Sharp Needle Research Articles

Multiplane hyaluronic acid (EME) in female Chinese rhinoplasty using blunt and sharp needle technique

Hyaluronic acid has been widely used for nonsurgical rhinoplasty. Little literature focuses on Chinese women of the Han nationality, who have a characteristic flattened facial contour. Projection of the nose, including the nasal dorsum, nasal tip, and columella, plays an important role in achieving an attractive face. The aim of this study was to investigate the application of multiplane hyaluronic acid in rhinoplasty using blunt and sharp needle technique. From June 2011 to February 2014, 280 cases of nonsurgical rhinoplasty by hyaluronic acid were applied; 1-9 months follow-up showed satisfactory appearance. Postoperative results showed no complications, such as infection or flap necrosis. For esthetic and safety considerations, we suggest multiple plane injections using blunt combined with sharp needle-filling techniques.

Growth of vertically oriented InN nanorods from In-rich conditions on unintentionally patterned sapphire substrates

Vertically oriented InN nanorods were grown on selective areas of unintentionally patterned c-oriented sapphire substrates exhibiting sharp needles that preferentially accommodate In-metal liquid droplets, using Migration Enhanced Afterglow (MEAglow) growth technique. We point out that the formation of AlN needles on selected areas can be reproduced intentionally by over-nitridation of unmasked areas of sapphire substrates. The liquid indium droplets serve as a self-catalyst and the nanorods grow from the supersaturated indium melt in the droplet in a vertical direction. X-ray diffraction measurements indicate the presence of hexagonal InN only, with preferred orientation along (0001) crystal axis, and very good crystalline quality. The room temperature Raman spectrum shows the presence of the A1(TO), E2(high) and A1(LO) phonon modes of the hexagonal InN.

Highly Coherent Electron Beam from a Laser-Triggered Tungsten Needle Tip.

We report on a quantitative measurement of the spatial coherence of electrons emitted from a sharp metal needle tip. We investigate the coherence in photoemission triggered by a near-ultraviolet laser with a photon energy of 3.1 eV and compare it to dc-field emission. A carbon nanotube is brought into close proximity to the emitter tip to act as an electrostatic biprism. From the resulting electron matter wave interference fringes, we deduce an upper limit of the effective source radius both in laser-triggered and dc-field emission mode, which quantifies the spatial coherence of the emitted electron beam. We obtain (0.80±0.05) nm in laser-triggered and (0.55±0.02) nm in dc-field emission mode, revealing that the outstanding coherence properties of electron beams from needle tip field emitters are largely maintained in laser-induced emission. In addition, the relative coherence width of 0.36 of the photoemitted electron beam is the largest observed so far. The preservation of electronic coherence during emission as well as ramifications for time-resolved electron imaging techniques are discussed.

Using a controlled trauma technique when injecting hyaluronic acid dermal fillers

The use of dermal fillers, as well as the effects of dermal needling on the skin, have been studied and confirmed to stimulate neocollagenesis. In this article, the author discusses the combination of these the two concepts in one technique to offer superior outcomes. The article supports the notion that hyaluronic acid (HA) stimulates collagen in the skin and uses evidence to suggest that specific techniques and instruments can greatly enhance the durability of results. Based on the controlled injury theory in which type I and type III collagen production occur at accelerated rates post trauma, the technique uses a sharp needle to create a modest subcuticular undermining effect. This controlled trauma disrupts fragmented collagen strands and replaces them with purposeful, elongated strands of promoted neocollagenesis. Controlled injury begins the wound healing cascade and creates new, non-fragmented collagen, providing improvement in the appearance and health of ageing skin. When neocollagenesis is increased, the duration of the desired outcome also increases. Type I and III collagen have been shown to last 4–7 years, creating an aesthetic result lasting long after the duration of the HA filler itself.

