Peristaltic Research Articles

Designing a Novel Coamorphous Salt Formulation of Telmisartan with Amlodipine to Enhance Permeability and Oral Absorption.

Coamorphous formulation is a useful approach for enhancing the solubility of poorly water-soluble drugs via intermolecular interactions. In this study, a hydrogen-bonding-based coamorphous system was developed to improve drug solubility, but it barely changed the apparent permeability (Papp) of the drug. This study aimed to design a novel coamorphous salt using ionic interactions to improve drug permeability and absorption. Telmisartan (TMS), with an acidic group, was used to form a coamorphous salt with basic amlodipine (AML). Evaluation of the physicochemical properties confirmed the formation of a coamorphous salt via ionic interactions between the amine group of AML and the carboxyl group of TMS at a molar ratio of 1:1. The coamorphous salt of TMS/AML enhanced the partitioning of both drugs into octanol, indicating increased lipophilicity owing to the interaction between TMS and AML. The coamorphous salt dramatically enhanced TMS solubility (99.8 times that of untreated TMS) and decreased AML solubility owing to the interaction between TMS and AML. Although the coamorphous salt showed a decreased Papp in the permeation study in the presence of a thicker unstirred water layer (UWL) without stirring, Papp increased in the presence of a thinner UWL with stirring. The oral absorption of TMS from the coamorphous salt increased by up to 4.1 times compared to that of untreated TMS, whereas that of AML remained unchanged. Although the coamorphous salt with increased lipophilicity has a disadvantage in terms of diffusion through the UWL, the UWL is thin in human/animal bodies owing to the peristaltic action of the digestive tract. Dissociation of the coamorphous salt on the membrane surface could contribute to the partitioning of the neutral form of drugs to the membrane cells compared with untreated drugs. As a result, coamorphous salt formation has the advantage of improving the membrane permeation and oral absorption of TMS, owing to the enhanced solubility and supply of membrane-permeable free TMS on the surface of the membrane.

Malnutrition and Developmental Delay Presenting as Complications of Late Onset Hirschprung’s disease : A Case Report

Background: Hirschsprung’s Disease is a congenital disorder characterized by the absence of ganglionic cells in the colon, causing loss of peristaltic movement in the bowel. Most cases are diagnosed before the age of one and marked by the delayed passage of meconium, vomiting, and distended abdomen. Here, we present a case of a 2-year-old boy with an atypical presentation of malnutrition and developmental delay as a complication of Hirschsprung’s Disease. Case Presentation: A 2-year-old boy who presented with abdominal distention and chronic constipation was referred to our hospital. Past personal history revealed that he frequently suffered from the symptoms but was previously diagnosed with regular constipation and only consumed symptomatic medication. On admission, his vital signs were all normal, but his appearance was pale and weak. Growth and developmental screening showed poor growth status and developmental delay in all four domains. From the physical examination, gross abdominal distention was found and the rectal examination demonstrated a tight anal sphincter, empty rectal vault, and a green-colored stool with no forceful expulsion. Radiologic and histopathological findings suggested Hirschsprung’s disease. Conclusion: Chronic abdominal distention followed by malnutrition and developmental delay can present as a complication of hirschsprung’s diseasein older children. Due to these subtle signs and symptoms, a thorough examination and proper diagnostic algorithm are

Insights on discovery, efficacy, safety and clinical applications of ghrelin receptor agonist capromorelin in veterinary medicine.

Growth hormone and insulin like growth factor-1 plays an important role in the regulation of body composition and metabolism. Growth Hormone is released from the pituitary through a specific G-protein coupled receptor (GPCR) called growth hormone secretagogue receptor 1a expressed in the hypothalamus. Ghrelin is a peptide hormone released from the cells in the stomach, which stimulates appetite and food intake in mammals, regulates gut motility, gastric acid secretion, taste sensation, circadian rhythm, learning and memory, oxidative stress, autophagy, glucose metabolism etc. When the release of the endogenous ligand GHSR-1a, i.e., ghrelin is malfunctioned or stopped, external substitutes are administrated to induce the stimulation of growth hormone and appetite. A class of compound known as ghrelin receptor agonists are developed as an external substitute of ghrelin for regulation and stimulation of growth hormone in frailty, for body weight gain, muscle mass gain, prevention of cachexia and for the treatment of chronic fatigue syndromes. Capromorelin [Entyce™ (Aratana Therapeutics, Leawood, KS, USA)] is the only FDA (Food and Drug Administration) approved (May 2016) drug used for stimulating appetite in dogs and was marketed in the fall of 2017. In 2020, USFDA approved Capromorelin [Elura™ (Elanco US Inc.)] for the management of weight loss in chronic kidney disease of cats. This article reviews the discovery of the ghrelin receptor agonist capromorelin, its efficacy, safety, clinical applications and aims to delineate its further scope of use in veterinary practice.

