Spontaneous Displacement Research Articles

Clinical and morphological features of the orbital floor in a patient with silent sinus syndrome: A clinical case report

Silent sinus syndrome (SSS) is a rare condition characterized by spontaneous unilateral displacement of the inferior and posterior globe due to maxillary sinus (MS) atelectasis. The mechanism of MS development is not fully understood, but orbital floor changes due to changes in MS pressure or subclinical inflammation are considered part of the potential pathogenesis. In addition, treatment strategy and optimal timing are not defined. We present a case report of a patient with MS who underwent successful uncomplicated two-stage treatment with good functional and aesthetic results. Orbital floor morphology data obtained for the first time in a patient with SSS may provide additional information about the pathogenesis of this rare disease.

Unforeseen challenge: bilateral, spontaneous, symmetrical displacement of toric implantable collamer lens: case report

Introduction: The phakic intraocular lenses represent a significant advancement in refractive correction particularly in patients for whom conventional procedures such as laser in situ keratomileusis (LASIK) are contraindicated. To our knowledge, although studies have extensively documented the occurrence and management of implantable collamer lens (ICL) rotation, spontaneous displacement of the ICL has not yet been documented. In this article, we present an interesting case of bilateral ICL displacement. Patient and Clinical Findings: After undergoing bilateral ICL surgery, the patient presented with blurring of vision the next day. On examination, there was symmetrical bilateral displacement of the ICL despite having implanted the maximum size of this lens. Diagnosis, Intervention, and Outcomes: After discussion and analysis, a bilateral explantation of the ICL was performed. Conclusions: Despite taking into consideration all the essential anterior segment parameters for ICL size calculation, there can still be a possibility of ICL displacement.

Ni-Pt Core-Shell Formation via Spontaneous Galvanic Displacement Reaction at Boron Doped Diamond Electrodes for Ammonia Oxidation Reaction

Ammonia is a major environmental pollutant that is highly toxic and may cause unfavourable effects to the human body, even in low concentrations. As a result, the monitoring and elimination of NH3 has been an important topic worth exploring in depth. Moreover, ammonia can be a suitable fuel cell source because its theoretical electrical charge density is relatively high and it’s possible to take this advantage by converting ammonia to nitrogen and electrical energy via the ammonia oxidation reaction (AOR). This reaction requires a catalyst to decrease the energy barrier that prevents the molecule from reacting and transforming into nitrogen.Ammonia electro-oxidation reaction has been paid much attention in recent years because it is widely used in various fields. However, the electro-oxidation of ammonia is a complex process, especially the reaction intermediate has a slow toxic effect on the electrode. To reduce the catalyst poisoning by the absorption of intermediate, the constituent and structure of the catalysts must be deeply researched.Herein, a bimetallic Pt–Ni catalyst-modified boron-doped diamond (BDD) electrode was done via spontaneous galvanic displacement reaction for the ammonia oxidation reaction. The synergistic properties may include the promotion of low-temperature oxidation, improvement of the oxidation resistance, and increased catalytic efficiency. BDD was used as the electrode substrate in this work due to its excellent resistance to corrosion and good stability over time in a highly corrosive environment. First, nickel was electro-deposited through chronoamperometry on the BDD electrode surface at a potential of -1.1V vs Ag/AgCl in 0.1M KClO4 & 5mM Ni (NO3)2.6H2O aqueous solution. Second, platinum was deposited on the nickel particles on the BDD electrode surface through a spontaneous galvanic displacement reaction by a redox process which involves the nickel oxidation and Pt2+ reduction, using a K2PtCl4 precursor on the BDD surface while forming a core shell structure. Lastly, the Pt-Ni deposited on the BDD surface was then characterized through different techniques such as XPS, SEM, EDS, and Raman before and after the ammonia oxidation reaction.Preliminary studies of the behaviour of BDD electrodes in the presence of Ni and Pt have been carried out to determine the electrochemical conditions at which the substrate works with these metal salts. The results found with these studies will show how Pt-Ni catalyst will improve AOR in alkaline media.

