The effect of charge screening for cationic surfactants on the rigidity of interfacial nanoparticle assemblies.

HYPOTHESIS: Functionalizing colloidal particles with oppositely charged surfactants is crucial for stabilizing emulsions, foams, all-liquid structures, and bijels. However, surfactants can reduce the attachment energy, the driving force for colloidal self-assembly at interfaces. An open question remains on how the inherent interfacial activity of cationic surfactants influences the interfacial rigidity of particle-laden interfaces. We hypothesize that charge screening among cationic surfactants regulates the rigidity of oil/water interfaces by reducing the attachment energy of nanoparticles. EXPERIMENTS: We investigate the interfacial rigidity of cetyltrimethylammonium bromide (CTAB) functionalized silica nanoparticles (Ludox® TMA) by analyzing the shape deformation of 1,4-butanediol diacrylate (BDA) droplets under varying salt and alcohol concentrations. The nanoparticle packing density is assessed using scanning electron microscopy. Attachment energy is characterized through interfacial tension measurements, three-phase contact angle analysis, and CTAB adsorption studies. We also examine the effects of interfacial rigidities on the structure of bijel films formed via roll-to-roll solvent transfer-induced phase separation (R2R-STrIPS) using confocal laser scanning microscopy. FINDINGS: Increasing salt and alcohol concentrations decrease the interfacial rigidity of CTAB-functionalized nanoparticle films by reducing the interfacial tension. The contact angle has a minor influence on the rigidity. These results indicate that CTAB charge screening weakens the nanoparticle attachment energy to the interface. Controlling the rigidity enables the mass production of bijel sheets with consistent flatness, which is crucial for their potential applications in catalysis, energy storage, tissue engineering, and filtration membranes.

Light-induced manipulation of ultra-low surface tension droplets on stable quasi-liquid surfaces.

HYPOTHESIS: Perfluorocarbon is commonly used as a coolant, chemical reaction carrier solvent, medical anti-hypoxic agents and blood substitutes. The realization of non-contact complex manipulation of perfluorocarbon liquids is urgently needed in human life and industrial production. However, most liquid-repellent interfaces are ineffective for the transport of ultra-low surface tension perfluorocarbon liquids, and struggle to maintain good durability due to unstable air or oil cushions in the surface. Therefore, preparing surfaces for stable non-contact complex manipulation of ultra-low surface tension droplets remains a challenge. EXPERIMENTS: In this paper, a novel solution, a photothermal responsive droplet manipulation surface based on polydimethylsiloxane brushes, has been reported. On this surface, droplets with different surface tensions (as low as 10 mN/m) can be efficiently manipulated through induced near-infrared light. Notably, this surface maintains its effectiveness after exposure to extreme anthropogenic conditions. FINDINGS: The interface effect between perfluorocarbon droplets and polydimethylsiloxane brushes by near-infrared light-induced was investigated in detail. In addition, ultra-low surface tension droplets demonstrate the ability to transport solid particles. The conductive droplets exhibit sophisticated manipulation realizing the controlled switching of smart circuits. This research opens up new possibilities for advancing the capabilities and adaptability of ultralow surface tension droplets in a range of applications.

A Tensioned Human Skin Explant Model Used for Preliminary Assessment of Chemexfoliant-Stimulated Bioeffects.

A tensioned ex vivo full-thickness human skin explant platform was used to assess the bioeffects arising from application of several commercial chemexfoliation agents. Although such treatments are well-established, and improved understanding of the underlying mechanistic processes continues to emerge, research into the optimum treatments for specific skin types/conditions is still needed for enhanced efficacy while minimizing recovery time. The 3 commercial chemexfoliation agents employed all contained trichloroacetic acid at well-defined concentrations (6, 10, and 20%) and were applied to the explants' stratum corneum. Subsequently, measurements of dermal remodeling factors (COL1A1, ELN, HAS2, HAS3, and procollagen type I) and inflammatory marker (IL-1b) were undertaken using qPCR and immunofluorescent analyses. Statistical analysis of these data facilitated the establishment of benchmarking biological responses to these trichloroacetic acid-containing agents against untreated controls. The performance of an innovative trichloroacetic acid-free chemexfoliation agent was then measured and, upon comparison with the previous benchmarking data, indicated that dermal remodeling factors could be upregulated in fashion comparable with that of the trichloroacetic acid-containing agents but with significant suppression of inflammatory response. Our measurements thus underscore the promise of the tensioned explant over prolonged study periods and also that potentially valuable insights to guide preclinical strategies may be forthcoming from the protocol developed.

