intradermal needling group than that of the sham needling group (P<0.01). Regulating liver and harmonizing spirit intradermal needling protocol could effectively improve depressive and anxious symptoms in patients with subthreshold depression, and enhance the efficiency of the alerting network.

Design and application of a disposable self-destructed and sheath-encased sterile acupuncture needle

A kind of disposable self-destructed and sheath-encased sterile acupuncture needle is designed to efficiently solve the issues of safety and sterilization encountered in the routine operation of acupuncture. The needle consists of three components, i.e. the needle body, the sheath and the locker. The needle body is movable and rotatable in the sheath, but can not be separated from the sheath. It is convenient for the operator to perform the lifting-thrusting and twisting techniques, and to prevent the non-punctured portion of the body from being out off the sheath so that a sterile confined room is formed between the needle and the skin of the operated area. With a locker installed between the sheath and the needle handle, after needle removal, the needle body can be returned and locked in the sheath, avoiding the exposure of needle tip, obtaining the self-destruction of needle and preventing from needling accident and reuse of needle. The devise is operated easily, which is effectively reduce the risk of infection and ensure the safety of medical staffs in practice.

Fabrication of microneedles using wire electric discharge machining and improving surface quality by electrochemical polishing

Microneedle (MN) arrays have many applications in biomedical engineering to deliver drugs transdermally or extract biomarkers from the interstitial fluid from the human skin. Several methods have been developed to fabricate different sizes and shapes of MN using polymers, ceramics and metals. However, most of these methods require expensive sophisticated machines and clean room facilities. So, it is difficult to fabricate microneedle arrays in large quantities at a reasonable cost. This study reports the fabrication of a high-quality stainless steel master pattern for an MN array using a wire-cut electric discharge machining process followed by electrochemical polishing (ECP). Different densities of a 5 × 5 array of microneedles with pyramidal shapes were fabricated by machining channels onto the workpiece surface in a criss-cross pattern. A systematic experimental study was carried out with reference to the offset between the two consecutive channel faces and the depth of channels. The output parameters are MN height (MNH), MN base (MNBW) and tip width (MNTW). The average needle tip width, base width, and height of microneedles were found to be 55.3 ± 5 µm, 679.8 ± 10 µm, and 914.7 ± 19 µm. Finally, the sharpness of the MN tips and the overall surface finish of the MN array were improved with ECP. The reductions in MNH, MNBW, and MNTW were reported to be −18.3%, −9.7%, and −95.4%, respectively, with a final tip width of 2.55 ± 1.62 µm. The MNs’ tip angle was reported to be 32.52° ± 1.56.

Relationship between epidural catheter migration beneath the skin and subcutaneous fat thickness assessed using postoperative CT imaging: a retrospective cross-sectional study.

The causes of epidural catheter migration beneath the skin have not been previously investigated. We hypothesized that greater subcutaneous fat thickness might be associated with increased catheter migration beneath the skin. We conducted a retrospective cross-sectional study of patients who had undergone combined general and epidural anesthesia, selecting individuals who received thoracic and abdominal CT scans within the first 5 postoperative days. Needle depth was defined as the distance from the needle tip to the skin surface when the anesthesiologist determined that the needle tip had reached the epidural space. We measured the length of the epidural catheter from the skin surface to the epidural space (catheter length), and subcutaneous fat thickness (fat thickness) using CT imaging. Migration distance was calculated by subtracting needle depth from catheter length. We analyzed 127 patients (72 males), all undergoing epidural catheter insertion in the left lateral decubitus position via a paramedian approach. The median age of the patients was 71years. Epidural catheters were postoperatively found to substantially curve beneath the skin. Regression analysis revealed no significant influence of fat thickness on catheter length (regression coefficient 0.10, 95% confidence interval [CI]: - 0.17, 0.38). However, it indicated a positive correlation between fat thickness and needle depth (regression coefficient 0.50, 95% CI: 0.30, 0.70), and a negative correlation between fat thickness and migration distance (regression coefficient - 0.40, 95% CI: - 0.65, - 0.14). We found a negative correlation between epidural catheter migration beneath the skin and subcutaneous fat thickness. Anesthesiologists should be aware of the possibility of substantial subcutaneous curving of the catheter, especially in patients with scant subcutaneous fat.