In situ constructing a porous organic component-zincophilic Cu clusters layer on zinc anode for high performance aqueous zinc ion batteries

Aqueous zinc ion batteries (AZIBs) with Zn metal anodes stand out as a promising candidate for large-scale energy storage systems, owing to their high safety, low cost, and environmental friendliness. However, the commercialization of AZIBs is plagued by issues such as Zn dendrite growth and side reactions. Herein, an organic component-Cu metal composite layer is constructed on Zn anode (Org-Cu@Zn) by a novel, one-step and in situ spontaneous displacement reaction. The outer porous organic layer with functional groups may serve as migration sites and transport channels for Zn2+ ions, promoting transfer kinetics. The inner zincophilic Cu clusters layer diminishes the interfacial resistance, facilitating Zn2+ ions diffusion and even Zn deposition. Compared to the bare Zn, the unique dual-layer structure exhibits stronger zincophilicity, smaller interface resistance, lower nucleation energy barrier, and stronger anti-corrosion capability, thus effectively suppressing the Zn dendrite growth and side reactions. Remarkably, the Org-Cu@Zn electrode shows an ultra-long lifespan of 3600 h (1800 cycles) with an average Coulombic efficiency of 99.7 %, realizes long cycling stability over 4300 h (1 mA cm−2) and 1350 h (5 mA cm−2), and assures the stable operation of Org-Cu@Zn||ZVO full cells with coin-type configurations.

Comparative study of nanoemulsion and micelle formed by surfactants containing benzene ring for spontaneous imbibition displacement

Nanoemulsion has a wide range of applications in oilfield chemistry due to its unique nanoscale size, excellent kinetic stability and high specific surface area. In this paper, a novel nanoemulsion oil flooding system was prepared using anionic surfactant sodium dodecyl benzene sulfonate (SDBS), the nonionic surfactant alkylphenol ethoxylates (OP-10), kerosene, n-butanol and deionized water. The particle size, Zeta potential, interfacial tension (IFT) and wettability properties were evaluated in the laboratory. The displacement performance of nanoemulsion was evaluated by the spontaneous imbibition experiment. Meanwhile, it compared with the same concentration of SDBS + OP-10 + n-butanol (SOB) system. The results showed that the particle size of the nanoemulsion was 70 ∼ 100 nm. When the concentration of nanoemulsion was 0.10 %, the oil–water IFT could reach 0.091 mN/m. The spontaneous imbibition oil recovery of the nanoemulsion (0.10 wt%) could reach 33.20 %, which was 23.02 % higher than that of SOB system. We also research the spontaneous imbibition displacement mechanism of nanoemulsion and micelle in low-permeability reservoirs. This paper will help to select the best oil displacement agent for the design of enhanced oil recovery (EOR) projects and promote the application of oil displacement agent in oilfield.

Robust Ferroelasticity and Carrier Dynamics Across the Domain Wall in Perovskite‐Like van der Waals WO2I2

AbstractAs a new group of van der Waals (vdWs) ferroic materials, transition metal dioxydihalides MO2X2 (M: Mo, W; X: halogen) with a perovskite‐like structure are theoretically predicted to exhibit intriguing physics and versatile ferroic characteristics, which is not achieved experimentally as far as it is known. In this work, the robust ferroelasticity in vdWs WO2I2 with the switching strain as low as ≈0.3%, accompanied with the striped optical contrast between adjacent domains, spot splitting of selected area electron diffraction (SAED) patterns at domain wall, and 90° domain wall is demonstrated. With the aid of ab‐initio calculations, the origin of ferroelasticity in WO2I2 is unveiled, where the imaginary phonon mode in the high‐symmetry paraelastic phase leads to the spontaneous displacement of W atom away from the center of the [WO4I2] octahedron, resulting in the switchable spontaneous strain under an external strain field. Moreover, transient absorption microscopy (TAM) measurements demonstrate that the diffusion of photogenerated carriers is significantly hindered by the ferroelastic domain walls. This study provides deep insights into the ferroic order and domain wall in perovskite‐like vdWs MO2X2 for new physics and functionalities.

