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Apical pressure during root canal irrigation is regarded as a key factor affecting the risk of irrigant extrusion. The aim of this study was to examine the effect of apical size on the apical pressure by positive and negative pressure syringe-needle and multisonic negative pressure irrigation. An extracted maxillary first molar with two separate buccal roots, one palatal root and four canals was selected. The roots of the molar were fixed in a specially made apparatus to acquire the apical pressure of the four root canals separately. The apical sizes tested were from sizes 10, 30, 40, 50, 60, 70, 80, 90, 110. Multisonic negative pressure irrigation protocol was as recommended by the manufacturer (45 mL/min), syringe-needle irrigation was done using 30-G side-vented needle 3 mm from the working length at 5 mL/min as a conventional positive pressure irrigation (SNI), and as negative pressure irrigation (NPSNI) using suction. Apical pressure by SNI was measured also at 10 mL/min with an open-ended 30G needle, for the smallest and largest apical sizes. Apical pressures by SNI stayed positive, except when suction was used (NPSNI). The apical pressure by multisonic negative pressure irrigation remained negative in all situations. With increasing apical size, apical pressure by SNI decreased, whereas with multisonic negative pressure irrigation and NPSNI, it was not affected by apical size. Large apical size did not result in higher apical pressure values compared to small apical sizes.

Drug delivery into the inner ear is a significant challenge due to its inaccessibility as a fluid-filled cavity within the temporal bone of the skull. The round window membrane (RWM) is the only delivery portal from the middle ear to the inner ear that does not require perforation of bone. Recent advances in microneedle fabrication enable the RWM to be perforated safely with polymeric microneedles as a means to enhance the rate of drug delivery from the middle ear to the inner ear. However, the polymeric material is not biocompatible and also lacks the strength of other materials. Herein we describe the design and development of gold-coated metallic microneedles suitable for RWM perforation. When developing microneedle technology for drug delivery, we considered three important general attributes: (1) high strength and ductility material, (2) high accuracy and precision of fabrication, and (3) broad design freedom. We developed a hybrid additive manufacturing method using two-photon lithography and electrochemical deposition to fabricate ultra-sharp gold-coated copper microneedles with these attributes. We refer to the microneedle fabrication methodology as two-photon templated electrodeposition (2PTE). We demonstrate the use of these microneedles by inducing a perforation with a minimal degree of trauma in a guinea pig RWM while the microneedle itself remains undamaged. Thus, this microneedle has the potential literally of opening the RWM for enhanced drug delivery into the inner ear. Finally, the 2PTE methodology can be applied to many different classes of microneedles for other drug delivery purposes as well the fabrication of small scale structures and devices for non-medical applications. Graphical Abstract Fully metallic ultra-sharp microneedle mounted at end of a 24-gauge stainless steel blunt syringe needle tip: (left) Size of microneedle shown relative to date stamp on U.S. one-cent coin; (right) Perforation through guinea pig round window membrane introduced with microneedle.

The repeated puncture of vessels with a conventional syringe needle causes frequent pain and fear in patients and particularly increases the risk of infections. An indwelling needle implanted in veins for a long time can avoid repeated punctures. However, blood coagulation during implantation and bleeding after the withdrawal of the needle are still key problems. Herein, we present a novel strategy to engineer a smart indwelling needle with on-demand switchable anticoagulation and hemostatic activities by modifying the outer surface and the inner surface of the indwelling needle with a coagulant catechol-functionalized chitosan coating and anticoagulant magnetic FeNP–dopamine-conjugated heparin (FeNP–HepDA), respectively. The smart indwelling needle is implanted into a rabbit's ear vein. Remarkably, under a magnetic field, the FeNP–HepDA-coated cannula inner wall maintains excellent anticoagulation activity, ensuing the patency of the needle due to the firm fixation of FeNP–HepDA. Upon removing the magnetic field, FeNP–HepDA can be shed. Under this condition, the cannular inner surface loses anticoagulation activity and when the needle is extracted from the vein, the hemostatic CHCS coating on the external surface serves to prevent bleeding. The strategy reported in this study opens up an avenue for designing biomaterials and biodevices exhibiting the coexistence of anticoagulation and coagulation.

