Wax Plug Research Articles

Development and validation of a smartphone-based deep-learning-enabled system to detect middle-ear conditions in otoscopic images

Middle-ear conditions are common causes of primary care visits, hearing impairment, and inappropriate antibiotic use. Deep learning (DL) may assist clinicians in interpreting otoscopic images. This study included patients over 5 years old from an ambulatory ENT practice in Strasbourg, France, between 2013 and 2020. Digital otoscopic images were obtained using a smartphone-attached otoscope (Smart Scope, Karl Storz, Germany) and labeled by a senior ENT specialist across 11 diagnostic classes (reference standard). An Inception-v2 DL model was trained using 41,664 otoscopic images, and its diagnostic accuracy was evaluated by calculating class-specific estimates of sensitivity and specificity. The model was then incorporated into a smartphone app called i-Nside. The DL model was evaluated on a validation set of 3,962 images and a held-out test set comprising 326 images. On the validation set, all class-specific estimates of sensitivity and specificity exceeded 98%. On the test set, the DL model achieved a sensitivity of 99.0% (95% confidence interval: 94.5–100) and a specificity of 95.2% (91.5–97.6) for the binary classification of normal vs. abnormal images; wax plugs were detected with a sensitivity of 100% (94.6–100) and specificity of 97.7% (95.0–99.1); other class-specific estimates of sensitivity and specificity ranged from 33.3% to 92.3% and 96.0% to 100%, respectively. We present an end-to-end DL-enabled system able to achieve expert-level diagnostic accuracy for identifying normal tympanic aspects and wax plugs within digital otoscopic images. However, the system’s performance varied for other middle-ear conditions. Further prospective validation is necessary before wider clinical deployment.

Research on the Calculation Method for the Wellbore Temperature of Hot Nitrogen Gas Circulation Wax Removal and Plug Removal in Offshore Oil Fields

The problem of wax deposition widely exists in offshore oil fields; waxing of the oil tubing will lead to a reduction in the cross-sectional area of the flow and, in serious cases, the flow path will be blocked, causing the well to stop production. In order to cope with this problem, a thermal dynamic wax removal method has emerged in recent years that utilizes hot nitrogen gas circulation between the oil tube and annulus to raise the temperature of the oil tube to achieve the purpose of wax removal and plug removal and is quick and easy to operate. Unlike conventional wellbore temperature calculation methods, the wellbore temperature field under hot nitrogen circulation conditions is influenced both by the reservoir temperature gradient and the hot nitrogen injection temperature, injection pressure, and injection rate. In this paper, a temperature calculation model for a wellbore considering both annulus injection temperature and tubing temperature and their interactions is modeled, which can consider the effects of different hot nitrogen injection temperatures, injection rates, and injection pressures. The model is used to calculate the temperature distribution for different injection parameters in order to ensure that the tubing temperature is higher than the wax precipitation temperature and that the annulus temperature is not higher than the maximum temperature resistance of the rubber in the packer. The study provides a design method for wax removal and plug removal with hot nitrogen gas circulation.

The implementation of fusion properties calculation to predict wax deposition

Deposition of wax on the pipe walls is one of the complex flow assurance problems that causes a decrease and complete blockage of oil production rates by reducing the cross-sectional area of flow in the pipelines. In addition, surface facilities require higher energy consumption and failure of facilities due to wax plugging. Effective design of oil recovery processes requires an adequate prediction of the thermodynamic conditions in which wax can precipitate from crude oil, depending on the pressure, temperature, and composition of the oil. In this paper, the modified melting and pour point temperatures were presented based on the fluid description. Other fusion properties such as the enthalpy of fusion, the solid-state transition enthalpies, and the heat capacity of fusion have been calculated to modify the multi-solid model for predicting wax deposition. The proposed modified equations for melting and pour point temperatures were showing reliable agreement with experimental data based on SARA analysis and demonstrated more accurate results compare to literature data. In order to justify the proposed model, the comparative approach has been implemented between literature, experimental, and data obtained based on proposed solutions. The detailed description of the Republic of Kazakhstan’s (RoK) oil fields, components from C1 up to C36+ has been used during this research and the most crucial components which tend to form wax precipitation from C15H32 to C20H42 were plotted, which showed an increasing accuracy of 11 % for melting point temperature and 7 % for pour point temperature compared to literature data. As a result, the proposed modified solutions for fusion properties demonstrated good agreement with literature and obtained results of modifications can be used for further research on Multi solid model of wax precipitation