Effect of deep needling "Tianshu" (ST25) on colonic motility in rats with slow transit constipation

To observe the effect of acupuncture of "Tianshu"(ST25) at different depths on colonic transportation function, expressions of colonic substance P (SP) and interstitial cells of Cajal (ICC) in rats with slow transit constipation (STC), so as to explore its mechanisms underlying improvement of STC．. Fifty male Wistar rats were selected and randomly divided into control，STC model，conventional acupuncture，deep needling group 1 and deep needling group 2 groups，with 10 rats in each group．The STC model was established by gavage of 1 mg/mL compound diphenoxylate suspension (10 mg/kg), once every other day for 21 days, and rats of the control group were given the same dose of distilled water by gavage．EA (2 Hz, 2 mA) was applied to "Tianshu"(ST25), with the acupuncture needle inserted to a depth of 3 mm for rats of the conventional acupuncture group, 4.5 mm for those of deep needling group 1, and 10 mm for those of the deep needling group 2. The acupuncture needle was twirled for 1 min, then retained for 15 min each time, once a day for 15 consecutive days．Following modeling, rats of the 4 groups and the control group received gavage of active carbon 2 mL (100 g/L) for observing the excretion time of the first black stool grain to assess the intestinal transit function. The colonic myoelectric activities (frequency and amplitude) were recorded by using BIOPAC multichannel physiograph. The immunoactivity of SP and c-kit (a transmembrane protein kinase for identification of ICC) of colonic musculature was detected by immunohistochemistry. Compared with the control group，the time of excretion of the first black stool grain, and the amplitude of colonic electromyogram (EMG) were significantly increased (P<0.01), while the frequency of EMG, expressions of SP and c-kit (ICC) were significantly decreased in the model group (P<0.01). In contrast to the model group, both deep needling group 1 and 2 had a decrease in the time of excretion of the first black stool grain, and amplitude of intestinal EMG, and an increase of frequency of intestinal EMG, and immunoactivity of SP and c-kit (P<0.01). The effect of deep needling 2 is superior to that of deep needling 1 in reducing the time of excretion of the first black stool grain (P<0.05), lowering the amplitude of EMG of the gut smooth muscle (P<0.05) and in increasing the frequency of EMG (P<0.05) and the expressions of SP and c-kit (P<0.05). No significant changes were found in the levels of frequency and amplitude of EMG, and expressions of SP and c-kit after routine needling in comparison with the model group (P>0.05), except the excretion time of the first black stool grain (P<0.05). Deep needling at ST25 at depth of 4.5 mm and 10 mm，especially at depth of 10 mm，has a significant effect in promoting gut motility to ameliorate constipation in rats with STC, which may be related to its function in up-regulating the expressions of SP and ICC activity.

Chagas disease is related to structural changes of the gut microbiota in adults with chronic infection (TRIPOBIOME Study).

The implications of the gut microbial communities in the immune response against parasites and gut motility could explain the differences in clinical manifestations and treatment responses found in patients with chronic Chagas disease. In this pilot prospective cross-sectional study, we included 80 participants: 29 with indeterminate CD (ICD), 16 with cardiac CD (CCD), 15 with digestive CD (DCD), and 20 controls without CD. Stool was collected at the baseline visit and faecal microbial community structure DNA was analyzed by whole genome sequencing. We also performed a comprehensive dietary analysis. Ninety per cent (72/80) of subjects were of Bolivian origin with a median age of 47 years (IQR 39-54) and 48.3% (29/60) had received benznidazole treatment. There were no substantial differences in dietary habits between patients with CD and controls. We identified that the presence or absence of CD explained 5% of the observed microbiota variability. Subjects with CD exhibited consistent enrichment of Parabacteroides spp, while for Enterococcus hirae, Lactobacillus buchneri and Megamonas spp, the effect was less clear once excluded the outliers values. Sex, type of visceral involvement and previous treatment with benznidazole did not appear to have a confounding effect on gut microbiota structure. We also found that patients with DCD showed consistent Prevotella spp enrichment. We found a detectable effect of Chagas disease on overall microbiota structure with several potential disease biomarkers, which warrants further research in this field. The analysis of bacterial diversity could prove to be a viable target to improve the prognosis of this prevalent and neglected disease.