Initial needle tracking with the first standalone combined infrared camera - CT system for brachytherapy-analysis of tracking accuracy and uncertainties.

Aprototype infrared camera - cone-beam computed tomography (CBCT) system for tracking in brachytherapy has recently been developed. We evaluated for the first time the corresponding tracking accuracy and uncertainties, and implemented atracking-based prediction of needles on CBCT scans. Amarker tool rigidly attached to needles was 3D printed. The precision and accuracy of tool tracking was then evaluated for both static and dynamic scenarios. Euclidean distances between the tracked and CBCT-derived markers were assessed as well. To implement needle tracking, ground truth models of the tool attached to 200 mm and 160 mm needles were matched to the tracked positions in order to project the needles into CBCT scans. Deviations between projected and actual needle tips were measured. Finally, we put our results into perspective with simulations of the system's tracking uncertainties. For the stationary scenario and dynamic movements, we achieved tool-tracking precision and accuracy of 0.04 ± 0.06 mm and 0.16 ± 0.18 mm, respectively. The tracked marker positions differed by 0.52 ± 0.18 mm from the positions determined via CBCT. In addition, the predicted needle tips in air deviated from the actual tip positions by only 1.62 ± 0.68 mm (200 mm needle) and 1.49 ± 0.62 mm (160 mm needle). The simulated tracking uncertainties resulted in tip variations of 1.58 ± 0.91 mm and 1.31 ± 0.69 mm for the 200 mm and 160 mm needles, respectively. With the innovative system it was possible to achieve ahigh tracking and prediction accuracy of marker tool and needles. The system shows high potential for applicator tracking in brachytherapy.

Ionization processes of negative corona discharge. Part 2. Theory. Comparison with experiment

The purpose of the research is a theoretical analysis of ionization processes in the air, which are initiated by a high-voltage field generated by the negative needle-flat electrode electrode system. Methods. Fe, Cu, Al electrodes are used. Calculations are carried out using the methods of quantum mechanics and mathematical physics. Results. The processes of cold and thermoelectron emission of electrons, enhanced by an external high-voltage field (Schottky emission), are analyzed. The conditions under which the generation of charges from the cathode surface due to plasma-chemical reactions and the capture of surface electrons by electronegative oxygen molecules are decisive are investigated. Based on the PE theory, a theory of injection of negative ions from the cathode into an electronegative gas is constructed and the theory is compared with experiment. It has been shown that at small radii of curvature of needle tips, when E ≥ 106 V/cm, the generation of charges is due to cold emission of electrons. In average fields E ≈ 105 V/cm, electron emission is due to the Schottky effect. In fields E ≈ 104 V/cm and below, injection is caused by electrochemical processes and PE capture. A theory has been developed for PEs that appear at electric field intensities on the electrode of the order of several tens of kV/cm, that is, on flat and slightly curved negative electrodes. The capture of PE by electron-withdrawing molecules causes an injection current and, as a consequence, the ignition of a corona discharge. Analytical expressions for the surface density as a function of the local electric field strength, as well as an expression for the injection current, are obtained. The agreement between theory and experiment is satisfactory. Conclusion. An analysis of the development of CR on negative needles is given. A theory of PE at the cathode in strong electric fields was developed. Based on the results of measuring dark negative current-voltage characteristics, it is possible to determine the patterns of surface processes involving electronic transitions, in particular, determine the concentration of PE and injection currents.

Fabrication and Characterization of Electrospun Ocimum sanctum and Curcumin-Loaded Nanofiber Membrane for the Management of Periodontal Disease: An In Vitro Study.