Estimating the viscosity of a highly viscous liquid droplet through the relaxation time of a dry spot

We discuss in this paper a technique which enables the estimation of the viscosity of microscopic droplets, with application to particles suspended in the atmosphere. The principle of this technique is to deposit a droplet of material approximately 30–100 μm in diameter on a substrate and poke it with a sharp needle hence generating a hole. The amount of sample needed to perform such measurement allows the viscosity of small sample volumes (less than a microliter), such as those generated from atmospheric sampling, to be determined. We show here that the time required for the droplet to relax to its equilibrium shape can be related to the viscosity. We hereby present two mathematical models based on the lubrication approximation which are able to capture the droplet relaxation dynamics. One model is fully transient and resolves the dynamics of the wetting front using a disjoining pressure approach. The other is quasistatic and requires a relationship between the contact line velocity and the contact angle. Comparing the computed relaxation time to that measured experimentally enables the approximate evaluation of the viscosity. The mathematical models are first tested against data from the literature for the closure of a hole in a continuous thin film and then demonstrated for droplets of the polybutene oil N450000 (trade name Cannon Standard Oil), a high-viscosity standard, which serve as a benchmark sample since it is precisely characterized. We also present here viscosity estimates for droplets consisting of secondary organic material and water which are present over forested region yet remain very poorly understood for a lack of adequate characterization technique.

SHARP VERSUS BLUNT DIALYSIS NEEDLE USE WITH BUTTONHOLE METHOD: OPEN RANDOMISED TRIAL.

Current protocols recommend the use of a blunt needle to access the arteriovenous fistula via a buttonhole. This study aims to demonstrate whether a sharp needle can be used at the same buttonhole site without causing complications. To measure and compare fistula cannulation failures between the use of blunt and sharp needles. PLAN: Open-crossover randomised controlled trial. Adult out-patients who had provided consent and were on dialysis with a mature arteriovenous fistula and buttonhole cannulation. Failed cannulation-difficulty in inserting the needle and the trampoline effect; incidence of complications, such as infection and haematomas; times to haemostasis; patients' pain; and patients' preferences. Based on analysis of the data from the 35 patients enrolled, no significant differences were detected in failed cannulation of the fistulae between the use of a blunt needle and a sharp needle for the 335 venous accesses (p = 0.071). However, a significant difference was detected for the 335 arterial accesses (p = 0.001), in which the sharp needle was more effective. Significant differences were also detected in the difficulty of insertion and in the trampoline effect for both venous and arterial access (p < 0.05); the use of a sharp needle was more favourable. This study demonstrates an increased incidence of failed cannulation using a blunt needle compared with using a sharp needle, although this was not significant. In addition, the use of a sharp needle did not result in any increase in complications.

The effect of needle gauge, needle type, and needle orientation on the volume of a drop.

The purpose of this study was to determine impact of needle gauge, type, and orientation on average volume of drop dispensed. Five needle gauges (22G, 23G, 25G, 27G, and 30G) were examined. For each gauge, volume of drop delivered was determined for standard sharp beveled tip, blunt tip, and after breaking off of the sharp needle from the hub. Vertical and horizontal orientation of the needle was tested for effect on drop volume for 22-G and 30-G sharp beveled needles. Mean drop volume was affected by needle gauge, needle orientation, and whether the needle had been broken off from its hub. Mean drop volume scaled directly with needle diameter with drop volumes of 25.0μL (±20.2) and 83.9μL (±16.5) being found for 30-gauge and 22-gauge needles, respectively. Intermediate gauges (27, 25, 23G) yielded intermediate drop volumes. Blunt needles tended to produce larger drop volumes compared to sharp beveled needles, but these differences did not reach statistical significance. Breaking off of the needle from the hub produced substantially larger drop volumes with little difference being found between needle gauges. Average volumes of 1 drop from a 22-G vertical, 22-G horizontal, 30-G vertical, and 30-G horizontal sharp beveled needle were 20.2, 9.1, 10.1, and 3.3μL, respectively. These findings have relevance for controlled delivery of topical ophthalmic medications to patients.

Performing subretinal injections in rodents to deliver retinal pigment epithelium cells in suspension.

