Low Pressure Research Articles

Unboxing: Exploring the Challenges of Green Supply Chain Initiatives in Thailand

Background: The increasing global focus on sustainability has made Green Supply Chain Management (GSCM) a critical strategy for businesses to balance environmental responsibility with operational efficiency. Despite its benefits, GSCM adoption in developing countries faces significant challenges. This study addresses the gap by investigating these barriers within the Thai context, providing actionable insights for policymakers and businesses. Methods: A mixed-methods approach was employed, including a survey of 480 business owners, executives, and supply chain employees, and expert analysis using Interpretive Structural Modeling (ISM). The ISM technique was used to determine the relationships and hierarchy among key barriers to GSCM implementation. Results: The findings reveal that weak legal frameworks, insufficient supplier engagement, and a lack of social responsibility are the most significant barriers. Secondary factors, such as low consumer demand and minimal competitive pressure, exacerbate these challenges. The ISM analysis highlighted the cascading effects of foundational barriers on other dimensions of GSCM adoption. Conclusions: Strengthening environmental regulations, promoting supplier collaboration, and embedding sustainability in corporate culture are key to overcoming GSCM barriers to sustainably enhance Thailand’s competitiveness.

Improved snow albedo evolution in Noah-MP land surface model coupled with a physical snowpack radiative transfer scheme

Abstract The widely-used community Noah-MP land surface model currently adopts snow albedo parameterizations that are semi-physical in nature and have systematic biases which impact the accuracy of weather and climate modeling systems that use Noah-MP as the land component. We hypothesized that integrating the snowpack radiative transfer scheme from the latest version of the Snow, Ice, and Aerosol Radiative (SNICAR) model can improve the physical representation of snow albedo processes and reduce corresponding land model uncertainties. Therefore, we evaluate Noah-MP simulations employing the SNICAR scheme and compare model accuracy to a Noah-MP simulation using the default semi-physical Biosphere-Atmosphere Transfer Scheme (BATS) scheme using in-situ spectral snow albedo observations at three Rocky Mountain field stations. The agreement between simulated and in-situ observed ground snow albedo is significantly enhanced in NoahMP-SNICAR simulations relative to NoahMP-BATS simulations (root mean square error reductions from 0.116 to 0.103). Especially, NoahMP-SNICAR improves modeled snow albedo variability for fresh snow and aged snowpack (correlation increase from 0.42 to 0.67). The underestimated variability of snow albedo in NoahMP-BATS is a result of inadequate representation of physical linkages between snow albedo evolution and environmental/snowpack conditions (temperature, snow density, snow water equivalent, and light-absorbing particles), which is substantially improved by the NoahMP-SNICAR scheme. This new development of NoahMP-SNICAR physics provides a means to improve snow albedo accuracy and reduce corresponding uncertainties while providing new modeling capabilities such as hyperspectral snow albedo, and effects of snow grain size, snow grain shape, and light-absorbing particles in future studies.

Short-term impact of low air pressure on plants’ functional traits

Lower atmospheric pressure affects biologically relevant physical parameters such as gas partial pressure and concentration, leading to increased water vapor diffusivity and greater soil water content loss through evapotranspiration. This might impact plant photosynthetic activity, resource allocation, water relations, and growth. However, the direct impact of low air pressure on plant physiology is largely unknown. This study examined the effects of low air pressure, alone and combined with two water inputs, on different functional traits of three plant species transplanted from montane grasslands at 1,500 m a.s.l. during the first four weeks of their early phenological stage: Trifolium pratense, Hieracium pilosella, and Brachypodium rupestre. Using the terraXcube Ecotron facility which can simulate different climatic conditions, we isolated the effect of air pressure from those of other, related environmental factors (temperature, humidity, and solar radiation) by simulating three different elevations with corresponding air pressures: 1,500 m a.s.l. (85 kPa, control scenario), 2,500 m a.s.l. (75 kPa), and 4,000 m a.s.l. (62 kPa) and we used two different water regimes to observe the combined effect of low air pressure and the impact of varying water inputs on plants. In T. pratense and H. pilosella, we observed an increase in stomatal conductance but a reduction in aboveground biomass at the lowest pressure compared to the control scenario after four weeks of incubation. Contrastingly, B. rupestre showed an interactive effect of air pressure and water treatment on chlorophyll and biomass nitrogen content, which were reduced under higher soil water conditions at 85kPa. This study serves as an initial step in isolating the specific impact of air pressure on plant physiology, demonstrating the potential of the facility for future research. The mixed response patterns across species highlight that atmospheric pressure could be a driving factor to consider when assessing plant responses along elevational gradient.