Background Periodontal disease is a chronic inflammatory condition that gradually deteriorates the supportive tissues of teeth, eventually leading to tooth loss. Mechanical debridement stands as the gold standard method for treating periodontitis. However, antimicrobial therapy is recommended for optimal results when used alongside mechanical debridement. Numerous studies have investigated local drug delivery as an adjunct to mechanical debridement of affected tooth surfaces. Ocimum sanctum exhibits anti-inflammatory, antioxidant, and antimicrobial properties. Similarly, curcumin, as documented in the literature, demonstrates a broad spectrum of anti-inflammatory and antimicrobial effects. Electrospinning has demonstrated itself to be a highly effective method for fabricating drug-loaded fibers. Electrospun nanofibers containing Ocimum sanctum and curcumin are expected to exhibit greater efficacy due to their increased surface area, facilitating the dispersion of larger quantities of drugs, and their ability to control drug release when employed as a local drug delivery system. This study aims to fabricate and characterize the properties of nanofiber membranes loaded with Ocimum sanctum and curcumin using the electrospinning technique. Methods About 50 mg each of Ocimum sanctum and curcumin were blended with 15% polyvinyl alcohol and 2% chitosan polymer in a 4:1 ratio and left to stir overnight. A 10 mL syringe was filled with this solution, and an 18 G blunt-end needle charged at 15.9 kV was used for extrusion. Continuous fibers were collected onto a collector plate positioned 12 cm from the center of the needle tip, at a flow rate of 0.005 mL/min. The morphology of the fabricated membrane was assessed through scanning electron microscopy (SEM), the strength of the material was assessed through tensile strength analysis using INSTRON, an Electropuls E3000 Universal Testing Machine(INSTRON, Norwood, MA), and the drug release pattern was analyzed using Jasco V-730 UV-visible spectrophotometer(Jasco, Easton, MD). Results The morphology of this nanofiber showed a random distribution of fibers with no bead formation. The average diameter of the membrane was 383±102 nm, and the tensile strength of this material was 1.87 MPa. The drug release pattern showed an initial burst release of Ocimum sanctum, followed by a controlled release in subsequent hours. However, curcumin showed very little drug release because of its solubility. Conclusion In summary, the Ocimum sanctum and curcumin-loaded nanofibers exhibited robust tensile strength, a controlled drug release profile, and uniform drug distribution within the nanofiber membrane. Consequently, it can be concluded that curcumin nanofibers and electrospun Ocimum sanctum serve as valuable agents for local drug delivery in the treatment of periodontitis.

Comparison of the effects of single injection and continuous infusion popliteal nerve block on pain and hemodynamics in diabetic foot surgery; prospective randomized clinical trial

ObjectivesIn patients undergoing surgery due to diabetic foot complications from uncontrolled diabetes may lead to neuraxial or general anesthesia-related issues. Regional anesthesia techniques can be preferred to prevent these complications. This study aimed to compare the hemodynamic effects and outcomes in terms of pain of continuous infusion and single injection methods of popliteal nerve block in patients undergoing surgery due to diabetic foot. Materials and methodsSixty-three patients in ASA II-IV risk group scheduled for diabetic foot surgery were randomized into two groups for popliteal nerve block as the anesthesia method. Group 1 (n:32), 30 mL of local anesthetic was administered around the popliteal nerve under ultrasound guidance and nerve stimulator. Group 2 (n:31) had a catheter placed beyond the needle tip by 4–5 cm. An elastomeric pump was prepared for the infusion of 2 mL/h of 0.25 % bupivacaine through the catheter. Hemodynamic parameters before and after the block, onset, block duration times, postoperative pain scores, time to analgesic requirement, patient satisfaction, and discharge time were recorded. ResultsPain scores were higher in Group 1 after 12 h postoperatively and in Group 2 after 60 h postoperatively (p = 0.006, p < 0.01, respectively). The time to the first analgesic requirement was not statistically different between Group 1 (mean 804.64 ± 1020.8 min) and Group 2 (mean 2012.78 ± 1424 min) (p = 0.072). There was no significant difference in systolic, diastolic, mean arterial blood pressure, and heart rate between groups before and after successful blockade (p > 0.05). ConclusionsContinuous infusion method of popliteal nerve block provides a longer pain-free period. Both methods showed similar hemodynamic data and low pain scores. Although continuous infusion method provides better analgesia, its procedural cost, technical difficulties, and adverse effects on patient comfort should also be considered.