A Novel Sliding Knot Technique Without a Knot Pusher for Laparoscopic Pelvic Floor Surgery.

INTRODUCTION AND HYPOTHESIS: Challenges in intracorporeal knot tying can be addressed with extracorporeal slip knots, simplifying the process of tying and managing tissue tension using a knot pusher. However, existing extracorporeal knot techniques are difficult owing to their complexity, the finesse required with thin yarns, and extensive training needs. We developed a new laparoscopic extracorporeal slip knot technique that can be used with a conventional needle driver or standard clamps, offering the advantages of being cost-effective and easy to learn. METHODS: The technique involves passing the active strand over another loop and securing it with the nondominant hand. A Kelly clamp is then wound around both loops three times in a tornado-like motion, passing the instrument over the active loop and under the passive one, and grasping the active strand. The passive strand is pulled to approximate the knot to the tissue and is tightened by the tension of the passive strand. RESULTS: This method has proven effective in various laparoscopic procedures such as sacrocolpopexy, colposuspension, pectopexy, myomectomy, and hysterectomy, facilitating surgeries without complications. CONCLUSIONS: The tornado knot technique is a feasible and safely locked sliding extracorporeal knot that can be easily learned, especially by surgeons who are accustomed to open surgery.

Babcock versus Scissor Tensioning for Retropubic Mid-Urethral Slings: Comparing Two Intra-Operative Techniques Through 5 Years of Follow-Up.

INTRODUCTION AND HYPOTHESIS: The objective was to determine if mid-urethral sling (MUS) tensioning with a Mayo Scissor as a sub-urethral spacer compared with a Babcock clamp holding a loop of tape under the urethra results in differences in patient-reported outcomes and rates of repeat surgery over a 5-year follow-up. METHODS: Follow-up 5 years after a randomized clinical trial, utilizing primary data collection linked to administrative health data, was carried out to create a longitudinal cohort. The primary outcome was participant-reported bothersome SUI symptoms, as defined by the Urogenital Distress Inventory (UDI-6) questionnaire. Secondary outcomes included participant-reported bothersome overactive bladder (OAB) scores, median scores of three validated urinary symptom questionnaires, and rates of subsequent surgery determined through patient report and administrative data. RESULTS: Two hundred and sixty (81.8%) of the original study participants provided participant-reported data at 5 years. Administrative data linkage was completed for all of the original participants (n = 318). Demographic characteristics remained similar in the two groups at the 5-year follow-up mark. No differences existed in the primary outcome of reported bothersome SUI symptoms (30.8% Scissors vs 26.8% Babcock, p = 0.559), proportion of participants with bothersome OAB, the median scores of three validated bladder questionnaires, or in rates and cumulative incidence of recurrent MUS surgery or surgical revision of mesh-related complications. CONCLUSION: Both the Scissor and Babcock tensioning techniques provided comparable outcomes at 5 years post-MUS surgery. The information from this study allows surgeons to better decide which technique to adopt in their practice, providing confidence in longer-term cure and safety.

Effects of surface tension and contact angle on pore structure development of coal samples under chemical solution erosion.

To explore the influence of surfactant concentration on the pore structure and permeability of coal samples during the chemical enhancement of coalbed methane production, different kinds and different concentrations of surfactants were added to the chemical solution, and the coal samples were soaked. Methods such as low-field nuclear magnetic resonance testing (NMR), fractal theory, permeability testing, surface tension testing, and contact angle testing were employed to analyze the variation patterns of coal sample pore structure, fractal characteristics, and permeability, and to explore the correlation between surface tension, contact angle, and the degree of pore structure development. The results show that the increase in total porosity of coal samples, the increase in the seepage pore porosity, the decrease in Dt, and the growth rate of permeability increase with the increase in surfactant concentration, and are negatively correlated with the surface tension of the solution and the contact angle of the coal-solution interface, while the decrease in Ds is not significantly correlated with surfactant concentration, surface tension, or contact angle. In terms of the erosion effect of a chemical solution on coal samples, the influence of contact angle is greater than that of surface tension, while surface tension has the greatest impact on the development of adsorption pores. By adding different surfactants, the surface tension of the chemical solution and the contact angle of the coal-solution interface can be controlled, further promoting the erosion of coal samples, which is of positive significance for the chemical enhancement of coalbed methane production.