Rheological Behavior of Gassy Marine Clay: Coupling Effects of Bubbles and Salinity

Understanding the rheological behavior of marine clay is crucial to analyzing submarine landslides and their impact on marine resource exploitation. Dispersed bubbles in marine clay (gassy clay) and electrolytes in seawater (e.g., NaCl concentration of 0.47 M) significantly impacts rheological properties. Under low ionic strength and low pore water pressure conditions, dispersed bubbles have a strengthening effect on the yield stress and the viscosity of clays. This effect turns into a weakening effect when the pore water pressure reaches 300 kPa or the ionic strength exceeds 0.18 M. It was proposed that the effect of bubbles, whether strengthening or weakening, was determined by the size of bubbles with respect to the characteristic size of the particle structure formed by clay particles. A theoretical model was developed, which reasonably captures rheological behaviors of gassy clays.

Tele-mentorship versus in-person mentorship for trainee performance of cricothyroidotomy

Introduction Physicians and other first-line medical care providers may find themselves in an airway management emergency where they cannot ventilate, cannot oxygenate, and have limited resources to aid them. The rise in use of tele-health and other virtual interfaces creates the opportunity to bring experienced guidance to a resource-poor critical airway situation. We aimed to compare in-person mentoring (IPM) by an emergency medicine (EM) physician to tele-mentoring (TM) by a trauma surgeon for an emergent surgical airway. Methods Thirty EM residents were randomized to cricothyroidotomy on a model with IPM or TM. The IPM preceptor was an EM attending, and TM preceptors were trauma surgeons. The procedure was timed and graded on a Global Rating Scale (GRS). Post-procedure, mentor and trainee completed a NASA Task Load Index (TLX). Results There was no difference in procedure success; however, the IPM group took longer (163.6 vs. 107.6 s, p < 0.05). TM trainees experienced greater temporal demand (4.27 vs. 2.73, p = 0.03). Telementors recorded improved performance compared to in-person mentors (2.30 vs. 4.17, p < 0.05). Comparing mentors and trainees in each arm, IPM trainees felt more temporal demand than their mentors (4.63 vs. 2.73, p < 0.05) while TM trainees felt they had worse performance than their mentors perceived (4.23 vs. 2.3, p = 0.01). Discussion Performance based on GRS between groups was equal; however, those with telementors secured the airway more rapidly. Telementors reported higher performance and lower time pressure than in-person preceptors. This data suggests that TM is effective for precepting cricothyroidotomy and may be the superior option in some settings.

Passivating Lattice Oxygen in ZnO Nanocrystals to Reduce its Interactions with the Key Intermediates for a Selective Photocatalytic Methane Oxidation to Methanol

An inevitable overoxidation process is considered as one of the most challenging problems in the direct conversion of methane (CH4) to methanol (CH3OH), which is limited by the uncontrollable cracking of key intermediates. Herein, we have successfully constructed a photocatalyst, the Fe‐doped ZnO hollow polyhedron (Fe/ZnOHP), for the highly selective photoconversion of CH4 to CH3OH under mild conditions. In‐situ experiments and density functional theory calculations confirmed that the introduction of Fe was able to decrease the energy level of the O 2p orbital, which passivated the activity of lattice oxygen in ZnO nanocrystals. This passivation effect greatly weakened the interaction between *CH3 and lattice oxygen, thus facilitating the conversion of *CH3O to *CH3 intermediate rather than the direct desorption of *CH3O. As a result, Fe/ZnOHP exhibited excellent CH3OH generation rate (ca. 1009 μmol gcat−1 h‐1) and selectivity (ca. 96%) in the photocatalytic conversion of CH4 at room temperature and low pressure.

Passivating Lattice Oxygen in ZnO Nanocrystals to Reduce its Interactions with the Key Intermediates for a Selective Photocatalytic Methane Oxidation to Methanol.

