Large Plug Research Articles

Intestinal Obstruction Following Barium Swallow

Intestinal obstruction following a barium examination is a rare complication. We report a case of distal large bowel obstruction caused by large barium plugs – Baroliths, occurring a few weeks after a barium swallow.

Exploratory Test of Horizontal Drilling Plugs and Water Shutoff Technology in X Horizontal Gas Well

In order to solve the problem that the tight gas X horizontal gas well could not be put into production due to the accumulation of fluid in the wellbore during the drainage stage after fracturation, based on the geological understanding of water flowing from the far end of the reservoir, and the actual situation of staged fractured with drillable bridge plug, water blocking has become the exploration direction of potential excavation and resuming production. Through the analysis of the type, structure, setting principle and unsealing principle of drillable bridge plug, put forward the technical idea of horizontal drilling plugs and mechanical water plugging. And determine the treatment method of drilling-grinding and fishing large inner diameter bridge plugs, and design the construction process. Moreover combined with theoretical calculation, the relationship between the debris carrying velocity and displacement in horizontal wells, the size of the debris and the angle of inclination was optimized. Besides that, the milling method that uses a wellhead rotating device to drive the drill pipe and grinding shoes for drilling and grinding was proposed. In the field test, successfully drill to the third large inner diameter bridge plug position according to the design requirements. And successfully put in the fishable bridge plug to achieve mechanical water blocking. After commissioning, the daily gas production volume reached 11000 m3/d. The test results show that: 1) It is feasible to use the wellhead rotating drive drill pipe and grinding shoes to drill and remove the steel drillable bridge plugs in the horizontal section of the horizontal well; 2) It is also feasible to use the fishable bridge to plug in the horizontal section of the horizontal gas well with drillable bridge plug staged fractured, and the plugging effect is good. In summary, it is shown that this technology test achieves the purpose of potential excavation and resuming production of the X horizontal gas well, which has good reference value.

Method Development for Determination of Doripenem in Human Plasma via Capillary Electrophoresis Coupled with Field-Enhanced Sample Stacking and Sweeping.

In this study, we established a novel capillary electrophoresis method for monitoring the concentration of doripenem in human plasma. As a time-dependent antibiotic, doripenem maximizes its antibacterial effects and minimizes the potential for antibiotic resistance through careful therapeutic drug monitoring. Two online preconcentration techniques, field-enhanced sample stacking (FESS) and sweeping, were coupled to enhance the detection sensitivity. Briefly, an uncoated fused silica capillary (40 cm × 50 μm i.d) was rinsed with a high conductivity buffer (HCB) composed of 150 mM phosphate buffer (NaH2PO4, pH 2.5) and 20% methanol. A large sample plug prepared in a low-conductivity phosphate buffer (50 mM NaH2PO4, pH 2.5) was then hydrodynamically injected (5 psi, 80 s) into the capillary. Under an applied voltage of -30 kV, the analyte was accumulated at the FESS boundary and swept by the negatively charged micelles toward the UV detector. Plasma samples were pretreated by solid-phase extraction (SPE) to eliminate endogenous interferences. The validation results demonstrated a high coefficient of determination (r2 > 0.9995) for the regression curve with impressive precision and accuracy: relative standard deviation (RSD) <5.86% and relative error <4.63%. The limit of detection (LOD, S/N = 3) for doripenem was determined to be 0.4 μg/mL. Compared to the conventional micellar electrokinetic chromatography method, our developed method achieved a sensitivity enhancement of up to 488-fold for doripenem. Furthermore, the newly developed method successfully quantified doripenem concentrations in plasma samples obtained from patients accepting doripenem regimens, proving its application potential in the clinical realm.

The Synergy Effect of Ignition Energy and Spark Plug Gap on Methane Lean Combustion with Addressing Initial Flame Formation and Cyclic Variation.