Simulating the ionic liquid mixing with organic-solvent clarifies the mixture's SFG spectral behavior and the specific surface region originating SFG.

Molecular dynamics (MD) simulation of the green ionic liquid [C4mim][PF6] mixed with polar benzonitrile (BNZ) solvent provides detailed insights into their structural and dynamic properties, essential for electrochemistry and materials science applications. The simulations we carried out at varying mole fractions (XBZN) reveal the mixtures' physical, structural, and dynamic properties, with radial, spatial, and combined distribution functions, highlighting the effective interaction through H-bonding involved. The simulation indicates that BZN stacks on the cation butyl tail, providing a significant explanation for the unique experimental observations (following). Adding BZN causes the mixture's liquid dynamics to increase linearly at low XBZN and exponentially at high XBZN, with a notable singular transition at 0.5XBZN. Comprehensive efforts were made to verify and support experimental sum frequency generation (SFG) spectroscopy by simulating the surface structure of the mixtures. Consequently, the simulated BZN stacking structure explains (1) the absence of the C≡N vibrational mode in the SFG spectrum for XBZN < 0.8, and (2) the gradual diminishing of the CH3 SFG signal, which disappears as XBZN approaches 0.5. Finally, this research removes a persistent ambiguity, proving that only the molecular moieties on the surface generate the SFG vibrational signal, while those in the subsurface do not.

A Narrative Review on Laryngeal Manual Therapy Methods in Muscle Tension Dysphonia: Manual Techniques, Target Structures, and Tension Criteria.

Background: Laryngeal manual therapy (LMT) has been known as one of the main techniques for decreasing musculoskeletal tension in the (para) laryngeal muscles in dysphonic patients, especially patients with muscle tension dysphonia (MTD). Objective: A narrative review on the available LMT methods in MTD. Study Design: (Method).A review on the literature regarding to the LMT methods in MTD was conducted using electronic databases up to December 2022. To identify all eligible literature, hand searching was also utilized. Moreover, articles and books in which LMT methods were introduced or used for the first time, or had innovation and were complementary for previous LMT methods were included. Relevant sources were identified by two reviewers based on screened titles/abstracts and full texts. Results: The authors found five main common and some miscellaneous LMT methods that may not be used as conventional methods in clinical and research settings. There are some similarities and differences between the available LMT methods based on the manual techniques, target anatomical structures, and tension criteria. Although there is not enough information about details of some LMT methods, we additionally tried to provide some details about LMT treatment protocol. Conclusion: The LMT is still at the beginning and it is necessary to revise the previous methods or develop new ones according to the similarities and differences have been found in this review. This paper will be useful for learning and teaching the LMT methods in MTD for clinicians and students who are interested in. Supplementary Information: The online version contains supplementary material available at 10.1007/s12070-024-04896-1.

The Risk of Obstructive Sleep Apnea in Patients with Primary Muscle Tension Dysphonia.

To explore the risk of obstructive sleep apnea (OSA) in patients with primary muscle tension dysphonia (MTD). The medical records of patients diagnosed with primary MTD between November 2021 and March 2023, were reviewed. The risk of having OSA was assessed by looking at the scores of two validated questionnaires, namely the STOP-BANG questionnaire and the Berlin questionnaire. A total of 40 patients with primary MTD were enrolled in this study, including 16 females (40%) and 24 males (60%). The mean total STOP-BANG score was 3.57 ± 1.67. Seventeen of the study group had intermediate risk of OSA, and 14 had high risk, accounting for 77.5% of patients with primary MTD. When using the Berlin questionnaire, the mean total score was 1.65 ± 0.95, and 67.5% of the study group had a score > 2 and were at high risk of having OSA. The results of this study indicate that patients with primary MTD are at moderate to severe risk of having OSA.

Comparative Study of Inferior Pole of Patella Fracture Treated with Transosseous Technique using Modified Krackow's Technique Versus Traditional Anterior Tension Band Wiring.