Prevalence and associated symptoms of cerumen in adults in Rio Grande do Norte

Objectives: To evaluate the prevalence and associated symptoms of cerumen impaction in adults in the state of Rio Grande do Norte. Methods: This is an analytical, cross-sectional and observational research, with a quantitative approach, in which users, companions and employees of a tertiary hospital aged 18 years or older participated, through otoscopy and evaluation of clinical otological complaints. Results: 1,067 adults aged between 18 and 87 participated, 64.9% (n=692) were women and 35.1% (n=375) were men. Among them, 11.6% (n=124) had earwax impaction in one of the ears and 90.3% (n=963) had earwax in at least one ear. Conclusion: The prevalence of cerumen impaction in the study was significantly higher than in similar literature and it was shown to be an issue related to “using a flexible swab with cotton-tipped tips” and “having had previous ear washing”. Otoscopy remains as the gold standard for the mostly asymptomatic clinic of patients with wax plugs.

Thermal system for a new flexible composite tank

A flexible thermal insulation system is proposed in this study, which considers the application and promotion of flexible composite materials in the field of marine engineering. This system is designed to provide a cost-effective and convenient thermal insulation solution for avoiding impurity precipitation and formation of wax plugs caused by extremely low temperature during mining, transportation, and storage of oil. The thermal insulation system includes two main parts: the insulation layer and the heating source. In accordance with the laws of thermodynamics and the primary characteristics of the flexible structure, two different insulation systems were designed and model tests were performed to compare performance in heating efficiency, thermal insulation, and temperature field distribution under identical environmental conditions. Compared with the plan 1 thermal insulation system, the plan 2 system has lower requirements for heating power, more uniform temperature field distribution inside the flexible structure, and a difference of only 7.18°C between the highest and lowest temperatures.

Foliar water uptake in Pinus species depends on needle age and stomatal wax structures.

Foliar water uptake (FWU) has been documented in many species and is increasingly recognized as a non-trivial factor in plant-water relationships. However, it remains unknown whether FWU is a widespread phenomenon in Pinus species, and how it may relate to needle traits such as the form and structure of stomatal wax plugs. In this contribution, these questions were addressed by studying FWU in current-year and 1-year-old needles of seven Pinus species. We monitored FWU gravimetrically and analysed the needle surface via cryo-scanning electron microscopy. Additionally, we considered the effect of artificial wax erosion by application of the surfactant Triton X-100, which is able to alter wax crystals. The results show for all species that (1) FWU occurred, (2) FWU is higher in old needles compared to young needles and (3) there is substantial erosion of stomatal wax plugs in old needles. FWU was highest in Pinus canariensis, which has a thin stomatal wax plug. Surfactant treatment enhanced FWU. The results of this study provide evidence for (1) widespread FWU in Pinus, (2) the influence of stomatal wax plugs on FWU and (3) age-related needle surface erosion.

Experiment and Application of Wax Deposition in Dabei Deep Condensate Gas Wells with High Pressure

The Dabei deep high-pressure condensate gas field occupies the paramount position in the Tarim Oilfield in China, the exploration and developments of which have been progressing. Since the initial development, the wax deposition and plugging in the wellbore and gathering pipeline have been the most bothering issues, resulting in the reduction or even shutdown of condensate gas well production. Therefore, the wax appearance temperature of Dabei condensate oil was studied using the capillary viscometer, differential scanning calorimetry (DSC), and polarizing microscope observation. The wax content was tested by using the DSC and crystallization separation test method. Finally, the wax appearance temperatures of degassed condensate oil and equilibrium condensate oil under different pressures were tested. Experimental results show that the wax appearance temperature measured by polarizing microscope observation was higher than that measured by the DSC and capillary viscometer, the lag of which can be recorded as the cloud point. The wax appearance temperature measured by polarizing microscope observation is of high accuracy. Secondly, the DSC method is not sufficient for measuring wax precipitation at low temperatures, showing a lower wax content than the crystallization separation test method. Thus, the wax content of Dabei condensate oil can be better measured by using the crystallization separation test method. Additionally, the wax precipitation law of equilibrium condensate oil is opposite to that of degassed condensate oil. The wax appearance temperature of equilibrium condensate oil increases as the pressure decreases. The results of wax appearance temperature of equilibrium condensate oil provide a useful and quick index to judge the potential risk of wax precipitation in the Tarim Oilfield, which can provide an efficient strategy for the development of waxy condensate gas reservoirs and the optimization of wax prevention and treatment technology.