The bilateral cavernous nerve (CN) injury rat model has been extensively used to simulate clinical cavernous nerve injury associated with erectile dysfunction (ED) for evaluating the effect of clinical therapeutic methods. However, the methods of CN injury model construction are flawed and varied in the ED research field. It is CN crush injury that is the most commonly used method in recent years. This study aims to provide a detailed description of the procedure of bilateral CN injury rat model construction and measurement of intracavernous pressure (ICP) recording, providing a reliable and reproducible CN injury rat model. This work successfully developed the CN injury method of hemostat crush injury using a syringe needle as hard support and a hemostat with a rubber sleeve. Also, this method concludes that a voltage of 1.0 V, frequency of 20 Hz, and pulse-width of 5 ms are the optimized stimulation parameters for ICP recording in a bilateral CN injury rat model.

The objective of the study was to evaluate the influence of syringe and needle sizes on production time and bead size of Lactobacillus plantarum-sodium alginate-banana peel. The bead was produced using the extrusion method. The 25G and 23G of needles produce 0.5 mm to 1 mm and 1 mm to 2 mm bead size, respectively. No different of bead sizes were observed when different syringe size was used. Higher internal diameter of syringe needle and smaller syringe size produced bead in fastest processing time (1 min). The extrusion using 23G syringe needle and 10 ml syringe obtained smallest bead size and fastest processing time. This crucial information could further optimise the extrusion process and future up-scaling process.

Superhydrophobic conical pillars have great industrial application potential in, for example, anti-icing of aircraft wings and protecting high voltage transmission lines from freezing rain because of their droplet pancake bouncing phenomenon, which is recognized to further reduce the liquid-solid contact time. However, there are still no methods that can fabricate robust superhydrophobic conical pillars in large scale. Here, a mold replication technology was proposed to realize the large-scale fabrication of superhydrophobic conical pillars with high mechanical strength. An Al mold with intensive conical holes decorated with micro/nanometer-scale structures was fabricated by nanosecond laser drilling and HCl etching. The conical shape originated from a near Gaussian spatial distribution of the energy and temperature in the radial direction in the laser drilling processes. Robust superhydrophobic conical pillars from syringe needle shape to straight conical pillar shape were easily fabricated through replication from the Al mold without any extra spray of superhydrophobic nanoparticles. It was also found that although all superhydrophobic conical pillars with different shapes could generate the droplet pancake bouncing, the shape had a great influence on the critical bottom space and the critical Weber number (We) to generate pancake bouncing. The pancake bouncing with the shortest contact time of a 68.5% reduction appeared on superhydrophobic straight conical pillars with the shape angle of 180°. Overcoming the difficulties in the large-scale fabrication and robustness of superhydrophobic conical pillars will promote practical applications of the droplet pancake bouncing phenomenon.

Fully integrated hydrogel channels were fabricated via interfacial bioorthogonal cross-linking, a diffusion-controlled method for the creation and patterning of synthetic matrices based on the rapid bioorthogonal reaction between s-tetrazines (Tz) and trans-cyclooctene (TCO) dienophiles. Injecting an aqueous solution of a bisTCO cross-linker into a reservoir of tetrazine-modified hyaluronic acid (HA-Tz), while simultaneously drawing the syringe needle through the reservoir, yielded a cross-linked hydrogel channel that was mechanically robust. Fluorescent tags and biochemical signals were spatially patterned into the channel wall through time-dependent perfusion of TCO-conjugated molecules into the lumen of the channel. Different cell populations were spatially encapsulated in the channel wall via temporal alteration of cells in the HA-Tz reservoir. The interfacial approach enabled the spatial patterning of vascular cells, including human abdominal aorta endothelial cells, aortic vascular smooth muscle cells, and aortic adventitial fibroblasts, into the hydrogel channels with high viability and proper morphology in the anatomical order found in human arteries. The bioorthogonal platform does not rely on external triggers and represents the first step toward the engineering of functional and implantable arteries.