Introduction: The inferior pole of patella constitutes around 9.3-22% of all the patella fractures presenting to the hospital. The management of inferior pole fractures has been debated since a long from early day of partial or full patellectomy to the current dictum of open reduction and fixation because of the importance of extensor mechanism of the knee. There are various modalities of management of the inferior pole of patella fracture. The use of braided polyester wire has shown to have a higher load to failure and less implant fatigue, leading to the use of trams osseous repair technique with fiber wire as an alternative to tension ban wiring. Materials and Methods: Twenty patients were divided into two groups of 10 each: Group A comprised of patients operated with tension band wiring (TBW) and Group B with patient operated with transosseous repair. Both groups underwent the same physiotherapy postoperatively and the results were compared. Results: Radiological outcomes and the WOMAC score of the patients are comparable in both groups. The return to full range of motion is also similar in both groups with similar physiotherapy given in both groups. Conclusion: This shows that with careful patient selection transosseous repair can be used as an alternative to TBW.

The Role of Nerve Tension on Nerve Repair Success.

Peripheral nerve injuries that are not acutely repaired may lead to a nerve gap because of the surrounding zone of injury and elastic recoil of nerve tissue after laceration. This can result in tension across the repair site during primary neurorrhaphy. Decades of basic science literature using in vivo models consistently demonstrate a relationship between increasing strain at a neurorrhaphy site and compromised microvascular blood flow. Clinical and laboratory data suggest tension-free repairs are associated with optimal outcomes; in the setting of a short segmental nerve gap, data suggest primary repair may continue to yield good functional results. In the case of high strain, nerve grafting or other methods should be considered given poor results of primary repairs performed under high tension because of local ischemia and fibrosis on a cellular level.

Myosin II tension sensors visualize force generation within the actin cytoskeleton in living cells.

Nonmuscle myosin II generates cytoskeletal forces that drive cell division, embryogenesis, muscle contraction, and many other cellular functions. However, at present there is no method that can directly measure the forces generated by myosins in living cells. Here we describe a Förster resonance energy transfer (FRET)-based tension sensor that can detect myosin associated force along the filamentous actin network. Fluorescence lifetime imaging microscopy (FLIM)-FRET measurements indicate that the forces generated by NMIIB exhibit significant spatial and temporal heterogeneity as a function of donor lifetime and fluorophore energy exchange. These measurements provide a proxy for inferred forces that vary widely along the actin cytoskeleton. This initial report highlights the potential utility of myosin-based tension sensors in elucidating the roles of cytoskeletal contractility in a wide variety of contexts.

High accuracy of component positioning and restoration of lower limb alignment using robotic medial unicompartmental knee arthroplasty.

PURPOSE: Unicondylar arthroplasty was performed using robotic medial unicompartmental knee arthroplasty (R-mUKA) and gap-balancing instrumentation. Our hypothesis was that robotic unicondylar knee arthroplasty accurately restores component positioning and lower limb alignment when compared to preoperative planning with actual implantation throughout the range of knee motion due to proper knee balancing. METHODS: Data were collected prospectively and were analysed for patients undergoing RM-UKA. A cemented UKA was implanted using the MAKO® robotic system. Lower limb alignment at 0°, 30°, 45°, 60° and 90° of flexion was recorded of the native knee, with the trial components in place and finally after component implantation. A spacer according to the femorotibial gap was introduced and the alignment was measured. The position of the final component was planned based on three-dimensional computed tomography images before making the bone cuts. The positioning of the femoral and tibial components was analysed in all three planes. RESULTS: A total of 52 patients were included (mean age 66.3 ± 6.7 years; 34 males, 18 females). The difference in femoral component position after planning and final implantation was 0.04° ± 0.58° more valgus in the coronal plane (p = 0.326) and 0.6° ± 1.4° more flexion relative to the sagittal plane (p = 0.034). The tibial component was placed in the coronal plane in 0.3° ± 0.8° of more varus (p = 0.113) and in the sagittal plane in 0.6° ± 1.2° of more posterior tibial slope (p = 0.001). Lower limb alignment of the native knee in extension was 5.8° ± 2.6° of varus and changed to 3° ± 2.1° varus after UKA (p ≤ 0.01). CONCLUSION: R-mUKA helps to achieve the target of alignment and component position without any significant differences to the planning. Ligament balancing causes non-significant changes in component position. It allows optimal component position even for off-the-shelf implants respecting the patient's specific anatomy. LEVEL OF EVIDENCE: II.