Development and optimization of the Glabridin-loaded dissolving microneedle for enhanced treatment of keloid

Glabridin (Gla) has been reported to have significant effects in scar treatment, and however, the water insolubility of Gla leads to its poor transdermal absorption ability, which affects its bioactivities. Therefore, we attempted to prepare the Gla dissolving microneedles (Gla-MN) to improve the absorbtion of Gla. After investigation of the 3 factors including the needle tip matrix concentration, the prescription concentration of backing material, and the dissolution method of Gla, we finally determined the process parameters of 10% hyaluronic acid (HA) as the needle tip and 5% polyvinyl alcohol (PVA) as the backing, according to which the Gla-MN was prepared with the good characteristics of high hardness, complete appearance and good in vitro dissolution ability. We then loaded Gla onto the microneedles and measured that the average drug loading of Gla-MN was 2.26 ± 0.11 μg/mg and the cumulative transdermal release of Gla-MN was up to 76.9% after 24 h. In addition, Gla-MN had good skin penetration properties, with Gla-MN penetrating at least 4 to 5 layers of parafilm. And the skin basically could return to normal after 4 h of piercing. Importantly, our results showed that Gla-MN had higher transdermal delivery and therapeutic effects against keloid than that of Gla at the same dosage.

Automated Capsular Decompression to Avoid Argentinian Flag Sign in Intumescent Cataract.

We describe an alternative automated technique that consists of simultaneous anterior capsule puncture and decompression of the capsular bag by using an insulin needle attached to the aspiration tubing of the phacoemulsification device to prevent the occurrence of the "Argentinian Flag sign" during capsulorhexis in intumescent cataract. Instituto de Olhos de Assis and Center of Specialties Hoftalmed, located in the state of São Paulo, Brazil. Prospective interventional study. Eighty-eight eyes of 88 patients with white or intumescent cataracts were included in this study. Routine clear cornea incision, capsule staining with trypan blue, intracameral anesthesia, and ophthalmic viscoelastic device were used before the procedure. A 26-gauge needle was connected to the phacoemulsification aspiration tubing using a double male Luer connector for irrigation, and aspiration was inserted into the anterior chamber through a new paracentesis incision with the bevel facing down. Immediately after insertion, automated aspiration of the liquefied cortex was performed to remove anterior intralenticular material and achieve capsular decompression. Compression of the nucleus with the needle tip was performed to remove any liquefied material trapped between the posterior surface of the nucleus and the posterior capsule. All surgeries were performed using the same phacoemulsification and parameters. The rate of complete continuous capsulorhexis was observed and noted. No complications were observed in any of the cases. A single-stage, continuous, and well-centered capsulorhexis was achieved in 100% of cases. We conclude that a simultaneous puncture and decompression of the capsular bag using an insulin needle attached to the aspiration tubing of the phacoemulsification machine effectively avoided the "Argentinian Flag sign" in intumescent cataract surgery.

Comparison of Transesophageal Echocardiography Probe as Surface Probe with Vascular Probe During Right Internal Jugular Vein Catheterization in Cardiac Surgeries.

USG vascular probe and TEE probe can help during central venous catheterization (CVC) and can confirm the location of guide wire in the neck vessels. We proposed this study, as there are only few studies comparing between TEE probe as surface probe and USG vascular probe for right IJV cannulation. To compare the TEE probe as a surface probe and USG vascular probe during right IJV catheterization in cardiac surgeries. Prospective, comparative study. One twenty-four patients of either sex posted for major elective cardiac surgery were included in this study. Patients were divided into two groups (TEE group and USG group) of 62 by assigning the study participants alternatively to each group. The goal of this study was to compare the puncture time, visualization of IJV to first successful puncture, quality of the imaging with needle tip positioning, and catheter positioning using both TEE probe and vascular probe. The primary outcome was comparison of time from visualization of the IJV to successful puncture using both TEE probe as a surface probe and vascular probe. Secondary outcome was to compare the quality of image with respect to needle tip positioning and compare quality of image with respect to catheter position using both probes. Statistical analyses were performed by using a statistical software package SPSS, version 20.0. The observation and results of our study clearly show the feasibility of TEE as surface probe for guiding central venous catheter in right IJV just like the vascular linear probe. There was no significant difference between the two groups (P > 0.05). No statistical differences were found in the puncture time, image quality, needle tip positioning, wire positioning, and catheter positioning between the two groups. All the P values were greater than 0.05. The TEE probe can be used as an alternative method to guide IJV puncturing and catheterization when the vascular probe is not available. It is feasible especially in cardiac surgeries where the TEE monitoring machine is a must in modern anesthesia and readily available than an ultrasound machine.