Effect of modification of formulation variables on physical characterization of superporouse hydrogel

Superporouse hydrogel (SPH) is widely used and investigated as a gastro retentive drug delivery system to extend drug residence time in the stomach&#x0D; &#x0D; However, their mechanical strength represents a problem because they need to withstand the peristaltic movement of the stomach. Properties of SPH are widely affected by the materials used for their synthesis. The aim of the research is to study the effect of changing the foaming agent and foam stabilizer amount on physical properties, in particular mechanical strength, and drug release from SPH. Trifluoperazine HCl will be used as model drug in the study.&#x0D; SPH formulations was prepared using fixed amount of acrylamide (AM) and polyvinyl alcohol (PVA) as monomers, polyethylene glycol diacrylate (PEGDA) as cross-linker, TRFP as model drug and variable amount of sodium bicarbonate (NaHCO3) as foaming agent, and tween 20 as foam stabilizer. Ammonium persulphate (APS) / tetramethyl ethylenediamine (TEMED) system was used as polymerization initiator. The effect of changing foaming agent and foam stabilizer on mechanical strength, buoyancy, porosity, density, drug release, drug content, swelling ratio, and swelling time was investigated.&#x0D; Modifying both factors affected all the physical properties and drug release profile. When tween 20 was increased the mechanical strength, density and floating lag time was increased with a reduction in porosity and drug release. While increasing NaHCO3 reduced mechanical strength, density and floating lag time with increased porosity and faster drug release was observed. Optimum physical properties were observed in formula 2 which had 230 µl of Tween 20 (v/v) and 50 mg of NaHCO3 in which the mechanical strength was 579±0.4, floating lag time 14 min and 80% of the drug was released within 12 hr.&#x0D; As a conclusion SPH with improved mechanical strength, physical properties and drug release pattern can be achieved by changing foam stabilizer and foaming agent amount in the formulations.

Development of and adherence to an ERAS® and prehabilitation protocol for patients undergoing pancreatic surgery: An observational study.

There are still gaps in knowledge concerning the adherence to different multimodal pathways in pancreatic surgery. The aim of this trial was to explore and evaluate an Enhanced Recovery After Surgery (ERAS®) and prehabilitation protocol in patients undergoing open pancreatic surgery. Three groups of patients were included: two prospective series of 75 patients undergoing open pancreatic surgery following an ERAS® protocol with or without prehabilitation, and one group of 55 historical controls. Variables regarding adherence to, and effects of the protocols, were collected from the local database and the patients' hospital records. Patients' adherence to advice given pre-operatively was followed up using a study-specific questionnaire. The patients reported high adherence to remembered advice given. The health care professionals' adherence to the various parts of the concepts varied. ERAS® implementation resulted in more frequent gut motility stimulation (p < 0.001) and shorter duration of epidural anesthesia, site drains, and urinary catheter (p = 0.001). With prehabilitation, more patients were screened concerning nutritional status and prescribed preoperative training (p < 001). There was a significant change in weight before surgery, a shorter time to first flatus and a shorter length of stay after implementation of the concepts (p < 0.05). Complications were rare in all three groups and there were no significant differences between the groups. The implementation of an ERAS® and a prehabilitation protocol increased adherence to the protocols by both patients and healthcare professionals. An implementation of an ERAS® protocol with and without prehabilitation decreases length of stay and may decrease preoperative weight loss and time to bowel movement.