Background: Ganglion is one lesion that is frequently seen in minor surgical practice. Treatment of dorsal wrist ganglia begins from basic reassurance to advanced endoscopic excision. Many a time’s treatment not often necessary, but patients seek consultation asking for some form of definitive treatment. Recurrence is frequently seen with cyst aspiration/injection or after surgical excision. Recurrence is the common problem, whatever is the treatment modality. Materials and Methods: In this study we evaluate results of 30 dorsal wrist ganglia treated by the transfixation technique using a syringe needle. Results: Out of 30 cases included in this study 28 were completely cured of the symptoms giving a success rate of 93.33%, One patient (3.33%) had recurrence at 4 months and was painful and he had to undergo excision, One patient (3.33%) had recurrence at the end of 6 months. Discussion: Compared to various other modalities this method is cost-effective, time consumption is less, low invasion, recurrence rate is low, and can be performed under local anaesthesia, and does not require any complicated instrument and an easy-to-master technique.

Host-plant volatiles play a key role in finding mate and suitable host plants of phytophagous scarab beetles. Hence it is immensely important to collect and identify these volatiles. The gas chromatography coupled with electroantennographic detection (GC-EAD) technique has been used as a rapid and convenient tool for the identification of physiologically active components from plants. Here, we describe a practical method for electrophysiologically recording from lamellated antenna of scarab beetles. This method enables direct electroantennogram (EAG) recordings from antennal club without damage to the antenna in a similar manner to the conventional cut-tip EAG recording technique for clavate antenna. The headspace volatiles from walnut (Juglans regia L.) trees were collected with a Poropak-Q trap at dusk and then analyzed with GC-EAD. Those volatile compounds that elicited electrophysiological responses on the antennae of a scarab beetle, Metabolus flavescens Brenske (Coleoptera: Scarabeidae: Melolonthinae) were determined by means of gas chromatography-mass spectrometry (GC-MS). The lamella directly connected to the recording electrode was held apart from the other two lamellae on the antenna with a minuten pin and a disposable syringe needle. In order to improve electrical contact, a surfactant, Tween® 80, was used to lower the surface tension of Beadle-Ephrussi Ringer solution. This study demonstrated that addition of 0.05% Tween® 80 to the Beadle-Ephrussi Ringer solution suppressed baseline noise and assured significantly greater EAG response in general. Due to its simplicity and efficiency, this method may also be useful for studying the electrophysiology of other insect species having club-like antennae.

Three-dimensional (3D) cell constructs composed only of cells and cell-secreted extracellular matrix have been attractive biomaterials for tissue engineering technology; however, controlling construct morphology and eliminating dead cells after fabrication remain a challenge. It has been hypothesized that moderate stress could shape constructs and eliminate dead cells. The purpose of this study was to establish an easily available technology for shaping 3D cell constructs and eliminating dead cells postfabrication. To achieve these objectives, spherical cell constructs composed of L-929 fibroblasts were processed using different sized syringe needles. Our results revealed that large-scale rod-shaped cell constructs could be fabricated, and that their diameters could be controlled according to the size of the syringe needle. Additionally, cell viability assays showed that >94% of cells in the rod-shaped constructs were viable, suggesting that dead cells, which have low adhesion force, were dispersed when compressive stress was applied during passage through the needle. The technology described in this study will be promising for future tissue engineering, especially for fabricating elongated tissues such as nerves and blood vessels. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 904-909, 2019.

Resistance to fracture of a soft elastic gel by a sharp object like a hypodermic syringe needle depends upon the macroscopic geometry of the tool. While this subject has been examined to some detail, somewhat less explored issue is the effect of vibration on gel fracture, particularly the coupled effect of geometry and vibration. The topic is however important as it is encountered in many natural systems: for example, the hierarchical structure of mosquito proboscis and its vibratory motion, both are thought to influence the puncturing load. In this context we have carried out displacement controlled fracture of a soft gel using a syringe needle while also subjecting the gel to longitudinal vibration at controlled frequency and amplitude. These experiments show that vibration reduces maximum puncturing load and arrests also the occurrence of side cracks thereby allowing stress concentration to attain critical level ahead of the needle tip for fracture to occur.