Self-adaptive gas flow and phase change behaviors during hydrate exploitation by alternate injection of N2 and CO2

Since hydrate resources play a part of the stratigraphic framework structure in sediments, establishing a safe and economic method for hydrates exploitation remains the primary challenge to this day. Among the proposed methods, the spontaneous displacement of CH4 from hydrate cages by CO2 seems to be a perfect mechanism to address gas production and CO2 storage, especially in today's strong demand for carbon reduction and replacing clean energy. After extensive lab researches, in the past decade, injecting a mixture of CO2 and small molecule gas has become a key means to enhance displacement efficiency and has great potential for application. However, there is a lack of in-depth research on gas flow in the reservoir, while the injected gas always passes through low-saturated hydrate areas with high permeability and then occurs gas channel in a short term, finally resulting in the decreases in gas production efficiency and produced gas quality. Therefore, we explored a new injection-production mode of alternate injection of N2 and CO2 in order to fully coordinate the advantages of N2 in enhanced hydrate decomposition and CO2 in solid storage and heat compensation. These alternate “taking” and “storing” processes perfectly repair the problem of the gas channel, achieving self-regulation effect of CH4 recovery and CO2 storage. The 3-D experimental results show that compared to the mixed gas injection, CH4 recovery is increased by >50% and CO2 storage is increased by >70%. Additionally, this alternate injection mode presented a better performance in CH4 concentration of produced gas and showed outstanding N2 utilization efficiency. Further, we analyzed its self-adaptive gas flow mechanism and proposed an application model of “one injection and multiple production”. We look forward to this study accelerating the application of CO2-CH4 replacement technology.

Investigating the behaviour of NaCl brines and hydrocarbons in porous alumina using low-field NMR relaxation and diffusion methods.

The behaviour of multiple fluid phases within a porous medium is hard to predict. NMR measurements offer an excellent tool to probe such systems in a fast and non-invasive way. Such systems can be relevant to hydrocarbon recovery, catalysis, and CO2 and H2 geo-storage, among others. Since electrolyte solutions are always present in subsurface reservoirs, understanding their behaviour within porous media is highly important. In this study, we use NMR relaxation and diffusion methods to investigate the diffusion coefficients and strength of interactions between alumina surfaces and brines at various NaCl concentrations, focusing on the effect of salt concentration on transport and interactions within the porous structure. Furthermore, we study the spontaneous displacement of dodecane, a model hydrocarbon, from the same alumina pellets using the same brine solutions. Results show that brines of lower salinity consistently displace more dodecane in total, after soaking dodecane-saturated pellets in a brine solution for several days. This indicates that increased salt concentrations can reduce wettability towards the aqueous phase in simple metal oxide surfaces and highlights the capabilities of NMR to efficiently study such systems.

Comprehensive analysis of influencing factors and mechanism of nano emulsion spontaneous imbibition oil displacement in tight sandstone reservoir

Comprehensive analysis of influencing factors and mechanism of nano emulsion spontaneous imbibition oil displacement in tight sandstone reservoir

Conversion to Trimolecular G-Quadruplex by Spontaneous Hoogsteen Pairing-Based Strand Displacement Reaction between Bimolecular G-Quadruplex and Double G-Rich Probes.

Bimolecular or tetramolecular G-quadruplexes (GQs) are predominantly self-assembled by the same sequence-identical G-rich oligonucleotides and usually remain inert to the strand displacement reaction (SDR) with other short G-rich invading fragments of DNA or RNA. Appealingly, in this study, we demonstrate that a parallel homomeric bimolecular GQ target of Tub10 d(CAGGGAGGGT) as the starting reactant, although completely folded in K+ solution and sufficiently stable (melting temperature of 57.7 °C), can still spontaneously accept strand invasion by a pair of short G-rich invading probes of P1 d(TGGGA) near room temperature. The final SDR product is a novel parallel heteromeric trimolecular GQ (tri-GQ) of Tub10/2P1 reassembled between one Tub10 strand and two P1 strands. Here we present, to the best of our knowledge, the first NMR solution structure of such a discrete heteromeric tri-GQ and unveil a unique mode of two probes vs one target in mutual recognition among G-rich canonical DNA oligomers. As a model system, the short invading probe P1 can spontaneously trap G-rich target Tub10 from a Watson-Crick duplex completely hybridized between Tub10 and its fully complementary strand d(ACCCTCCCTG). The Tub10 sequence of d(CAGGGAGGGT) is a fragment from the G-rich promoter region of the human β2-tubulin gene. Our findings provide new insights into the Hoogsteen pairing-based SDR between a GQ target and double invading probes of short G-rich DNA fragments and are expected to grant access to increasingly complex architectures in GQ-based DNA nanotechnology.