NANOTECHNOLOGY APPROACH-SELF NANOEMULSIFYING DRUG DELIVERY SYSTEM (SNEDDS)

This review article aims to develop nanotechnology in novel drug delivery systems using self-nano emulsifying drug delivery systems (SNEDDS). This Article was selected using a database with Prism Guideline diagrams. A total of 18 articles obtained from 2010-2020 were used as the primary reference to be analyzed using a systematic review method in the form of meta-synthesis. This review describes the mechanism of SNEDDS in increasing absorption, the components of the SNEDDS formula, the characterization of self-nano emulsifying drug delivery systems (SNEDDS), the effect of the physicochemical properties of SNEDDS on in vivo activity, and the basis for selecting compounds in the SNEDDS formulation. Self-Nanoemulsifying Drug Delivery System (SNEDDS) is a novel drug delivery system from nanoemulsion used to increase the solubility of lipophilic drugs. SNEDDS is an isotropic mixture consisting of oil, surfactant, and co-surfactant. SNEDDS is considered pre-concentrated nanoemulsions or anhydrous forms of nanoemulsions. In SNEDDS, the formation of nanoemulsions occurs when self-nanoemulsions come into contact with gastrointestinal fluids in the presence of light stirring in the peristaltic motion of the gastrointestinal tract. In general, SNEDDS have small particle sizes in the range of 10-200 nm. The application of the self nanoemulsion development system can be used for BCS Class II lipophilic drug compounds and BCS Class IV drugs. SNEDDS is a novel drug delivery system that can be used for oral drug delivery. In occlusion, a self-nanoemulsifying drug delivery system (SNEDDS) is a new approach for the formulation of drug molecules with poor water solubility. Self Nanoemulsifying drug delivery system (SNEDDS) is an isotropic mixture of oil, surfactant, and co-surfactant.

Thermally radiative slip flow of viscous fluid through a microfluidic vessel having sinusoidal walls with variable viscosity

AbstractThis article explores the influence of variable viscosity on the peristaltic movement of viscous fluid through a tapered microfluidic vessel having sinusoidal walls. The aspect of slip velocity has been considered on the channel walls. Furthermore, the heat transfer phenomenon is explored under the effectiveness of thermal radiation and viscous dissipation. The nonlinearity of the problem is scrutinized by the lubrication approximation hypothesis. Analytic outcomes have been acquired for liquid velocity, temperature, pressure rise, and streamlines. The impact of dissimilar physical parameters influencing the liquid flow features is revealed and deliberated through graphs. The study revealed that the velocity at the central region diminishes with increasing values of the velocity slip parameter. The number of boluses in the streamlines pattern is enhanced by enhancing the viscosity parameter. The current model has been used in bio‐engineering processes, industrial fluid mechanics, thermal processing, and cooling systems.

Comparative study between early versus late enteral nutrition after gastrointestinal anastomosis operations

Introduction An anastomosis of the digestive tract is a common operation, whether it be an unexpected medical crisis or a planned procedure. Feeding soon after gastrointestinal anastomosis is not only physiological, but also protects against morphologic and functional trauma-related modifications in the gut. Aim of work This research aimed to evaluate the advantages and disadvantages of initiating Enteral Nutrition immediately following gastrointestinal anastomosis surgery versus delaying it for a later time. Additionally, the frequency of Adverse Events. Patients and methods Thirty patients underwent abdominal surgery, with treatments ranging from small- to large-intestine anastomosis, for both urgent and elective reasons. Early postoperative enteral feeding in the early feeding group commenced within 24 h of surgery or immediately following nasogastric tube removal. The delayed feeding group began enteral feeding using the standard technique once bowel sounds were restored, distention was gone, and the patient passed flatus or stool. 14 patients were in the early enteral feeding group (A) while 16 patients were in the late enteral feeding group (B). Data regarding blood loss and transfusion, NGT removal time, time of intestinal sounds return, time of passage flatus and stool, hospital stay and postoperative complications were recorded. Results Among those who ate too early (46.6%), those who ate late (53.3%), abdominal distension was noted in 28.6%,in the early group and 43.8% in late feeding group and vomiting was reported in 50.0%, and 62.5%, respectively. In the first group, 57.1% of those who fed early experienced fever, while in the second group, 75.0% of those who fed late did so. Late feeding is associated with a statistically significant rise in both the Day of NGT removal and the Length of stay. When patients were admitted for early feeding, they stayed in the hospital for an average of 5.71 days. There was no statistically significant difference according serum albumin between the early feeding (3.79) and late feeding (3.50). There was a significantly higher concentration of potassium in the blood in the early feeding group (3.93) compared to the late feeding group (3.219). Anastomotic leaking, surgical site infection, and intensive care unit admission were not significantly different between early and late feeding. Conclusion Early enteral feeding has the upper hand on late enteral feeding as it goes with GIT physiology, we found that early postoperative feeding following gastrointestinal anastomosis surgery significantly reduced the day of NGT removal and the length of hospitalization, which may be attributable to fewer problems and better gut motility and healing.