Aninevitable overoxidation process is considered as one of the most challenging problems in the direct conversion of methane (CH4) to methanol (CH3OH), which is limited by the uncontrollable cracking of key intermediates. Herein, we have successfully constructed a photocatalyst, the Fe-doped ZnO hollow polyhedron (Fe/ZnOHP), for the highly selective photoconversion of CH4 to CH3OH under mild conditions.In-situ experiments and density functional theory calculations confirmed that the introduction of Fe was able to decrease the energy level of the O 2p orbital, which passivated the activity of lattice oxygen in ZnO nanocrystals. This passivation effect greatly weakened the interaction between *CH3 and lattice oxygen, thus facilitating the conversion of *CH3O to *CH3 intermediate rather than the direct desorption of *CH3O. As a result, Fe/ZnOHP exhibited excellent CH3OH generation rate (ca. 1009 μmol gcat-1 h-1) and selectivity (ca. 96%) in the photocatalytic conversion of CH4 at room temperature and low pressure.

Influence of large-scale atmospheric circulation and Mediterranean Sea surface temperature to extreme land precipitation: the case of storm Alex

Abstract Extreme (greater than 500 mm) amount of rain fell in southeastern France and northern Italy on 2nd and 3rd October 2020 during a "Mediterranean episode" triggered by the powerful extratropical cyclone Alex. Here we use a dynamical adjustment methodology based on constructed analogues to assess the contributions of different drivers to the magnitude of this extreme precipitation event. We first show that the mean effect of the observed atmospheric circulation pattern, an intense low-pressure system centered over the coasts of Western Europe associated with a cold pool and a secondary low-pressure system, can explain about 80 percent of the precipitation event magnitude. By contrasting the effect of Alex atmospheric circulation with an anomalously warm Mediterranean sea and eastern Atlantic ocean versus neutral sea surface temperature conditions, we show that the influence of September 2020 positive sea surface temperature anomalies can explain a large fraction of the 20 percent residual precipitation over southeastern France and northern Italy. Finally, based on a storyline approach, we find that the dynamic component, the atmospheric circulation contribution to the extreme precipitation event, was more extreme than it would have been, had it occurred during the mid-20th century. The increase in the magnitude of the dynamic component since 1950 follows a Clausius-Clapeyron scaling, in agreement with previous studies about the intensity changes of Mediterranean extreme precipitation episodes. (limit =300 words)

Vascular endothelial growth factor-C increases lymphatic vessels in the conjunctiva and maintains low intraocular pressure after trabeculectomy in rabbits

The aim of this study is to determine the effect of Vascular Endothelial Growth Factor-C (VEGF-C) in stimulating the growth of functional lymphatic vessels of postoperative conjunctival filtration blebs in rabbits. Twelve New Zealand Red Eye rabbits were allocated to four treatment groups, each receiving an injection of recombinant VEGF-C at doses of 0 µg (control), 1 µg, 3 µg, and 10 µg following trabeculectomy surgery. The effects of the VEGF-C injection on lymphatic vessels were analyzed using FLT4 fluorescence immunostaining and trypan blue filling techniques. Additionally, vascular vessels were examined using CD31 immunostaining, and post-surgical intraocular pressure (IOP) was compared across the treatment groups. Lymphatic vessels in treatment groups exhibited higher mean values of 11.7, 12.7, and 19.0 in groups treated with 1 µg, 3 µg, and 10 µg of VEGF-C, respectively, compared to a mean value of 5.3 in the control group (p = 0.00). Blood vessel count revealed using CD31 did not indicate any increase in vascular vessels between the groups. Intraocular pressure (IOP) levels ten days after trabeculectomy were significantly lower in the 3 µg and 10 µg treatment groups (7.00 mmHg) compared to 10.33 mmHg in the control group (p = 0.047). The study demonstrates that trabeculectomy augmented with VEGF-C injection in rabbits results in an increased lymphatic vessel count in the conjunctiva and a decrease in IOP levels on the tenth post-operative day. These findings suggest that VEGF-C may be a potential adjuvant agent for enhancing the efficacy of trabeculectomy.