Controlling carbon emissions could be a win-win for both the environment and humans, and the use of low-carbon fuels is the key to being carbon-neutral in traffic transportation. Natural gas can achieve low carbon emissions and obtain high efficiency, but the poor lean combustion performance may result in large cycle-by-cycle variations. In this study, the synergy effect of high ignition energy and spark plug gap on methane lean combustion was optically studied under low-load and low-EGR conditions. High-speed direct photography combined with simultaneous pressure acquisition was used to analyze early flame characteristics and engine performance. The results show that high ignition energy can improve the methane engine's combustion stability, especially under high excess air coefficient conditions, and the main reason is that the initial flame formation is improved. However, the promoting effect may become marginal when the ignition energy increases above a critical value. As for the effect of spark plug gap, it varies with the ignition energy, and there exists an optimal spark plug gap for a given ignition energy. In another word, high ignition energy must combine with a large spark plug gap; thus, the promoting effect on combustion stability can be maximized and the lean limit can be extended. The statistical analysis of the flame area shows that the speed of initial flame formation is more important in determining combustion stability. As a result, a large spark plug gap (1.20 mm) can extend the lean limit to 1.4 under high ignition energy conditions. The current study shall give some insights into the spark strategies for natural gas engines.

Influence of mating strategies on seminal material investment in crabs

Reproduction involves high energetic costs which are related to behaviour and gamete production. In females energy allocation to gamete production has been well documented. However, estimations of male investment in seminal material are scarce. The present study aims to assess and compare male investment in four brachyuran species by determining biochemical substrates present in the vasa deferentia to subsequently estimate energetic investment during the reproductive cycle. We identified two groups with contrasting energy investments. Two species, Homalaspis plana and Romaleon setosum, showed high investment due to significant quantities of proteins and lipids. Both species are characterised by large and complex vasa deferentia, and the formation of a remarkably large sperm plug deposited to the female after copulation as a sperm competition avoidance strategy. In contrast, Metacarcinus edwardsii and Taliepus dentatus invested little energy in their smaller-sized and simpler vasa deferentia. Morpho-functional traits may play a key role in determining the investment, which may also be influenced by mechanisms (i.e. mating tactics) to prevent sperm competition and the intensity of polygyny. This study emphasises the high amount of energy males invest in seminal material and highlights the diversity of mating strategies in Brachyura, which are reflected even on the physiological level.

Thermal Processing of a Degradable Carboxylic Acid-Functionalized Polycarbonate into Scaffolds for Tissue Engineering.

Degradable polymers are often desirable for the fabrication of medical implants, but thermal processing of these polymers is a challenge. We describe here how these problems can be addressed by discussing the extrusion of fibers and injection molding of bone pins from a hydrolytically degradable tyrosine-derived polycarbonate. Our initial attempts produced fibers and pins with bubbles, voids, and discoloration, and resulted in the formation of large polymer plugs that seized screws and blocked extruder dies. The material and process parameters that contribute to these issues were investigated by studying the physical and chemical changes that occur during processing. Differential scanning calorimetry (DSC) scans and thermogravimetric analysis combined with IR (TGA-IR) analysis revealed the role of residual moisture and residual solvents that in conjunction with heat cause degradation and crosslinking as indicated by gel permeation chromatography (GPC). Rheology and melt-flow index measurements were useful in characterizing the extent of dependence of polymer viscosity on temperature and molecular weight. With these insights, we could process our polymer into fibers and rods by controlling residual moisture, time and temperature, and by adjusting processing parameters in real-time. The systematic approach described here is applicable to other degradable polymers that are difficult to process.

Regulated Roman Coins and Their Imitations from India: Did Roman Coins Circulate as Money in the Subcontinent?