Comparative analysis of medical treatments for long-term control of normal tension glaucoma: A systematic review and model-based network meta-analysis.

BACKGROUND: To evaluate and compare the long-term efficacy of medical treatments for normal tension glaucoma (NTG) in controlling intraocular pressure (IOP), and establish a hierarchical ranking based on their effectiveness. 'Long-term' is defined as a treatment duration of over 12 weeks in randomised controlled trials (RCTs). METHODS: This systematic review and model-based network meta-analysis (MBNMA) collected data of 795 patients with 997 eyes from RCTs. Patients with NTG were selected based on strict inclusion/exclusion criteria, with randomsation procedures and masking as reported in the individual trials. Eight different medications were compared, including prostaglandin analogues, beta-blockers, brimonidine, unoprostone isopropyl, brovincamine, and palmitoylethanolamide (PEA). Notably, PEA is an oral medication, while other drugs are topical agents. RESULTS: Primary outcome is the long-term efficacy of IOP control across medications with different follow-up durations. Among the eight medications, PEA demonstrates the highest efficacy (Surface under the cumulative ranking, SUCRA = 7.46%), followed by two prostaglandin analogues: travoprost (SUCRA = 6.86%) and latanoprost (SUCRA = 6.76%), then two beta-blockers: nipradilol (SUCRA = 4.90%) and timolol (SUCRA = 4.89%). Both brimonidine and unoprostone isopropyl have SUCRA scores below 4.0%, indicating modest but limited efficacy. Brovincamine has the lowest SUCRA score (1.32%), reflecting minimal effectiveness. CONCLUSIONS: This study revealed PEA as a promising agent for long-term IOP control in NTG patients, suggesting potential use as primary or adjunctive therapy. The outcomes call for PEA's consideration in clinical practice and highlight the need for further research into its long-term efficacy and safety for NTG.

Is sexual function impaired in patients with primary headaches? A systematic review of observational studies.

INTRODUCTION: Primary headaches, particularly migraine and tension-type headaches, as chronic and painful conditions, have a significant impact on individuals' health and overall quality of life, including aspects such as sexual health parameters. OBJECTIVES: The aim of this study was to review observational studies and to summarize the presence of sexual dysfunction in patients with primary headache and to discern whether it is more common in patients with primary headache than in healthy control subjects. METHODS: Observational studies published between January 1, 2000, and May 21, 2023 were searched in Medline (PubMed), Web of Science, Scopus, and EBSCO. This review included 23 observational studies that evaluated sexual dysfunction with or without comparison with healthy control subjects. RESULTS: As a result, the mean Female Sexual Function Index score, a score of <26.55 indicating sexual dysfunction, ranged from 19.25 ± 8.18 to 27.5 ± 7.5 in patients with primary headache. The prevalence of sexual dysfunction and erectile dysfunction was found to be between 10.7% and 93.75% in female patients and between 54.83% and 80% in male patients. Both migraineurs and tension-type headache sufferers had statistically significantly lower sexual function scores in females and lower erectile function scores in males compared with healthy control subjects. CONCLUSION: Sexual function is significantly affected in patients with primary headache, which is a chronic painful disorder. Therefore, it is very important to ask these patients about their sexual health and, if necessary, to seek support from a sexual health professional. Additionally, future studies may prioritize tension-type headaches and male patients due to the limited amount of research available on these subjects.

Clinical challenges and management of late presenting congenital diaphragmatic hernia mimicking tension pneumothorax in a child: a case report and review of literatures.