Short-Term Safety and Efficacy of PreserFlo™ Microshunt in Patients with Refractory Intraocular Pressure Elevation After Dexamethasone Implant Intravitreal Injection

Background: The PreserFlo™ MicroShunt (PFMS) is a bleb-forming device considered to be less invasive than traditional glaucoma surgery such as trabeculectomy. This study evaluates the 1-year success rates as well as safety profile of PFMS in patients having high intraocular pressure (IOP) and/or glaucoma refractory to drop therapy with a history of prior intravitreal dexamethasone therapy. Methods: A total of 16 eyes after PFMS implantation due to elevated IOP after intravitreal dexamethasone implant (DEX-I) administration were included in this retrospective cohort study. Success rates and secondary outcomes were evaluated. Results: Qualified and complete success rates at 12 months, respectively, were 14/16 and 12/16 eyes for criterion A, 13/16 and 11/16 eyes for B, 13/16 and 11/16 eyes for C, and 6/16 and 6/16 eyes for D. The overall mean (range) preoperative IOP decreased from 27 (16–38) mmHg to 13 (10–17) mmHg at 12 months. BCVA was not significantly different up to 12 months (p = 0.63). The preoperative mean (range) number of medications decreased from 3.56 (2–4) to 0.31 (0–3) at 12 months. One eye underwent needling twice, and two eyes were revised surgically. One patient needed replacement of the PFMS. There were no hypotony-related complications. Conclusions: The PFMS is an effective surgical option for patients with steroid-induced IOP elevation. It demonstrates satisfactory short-term success rates, a reduced need for pressure-lowering eye drops, an excellent safety profile with minimal postoperative care, and a low complication rate. Additional interventions such as needling or revisions were infrequently necessary. However, PFMS may not be the ideal choice for cases requiring a low target pressure (≤12 mmHg).

Can preoperative urodynamic studies predict de novo stress urinary incontinence following advanced pelvic organ prolapse surgery?

Introduction: We aimed to assess the predictivity of preoperative urodynamics (UDS) on de novo stress urinary incontinence (SUI) in patients having advanced pelvic organ prolapse (POP). Methods: Between January 2016 and June 2019, 133 patients with symptomatic POP at stage 3 or higher were included in the study. The presence of postoperative SUI symptoms after a minimum of six months of followup was considered the primary outcome. The results of all patients' preoperative UDS were compared to their postoperative SUI symptoms. In addition, patients were divided into two groups based on whether SUI was detected during preoperative UDS testing (Group 1) or not (Group 2). Results: Although preoperative measurements, such as bladder capacity and residual urine volume, were not different between groups, group 1 had lower maximal urethral closure pressures (p=0.001). Preoperative SUI symptoms had a sensitivity of 32.1% and a specificity of 91.4% for predicting de novo SUI. In patients with advanced POP, preoperative UDS had a sensitivity of 60.7% and a specificity of 87.6% for predicting de novo SUI. Conclusions: Urodynamic examination with a pessary can significantly predict the development of de novo SUI.

The study of barocaloric effect in ferroelastic Pb3(VO4)2

Abstract The barocaloric effect is considered as one of the most promising refrigeration with the potential to replace traditional gas compression refrigeration. One of the main obstacles to the application of barocaloric materials lies in the requirement for high driving pressures. In this paper, we report on the barocaloric effect of Pb3(VO4)2, which exhibits a ferroelastic transition from a high-temperature trigonal structure to a low-temperature monoclinic structure at 357 K, accompanied by a substantial volume change. The entropy change induced by hydrostatic pressure can reach up 14 J·kg-1·K-1 under a relatively low pressure of 80 MPa. This work is expected to expand the selection range of barocaloric materials.

Impact of Sudden Stratospheric Warmings on the Stratosphere‐To‐Troposphere Transport of Ozone

AbstractSudden stratospheric warmings (SSWs) can significantly impact tropospheric weather systems. Previous studies suggest that SSWs may also influence stratosphere‐to‐troposphere transport (STT), but their spatial and temporal distribution and mechanisms are not fully understood. The complex relationships between SSWs and the El Niño‐Southern Oscillation (ENSO) have also made it difficult to isolate the effects of SSWs on STT. From an idealized ENSO simulation with the WACCM4 model using a stratospheric origin ozone tracer, we investigate the effect of SSWs on the STT of ozone under different ENSO phases. We find a significant increase in lower tropospheric ozone from the SSW onset up to 3 months later over the Arctic, North America, and Europe, regardless of the ENSO phase. This study highlights the significant influence of SSWs on STT on a subseasonal scale. Our results also emphasize the need to consider SSWs when addressing the ENSO impact on STT.