Investigation on synergistic deposition of wax and hydrates in waxy water-in-oil (W/O) flow systems

Elucidating the synergistic effect of wax and hydrates, involving formation, aggregation and deposition, is imperative to the operation and transportation safety for offshore petroleum fields. To understand the characteristics and mechanism of synergistic deposition of wax and hydrates, flow and deposition experiments of systems with different wax contents (0–2.89 wt%), initial flow rates, pressures and temperatures were conducted in a high pressure visual flow loop. According to the flow rate and pressure drop data as well as the visual window observation, four different types of plugging scenarios of wax-hydrate coexisting systems with different flow properties and wall deposition state were summarized, including rapid plugging, transition plugging, gradual plugging type I and gradual plugging type II. Compared with the wax-free system after hydrate formation, even with the addition of anti-agglomerant (AA) with the same concentration, wax-hydrate coexisting systems could not reach stable hydrate slurry flow state, indicating that the existence of wax deteriorated the performance of AA. Aside from the influence of wax crystals on hydrate agglomeration, it was found that wax deposition layer would alter the adhesion and bedding of hydrates, resulting in the variation of flow properties and wall deposition state. For low wax content systems (0.75 wt%) where rapid plugging occurred, the synergistic effect between wax and hydrates promoted the formation of wax-hydrate coupling aggregates, resulting in severe local deposition when the coupling aggregates attained critical deposition size and consequently decreasing flow rate, forming a vicious circle of decreasing transportability. Since bedding of coupling aggregates was hindered by the uniformly coated wax deposition layer on pipe wall, gradual plugging rather than rapid plugging occurred in medium wax content systems (1–1.25 wt%), predominately caused by the gradual increment in viscosity of waxy hydrate slurry. For relatively high wax content systems (2.89 wt%), hydrate formation and plugging did not occur, due to the insulation effect of wax deposition layer. A physical model for the synergistic deposition of wax and hydrates was also presented, which was meaningful to the development of a mathematical model for the prediction of blockage formation and risk analysis.

Capillary Flow-Driven and Magnetically Actuated Multi-Use Wax Valves for Controlled Sealing and Releasing of Fluids on Centrifugal Microfluidic Platforms.

Compact disc (CD)-based centrifugal microfluidics is an increasingly popular choice for academic and commercial applications as it enables a portable platform for biological and chemical assays. By rationally designing microfluidic conduits and programming the disc’s rotational speeds and accelerations, one can reliably control propulsion, metering, and valving operations. Valves that either stop fluid flow or allow it to proceed are critical components of a CD platform. Among the valves on a CD, wax valves that liquify at elevated temperatures to open channels and that solidify at room temperature to close them have been previously implemented on CD platforms. However, typical wax valves on the CD fluidic platforms can be actuated only once (to open or to close) and require complex fabrication steps. Here, we present two new multiple-use wax valve designs, driven by capillary or magnetic forces. One wax valve design utilizes a combination of capillary-driven flow of molten wax and centrifugal force to toggle between open and closed configurations. The phase change of the wax is enabled by heat application (e.g., a 500-mW laser). The second wax valve design employs a magnet to move a molten ferroparticle-laden wax in and out of a channel to enable reversible operation. A multi-phase numerical simulation study of the capillary-driven wax valve was carried out and compared with experimental results. The capillary wax valve parameters including response time, angle made by the sidewall of the wax reservoir with the direction of a valve channel, wax solidification time, minimum spin rate of the CD for opening a valve, and the time for melting a wax plug are measured and analyzed theoretically. Additionally, the motion of the molten wax in a valve channel is compared to its theoretical capillary advance with respect to time and are found to be within 18.75% of the error margin.

STRUCTURAL MODIFICATIONS IN BLACK PINE NEEDLES AS POTENTIAL BIOMARKERS OF ENVIRONMENTAL POLLUTION

This study presents micro-morphological characters and anatomical modifications detected in black pine needles collected from urban polluted areas in order to propose new biomarkers useful in air pollution biomonitoring. The plant samples were collected during the July 2021 from 10 different polluted sites from Bucharest and analyzed using light and scanning electron microscopy. When compared with the samples collected from less polluted sites, needle micromorphology and structure have showed significant alterations such as injured stomatal complex, eroded forms of tubular wax type and complete degradation of wax crystalline structure, raised peristomatal areas, early wax plugs perforations and abnormal epidermal teeth. The loads of heavy metal of samples were assessed by X-ray fluorescence spectrometry and the results showed a positive correlation between structural alteration incidence and needle heavy metal surface depositions.