This paper focuses on a relatively unknown group of published and unpublished Roman gold coins and their imitations from India with a large gold plug placed behind the head of an emperor. This phenomenon was briefly discussed by Peter Berghaus, who rightly noticed that the size of the filling on those coins suggests that the purpose for placing such material into the hole was different than simply the repair of a piercing made previously for a piece of jewellery. He considers the possibility that the holes were made in order to check whether those coins were plated or not and were later refilled with gold so that the coins could return to the money market. I would like to present a different explanation of this phenomenon. I would argue that those coins were perforated and plugged in order to adjust their weight. Such an adjustment let them be used as money in the Subcontinent. Similar phenomena from various parts of the world and time periods constitute the key to understand the purpose of plugging those coins and those analogies are examined in this paper as well.

The occurrence of a sphragis and genital modification in Hypermnestra, Archon and Sericinus (Lepidoptera: Papilionoidea: Papilionidae)

ABSTRACT In certain butterfly species males attach a large external mating plug termed a sphragis to the female abdomen during mating. This is derived from male accessory secretions and covers the female ostium bursae and surrounding areas, thus preventing or delaying remating. Specimens of the poorly studied parnassiines, Hypermnestra helios, Archon apollinus, A. apollinaris and Sericinus montela, were examined for the presence or absence of a sphragis. The morphology of the female genitalia, normally modified in sphragis-bearing species, was also examined, as was that of males. In H. helios, the female sterigma was membranous, with a fleshy projection behind the ostium bursae. The sphragis of this species was a solidified secretion deposited over the sterigma, especially thickly on the projection, so that it consistently assumed an irregular conical shape. In the Archon species, the sclerites of the sterigma are fused to form a large sclerotised plate around the ostium bursae, and a sphragis was present as an irregularly smeared male secretion covering the genital plate, associated with long scales from the male valvae attached laterally in rows on either side; this was found at low frequency in mated A. apollinus and A. apollinaris. In S. montela, the area surrounding the ostium bursae is sclerotised and deeply invaginated, forming a small cup. Mated females of S. montela bore a sphragis that formed a lid sealing the cup, being typically a thin wafer of solidified secretion and found at a somewhat low frequency, and also the inner wall of the cup often had a thin lining of a male accessory secretion. The evolutionary status of the sphragis in relation to the modification of the genitalia of both sexes in each genus is discussed.

Analysis of ZTE MRI application to sandstone and carbonate

AbstractMicrotomography (μCT) and nuclear magnetic resonance (NMR) have been used to characterize porous media for decades. Magnetic resonance imaging (MRI) enables direct visualization of pore architecture and many pulse sequences exist. In this work, we tested the MRI pulse sequence Zero Echo Time (ZTE) to study sandstone and carbonate for its ability to address short relaxation times. We aimed at resolving two fluid conduit scales, that is, pores and fractures. In this research, we study tighter porous systems than those previously reported using ZTE. Additionally, pore cluster analysis (PCA), combined with ZTE, can be used to analyze pore‐fracture connectivity of relatively large core plugs. We show that ZTE can resolve two‐scale pore systems simultaneously, that is, fractures and pores. By combining time‐domain NMR pore‐size analysis and PCA, we show that careful selection of resolution is necessary to understand transport in porous media.

Successful Pregnancy in a Patient with Infertility Due to Congenital Plasminogen Deficiency Treated with Intravenous Plasminogen (Human) Replacement Therapy