Pasteurized Akkermansia muciniphila improves glucose metabolism is linked with increased hypothalamic nitric oxide release

Background and objectivePasteurized Akkermansia muciniphila cells have shown anti-diabetic effects in rodents and human. Although, its primary site of action consists in maintaining the gut barrier function, there are no study exploring if A. muciniphila controls glycemia via a gut to brain axis. Targeting the gut motility represents an alternative pathway to treat hyperglycemia. Here, we tested the impact of pasteurized A. muciniphila on gut motility, gut-brain axis and glucose metabolism. MethodsWe used mice fed a 45% high-fat (HFD) treated or not with pasteurized A. muciniphila MucT during 12 weeks. We measured the effects of the treatment on body weight gain, glucose metabolism (insulin, glycemia, glucose tolerance), gut contraction and enteric neurotransmitter release, and hypothalamic nitric oxide (NO) release. ResultsWe show that pasteurized A. muciniphila exerts positive effects on different metabolic parameters such as body weight, fat mass, insulin, glycemia and glucose tolerance. This could be explained by the ability of pasteurized A. muciniphila supplementation to decrease duodenal contraction and to increase hypothalamic NO release in HFD mice. ConclusionWe demonstrate a novel mode of action of pasteurized A. muciniphila explaining its beneficial impact on the control of glycemia in a preclinical model of type 2 diabetes via gut-brain axis signaling.

A Technique of Measurement of Gastrointestinal Luminal Nutrient Sensing and These Absorptions: Ussing Chamber (Short-Circuit Current) Technique.

The gastrointestinal (GI) tract is a series of hollow organs that play roles in food digestion and nutrient absorption. To perform these functions, they should recognize the luminal environment and elicit adequate physiological responses, including digestive juice secretion, peristaltic movements, etc. The Ussing chamber technique is an electrophysiological method for measuring transepithelial ion transport and permeability as short-circuit current (Isc) and transepithelial electrical tissue conductance (Gt) or resistance (TEER), respectively, in vitro. This technique can be applied for the measurement of luminal nutrient sensing and absorption. This article introduces practical methods for measuring luminal nutrient sensing and absorption using intestinal mucosa specimens isolated from humans and experimental animals.

Probing Gut Participation in Parkinson's Disease Pathology and Treatment via Stem Cell Therapy.

Accumulating evidence suggests the critical role of the gut-brain axis (GBA) in Parkinson's disease (PD) pathology and treatment. Recently, stem cell transplantation in transgenic PD mice further implicated the GBA's contribution to the therapeutic effects of transplanted stem cells. In particular, intravenous transplantation of human umbilical-cord-blood-derived stem/progenitor cells and plasma reduced motor deficits, improved nigral dopaminergic neuronal survival, and dampened α-synuclein and inflammatory-relevant microbiota and cytokines in both the gut and brain of mouse and rat PD models. That the gut robustly responded to intravenously transplanted stem cells and prompted us to examine in the present study whether direct cell implantation into the gut of transgenic PD mice would enhance the therapeutic effects of stem cells. Contrary to our hypothesis, results revealed that intragut transplantation of stem cells exacerbated motor and gut motility deficits that corresponded with the aggravated expression of inflammatory microbiota, cytokines, and α-synuclein in both the gut and brain of transgenic PD mice. These results suggest that, while the GBA stands as a major source of inflammation in PD, targeting the gut directly for stem cell transplantation may not improve, but may even worsen, functional outcomes, likely due to the invasive approach exacerbating the already inflamed gut. The minimally invasive intravenous transplantation, which likely avoided worsening the inflammatory response of the gut, appears to be a more optimal cell delivery route to ameliorate PD symptoms.