Stability of Proton Superoxide and its Superionic Transition Under High Pressure.

Under extreme conditions, condensed matters are subject to undergo a phase transition and there have been many attempts to find another form of hydroxide stabilized over H2O. Here, using Density Functional Theory (DFT)-based crystal structure prediction including zero-point energy, it is that proton superoxide (HO2), the lightest superoxide, can be stabilized energetically at high pressure and temperature conditions. HO2 is metallic at high pressure, which originates from the 𝜋* orbitals overlap between adjacent superoxide anions (O2 -). By lowering pressure, it undergoes a metal-to-insulator transition similar to LiO2. Ab initio molecular dynamics (AIMD) calculations reveal that HO2 becomes superionic with high electrical conductivity. The possibility of creating hydrogen-mixed superoxide at lower pressure using a (Lix,H1-x)O2 hypothetical structure is also proposed. This discovery bridges gaps in superoxide and superionicity, guiding the design of various H-O compounds under high pressure.

Venous compression causes chronic cerebral ischaemia in normal pressure hydrocephalus patients

BackgroundCerebral autoregulation is a robust regulatory mechanism that stabilizes cerebral blood flow in response to reduced blood pressure, thereby preventing cerebral ischaemia. Scientists have long believed that cerebral autoregulation also stabilizes cerebral blood flow against increases in intracranial pressure, which is another component that determines cerebral perfusion pressure. However, this idea was inconsistent with the complex pathogenesis of normal pressure hydrocephalus, which includes components of chronic cerebral ischaemia due to mild increases in intracranial pressure.MethodsTwenty-one patients who underwent ventriculoperitoneal shunt surgery for normal pressure hydrocephalus were included in this study. To determine the pressure setting of the Codman-Hakim programmable valve, intracranial pressure was measured after shunt surgery by puncturing the Ommaya reservoir, which formed a closed circuit with the needle and the syringe. Then, intracranial pressure was continuously measured with intermittent infusion of cerebrospinal fluid from the same closed circuit. We also continuously measured oximetry data, such as regional cerebral oxygen saturation derived from near-infrared spectroscopy monitoring. These data were digitized, recorded, and used for calculating intracranial compliance and the relationship between cerebrospinal fluid volume loading and intracranial pressure.ResultsThis study demonstrates that in patients with normal pressure hydrocephalus, cerebral venous vascular bed compression induces mild cerebral ischaemia when intracranial pressure is slightly higher than physiological venous pressure. Cerebral venous compression impairs cerebral blood flow by quadratically increasing circulatory resistance according to Poiseuille’s law. Furthermore, chronic cerebral ischaemia occurred even at low or normal intracranial pressures when deep and subcortical white matter hyperintensities (DSWMHs) were severe.ConclusionThe fact that cerebral blood flow impairment begins at very low intracranial pressures indicates that cerebral autoregulation to compensate for reduced venous blood flow is not functioning adequately in NPH. These processes provide a link between impaired cerebrospinal fluid circulation, cerebral autoregulation, and neurological dysfunction, which has been missing in patients with NPH involving small vessel arteriosclerosis. These findings may provide insight into similar conditions, such as normal-tension glaucoma and chronic kidney disease, in which a mild increase in local compartment pressure leads to chronic ischemia in organs protected by autoregulatory mechanisms.