A novel approach for the online coupling of solid-phase microextraction (SPME) and liquid chromatography (LC) is introduced. An innovative Si@GO@βCD coated needle-sleeve extractant device was developed and then employed in the automated online SPME-LC-UV determination of estrogen-like isoflavones from human urine samples. The extractant SPME device is easily attachable at the endpoint of an analytical syringe needle and operated by a lab-made autosampler. Fully automated online SPME-LC is accomplished by proper autosampler programming to perform the following steps: i) the analytes extraction by direct immersion of the extractant device into the stirred sample, ii) a rinsing step iii) the analytes desorption/enrichment, iv) the online transference of the extract to the LC injection valve. Besides allowing the online SPME hyphenation, this extraction modality efficiently addressed the drawbacks associated with the clogging and dispersion of graphene-based microextraction techniques performed in packed-bed and dispersive formats. The main extraction parameters and the performance of the automated online SPME-LC method developed were carefully studied. The results show a good sensitivity, reliability, and straightforward analytical strategy for the determination of organic compounds in complex samples. The detection limit of the method was 20 μg L1 for DAI and 10 μg L−1 for GEN, FOR and BIO. The intra-day RSD was below 10% and inter-day RSD was below 13%. The total analysis time was less than 17 min per sample.

Tissue puncture is an effective means in the diagnosis and treatment of diseases, providing important information for clinical doctors. Yet, haemorrhage is still a main and unavoidable complication, which can cause serious outcomes, especially in patients with abnormal coagulation function. Herein, we present a facile yet effective strategy to prepare haemostatic needles by coating the syringe needles surface with alginate-CaCl2-based hydrogel with carefully optimized mechanical and chemical properties, which can effectively prevent bleeding following tissue puncture. The needle with haemostatic coating exhibits complete prevention of blood loss following vessel and viscera puncture in the normal animal as well as in animal models with hemorrhagic diathesis. The syringe needle with haemostatic coating in this work holds enormous potentials for clinical applications, including sampling and injection.

Background Warts, or verrucae, are benign epithelial profilerations of skin and mucosa caused by infection with HPV and poses a challenge to treat. Objective To compare between single and microneedling-assisted multipuncture techniques of intralesional application in treatment of plantar warts. Methods The study included 60 Patients who were divided into two groups (A&B). Each group consisted of (30) patients. Group (A) subjects received intralesional bleomycin with a single injection using syringe needle. For Group (B) subjects, we combined microneedling with topical spraying of bleomycin (MN + Bleo) and followed by occlusion for 2 hours. Results The results revealed complete clearance of warts in 21 patients in group (A) (70%) whom were treated by intralesional (IL) bleomycin vs 25 patients (83.3%) in group (B) whom were treated by spraying of bleomycin following microneedling. Side effects other than pain, erythema, and transient induration were relatively infrequent, and no nail changes or Raynaud's phenomenon was observed in both groups. Conclusion We established a good safety and efficacy profile for bleomycin in plantar wart treatment and we demonstrated that microneedling followed by bleomycin spraying had a higher clearance and proved less painful as opposed to bleomycin injection.

The accelerator-based syringe needle-type proton-induced X-ray source, which was proposed by the authors in 2013 as an alternative for prostate cancer brachytherapy, has an essential issue in that its dose distribution is affected by many factors, such as the structure of the needle and incident proton beam conditions. In this paper, as a method of evaluating dose distribution, we propose a Geant4 simulation to study the effect of the incident proton beam condition on the spectrum and distribution of X-ray emission, using experimentally measured proton beam emittance as input data. The results showed that the effect of beam misalignment was significant and confirmed the effectiveness of this method. It is expected that improving this method will clarify the other factors that affect X-ray distribution, so that finally, we can optimize such factors in designing a special dose distribution for the irradiation of tumors of arbitrary size and shape in the tissue. Copyright © 2017 John Wiley & Sons, Ltd.

Herein, we report a sheet-type device capable of self-deployment and sustained release of protein type drugs. The device consisted of a thin photopolymerized polyethylene glycol dimethacrylate (PEGDM) sheet and collagen microparticles (COLs), which were embedded in the sheet as drug carriers and for increased drug permeation. When the density of the COLs in the sheet was increased to be sufficiently interconnected, the drug permeability was increased. In addition, since protein type drugs electrostatically interacted with the COLs, a prolonged sustained release was possible. The PEGDM/COLs device was flexible enough to be rolled up, and the device maintained its structure due to van der Waals attractive forces between the sheet surfaces. When the device was immersed in water, the attractive forces acting between the sheet surfaces were relieved by water. Subsequently, the device unfolded by bending-stress relaxation. Moreover, the rolled-up device could be injected through a conventional syringe needle into water to recover its original shape. The developed sheet-type device provides the possibility of minimally invasive transplantation into diseased tissues and organs, and could provide better therapeutic outcomes and reduce possible side effects. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 780–786, 2018.