Congenital plasminogen deficiency (C-PLGD) is a rare autosomal recessive multisystem disorder of the fibrinolytic system that is often underdiagnosed. It is caused by mutations in the PLG gene and is characterized by extravascular fibrinous deposits on mucus membranes resulting in tissue injury or organ dysfunction. The abnormal accumulation or growth of fibrin-rich pseudomembranous lesions on mucous membranes, such as the conjunctiva, gingiva, linings of airways and genitourinary tract have been termed ligneous for their "woody" appearance. Ligneous conjunctivitis is the most common manifestation of C-PLGD occurring in greater than 80% of affected patients. Ligneous lesions affecting the female reproductive system have been reported in one large case series in 9% of patients (Shuster et. al. JTH 2007). An extensive review of the literature (Baithun et. al. Haemophilia 2018) identified 30 cases of C-PLGD patients with gynecologic involvement. A diagnosis of infertility, when performed, was reported in 8 (26.7%) of these females of child-bearing age. Due to the rarity of the disease, infertility may be under diagnosed and under reported in the literature as no natural history studies of this disease have been conducted. We report a case of a patient with C-PLGD with a documented diagnosis of infertility who received intravenous plasminogen therapy. Although the protocol stated that adequate contraceptive measures be taken to avoid becoming pregnant during the study, she became pregnant, went to term and had a successful delivery of a healthy child. She was a 33-year-old woman with a diagnosis of C-PLGD in childhood, after developing ligneous conjunctivitis before the age of 1, developed uterine ligneous lesions and dysmenorrhea as a teenager. At age 27, a hysteroscopy was attempted and laparoscopy was performed which revealed fibrosis and web-like fibrin-rich adhesions in the uterus and fallopian tubes. She was referred to the Oslo University Hospital, Norway, for evaluation and management of her infertility and eye lesions at the age of 28. She was treated with fresh frozen plasma (FFP) infusions with improvement in eye symptoms and dysmenorrhea. At the age of 29, a vaginoscopy and hysteroscopy were performed which again demonstrated fibrin membranes in the uterus. A repeat evaluation at the age of 30 revealed fibrin membranes in the cervix, fibrin accumulation in the uterus, and tube ostia obstructed. At age 33 she was enrolled in a clinical trial, an open-label phase 2/3 study of human Glu-plasminogen administered intravenously at 6.6 mg/kg every 2-4 days in 15 patients with plasminogen deficiency, registered at www.clinicaltrials.gov as #NCT02690714. She received intravenous plasminogen replacement therapy, starting in October 2016. At baseline, she had ligneous conjunctivitis and gynecologic lesions with regular, but atypical menstrual bleeding, discharging very small amounts of thick, mucus-like material over 1-2 days. Her eye lesions had resolved by week 12 of treatment. At the end of the first menstrual cycle on plasminogen treatment, she discharged a large mucus-like plug from the vagina, and had regular and normal menstrual bleeds after that. Approximately 20 weeks into treatment, she reported being pregnant to the investigator. After discussion with the clinical study sponsor, regulatory agencies and the regional ethical committee, the patient and her physician, it was agreed to continue plasminogen replacement therapy through the pregnancy, delivery and recovery period. After approximately 55 weeks into the study treatment, the patient had an uncomplicated pregnancy and delivered a healthy child with APGAR score of 9. The patient remained on PLG treatment post-partum, and her PLG activity trough levels were maintained until she came off the study when her levels went back to baseline. (Figure 1) This is the first reported case of intravenous plasminogen used in a patient with C-PLGD and documented infertility who subsequently became pregnant and delivered a healthy child. Figure Disclosures Parker: Liminal BioSciences: Current Employment, Current equity holder in publicly-traded company. Trybul:Liminal BioSciences: Current Employment, Current equity holder in publicly-traded company. Sandset:Liminal BioSciences: Other: Investigator Clinical Trial.

Evaluation of a Novel Shallow Aggregate Ebb-and-flood Culture System and Transplant Size Effects on Hydroponic Basil Yield