Fundamentals of liquid metal displacement reactions: Emf measurements of Na-Sn, Li-Sn, Mg-Sn, and Ca-Sn

The driving force of spontaneous displacement reactions between Na-Sn alloys and molten LiCl, MgCl2, and CaCl2 salts stems from the difference of chemical potential between Na and Li, Mg, or Ca in liquid Sn. However, fundamental thermodynamic data are absent. Herein, electromotive force (emf) values of Na-Sn, Li-Sn, Mg-Sn, and Ca-Sn alloys (electrodeposition of Na, Li, Mg, and Ca in liquid Sn via the coulometric titration) were measured in NaF-NaCl-NaI, LiF-LiCl, MgCl2-NaCl-KCl, and CaCl2-LiCl-NaCl salts respectively at 650 °C. The measured emf values of these alloys were normalized with respect to the Cl−/Cl2 potential that −3.14 V to −3.35 V for Na-Sn (mole fractions xNa = 0.02–0.30) alloy, −2.90 V to −3.21 V for Li-Sn (xLi = 0.02–0.30) alloy, −2.38 V to −2.45 V for Mg-Sn (xMg = 0.01–0.15) alloy, and −2.90 V to −3.06 V for Ca-Sn (xCa = 0.01–0.15) alloy. And Li20Sn, Mg10Sn, and Ca10Sn alloys were successful prepared by displacement reactions between Na20Sn alloys and LiCl-NaCl, MgCl2-NaCl, and CaCl2-NaCl salts, which offers theoretical guidelines for s-block elements extraction and separation.

Applying video motion magnification to reveal spontaneous tympanic membrane displacement as an indirect measure of intracranial pressure in patients with brain pathologies

BackgroundThe observation of tympanic membrane displacement (TMD) opens up the possibility of indirect intracranial pressure (ICP) estimation. In this study, we applied a phase-based video motion magnification (VMM) algorithm to reveal spontaneous pulse TMD waveforms (spTMD) and compare them with invasively measured ICP in patients with intracranial pathologies.MethodsNine adults (six traumatic brain injury and three aneurysmal subarachnoid haemorrhage; median age 44 (29–53) years admitted to the intensive care unit of Wroclaw Medical University between October 2021 and October 2022 with implanted ICP sensors were included in this retrospective study. Video recordings of the tympanic membrane were performed using a portable otoscope with a video camera and analysed by a custom-written VMM algorithm. ICP was monitored using intraparenchymal sensors and arterial blood pressure (ABP) was measured in the radial arterial lines. ICP, ABP, and spTMD videos were captured simultaneously. The pulse amplitudes of ICP (Amp_ICP), ABP (Amp_ABP) and spTMD (Amp_spTMD) were estimated using fast Fourier transform within the heart rate (HR)–related frequency range.ResultsAmp_spTMD was significantly correlated with mean ICP (rS = 0.73; p = 0.025) and with Amp_ICP (rS = 0.88; p = 0.002). Age was not a significant moderator of this association. There were no significant relationships between Amp_spTMD and either mean ABP, HR, or Amp_ABP.ConclusionsThe study suggests that Amp_spTMD increases with the increase in mean ICP and Amp_ICP. Estimation of Amp_spTMD using the VMM algorithm has the potential to allow for non-invasive detection of the risk of elevated ICP; however, further investigation in a larger group of patients is required.

Efficient separation and recovery process of Pd(II) based on sintering-leaching method by silica-based aluminum hexacyanoferrate

In the present work, several hexacyanoferrates (K2CoFe(CN)6, KAlFe(CN)6 and K2NiFe(CN)6) were theoretically analyzed based on density functional theory (DFT). Their stable structures and adsorption capabilities were compared. A silica-based hexacyanoferrate (KAlFe(CN)6/SiO2) was selected and synthesized for Pd(II) separation and recovery process. Its estimated mode particle size was 67 μm, and its average crystal size was 18.8 nm. The Fe 2p and Pd 3 d X-ray photo-electron spectra (XPS) of Pd-loaded KAlFe(CN)6/SiO2 and density functional theory calculation revealed that the adsorption mechanism is the spontaneous displacement of K+ by Pd2+. A novel sintering-leaching method was developed for the recovery of Pd(II) from spent adsorbent. The effects of different sintering times, leaching temperatures, and leaching media were investigated, indicating that the optimal condition (sintering at 400 °C for 24 h, leaching in 3 M HCl at 50 °C) could reach a Pd(II) recover ratio of 88%. Energy-dispersive spectroscopy (EDS) and XPS tests were performed on the leaching product, and the results confirmed that the recovered product was PdO with purity of 91.8%.