Strategies for Safe Transurethral Injections of Botulinum Toxin into the Bladder Wall.

Introduction: Transurethral injections into the bladder wall with botulinum toxin are an established treatment for refractory overactive bladder or detrusor overactivity. With the current injection technique, an average of approx. 18% and up to 40% of botulinum toxin is injected next to the bladder wall, potentially causing reduced efficacy or non-response. The article aims to evaluate the reasons for incorrect injections and propose strategies for complete delivery of the entire botulinum toxin fluid into the bladder wall. Material and Methods: Unstructured literature search and narrative review of the literature. Results: Incorrect injection of botulinum toxin fluid next to the bladder wall is caused by pushing the injection needle too deep and through the bladder wall. Bladder wall thickness decreases with increasing bladder filling and has a thickness of less than 2 mm beyond 100 mL in healthy individuals. Ultrasound imaging of the bladder wall before botulinum toxin injection can verify bladder wall thickness in individual patients. Patient movements during the injection therapy increase the chance of incorrect placement of the needle tip. Conclusions: Based on the literature search, it is helpful and recommended to (1) perform pretreatment ultrasound imaging of the bladder to estimate bladder wall thickness and to adjust the injection depth accordingly, (2) fill the bladder as low as possible, ideally below 100 mL, (3) use short needles, ideally 2 mm, and (4) provide sufficient anesthesia and pain management to avoid patient movements during the injection therapy.

The Power of Color Flow Doppler Ultrasonography Versus Blind Technique in Localization of Epidural Catheter: A Randomized Prospective Study.

The success of epidural analgesia hinges on the precise insertion of the needle within the epidural space; failure rates have been reported to reach 32%. We report a new method using color Doppler to help verify the accurate location of the epidural needle tip. This is a randomized prospective study. Sixty patients undergoing hysterectomy were enrolled, with 30 patients in each group. Color flow Doppler (CFD) ultrasonography was employed to guide epidural catheter placement. The ultrasound-guided epidural technique was used for patients where challenges in identifying traditional landmarks for epidural space localization were anticipated. The procedure commenced with a spinal epidural technique. After sterile preparation and draping of the area, a curvilinear ultrasound transducer, encased in a sterile sheath, was used to locate the interspinous space. The primary outcome measure focused on flow visualization at different insertion levels. Secondary outcome measures included the duration of catheter implantation, intervertebral level of insertion, and dermatome sensory levels. The study also assessed the quality of epidural analgesia and patients' assessment of analgesic quality using a Verbal Numerical Rating Scale. The study reported a successful and predominantly safe outcome, with high success rates in flow visualization and effective anesthesia coverage. Flow visualization at the insertion and surrounding levels demonstrated a 100% success rate at all observed points. The Visual Numeric Rating Scale (VNRS) results indicated a median pain score of 2 with an interquartile range (IQR) of 2 - 3, showcasing a generally low level of post-procedural pain among the subjects, reflecting good quality post-operative analgesia. Regarding dermatome sensory levels after 2 hours, the distribution across various levels, including T4, T6, T7, T8, T10, and T12, exhibited a favorable outcome. The highest proportion was observed at T10 (68.3%), suggesting effective anesthesia coverage in the targeted areas. The study demonstrated comparable efficiency between the CFD-guided and blind techniques in terms of procedural aspects. However, notable distinctions were observed in patients' reported pain levels, with the CFD group experiencing lower pain compared to the blind technique group. Additionally, the study highlighted the association between CFD and improved procedural accuracy and safety. This study advocates for the integration of CFD into routine clinical practice to enhance procedural outcomes and patient safety during hysterectomy surgeries.