Ornamental bedding plant operations transitioning to leafy greens and herb production must decide whether to invest in new hydroponic equipment or modify existing culture systems for edible crops. In addition, common practices used to increase space-use and production efficiencies during bedding plant production may be modified for hydroponic leafy greens and herbs, such as purchasing large seedlings for transplant. The objective of the first experiment was to evaluate plant growth in a modified and novel shallow aggregate ebb-and-flood (SAEF) system intended for bedding plant growers with an emphasis on comparing yield across four basil (Ocimum basilicum) cultivars grown in the SAEF system to those grown using the traditional nutrient film technique (NFT) and deep water culture (DWC) hydroponic systems. The second experiment objective was to evaluate basil seedling size and the time of transplant to NFT hydroponic systems to determine effects on the final yield. ‘Genovese’ basil seedlings were grown in trays with cell counts of 32, 50, 72, 105, and 162 cells with corresponding root volumes per plant of 98.1, 50.2, 38.5, 19.6, and 16.3 cm3, respectively. Seedlings were transplanted to NFT systems at 14, 21, and 28 days after sowing and were harvested at 35 days. In the first experiment, overall basil shoot fresh and dry weights per plant were intermediate in the SAEF system (90.4 and 8.3 g) compared with the DWC (102.6 and 9.1 g) and NFT (75.8 and 6.6 g) hydroponic systems. In the second experiment, final shoot fresh and dry weight per plant increased as seedling root volume increased from 16.3 cm3 [72.8 and 5.5 g (162-cell tray)] to 98.1 cm3 [148.5 and 12.2 g (32-cell tray)]. Transplanting seedlings at later dates decreased yield across tray size and root volume treatments. Differences in yield between culture systems may have resulted from differences in nutrient supply and availability for plant uptake. Transplant of large seedling plugs to hydroponic culture was not shown to increase space-use efficiency after transplant without compromising yield, likely because root zone factors limited growth during seedling production. Further investigation into maximizing plant growth during seedling production and evaluating the effects of seedling size and transplant practices are needed to determine the potential for increasing space-use and production efficiencies.

ROLE OF DERMATOSCOPY IN CHRONIC DERMATOSES DIAGNOSIS

Dermatoscopy is a valuable auxiliary non−invasive method used in the diagnosis of inflammatory, parasitic and viral skin diseases. Treatment of dermatoses is based on the results of analysis of melanin, follicular−horny and vascular components. Diagnosis begins with polarized dermatoscopy and then progresses to non−polarized using immersion fluid. At dermatoscopic inspection of a psoriatic plaque the point vessels evenly distributed along all the surface (a symptom of "scattered red pepper") are noted. Eczema is characterized by focal accumulation of blood vessels in the form of dots, peeling, yellowish crusts. Examination of discoid lupus erythematosus foci often reveals individual linear or branched vessels, their location is random. Red herpes zoster is dermatoscopically characterized by vascular structures in the form of large granular horny plugs of whitish color with a pearly sheen. The most informative is dermatoscopy in the differential diagnosis of erythematous form of rosacea and seborrheic dermatitis. On the erythematous background, dilated vessels around the sebaceous hair follicles, large vascular polygons formed from vessels thicker than in healthy skin and seborrheic dermatitis are found. At inspection of the fresh centers of a sclero−atrophic lichen diffuse unstructured zones of white color with a peripheral erythematous corolla and with numerous light comedic structures on a surface are visualized. At dermatoscopy of the Little − Lassueur syndrome in follicular papules on skin gray, violet points located in the form of a circle are noted. Dermatoscopy is increasingly used in dermatology, especially in the differential diagnosis of dermatoses of inflammatory and parasitic nature.

The Hydrophobic Ligands Entry and Exit from the GPCR Binding Site-SMD and SuMD Simulations.

Most G protein-coupled receptors that bind the hydrophobic ligands (lipid receptors and steroid receptors) belong to the most populated class A (rhodopsin-like) of these receptors. Typical examples of lipid receptors are: rhodopsin, cannabinoid (CB), sphingosine-1-phosphate (S1P) and lysophosphatidic (LPA) receptors. The hydrophobic ligands access the receptor binding site from the lipid bilayer not only because of their low solubility in water but also because of a large N-terminal domain plug preventing access to the orthosteric binding site from the extracellular milieu. In order to identify the most probable ligand exit pathway from lipid receptors CB1, S1P1 and LPA1 orthosteric binding sites we performed at least three repeats of steered molecular dynamics simulations in which ligands were pulled in various directions. For specific ligands being agonists, the supervised molecular dynamics approach was used to simulate the ligand entry events to the inactive receptor structures. For all investigated receptors the ligand entry/exit pathway goes through the gate between transmembrane helices TM1 and TM7, however, in some cases it combined with a direction toward water milieu.