The conversion of light into electrical impulses occurs in the outer retina and is accomplished largely by rod and cone photoreceptors and retinal pigment epithelium (RPE) cells. RPE provide critical support for photoreceptors and death or dysfunction of RPE cells is characteristic of age-related macular degeneration (AMD), the leading cause of permanent vision loss in people age 55 and older. While no cure for AMD has been identified, implantation of healthy RPE in diseased eyes may prove to be an effective treatment, and large numbers of RPE cells can be readily generated from pluripotent stem cells. Several interesting questions regarding the safety and efficacy of RPE cell delivery can still be examined in animal models, and well-accepted protocols used to inject RPE have been developed. The technique described here has been used by multiple groups in various studies and involves first creating a hole in the eye with a sharp needle. Then a syringe with a blunt needle loaded with cells is inserted through the hole and passed through the vitreous until it gently touches the RPE. Using this injection method, which is relatively simple and requires minimal equipment, we achieve consistent and efficient integration of stem cell-derived RPE cells in between the host RPE that prevents significant amount of photoreceptor degeneration in animal models. While not part of the actual protocol, we also describe how to determine the extent of the trauma induced by the injection, and how to verify that the cells were injected into the subretinal space using in vivo imaging modalities. Finally, the use of this protocol is not limited to RPE cells; it may be used to inject any compound or cell into the subretinal space.

Membrane funnel-based spray ionization for protein/peptide analysis by Fourier transform ion cyclotron resonance mass spectrometry.

Samples analyzed in proteomic studies by nanoelectrospray ionization (nanoESI) are extremely limited in quantity requiring careful sample handling to prevent loss upon transfer and to maintain sample concentration. To alleviate the operational process and reduce the cost of nanoESI, it is essential to develop more robust, simple and sensitive analytical variants of the process. Membrane funnel-based spray was developed for analysis of proteins/peptides in this study. The membrane funnel was fabricated from thin flexible membrane by a punching method using a homemade device. The performance of the membrane funnel-based spray was demonstrated by analyzing peptides, proteins and trypsin-digested samples in comparison of nanoESI and the Teflon sheet based microfunnel. Compared with the microfunnel, the membrane funnel can be fabricated easily by punching a thin flexible membrane using a sharp needle. Only 50 nL of sample was required for an analysis. The membrane funnel enhanced the spray sensitivity 100-fold. A total of 5 amol of on-spot sample loading was sufficient to provide a measurable signal on a 9.4 Tesla Fourier transform ion cyclotron resonance mass spectrometry system. High-mass proteins (up to 66 kDa) could be analyzed using this funnel-based spray system. Good sequence coverage was obtained for tryptic digested samples. A rapid, simple and cheap membrane funnel-based sample plate fabrication method was developed. The membrane funnel-based spray is a promising new variant of nanoESI capable of fast and sensitive analysis of peptides/proteins with great potential that could be extended to other applications, including quantitative analysis at high throughput and imaging mass spectrometry.

Buttonhole Tunnel Tract Creation with the BioHole® Buttonhole Device.

Cannulation, and in particular, skilled cannulation is the cornerstone to preserving the arteriovenous fistula, the lifeline for a patient receiving long-term hemodialysis therapy. The buttonhole cannulation method has seen a huge revival in the 2000s, but it can sometimes prove challenging to implement successfully. This chapter discusses and describes the method of creating a buttonhole tract using the BioHole® device (a sterile polycarbonate peg), and describes the associated advantages and disadvantages. In a busy hemodialysis unit, use of the thumbtack-shaped 5-mm peg allows a fixed puncture route to be created quickly in just 7-14 days. The peg is placed at the site where the sharp puncture needle has just been removed by the designated primary cannulator. The peg remains in place until the next dialysis session when it is removed, the dialysis therapy completed as usual, and a new peg is inserted after hemostasis has been achieved. These steps are repeated for 1-2 weeks. Once the tunnel is formed, use of the peg is no longer needed and a blunt-ended puncture needle is inserted along the track each time. Buttonhole cannulation using the BioHole peg device offers advantages including reduced risk of needling complications and arteriovenous fistula failure, speedy transition to blunt needles, the tunnel track remaining narrow thus reducing the risk of developing an exit site infection, and suitability in difficult sites. Possible disadvantages are increased cost for purchase of the pegs during the track break-in period and potential complications such as discomfort, bleeding, and risk of infection. These risks/disadvantages minimize after the transition to blunt needles which in itself is a safer option than using sharp needles. As supported by KDOQI (2006) and the UK Renal Association (2011), adoption of the buttonhole method as the cannulation technique of choice is recommended in the majority of patients undergoing hemodialysis who have a native fistula.

Causes and Solutions of the Trampoline Effect.