Analytical Modeling of Wax Plug Transportation during Pipeline Pigging Using a Foam Pig

Summary In our previous article (Gao et al. 2020), a mathematical model including elastic and yield components but not viscous component was developed to predict the wax plug transportation force. In this work, an analytical model was developed to calculate the wax plug transportation force, and the viscous component was introduced into the analytical model to capture some of the time effects. In this analytical model, the viscoelastic behavior of the wax deposit was characterized by a three-parameter model, formulated by adding an additional spring element to the Kelvin-Voight model. The Laplace transformation was used to solve the model. According to the calculated results of the analytical model, the transportation force of the wax plug was observed to slightly increase with time and then tended to level off. To obtain a parameter in the model and verify the model, the pigging experiments were conducted using foam pigs. During the pigging process of the foam pig, the wax plug transportation force in a five-phase wax removal profile was determined by taking the steady wax breaking force from the resistive force of the wax layer. Moreover, the linear increase of the wax plug transportation force per unit contact area with the shear strength of the wax layer was found, as described by the functional relationship in the analytical model. The interfacial lubrication coefficient calculated from the experimental data based on the analytical model is between the coefficient for diesel-prepared deposits and coefficient for oil-A-prepared deposits. Experimental verification results show that the average relative error of the model is 12.47%. Field implication was proposed to illustrate the application of the model and the formation condition of the wax blockage.

Impact of Reconstruction With Hydroxyapatite Bone Cement on CSF Leak Rate in Retrosigmoid Approach to Vestibular Schwannoma Resection: A Review of 196 Cases.

To assess the impact of reconstructive technique on the incidence of cerebrospinal fluid (CSF) leak following retrosigmoid approach to acoustic neuroma resection. Retrospective case series. Academic medical center. A total of 1,200 patients with acoustic neuromas presented to our institution from 2005 to 2018. Of these, 196 patients underwent surgical resection via a retrosigmoid approach. At our institution, internal auditory canal (IAC) reconstruction following a retrosigmoid approach was performed with bone wax and muscle plug or Norian hydroxyapatite bone cement from 2005 to 2013. Starting in 2014, a newer model of bone cement, Cranios hydroxyapatite, was used exclusively for reconstruction. Rates of CSF leak were evaluated across different methods of IAC reconstruction and types of bone cement. Patients whose leaks were attributable to the craniectomy site were excluded from analysis. The postoperative CSF leak rate among patients who did not receive bone cement for IAC reconstruction was 15.6% (n.5). The leak rate amongst patients who received Norian bone cement was 6.3% (n.4). After introduction of Cranios bone cement, the total leak rate decreased to 1% (n.1). Compared with all other types of closure, Cranios had a significantly reduced rate of postoperative CSF leak (p < 0.005). The leak rate following Cranios versus Norian was also significantly reduced (p < 0.05). Leak rate was not affected by tumor size (p.0.30) or age (p.0.43). CSF leak rate following acoustic neuroma resection was significantly reduced by introduction of Cranios hydroxyapatite bone cement.

Mechanical analysis of coiled tubing in the process of hydrate and wax plugs removal in subsea pipelines

ABSTRACT Hydrate formation and wax deposition in submarine pipelines hinder the transportation of oil and gas. Pigging operation is an important means to ensure pipeline flow assurance. In this paper, the idea of coiled tubing (CT) intervening in hydrate and wax removal of underwater pipeline is put forward, and the feasibility of this method is discussed from the point of view of the ultimate extension capacity of coiled tubing. To this end, theoretical analyses and experimental tests are performed on the mechanical behaviour of coiled tubing in submarine pipelines. The present paper mainly analyses the axial force transfer characteristic of coiled tubing with different sizes and the contact force coefficient values of coiled tubing with fixed and loaded end conditions under different boundary conditions. Besides, the effects of CT size and friction coefficient on the reachable depth of hydrate or wax plugs removal are also studied and the obtained maximum depth of the CT inlet is compared with the total length of the five-segment centreline of the South China Sea submarine pipelines. The results show that CT can further achieve more plug removal as the reduction of friction coefficient, while the depth of plug removal reduces with the decrease of CT size. CTs only with limited sizes can be used to complete the plug removal process in submarine pipelines.