Synergistic and Antagonistic Effects of Aromatics on the Agglomeration of Gas Hydrates

Surfactants are often used to stabilize aqueous dispersions. For example, surfactants can be used to prevent hydrate particles from forming large plugs that can clog, and sometimes rupture pipelines. Changes in oil composition, however dramatically affect the performance of said surfactants. In this work we demonstrate that aromatic compounds, dissolved in the hydrocarbon phase, can have both synergistic and antagonistic effects, depending on their molecular structure, with respect to surfactants developed to prevent hydrate agglomerations. While monocyclic aromatics such as benzene were found to disrupt the structure of surfactant films at low surfactant density, they are expelled from the interfacial film at high surfactant density. On the other hand, polycyclic aromatics, in particular pyrene, are found to induce order and stabilize the surfactant films both at low and high surfactant density. Based on our simulation results, polycyclic aromatics could behave as natural anti-agglomerants and enhance the performance of the specific surfactants considered here, while monocyclic aromatics could, in some cases, negatively affect performance. Although limited to the conditions chosen for the present simulations, the results, explained in terms of molecular features, could be valuable for better understanding synergistic and antagonistic effects relevant for stabilizing aqueous dispersions used in diverse applications, ranging from foodstuff to processing of nanomaterials and advanced manufacturing.

Airway emergency during general anesthesia in a child with plastic bronchitis following Fontan surgery: a case report

BackgroundPlastic bronchitis (PB) is a complication of Fontan surgery, results in the formation of mucus plug in the tracheobronchial tree, causing potentially fatal airway obstruction. We report critical airway emergency during general anesthesia in a child with plastic bronchitis.Case presentationA 5-year-old boy was scheduled for intrapulmonary lymphatic embolization through percutaneous catheterization under general anesthesia. He underwent Fontan surgery at the age of 2 and frequently developed respiratory failure due to plastic bronchitis. After induction of general anesthesia and tracheal intubation, mechanical ventilation became difficult even with an inspiratory pressure ≥ 50 mmHg due to airway obstruction. He expectorated a large mucus plug through the tracheal tube after administration of sugammadex, naloxone, and flumazenil, and respiratory condition was stabilized thereafter.ConclusionGeneral anesthesia for a patient with plastic bronchitis should be planned with extracorporeal membrane oxygenation or cardiopulmonary bypass stand by.

Ulcerative nodules on the entire body

Ulcerative nodules on the entire body

Analytical approaches for the determination of deferiprone and its iron (III) complex: Investigation of binding affinity based on liquid chromatography-mass spectrometry (LC-ESI/MS) and capillary electrophoresis-frontal analysis (CE/FA)

Two rapid and highly sensitive separation techniques were developed for the determination of free and metal-bound deferiprone for binding affinity studies. The chromatographic method was carried out on a high-resolution monolithic column using gradient elution with a mobile phase consisting of ammonium formate solution (pH 7.4; 10 mM), H2O, and methanol pumped at a flow rate of 1.0 mL min−1. Identification was performed on single quadrupole mass spectrometer using electrospray ionization interface at positive polarity. The assay was found to be linear in the concentration range of 0.5–17.5 mM with regression coefficient of r2 > 0.999. The electrophoretic method has been developed to achieve sufficient separation between free drug and the complex using capillary length of 48.5/8.5 cm (Ltot/Leff), 10 kV of applied voltage in negative mode, and large plug of sample injected hydrodynamicallyat10 mbar for 50 s. The linear range of the drug concentrations was 40–240 μM, with regression coefficient r2 > 0.998. The binding parameters have been estimated for both methods in terms of binding constant (LogKa) and number of binding sites (ni). The values LogKa and ni8.3 ± 0.17 and 3.4 ± 0.65 respectively were obtained from the data of liquid chromatography while, the data obtained from capillary electrophoresis resulted in LogKa10.4 ± 0.12 and ni 3.0 ± 0.10.