Study on spontaneous imbibition and displacement characteristics of mixed-wet tight sandstone reservoir based on high-precision balance and NMR method

Wettability is the key to understanding the complex seepage characteristics of tight sandstone reservoirs, which will affect the distribution of the residual hydrocarbon resources during the reservoir exploitation process. Complex wettability, strong heterogeneity and tiny pore space make it more challenging to study the imbibition characteristics of mixed-wet tight sandstone reservoirs. In this study, the spontaneous imbibition (SI) and displacement characteristics of mixed-wet tight sandstone reservoirs are studied by high precision balance and nuclear magnetic resonance (NMR) T2 experiment. 3 rock plungers (A1, B1, C1) were put into the CaCl2 solution for SI, while their parallel samples (A2, B2, C2) were carried out SI experiments in the experimental oil. Then all the plungers are respectively displaced by the imbibition liquid after SI experiments. The weight and NMR T2 spectra of the plungers in the above different conditions were measured. According to the experiment results, the pores of tight sandstone can be divided into 3 types with different wettability. The adsorption pores with T2 distribution of 0.01–2.5 ms are water-wet, the capillary bound fluid pores with T2 between 2.5 and 50 ms and the movable fluid pore with T2 greater than 50 ms are mainly oil-wet. The SI and displacement behaviors of different pores were studied, the results show the oil absorbed per cc rock is more than 4 times that of brine. The weight gain after SI in the first 24 h can indicate the total SI result. The study results can accurately characterize the wettability of different pores and contribute to a novel wettability evaluation method in mixed wettable tight sandstone.

Reliability and Repeatability of a Postural Control Test for Preterm Infants.

the current study aims to evaluate the reliability and repeatability of a new PT based on Center of Pressure (CoP) movement analysis in a repeated measures design. the examination consisted of two parts: (1) the videotaping of General Movements (GMs) and GMs assessment (GMA) and (2) Posturometric Tests (PT) in supine and prone positions. PTs were performed twice (by two investigators) in the supine and prone positions using a force plate. Based on the GMA results, infants were stratified into two groups: (1) infants with normal FMs (indicating normal future motor outcomes) (n = 18) and (2) infants with abnormal FMs (indicating later neurological dysfunction) (n = 19). the comparative analysis between the groups of infants with normal FMs and abnormal FMs in PT in supine showed significant differences for all parameters that described spontaneous CoP displacement. The reliability analysis determined that all ICCs of the outcomes presented at least a moderate level of reliability. The ICCs were higher for outcomes of PT performed in the supine position than in the prone position. The ICCs were higher for outcomes of PT performed in infants with abnormal vs. normal FMs. although the current study yielded promising results, further longitudinal research in preterm infants should identify whether altered postural control parameters prognose future motor outcomes.

Alkyne-tethered oligodeoxynucleotides that allow simultaneous detection of multiple DNA/RNA targets using Raman spectroscopy.

Detection of multiple DNA/RNA targets is essential for understanding cellular function. Herein, we propose a general method for the simultaneous detection of plural nucleic acids based on surface-enhanced Raman scattering (SERS) using gold nanoparticles bearing functional oligodeoxynucleotides (ODNs) on their surface. Modified ODNs bearing an acetylene tag hybridized with their complementary ODNs on the surface of the gold nanoparticles, inducing a strong SERS signal of the acetylene tag. The addition of the target nucleic acid to the system resulted in a spontaneous displacement of the strand on the particle and dissociation of the alkyne-tagged ODN from the particle, resulting in a dramatic decrease in signal intensity. By using an alkyne tag for each of the multiple target nucleic acids, each target could be detected simultaneously. In addition, we successfully detected cellular microRNA. Different targets showed changes with different wavenumbers in the Raman spectra, allowing for the detection of multiple nucleic acids.