Advances and Future Challenges of Wax Removal in Pipeline Pigging Operations on Crude Oil Transportation Systems

Wax deposition is a severe flow assurance challenge that threatens waxy crude oil production and transportation. For wax remediation, pipeline pigging is the most widely used technique. However, the elusiveness of wax removal mechanism and the lack of reliable methods to evaluate wax breaking force and wax removal efficiency easily trigger pig stalling and wax blockage in field pigging operations. Modeling wax breaking force and wax removal efficiency, therefore, promotes the pigging confidence. This Review seeks to clarify the current picture of wax removal research in crude oil pipeline pigging. Relevant wax deposit properties including wax layer thickness and strength are discussed. Wax removal mechanisms are summarized from perspectives of wax–pig interaction, macroscopic force response, and scenarios with oil flow. Prediction models of wax breaking force and wax removal efficiency are analyzed comprehensively. Pig geometry optimization using this model is given. In addition, the key roles of wax deposit strength, viscoelasticity and thixotropy, foam pig investigation, and wax plug prediction are highlighted for guiding future endeavors in this area.

Zebrafish Astroglial Morphology in the Olfactory Bulb Is Altered With Repetitive Peripheral Damage.

Zebrafish do not possess the typical astrocytes that are found in mammalian systems. In some brain areas, this teleost has radial glia that appears to perform astrocyte-like functions, but these cells have not been described in the zebrafish olfactory bulb. Mammalian astrocytes facilitate neuroplasticity and undergo astrogliosis after insult. The role of these cells in the zebrafish olfactory system after the damage has been poorly explored. This is important to examine because zebrafish have a high degree of neuroplasticity and the olfactory bulb is a brain area renowned for plasticity. The goal of this study was to explore the potential role of zebrafish astrocytes in the olfactory bulb damage response, with a goal to exploit the high level of regeneration in this system. We found that anti-glial fibrillary acidic protein (GFAP) labels numerous processes in the zebrafish olfactory bulb that are concentrated in the nerve and glomerular layers (GL) and do not show radial glial-like morphology. We propose to term this astroglia, since their location and response to damage suggests that they are similar in function to the mammalian astrocyte. To induce repetitive peripheral damage to the olfactory organ, a wax plug was inserted into the nasal cavity of adult zebrafish every 12 h for up to 7 days; this crushes the olfactory organ and leads to degradation of olfactory sensory neuron axons that project to the olfactory bulb. After 1 day, we found a significant increase in astroglial labeling in the affected bulb when compared to the internal control bulb and astroglial branches appeared to increase in number and size. By the third day of plug insertions there was no significant difference in astroglial labeling between the affected bulb and the internal control bulb. These data lead us to believe that astrogliosis does occur in the presence of peripheral damage, but this process attenuates within 1 week and no glial scar is evident upon recovery from the damage. Further exploration of astrocytes in zebrafish, in particular this apparent attenuation of astrogliosis, has the potential to elucidate key differences in glial function between teleosts and mammals.

Estimating Wax Plug Transportation Force in Crude Oil Pipeline Pigging

Wax plug growth in pipeline pigging significantly impacts the crude oil transportation, even resulting in a wax blockage accident of pipeline. A pigging facility was constructed to conduct the pigg...

NOTES ON BRONZE POLE-TOPS WITH A GRIFFIN FROM SCYTHIAN ALEKSANDROPOL BARROW

The article proposes a scheme and algorithm for the manufacture of four bronze pole-tops from the Scythian Royal Alexandropol burial mound dated to the second half of the 4th century BC, which can serve as a basis for understanding the manufacturing process or the ancient repair of the similar Scythian replicated products.&#x0D; There is both a general idea of the manufacture of such bronze pole-tops by casting (according to a wax model or in detachable forms), and private judgments about the nature of castings, the correction of defects and the repair of pole-tops and their parts. But at the same time, specific details of the production process by different researchers (S. V. Polin, B. N. Mozolevsky, A. I. Melyukova, L. I. Babenko, A. R. Kantorovich, V. R. Erlikh, etc.) are assumed different, showing a very colorful picture.&#x0D; The process of making bronze pole-tops which were similar in composition, but different in the elaboration and decoration, most likely consisted of the following successive steps: creating a stencil of wax models of griffins in a rectangular frame; revision and decoration by hand of some individual parts on the surface of these wax figures (wings, paws, etc.), giving individuality to each object; attachment and molding of wax plugs; closure of the wax model by the clay mold, its drying and firing (?); casting in metal; destruction of clay mold; machining the surface of the casting.&#x0D; The pole-tops are casted from lead-tin bronze (copper is the base, tin is 9—12 %, lead is 2—3 %, traces of arsenic, iron and nickel). The pole-top (no. Dn 1853 1/6) differs by one feature. On the side edges of the nozzle are high dark triangles with clear boundaries, made by lead-tin plating. On the other objects such ornamentation (?) is not visible.&#x0D; Thus, the considered pole-tops were made using a single stencil and cast according to a single technical scheme.