Puncture Accuracy of Robot-Assisted CT-Based Punctures in Interventional Radiology: An Ex Vivo Study.

The purpose of this study was to assess the performance of an optically tracked robot for computed-tomography (CT)-guided needle placements in a phantom study. In total, 240 needle punctures were carried out with the help of an optically tracked robotic device (Micromate) based on CT image datasets at three different slice thicknesses (1, 3, and 5 mm). Conically shaped targets inside a gelatin-filled plexiglass phantom were punctured. The target positioning error between the planned and actual needle trajectory was assessed by measuring the lateral positioning error (ND) between the target and the puncture needle and the Euclidean distance (ED) between the needle tip and target in control CTs. The mean ND and ED for the thinnest CT slice thickness were 1.34 mm (SD ± 0.82) and 2.1 mm (SD ± 0.75), respectively. There was no significant impact of target depth on targeting accuracy for ND (p = 0.094) or ED (p = 0.187). The mean duration for the planning of one trajectory and for needle positioning were 42 s (SD ± 4) and 64 s (SD ± 7), respectively. In this ex vivo study, the robotic targeting device yielded satisfactory accuracy results at CT slice thicknesses of 1 and 3 mm. This technology may be particularly useful in interventions where the accurate placement of needle-like instruments is required.

Multifunctional Microneedle Patch Based on Metal-Phenolic Network with Photothermal Antimicrobial, ROS Scavenging, Immunomodulatory, and Angiogenesis for Programmed Treatment of Diabetic Wound Healing.

In diabetic patients with skin injuries, bacterial proliferation, accumulation of reactive oxygen species (ROS) in the tissues, and impaired angiogenesis make wound healing difficult. Therefore, eliminating bacteria, removing ROS, and promoting angiogenesis are necessary for treating acute diabetic wounds. In this study, benefiting from the ability of polyphenols to form a metal-phenolic network (MPN) with metal ions, TA-Eu MPN nanoparticles (TM NPs) were synthesized. The prepared photothermal agent CuS NPs and TM NPs were then loaded onto the supporting base and needle tips of PVA/HA (PH) microneedles, respectively, to obtain PH/CuS/TM microneedles. Antibacterial experiments showed that microneedles loaded with CuS NPs could remove bacteria by the photothermal effect. In vitro experiments showed that the microneedles could effectively scavenge ROS, inhibit macrophage polarization to the M1 type, and induce polarization to the M2 type as well as have the ability to promote vascular endothelial cell migration and angiogenesis. Furthermore, in vivo experiments showed that PH/CuS/TM microneedles accelerated wound healing by inhibiting pro-inflammatory cytokines and promoting angiogenesis in a diabetic rat wound model. Therefore, PH/CuS/TM microneedles have efficient antibacterial, ROS scavenging, anti-inflammatory, immunomodulatory, and angiogenic abilities and hold promise as wound dressings for treating acute diabetic wounds.

A Randomized Study Comparing Ultrasound-Guided Internal Jugular Vein Cannulation Using Two Techniques: Short-Axis Out-of-Plane With Dynamic Needle Tip Positioning Versus Long-Axis In-Plane.

Introduction Internal jugular vein (IJV) cannulation is a routine procedure in operating rooms, critical care units, and perioperative settings. Ultrasound guidance has notably increased the success rates of IJV cannulation. A modified ultrasound technique known as the short-axis out-of-plane method with dynamic needle tip positioning (DNTP) allows for continuous visualization of the needle tip throughout the procedure. This study aims to compare the first-pass success rate of IJV cannulation using the DNTP and long-axis in-plane (LAIP) approaches. Methods One hundred patients between 18 and 70 years undergoing elective surgery requiring IJV cannulation were recruited.Patients were assigned randomly to the DNTP group (n = 50) or the LAIP group (n = 50). We recorded the first-pass success rate, time to achieve successful cannulation, number of skin punctures, overall success rate within five minutes, and potential complications such as pneumothorax and hematoma. Results The first pass success rate was higher in the DNTP group (48/50, 96%) as compared to the LAIP group (38/50, 76%, relative risk, 1.67; 95% confidence interval, 0.039-0.707; p = 0.008). The cannulation time was shorter in DNTP (116.98 ± 22.90 seconds) versus the LAIP group (213.04 ± 52.08 seconds; p < 0.001). No complications like pneumothorax or hematoma were noted in both groups. Conclusion We conclude that the ultrasound-guided DNTP technique for IJV cannulation, as compared with the LAIP technique, may significantly improve the first attempt cannulation, number of attempts, and cannulation time.