A trampoline effect may occur mainly when a buttonhole tract and the vessel flap fail to form a straight line. Certain findings, however, suggest another cause is when the vessel flap is too small. The frequency of the trampoline effect, for example, is lower when a buttonhole tract is created by multiple punctures of the arteriovenous fistula (AVF) vessel than when it is done by one-time puncture of the vessel. Lower frequency of the trampoline effect with multiple punctures of the AVF vessel may be due to enlargement of the initial puncture hole on the vessel every time the vessel is punctured with a sharp needle. Even if aiming at exactly the same point on the AVF vessel every time, the actual puncture point shifts slightly at every puncture, which potentially results in enlargement of the initial hole on the AVF vessel. Moreover, in some patients, continued use of a buttonhole tract for an extended period of time increases the frequency of the trampoline effect. In such cases, reduction of the incidence of the trampoline effect can be achieved by one buttonhole cannulation using a new dull needle with sharp side edges that is used to enlarge the vessel flap. Such single buttonhole cannulation may suggest that the increased frequency of the trampoline effect also potentially occurs in association with gradually diminishing flap size. As a final observation, dull needle insertion into a vessel flap in the reverse direction has been more smoothly achieved than insertion into a vessel flap in the conventional direction. A vessel flap in the reverse direction can be adopted clinically.

Magnetic nanotechnology to study and promote axon growth

After injury of the central and peripheral nervous systems, functional recovery is impaired by axon regeneration failure. Various approaches for promoting axon growth have been attempted but their low efficacy has prevented them from being clinically applicable. It is possible that in spite of all the research that has been performed regarding axon growth, we are still missing key aspects of axon growth biology that are essential in order to design effective treatments for axon regeneration. Most of what we know about how an axon grows has been discovered by using tools that delete, add, block, or activate macromolecules in the whole cell and by looking at its corresponding effect on axon growth. Less is known about the spatiotemporal actions of macromolecules and organelles at the growth cone and its relation with axon growth. Macromolecules and organelles are heterogeneously distributed in the cell and their resulting function depends heavily on when and where they exert their actions. We need tools that allow us to manipulate these macromolecules and organelles in a temporal window during which axon growth events are taking place. The development of such tools will provide enhanced knowledge of how an axon grows and lead to design more effective therapies to promote axon growth.

Iatrogenic Central Retinal Artery Occlusion Following Retrobulbar Anesthesia for Intraocular Surgery.

PurposeTo present clinical features of central retinal artery occlusion (CRAO) following retrobulbar anesthesia for intraocular surgery.MethodsThis observational case series describes 5 consecutive patients with acute CRAO following retrobulbar anesthesia for intraocular surgery. Data collected for this study included subject characteristics, retrobulbar anesthesia technique, treatment type, initial and final best-corrected visual acuity, and other ophthalmologic examinations.ResultsMean subject age was 67.0 ± 8.2 years (range, 53 to 72 years). All patients had one or more vascular risk factors (e.g., hypertension, cerebral infarction, carotid artery stenosis) and presented with acute vision loss 1 day after uneventful intraocular surgery (cataract surgery in 2 eyes and vitrectomy in 3 eyes). All 5 patients received retrobulbar anesthesia during surgery, 4 of which involved the use of a sharp needle. No immediate complications were noted during intraocular surgery. Final visual prognosis was poor (from finger count to no light perception) although intraocular thrombolysis was attempted in 3 patients.ConclusionsIatrogenic CRAO is a potential complication of retrobulbar anesthesia for intraocular surgery in elderly patients with vascular risk factors. Unfortunately, this complication can lead to severe vision loss. We conclude that retrobulbar anesthesia for intraocular surgery should be performed with great care and special consideration for elderly patients with vascular risk factors.