Silk‐ and volatile‐based male mate choice in the genital plug‐producing spider

AbstractFemale mating history can have a strong effect on male fertilization success. Although males often prefer to mate with virgin females, they often also engage with mated females. As the intensity of sperm competition can differ among mated females, males are expected to evolve means to identify their status. In spiders, males often use female silk to gather information about female quality. Males of many spider species deposit mating plugs into female genitalia to hinder further copulations. We tested whether males of the foliage‐dwelling, plug‐producing spider Philodromus cespitum, which is an important natural enemy of pests, discriminate between females of different mating status and whether they can determine the extent of genital plugging in mated females solely on the basis of cues gained from deposited female silk. We presented males with draglines of females that varied in either mating status (virgin vs. mated), the extent of plugging (small vs. big plug), or the age of the plug (fresh vs. old plug) and examined their mate preferences. Additionally, we tested whether males were attracted to volatile cues produced by female bodies. Our experiments revealed that males preferred draglines of virgin females to those of mated females, and mated females with small plugs to those with large plugs. They were also attracted to female volatile cues. This study suggests that males are able to extract fine‐scale information on mating status from female draglines.

Pancreaticobiliary maljunction (PBM) complicated with complete pancreas divisum

Abstract A rare pediatric case of pancreaticobiliary maljunction (PBM) with pancreas divisum is reported. The case showed extremely rare arrangement of the biliary tree and pancreatic duct; the common channel usually seen in PBM did not exist and the common bile duct was connected to the dorsal pancreatic duct via a dilated intermediary duct, in which a large protein plug had formed. The common bile duct was not dilated at all. All of these anomalies may have been caused by abnormal development of the ventral and dorsal pancreatic ducts at an early gestational age. We report a very rare pediatric case of pancreaticobiliary maljunction (PBM) complicated with pancreas divisum. In this case, the common bile duct showed a normal caliber and it was connected to the dorsal pancreatic duct through an intermediary dilated duct, which contained a protein plug that dammed up bile and pancreatic juice flow. This anomaly is very similar to type IIIc3 choledochal cyst, whose classification was addressed by Komi et al. (1), but it differed in the following point; in our case, the common bile duct did not connect to the duodenum through the ampulla of Vater (the common channel was absent) and bile was drained to the duodenum through Santorini duct. These quite rare anomalies might have been caused in the fetus by some kind of maldevelopment of the ventral and dorsal pancreatic ducts.

How Do Surfactants Control the Agglomeration of Clathrate Hydrates?

Clathrate hydrates can spontaneously form under typical conditions found in oil and gas pipelines. The agglomeration of clathrates into large solid masses plugs the pipelines, posing adverse safety, economic, and environmental threats. Surfactants are customarily used to prevent the aggregation of clathrate particles and their coalescence with water droplets. It is generally assumed that a large contact angle between the surfactant-covered clathrate and water is a key predictor of the antiagglomerant performance of the surfactant. Here we use molecular dynamic simulations to investigate the structure and dynamics of surfactant films at the clathrate–oil interface, and their impact on the contact angle and coalescence between water droplets and hydrate particles. In agreement with the experiments, the simulations predict that surfactant-covered clathrate–oil interfaces are oil wet but super-hydrophobic to water. Although the water contact angle determines the driving force for coalescence, we find that a large contact angle is not sufficient to predict good antiagglomerant performance of a surfactant. We conclude that the length of the surfactant molecules, the density of the interfacial film, and the strength of binding of its molecules to the clathrate surface are the main factors in preventing the coalescence and agglomeration of clathrate particles with water droplets in oil. Our analysis provides a molecular foundation to guide the molecular design of effective clathrate antiagglomerants.