Experimental and numerical study on direct electrical heating for plug removal of subsea waxy crude pipelines

Subsea pipeline of waxy crude oil may face a high risk of the wax plug during shut down or pigging. Direct Electrical Heating (DEH) technology is expected to be an efficient and convenient way to melt the wax plug in the subsea pipeline. An industrial-scale experimental facility with a test tube of 10-in. diameter and a power supply of 0–1350 A is set up, and then several sets of experiments are carried out. Simultaneously, the melting process of the wax plug is simulated by FLUENT software. The numerical model is validated from the aspects of liquid fraction and solid patterns. The melting rate and temperature of the wax plug with different wax content and current are analyzed, and the temperature of the pipe wall is considered for the sake of pipeline integrity. Furthermore, to avoid secondary solidification, the recooling process of the wax plug and pipe wall is also discussed. Finally, the effects of the “Maximum Allowable Temperature”, “Maximum Safe Power”, “Effective Liquid Fraction” and “Applicable Heating Time” on economic evaluation are investigated, and the correlations are developed between the above factors and common pipe diameters (6–32-in.), which shows heating with maximum safe power is also the most economical method in engineering.

Experimental study of wax deposition pattern concerning deep condensate gas in Bozi block of Tarim Oilfield and its application

The Bozi block of the Tarim Oilfield is a typical tight sand condensate gas reservoir with serious wax plugging. So it is necessary to study the phase behavior and the wax deposition pattern of well fluids in Bozi gas reservoir, which will provide the phase enveloping diagram of the condensate gas and then help to control the paraffin deposition. In this study, the PVT tester and the self-designed microscopic solid deposition tester are used to get the phase enveloping line of the condensate gas. Such testing methods allow us to monitor phase changes of “gas-liquid-solid” system at different temperatures and pressures. In addition, the real reservoir conditions can be fully simulated with visibility. The result shows that the phase behaviors of the wax-containing condensate gas is extremely complex. Under different temperature and pressure, gas phase, gas-liquid, gas-solid, and gas-liquid-solid multiphase appear respectively. The main wax components of Bozi 104 well are C16∼C30, and their content is 0.111% mol per unit mole of condensate gas. The wax precipitation temperature of condensate oil is 15.4°C, the maximum instantaneous wax deposition volume is 0.2258% per unit mass of condensate oil, and its cumulative volume is 9.49% per unit mass of condensate oil. When the pressure is above the dew point, the solid wax is not dominated by the condensate oil but by long plate-like coarse wax crystals. When the pressure is below the dew point, the solid wax is condensed from the gas. The wax is soluble to the condensate oil. Then they form a transparent colloidal, glassy block material, which has a strong binding effect on the condensate oil.

Reversible deafferentation of the zebrafish olfactory bulb with wax plug insertion

BackgroundDeafferentation of the zebrafish olfactory bulb allows investigation of neuroplasticity in a particularly dynamic brain region of a popular model animal known for its regenerative abilities. Current methods to remove sensory input to the zebrafish olfactory bulb differ in the extent of deafferentation and potential for recovery. New methodWe present a novel method of olfactory bulb deafferentation using continuous wax plug insertions into the nasal cavity of zebrafish. Wax plugs were placed in the nasal cavity and replaced if needed over 1wk or 3wk survival periods. Wax plugs were removed from fish after 1wk of occlusion to analyze the potential recovery of the olfactory organ and bulb. ResultsWax plug insertions caused a dramatic reduction in olfactory organ size and structure and significantly reduced afferent input to the olfactory bulb after 1wk and 3wk. Removal of the wax plugs after 1wk allowed for recovery of the olfactory organ and subsequent reinnervation of the olfactory bulb. Comparisons with existing methodsChemical ablation with detergent causes partial, temporary deafferentation of the olfactory bulb. Cautery ablation causes complete, permanent deafferentation of the olfactory bulb. Wax plug insertions cause nearly complete, temporary deafferentation, allowing both significant deafferentation and the potential for reinnervation of the olfactory bulb. ConclusionsThe wax plug insertion method of deafferentation described here is unique in that it destroys almost completely the structure of the olfactory organ and removes almost completely sensory input to the olfactory bulb, yet the organ returns to its typical morphology and afferent innervation returns.