Combined Rotating Disk Slurry Electrodeposition–Spontaneous Galvanic Displacement for Pt-M (M = Co, Ni, and Cu) Catalyst Synthesis for the Oxygen Reduction Reaction in Alkaline Media

Combined Rotating Disk Slurry Electrodeposition–Spontaneous Galvanic Displacement for Pt-M (M = Co, Ni, and Cu) Catalyst Synthesis for the Oxygen Reduction Reaction in Alkaline Media

Effect of crude oil self-emulsification on the recovery of low permeability reservoir after well soaking

The emulsification phenomenon exists during crude oil exploitation in the Jimsar area of Xinjiang. In the field, the emulsification mechanism and its influence on production are unclear. To clarify the self-emulsifying law of crude oil and its influence on production during soaking, this study carried out microscopic visualization displacement experiments, spontaneous imbibition displacement, and oil–water displacement experiments. Results show that oil–water contact time and water phase type affect the size of the emulsified layer between crude oil and water phase. The oil–water distribution type affects the formation mode of crude oil emulsification. After the opening of the water phase channel, crude oil mainly migrates in the form of a water-in-oil emulsion. The crude oil attached to the pore wall and stuck in the pore throats is the main source of the dispersed phase in the emulsion. When crude oil moves through pores, the high-curvature boundary changes the interfacial tension and capillary force. Thus, this case makes the crude oil easily stuck to form small oil droplets and promotes the dispersion of crude oil to form an emulsion. In the tight core, a decrease in the spontaneous imbibition ability was attained by increasing nano-emulsion concentration. However, the oil displacement effect of 0.3% nano-emulsion is better than that of the 0.6% concentration. Therefore, ensuring a certain spontaneous imbibition ability and a certain displacement efficiency is necessary. Oil recovery can be enhanced to a certain extent after self-emulsification in the pores of Jimsar crude oil. When oil displacement depends on the capillary force or driving pressure difference, the oil–water interfacial tension is not the lower, the better, and a suitable range exists. The suitable oil–water interfacial tension in this region is between 0.1 and 1 mN/m.

Sandwich structure confined gold as highly sensitive and stable electrochemical non-enzymatic glucose sensor with low oxidation potential

• Fe 3 O 4 @Au@CoFe-LDH is prepared through a spontaneous galvanic displacement reaction. • In Fe 3 O 4 @Au@CoFe-LDH, the metallic Au intercalates between Fe 3 O 4 and LDH forming the sandwich structure. • Fe 3 O 4 @Au@CoFe-LDH possesses high sensitivity of 6342 μA mM −1 cm −2 , broad linear detection range of 0.0375 to 15.64 mM and low limit of detection of 12.7 μM, with an extremely low oxidation potential of 0.82 V vs. RHE. • The small quantity of Au laying between LDH and Fe 3 O 4 is the active part of glucose oxidation and the existence of Fe 3 O 4 nanoparticles significantly improves the stability of the electrocatalyst. The preparation of highly sensitive and stable non-enzymatic glucose sensors is critical to the prevention and treatment of diabetes. Fe 3 O 4 @Au@CoFe-LDH is prepared through a spontaneous galvanic displacement reaction. A series of structural characterizations testify the successful formation of Fe 3 O 4 @Au@CoFe-LDH electrocatalyst, with the Au intercalating between Fe 3 O 4 and LDH to form the sandwich structure. Cyclic voltammetry tests indicate that Au is responsible for the electrocatalytic oxidation of glucose. The characterizations of the electrochemical sensor for glucose detection indicate that Fe 3 O 4 @Au@CoFe-LDH possesses high sensitivity of 6342 μA mM −1 cm −2 , with an extremely low oxidation potential of 0.82 V vs. RHE. Even with the high glucose concentration of 15 mM, the sensitivity remains at 4359 μA mM −1 cm −2 . Due to the broad linear detection range (0.0375 to 15.64 mM) and the low limit of detection (12.7 μM), Fe 3 O 4 @Au@CoFe-LDH is applicable towards practical application. Thanks to the sandwich structure, which confines the Au in between Fe 3 O 4 and CoFe-LDH, the Fe 3 O 4 @Au@CoFe-LDH glucose sensor shows high long-term stability and satisfactory selectivity. The successful synthesis of the sandwich-structured Fe 3 O 4 @Au@CoFe-LDH provides a new conception for the design of highly sensitive and stable non-enzymatic glucose electrodes.

A RARE CASE: CHEMOPORT TIP DISPLACEMENT FROM PERSISTENT VOMITING AND RETCHING

A RARE CASE: CHEMOPORT TIP DISPLACEMENT FROM PERSISTENT VOMITING AND RETCHING