Background: Thorough cleaning of the pulp space is a challenging task. The mechanical instrumentation alone is usually not sufficient to completely debride the canals, and therefore, it requires the chemical action of irrigants also to disinfect the difficult to reach areas. Aim: The purpose of this study was to determine apical extrusion and assess irrigant penetration through cone-beam computed tomography (CBCT) for EndoActivator (EA) and XP Endo Finisher (XP). Materials and Methods: Sixty single-rooted mandibular premolars with oval-shaped canals were equally divided into three groups after instrumentation, based on the final irrigation: Group-1 syringe needle (30G Max-I-probe), Group-2 EA, and Group-3 XP. After the final irrigation, the weight of the extruded sodium hypochlorite was calculated. The prepared canals were then irrigated with a radiopaque contrast medium, which was activated according to the group of the sample (Group-1, 2, or 3). The volume of irrigant filled in the canal, especially in the apical third was determined through special tools in CBCT imaging. Statistics: One-way ANOVA test was used to compare the different groups. Results and Conclusion: Significantly more apical extrusion was seen in XP (P < 0.001). Both XP and EA have shown complete penetration of irrigant in the canal (100%).

Material production processes have evolved in a variety of ways over the past decades. Three-dimensional printing is an additive manufacturing process that fabricates structures and geometries based on consistent layer formation guided by a three- dimensional model. In 3D bioprinting, bioinks comprising of cells, polymers, growth modulators, and drugs are utilized for the fabrication of cellular constructs that mimic the functionality of their natural counterparts. In this study, an extrusion-based 3D bioprinter for bioprinting of hydrogel-based biomaterials was developed using DVD drives with an adjustable syringe pump. Moving axis comprising of stepper motor PL15S-020 were joined for construction of X, Y, and Z-axis and mechanical support was constructed using 3mm poly (methyl methacrylate). For control of the 3D bioprinter, RepRap Arduino Mega Polulu Shield 1.4 was interfaced with Arduino Mega 2560 R3 and A4988 stepper motor drivers. CAD operations were performed using Matter Control 2.0 and gcode was generated using Cura which was afterward sent to the printer via Pronterface. For 3D bioprinting, a variety of bioinks with sodium alginate and agarose as a key ingredient were developed. Print quality was optimized by varying printhead speed, extrusion rate, concentrations of hydrogel ingredients, and syringe needle size. The 3D bioprinter developed from DVD drives had printing area of 35mm*35mm*15mm with optimum printing quality by using 0.1 mm nozzle and 5% agarose-based biomaterials. The ease of utilization and cost-effectiveness of the development of 3D bioprinter will allow life sciences researchers to adapt the 3D bioprinting process more effectively for a wide range of applications.

Serial crystallography (SX) allows crystal structures to be observed at room temperature through the steady delivery of crystals to the X-ray interaction point. Viscous delivery media are advantageous because they afford efficient sample delivery from an injector or syringe at a low flow rate. Hydrophobic delivery media, such as lipidic cubic phase (LCP) or grease, provide a very stable injection stream and are widely used. The development of new hydrophobic delivery materials can expand opportunities for future SX studies with various samples. Here, I introduce fat-based shortening as a delivery medium for SX experiments. This material is commercially available at low cost and is straightforward to handle because its phase (i.e., solid or liquid) can be controlled by temperature. Shortening was extruded from a syringe needle in a very stable injection stream even below 200 nl/min. X-ray exposed shortening produced several background scattering rings, which have similar or lower intensities than those of LCP and contribute negligibly to data processing. Serial millisecond crystallography was performed using two shortening delivery media, and the room temperature crystal structures of lysozyme and glucose isomerase were successfully determined at resolutions of 1.5–2.0 Å. Therefore, shortening can be used as a sample delivery medium in SX experiments.