BACKGROUND: Congenital diaphragmatic hernia(CDH) is a rare congenital anomaly characterized by herniation of abdominal contents into thoracic cavity through a defect in diaphragm. While commonly diagnosed prenatally or in neonatal period, late-presenting CDH can occur and may mimic other thoracic emergencies such as tension pneumothorax, complicating diagnosis and management. CASE PRESENTATION: A two-year old male black child from Ethiopia presented to the emergency department with sudden onset of acute respiratory distress. Initial clinical assessment and chest radiography suggested a diagnosis of tension pneumothorax due to the presence of significant mediastinal shift and apparent pleural air. Despite insertion of chest tube, the child's condition did not improve, raising suspicion of alternative diagnosis. Careful observation of initial chest x-ray and subsequent chest ultrasound revealed a left sided congenital diaphragmatic hernia with herniation of stomach and intestine into thoracic cavity compressing the left lung and causing mediastinal shift. After the diagnosis of CDH was confirmed, the child was stabilized and emergent surgical repair performed. Postoperative recovery was uneventful, and the child was discharged with no significant long-term complications. CONCLUSION: This case underscores the importance of considering CDH in the differential diagnosis of acute respiratory distress in a child. It highlights the diagnostic challenges and potential risks of emergency interventions based on initial misdiagnosis. Even if x -ray looks like typical of tension pneumothorax, it showed giant cystic air filled structure pushing the mediastinal structure to contralateral side with loss of left diaphragmatic outline which raised suspicion of congenital cystic lung mass or congenital diaphragmatic hernia. Advanced imaging and high index of suspicion are crucial for accurate diagnosis and timely management, ultimately improving patient outcomes. Consideration of alternative diagnosis when our initial intervention with insertion of chest tube fail to provide symptom improvement in suspected pneumothorax should raise suspicion of congenital diaphragmatic hernia like in our case.

Treatment of anal fissures using the new TRPM8 receptor therapy - own experience.

<b>Introduction:</b> Anal fissure, a longitudinal or oval crack in the anal anoderm above the dentate line, is one of the most common diseases of the anal area. The following article shows the effectiveness of anal fissure treatment based on our own experience, using new receptor therapy in the form of Procto-Zac Memethol Barrier Spray [(1R,2S,5R)-2-isopropyl-5-methylcyclohexanol, sodium hydrogen carbonate, 7-(dimethylamino) phenothiazin-3-ylidene]- dimethylazanium; chloride, 1,2-propanediol, purified water], preparation containing soluble fiber and oral probiotic.<b>Aim:</b> The aim of the following article is to present our experience and observations in the conservative treatment of acute and chronic anal fissure using Procto-Zac Memethol Barrier Spray and preparations containing soluble fiber and oral probiotic.<b>Material and methods:</b> The study included a group of 120 patients with anal fissure between 18 and 45 years of age. Each patient in the group received a therapy consisting of Procto-Zac Memethol Barrier Spray (8 sprays once a day, 2 packages) and preparation containing fiber and oral probiotic. A high-fiber, gluten-free and lactose-free diet was also recommended. A follow-up was carried out in our clinic after 4 and 8 weeks. If the symptoms do not disappear completely, also after 3 months from the start of treatment.<b>Results:</b> Complete relief of symptoms was achieved in 62 patients after 4 weeks of treatment. After 8 weeks, complete relief of symptoms was achieved in another 49 people. In 6 people, after 3 months of treatment, the symptoms were partially relieved, but the anal fissure was not completely healed. Three people did not come for a follow-up visit. In 20 patients, skin burning around the anus was observed during the above therapy.The above symptoms did not require discontinuation of Procto-Zac Memethol Barrier Spray therapy and disappeared after completion of treatment. No other side effects of the preparations used were found.<b>Conclusions:</b> According to our observations, the use of new TRPM8 receptor therapy MemeThol Barrier Spray, a preparation containing soluble fiber and oral probiotic, turned out to be an effective method of treating anal fissure. In the future, it is advisable to conduct further studies, including multicenter studies, to assess the full tolerability and effectiveness of the described therapy.

Experimental evaluation of acid number effect on interfacial tension between nitrogen and mixtures of petroleum fractions including diesel fuel and gasoline at different pressures.