Blunt wires in oral and maxillofacial surgery

he use of wires in maxillofacial surgery is simple, quick, conomical, and minimally invasive.1 However, the sharp nds can lead to a higher than normal number of wire-stick njuries (Fig. 1) with the potential risk of virus-associated iseases and infections such as hepatitis B (HBV), hepatiis C (HCV), and human immunodeficiency viruses (HIV).2 homas et al. reported that anti-HCV was found in 2.0% of ral surgeons, and serological markers of HBV infection in 1.2%.3 Most percutaneous injuries sustained by medical practiioners occur with sharp needles. Over the last 2 decades, dvances in the prevention of accidental needlestick injuries uring operation have included the development of needles ith blunt, tapering points, and this suggests that the use f blunt wires would also reduce the risk of percutaneous njuries (Fig. 1).4 Surgical wires are made of surgical stainless steel, and for edical purposes are delivered as a round bar. The sharp, ut ends can be blunted on a grinding disc but this is timeonsuming and has a high risk of injury. Another method is o cut and blunt the wires using a laser-beam welding system. aser-beam welding, which has high power density (around MW/cm2), can result in the rapid heating and cooling of mall zones. Cutting is done manually with a neodymiumoped yttrium aluminium garnet (Nd:YAG) Dentaurum laser Dentaurum, JP Winkelstroeter KG, Ispringen, Germany) for anual use. The workpiece is positioned under the stereomicroscope f the device. After a short exposure (0.5–20 ms), the wire elts to form beads at the ends (Fig. 2). The wires are held in

Local Anesthetics: What's New in Minimal Pain Injection and Best Evidence in Pain Control.

Local anesthesia in plastic surgery is undergoing a revolution. In the last 10 years, significant improvements in technique have permitted surgeons to do more and more under pure local anesthesia to increase patient safety and convenience while maintaining total patient comfort during the injection of the local anesthesia and while the procedure is accomplished. Many procedures which used to require sedation are now being performed without it. This article explores some of the new advances in local anesthesia such as painless blunt-tipped cannula local anesthetic infiltration, decreased pain with sharp needle tip injection, and long-lasting local anesthetics with delayed release from liposomal encapsulation. This article also examines the best evidence of the last 10 years of advances of pain control with local anesthesia.

Challenges for the cataract surgeon treating people with dementia: a qualitative study exploring anesthetic choices.

BackgroundIn light of the growing number of people with dementia and age-related cataract, as well as changing anesthetic practices for cataract surgery, this study aimed to explore the experiences of cataract surgeons in managing patients with dementia and making anesthetic decisions.MethodsThis was a qualitative study using semistructured interviews with senior cataract surgeons from two centers in England. Fourteen surgeons were interviewed, and a thematic approach informed by grounded theory was used for the analysis.ResultsChoice of anesthesia for people with dementia was a central theme arising from the data. Surgeons varied in their thresholds for using general anesthesia. Decisions about suitability for local anesthesia were limited by time constraints and generally made rapidly and based on instinct; dementia was not always apparent at the point of preassessment. Surgeons used a variety of topical, sub-Tenon’s, and sharp needle blocks for people with dementia. Surgeons discussed techniques to help patients tolerate local anesthesia, such as clear communication, a primary nurse, hand-holding, and support from an anesthetist. However, within our sample, some surgeons had had negative experiences of operating on people with dementia, where an incorrect judgment had been made that they could tolerate local anesthetic cataract surgery.ConclusionThis study highlights the differing practices of cataract surgeons when making anesthetic choices for people with dementia and the challenges they face. In order to avoid the situation of a patient with dementia becoming distressed during awake surgery, increased time at preassessment and anesthetic support may be beneficial.