Resonating Electrostatically Guided Electrons.

An essential component for quantum-enhanced measurements with free electrons is an electron resonator. We report stable guiding of free electrons at 50eV energy for up to seven round trips in a linear autoponderomotive guiding structure, which is realized with two microstructured printed circuit boards that generate the required electromagnetic fields. Free electrons are laser triggered from a sharp tungsten needle tip and coupled in at the front of the electron resonator with the help of sub-nanosecond-fast switchable electron mirrors. After a variable time delay, we open the rear electron mirror and measure the number of trapped electrons with a delay-line detector. We demonstrate, simulate, and show ways of optimizing an electron resonator in simulations, which will help enable "interaction-free" measurement setups, including multipass and quantum-Zeno effect based schemes, helping to realize the quantum electron microscope.

Ultrasound Contrast Agent Needle Priming: Impact on Sonographic Biopsy Needle Visibility in a Porcine Liver Model

PurposeThe visibility of biopsy needles in contrast-specific imaging mode can be improved by priming them with an ultrasound contrast agent (previously demonstrated in a phantom model/ex vivo). The purpose of this study was to validate this priming method in a porcine in vivo model.Materials and MethodsUsing a small syringe, full-core biopsy needles were primed with sulfur hexafluoride, an ultrasound contrast agent, with non-primed needles serving as controls (n = 30 + 30). Liver punctures were performed in a porcine model following intravenous administration of the same ultrasound contrast agent. Needle visibility, both in their entirety and at the tips, was evaluated in split-screen mode using contrast-specific imaging and B-mode (low mechanical index). The assessment included quantitative analysis, calculating the contrast-to-noise ratio, and qualitative evaluation through structured grading by three radiologists.ResultsAfter needle priming, the contrast-to-noise ratio was superior for the needle in its entirety in contrast-specific imaging mode (p < 0.001) and slightly inferior in B-mode (p = 0.008). No differences were observed for the needle tips in either imaging mode. Qualitatively, the needle visibility was deemed clinically superior after needle priming throughout in contrast-specific imaging mode (p < 0.001), whereas no clinically relevant differences in B-mode for either the needle in its entirety (p = 0.11) or the needle tip (p = 1) were observed.ConclusionIn this in vivo porcine liver model experiment, priming biopsy needles with ultrasound contrast agent improved needle visibility in contrast-specific imaging mode but slightly reduced it in B-mode. These findings support the method’s use for biopsies requiring target visualization in contrast-specific imaging mode.No level of evidence.Graphical

Embryo Microinjection for Transgenesis in Drosophila.

Transgenesis in Drosophila is an essential approach to studying gene function at the organism level. Embryo microinjection is a crucial step for the construction of transgenic flies. Microinjection requires some types of equipment, including a microinjector, a micromanipulator, an inverted microscope, and a stereo microscope.Plasmids isolated with a plasmid miniprep kit are qualified for microinjection. Embryos at the pre-blastoderm or syncytial blastoderm stage, where nuclei share a common cytoplasm, are subjected to microinjection. A cell strainer eases the process of dechorionating embryos. The optimal time for dechorionation and desiccation of embryos needs to be determined experimentally. To increase the efficiency of embryo microinjection, needles prepared by a puller need to be beveled by a needle grinder. In the process of grinding needles, we utilize a foot air pump with a pressure gauge to avoid the capillary effect of the needle tip. We routinely inject 120-140 embryos for each plasmid and obtain at least one transgenic line for around 85% of plasmids. This article takes the phiC31 integrase-mediated transgenesis in Drosophila as an example andpresents a detailed protocol for embryo microinjection for transgenesis in Drosophila.