Significance of chemically reactive magnetized Eyring-Powell nanofluid flow comprising gyrotactic moment of microorganism and radiative analysis

The emerging attention in nano-technology and thermal engineering has led to the concept of nanoparticles with improved theoretical mechanisms and accomplished influenced innovative usages in cooling and heating conveniences, air conditioning arrangements, heat carrying systems, bio-medical applications such as cancer cure, micromechanics, solar energy, artificial heart surgery etc. Currently, peristaltic movements joined with non-Newtonian fluids have enlarged innumerable devotion due to their enormous applications in physical, medical, engineering processes and medical. Eyring - Powell is unique type of non-Newtonian model consequential commencing the theory of motion of fluids. This research work inspects the 3D steady magnetohydrodynamic flow (MHD) containing microorganisms of a Powell-Eyring nanofluid with double stratification over a bidirectional stretched surface. Furthermore, the characteristics of the heat transfer phenomenon are prescribed out by means of thermal radiation. For changing nonlinear PDEs to nonlinear ODEs, we use the appropriate transformations and then numerically solve them with the help of bvp4c procedures. The possessions of several parameters modulating the heat and mass transfer properties are graphically depicted and illustrated in particular. It is interesting to perceived that the temperature field deteriorates for established estimates of the stretching parameter and the Prandtl number. The microorganism as well as concentration field improve for increasing estimates of magnetic parameter and the Biot number.

Lipids regulate peripheral serotonin release via gut CD1d

The crosstalk between the immune and neuroendocrine systems is critical for intestinal homeostasis and gut-brain communications. However, it remains unclear how immune cells participate in gut sensation of hormones and neurotransmitters release in response to environmental cues, such as self-lipids and microbial lipids. We show here that lipid-mediated engagement of invariant natural killer T (iNKT) cells with enterochromaffin (EC) cells, a subset of intestinal epithelial cells, promoted peripheral serotonin (5-HT) release via a CD1d-dependent manner, regulating gut motility and hemostasis. We also demonstrated that inhibitory sphingolipids from symbiotic microbe Bacteroides fragilis represses 5-HT release. Mechanistically, CD1d ligation on EC cells transduced a signal and restrained potassium conductance through activation of protein tyrosine kinase Pyk2, leading to calcium influx and 5-HT secretion. Together, our data reveal that by engaging with iNKT cells, gut chemosensory cells selectively perceive lipid antigens via CD1d to control 5-HT release, modulating intestinal and systemic homeostasis.

A Colic Adenocarcinoma as the Primary Cause of Colo-Colic Intussusception: A Rare Case of Obstruction

This article discusses the case of a 70-year-old woman who presented with abdominal pain and vomiting, and was diagnosed with colonic-colonic intussusception caused by a tumor. Colonic intussusception is a rare cause of acute abdomen in adults, and malignant tumors are the most frequent cause of colonic intussusception. The article highlights the importance of imaging, specifically abdominal CT scans, in diagnosing and managing this condition. The CT scan can confirm the site of intussusception and specify the severity signs, and it is more specific than ultrasound and endoscopy. The article also describes the different intussusception patterns seen on CT scans and their significance. Early diagnosis is important in preventing complications such as infarction and perforation. The authors suggest that colonic intussusception may be the result of infiltration of the colonic wall musculature by the malignant tumor despite the colon being devoid of peristaltic activity. Overall, the article emphasizes the importance of a combination of clinical and radiologic data in diagnosing and managing colonic intussusception caused by tumors.

Peristaltic transportation of thermally radiative Sutterby fluid in a tapered microfluidic vessel with convective conditions

Fluid transport from one place to another place by peristaltic pumping is being employed to design the advanced pumping device widely applied in biomedical and industrial applications. Therefore, the peristaltic motion of electrically conducting Sutterby fluid in a tapered channel with slip velocity and convective conditions has been analyzed in this examination. The heat transfer mechanism is also scrutinized in conjunction with thermal radiation and viscous dissipation. The governing expressions of the proposed model are followed under the assumptions of the small Reynolds number hypothesis and long wavelength. The perturbation technique has been implemented to yield the outcome for velocity, energy, and streamlining. The pumping characteristic has been estimated by the Weddles rule. The impressions of numerous pertinent parameters on the flow fields are highlighted via graphs. It is observed from the current flow analysis that the velocity of the flow increases by increasing the Sutterby fluid parameter while it declines with the magnetic parameter. Furthermore, the thermal radiation parameter decreases the temperature distribution of fluid. The current model has been used in bio-engineering processes, industrial fluid mechanics, thermal processing, and cooling systems.