Crude oil is made up of very complex compounds, which are found in polar organic substances especially organic acid compounds in the majority. Although organic acid content in crude oil is low, the presence of organic acids affects the interfacial tension (IFT) in oil reservoirs thereby altering the enhancement of oil recovery using nitrogen gas (N2) injection. Therefore, in this study, the effects of pressure (1 to 35 bar), the percentage of aromatic compounds (0.0 to 100 vol%) in the aliphatic hydrocarbon samples and the organic acid (benzoic acid) content (0.0 to 0.8 g.L- 1) on IFT between a mixture of gasoline/diesel fuel and N2 were investigated at a temperature of 298 K. IFT does not necessarily decrease as pressure increases for the sake of existence of aromatic compounds. IFT alteration for gasoline was more (about 8 dyne.cm- 1) than for diesel fuel (approximately 4 dyne.cm- 1) during pressure increased from 1 to 35 bar due to the replacement of heavy long chain aliphatic compounds instead of light aromatic matters. The effect of IFT alteration between N2 and diesel fuel during increasing the organic acid content was little (approximately 1.5 dyne.cm- 1), in contrast, this effect was more noticeable for N2/gasoline (about 8 dyne.cm- 1). In addition, a reduced cubic model for estimating IFT between N2 and petroleum fractions in terms of pressure, petroleum fraction composition and organic acid content was proposed with an average relative error of less than 2.6%.

Study on interfacial tension, wettability and viscosity in different salinities of synthesized a new polymeric surfactant for improving oil recovery.

Over 50% of the original oil in place (OOIP) is immobile or trapped in the reservoir. Therefore, today, more efficient methods have been introduced in the tertiary oil recovery sector as a scheme of enhanced oil recovery (EOR). Due to the decline of conventional hydrocarbon reserves, polymers are increasingly used in EOR methods, such as surfactant-polymer (SP) and alkaline-surfactant-polymer (ASP) flooding. SP flooding has a complex formulation and design, leading to undesirable phase separation if improperly mixed. Polymeric surfactants are a promising alternative to SP flooding. They consist of hydrophobic groups attached to hydrophilic polymers, which help to improve the mobility ratio and reduce interfacial tension (IFT). This paper examines the rheological and synthesis properties of a new polymeric surfactant produced through bond co-polymerization reaction using different hydrolyzed polyacrylamide (HPAM) ratios and a zwitterion hydrophobic group. The synthesized hydrophobically modified zwitterionic polyacrylamide (HMZPAM) was characterized by FTIR and HMNR analysis. HMZPAM performed better than other substances in IFT, viscosity, wettability, oil recovery, and resistance to different one and two-valence cations. The results indicate that HPAM reduced the IFT to 13.65, while HMZPAM reduced it to 0.441 mN/m. Wettability change evaluated on a rock carbonate/crude oil/HMZPAM system that changed the water-wet state of the primary oil-wet rock carbonate to strongly water-wet state as wettability change measurements showed a decrease in contact angle from 62.76 to 21.23 degree. Comparative studies on the effectiveness of HPAM and HMZPAM were also conducted according to the measurement of viscosity and shear rate in the presence of salt, which indicates the higher shear rate and viscosity of HMZPAM. Core flooding tests revealed that HMZPAM resulted in better additional recovery due to microscopic displacement, resulting in a total oil recovery of 84%, compared to 48% of residual oil saturation for HPAM. Also, salts decreased oil recovery in HPAM injection but increased oil recovery in HMZPAM injection.

Developmental nicotine exposure alters cardiovascular structure and function in neonatal and juvenile rats.

Here we test the hypothesis that continuous nicotine exposure throughout pre- and postnatal development (developmental nicotine exposure, DNE) alters cardiovascular structure and function in neonatal and juvenile rats. Echocardiography showed that DNE reduced left ventricular mass, left ventricular outflow tract (LVOT) diameter, and posterior wall thickness, but only in females. Both male and female DNE rats had a lower end-systolic volume, higher ejection fraction, and increased fractional shortening, with unchanged stroke volume and cardiac output. Left ventricular single cardiac myocytes from male and female DNE animals exhibited increased calcium-evoked maximal tension with no effect on EC50. Tail-cuff plethysmography in awake rats showed that DNE males had lower systolic blood pressure and higher heart rate than control males. No significant changes in preload, afterload, or the in vitro renal artery response to vasodilators was observed. The results suggest that DNE enhances myocyte tension-generating capacity, possibly compensating for an unknown developmental insult, which may differ in males and females. While this adaptation maintains normal resting cardiac function, it may lead to reduced cardiac reserve, increased energy demand, and elevated oxidative stress, potentially compromising both short-and-long-term cardiovascular health in developing neonates.