A Rare Cause of Noncirrhotic Intrahepatic Portal Hypertension

Question: A 38-year-old woman with history of splenomegaly and thrombocytopenia was referred to the outpatient hepatology office after an extensive negative hematologic and infectious workup. On physical examination, the patient seemed to be comfortable with a blood pressure of 110/65 mm Hg and heart rate of 72 bpm. Her abdominal examination showed an enlarged spleen. A rectal examination revealed brown stool without melena. Laboratory evaluation revealed a white blood cell count of 4,800/mL, hemoglobin of 11.3 g/dL (baseline, 12.2 g/dL), platelets 53 10/mL (baseline, 70 10/mL), creatinine of 0.6 mg/dL, prothrombin time of 12 seconds, and International Normalized Ratio of 1.1. Electrolytes, amylase, lipase, liver chemistry tests, ceruloplasmin, and immunoglobulin levels were normal. Anti-smooth muscle antibody and antimitochondrial antibody were negative. Pertinent review of systems revealed that the patient is a current tobacco user with a 10-year pack history and a former user of intravenous heroine. Abdominal ultrasonography with Doppler revealed a diffusely heterogeneous liver parenchyma and enlarged spleen measuring 20.2 cm with a patent splenic vein (Figure A). Esophagogastroduodenoscopy demonstrated multiple columns of large esophageal varices in the lower third of the esophagus (Figure B). A colonoscopy demonstrated small to medium sized, nonbleeding rectal varices. Both studies were consistent with portal hypertension. A transjugular core liver biopsy was performed and the slides demonstrated liver cell plate atrophy alternating with hepatocellular regeneration (hematoxylin and eosin, and reticulin stains), and focal portal and pericellular fibrosis (trichrome stain). A minimal to mild inflammatory infiltrate composed of lymphocytes and clutters of macrophages containing brown granular refractive material was noted in the portal tracts without evidence of cirrhosis (Figure C, D). No significant bile duct injury, steatosis, granulomas, siderosis, or alpha1-antitrypsin globule was identified on histology. These findings were consistent with nodular regenerative hyperplasia, a condition of noncirrhotic intrahepatic portal hypertension (NCIPH). However, further inquisition of the same region under polarized light revealed multiple scattered, white, birefringent, irregular or needle-shaped material within some of the portal tracts (Figures E [arrow head], F [arrow head]).

Towards quantitative off-axis electron holographic mapping of the electric field around the tip of a sharp biased metallic needle

We apply off-axis electron holography and Lorentz microscopy in the transmission electron microscope to map the electric field generated by a sharp biased metallic tip. A combination of experimental data and modelling provides quantitative information about the potential and the field around the tip. Close to the tip apex, we measure a maximum field intensity of 82 MV/m, corresponding to a field k factor of 2.5, in excellent agreement with theory. In order to verify the validity of the measurements, we use the inferred charge density distribution in the tip region to generate simulated phase maps and Fresnel (out-of-focus) images for comparison with experimental measurements. While the overall agreement is excellent, the simulations also highlight the presence of an unexpected astigmatic contribution to the intensity in a highly defocused Fresnel image, which is thought to result from the geometry of the applied field.

Influence of electrode configuration on the heat transfer performance of a LED heat source

In this study, the effects of electrode configuration on the cooling of LED are presented. A total of six needle type electrodes, including sharp, 0.08, 0.12, 0.37, 0.49R and flat tip, are used to generate ionic wind for cooling of the LED. The effects of electrode configuration, vertical separation height, and tilt angle on the cooling performance of a LED are reported in this study. It is found that the thermal resistance is reduced with the supplied voltage and a maximum 50% reduction is achieved before the spark-over voltage. For the same supplied voltage, the thermal resistance with a larger vertical separation is also higher. However, the operational range is also longer. The effect of tilt angle on the cooling performance of LED depends on the supplied voltage. With a supplied voltage being less than 6.5kV, it is found that the thermal resistance is increased when the tilt angle is reduced with a tip radius of 0.12R. However, the trend is reversed when the supplied voltage is higher than 6.5kV where the thermal resistance of a smaller tilt angle is lower than that of a larger tilt angle. For the same mesh ground, the effect of electrode configurations cast little influence on the final thermal resistance. All the electrodes show an approximately 50% reduction of thermal resistance in association with its original thermal resistance. However, the corresponding threshold voltage and operational voltage differs significantly. The threshold voltage is lowest for the sharp needle and is increased with the rise of tip radius. On the other hand, the corresponding operational range becomes narrower when the tip radius is increased. Yet the spark-over voltage is also insensitive to change of electrode configuration.

Electrical Measurements for Nanosecond Repetitive Pulsed Discharges

In this paper, a device for accurate electrical measurements for nanosecond repetitive pulsed discharges (NRPDs) is presented. The experimental setup developed is based on an interelectrode system integrated in a transverse electromagnetic cell. This setup allows synchronizing the voltage and current measurements with a 4-GHz frequency bandwidth, corresponding to 250-ps pulse duration. A coaxial-shaped sharp metallic needle serves as a probe for current measurements. The needle probe is also the point electrode of a point-to-plane system used to generate discharges. The experimental setup was used to electrically characterize NRP corona and diffuse discharges, in negative polarity. Discharge current pulses with rise times less than 1 ns and amplitudes up to 120 mA were measured. The energy deposited by discharges was also determined.