Electro-osmotic effect on the heat and mass transfer of a viscoelastic nanofluid flow in a curved channel

For the past two decades, nanofluids have become the interest of researchers and engineers because of their thermo-physical features. The aim of the current investigation is to investigate the thermal behavior of peristaltically supporting viscoelastic tiny particles endorsed by electro-osmotic force. The Debye-Huckel linearization scheme and zero Reynolds assumptions are used to simplify the governing equations. The current formulation deals with the peristaltic motion of nanofluid in a two-dimensional curved channel. The complex arrangement of sinusoidal waves is used to enhance the pumping performance at the boundary walls. In the present analysis, the Buongiorno formulation is used for nanofluids. The Jeffrey fluid model is used in the current study as a viscoelastic fluid due to its both viscous and elastic features. The numerical solution is obtained using the NDsolve procedure. The graphs of flow features, such as stream function, axial velocity, temperature field, mass concentration, and electric potential function are plotted for various rheological parameters. Quantitative results related to the heat transfer coefficient and Sherwood number for different values of flow parameters are also provided. The asymmetry nature is observed in the diagram of axial velocity due to the curved shape of the flow regime. The mass concentration is enhanced (reduced) by aggregating thermal (Brownian) motion parameter. The temperature and mass concentration are enhanced by increasing Prandtl and Eckert numbers. Comparison between Newtonian and viscoelastic model is also argued in the current formulation. This study gives information of biological fluids flow relevance to micro-medical devices, nanoscale devices, electro-osmotic separation devices and complex pumps via peristaltic pumping.

New Pieces for an Old Puzzle: Approaching Parkinson's Disease from Translatable Animal Models, Gut Microbiota Modulation, and Lipidomics.

Parkinson's disease (PD) is a severe neurodegenerative disease characterized by disabling motor alterations that are diagnosed at a relatively late stage in its development, and non-motor symptoms, including those affecting the gastrointestinal tract (mainly constipation), which start much earlier than the motor symptoms. Remarkably, current treatments only reduce motor symptoms, not without important drawbacks (relatively low efficiency and impactful side effects). Thus, new approaches are needed to halt PD progression and, possibly, to prevent its development, including new therapeutic strategies that target PD etiopathogeny and new biomarkers. Our aim was to review some of these new approaches. Although PD is complex and heterogeneous, compelling evidence suggests it might have a gastrointestinal origin, at least in a significant number of patients, and findings in recently developed animal models strongly support this hypothesis. Furthermore, the modulation of the gut microbiome, mainly through probiotics, is being tested to improve motor and non-motor symptoms and even to prevent PD. Finally, lipidomics has emerged as a useful tool to identify lipid biomarkers that may help analyze PD progression and treatment efficacy in a personalized manner, although, as of today, it has only scarcely been applied to monitor gut motility, dysbiosis, and probiotic effects in PD. Altogether, these new pieces should be helpful in solving the old puzzle of PD.

Non-pharmacologic approaches to treatment of pediatric functional abdominal pain disorders.

Functional abdominal pain disorders (FAPDs) affect up to 25% of children in the United States. These disorders are more recently known as disorders of "brain-gut" interaction. The diagnosis is based on the ROME IV criteria, and requires the absence of an organic condition to explain the symptoms. Although these disorders are not completely understood, several factors have been involved in the pathophysiology including disordered gut motility, visceral hypersensitivity, allergies, anxiety/stress, gastrointestinal infection/inflammation, as well dysbiosis of the gut microbiome. The pharmacologic and non-pharmacologic treatments for FAPDs are directed to modifying these pathophysiologic mechanisms. This review aims to summarize the non-pharmacologic interventions used in the treatment of FAPDs including dietary modifications, manipulation of the gut microbiome (neutraceuticals, prebiotics, probiotics, synbiotics and fecal microbiota transplant) and psychological interventions that addresses the "brain" component of the brain-gut axis (cognitive behavioral therapy, hypnotherapy, breathing and relaxation techniques). In a survey conducted at a large academic pediatric gastroenterology center, 96% of patients with functional pain disorders reported using at least 1 complementary and alternative medicine treatment to ameliorate symptoms. The paucity of data supporting most of the therapies discussed in this review underscores the need for large randomized controlled trials to assess their efficacy and superiority compared to other treatments.