Thermodynamic Analysis of the Steam Reforming of Acetone by Gibbs Free Energy (GFE) Minimization

Steam reforming is an important industrial process for hydrogen production. Acetone, the by-product of phenol production from cumene peroxidation, is a useful source of hydrogen due to its availability and low value compared to hydrogen fuel. This study aimed to utilize the Gibbs free energy minimization method using the Soave–Redlich–Kwong (SRK) equation of state (EOS) to conduct a thermodynamic analysis of the steam reforming process for pure component acetone. The steam reforming process is temperature dependent, with increasing temperatures leading to higher hydrogen production. Competing reactions, particularly the exothermic reverse water–gas shift, impact hydrogen yields beyond 650 °C. The study identified 600 °C as the optimum temperature to strike a balance between maximizing hydrogen production and minimizing the reverse water–gas shift’s impact. The optimal hydrogen yield (70 mol%) was achieved at a steam-to-oil ratio (STOR) of 12. High STOR values shift the equilibrium of the water–gas shift reaction towards hydrogen production due to increased steam, effectively consuming acetone and favoring the desired product. Atmospheric pressure is optimum for hydrogen production because the equilibrium of gas phase reactions shifts in favor of the lighter components at lower pressures.

Ultrasensitive iontronic pressure sensor based on microstructure ionogel dielectric layer for wearable electronics

Flexible pressure sensors show great promise for applications in such fields as electronic skin, healthcare, and intelligent robotics. Traditional capacitive pressure sensors, however, face the problem of low sensitivity, which limits their wider application. In this paper, a flexible capacitive pressure sensor with microstructured ionization layer is fabricated by a sandwich-type process, with a low-cost and simple process of inverted molding with sandpapers being used to form a thermoplastic polyurethane elastomer ionic film with double-sided microstructure as the dielectric layer of the sensor, with silver nanowires as electrodes. The operating mechanism of this iontronic pressure sensor is analyzed using a graphical method, and the sensor is tested on a pressure platform. The test results show that the sensor has ultrahigh pressure sensitivities of 3.744 and 1.689 kPa−1 at low (0–20 kPa) and high (20–800 kPa) pressures, respectively, as well as a rapid response time (100 ms), and it exhibits good stability and repeatability. The sensor can be used for sensitive monitoring of activities such as finger bending, and for facial expression (smile, frown) recognition, as well as speech recognition.

Population dynamics and seasonal variation in biological characteristics of black sea bream (Acanthopagrus schlegelii) in Zhanjiang coastal waters, China

This study examined the population dynamics and seasonal variation (winter-summer) in the biological characteristics of black sea bream (Acanthopagrus schlegelii) in Zhanjiang coastal waters, China. Key growth parameters were estimated using the von Bertalanffy growth model, revealing an asymptotic length (L∞) of 505.05 mm and a growth coefficient (K) of 0.26 year-¹, with an estimated longevity of 11.24 years. Mortality analysis showed a total mortality rate (Z) of 0.35 year-¹, primarily driven by natural causes (M = 0.33 year-¹) with minimal fishing impact (F = 0.02 year-¹), resulting in a low exploitation rate (E) of 0.05. Length-weight relationship (LWR) analysis indicated positive allometric growth in females and nearly isometric growth in males, with significant seasonal variations in condition factors (K). Yield Per Recruit (YPR) analysis identified a maximum sustainable exploitation rate (Emax) of 0.421, with a conservative management approach suggested at E0.1 = 0.355. Seasonal variations in reproductive indices, with higher Gonadosomatic Index (GSI) and Hepatosomatic Index (HSI) in winter, highlight the species’ reproductive cycle. The findings suggest that Acanthopagrus schlegelii is stable, with low fishing pressure. Seasonal GSI and HSI variations suggest fisheries management should time fishing to reduce impacts on reproductive success. Maintaining exploitation rates below Emax is essential for sustainable management, contributing valuable insights for fisheries conservation in coastal China.

Novel gel-immersion endoscopic injection sclerotherapy method for prophylactic hemostasis of esophageal varices: A pilot feasibility and safety study (with video).

Endoscopic injection sclerotherapy (EIS) is a useful prophylactic hemostatic procedure for esophageal varices. However, injecting sclerosing agents into blood vessels is technically challenging and often ineffective. Gel-immersion EIS (GI-EIS) may facilitate easier intravascular sclerosing agent injection by dilating the varices and enhancing scope stability by maintaining low intra-gastrointestinal pressure. Therefore, we aimed to evaluate the effectiveness and safety of this procedure. This retrospective study included 18 patients (14 men and four women; median age, 70 years; age range, 18-83 years) who underwent GI-EIS at Osaka Medical Pharmaceutical University Hospital between December 1, 2022, and January 30, 2024. Patients who were at least 18 years of age at the time of treatment were included. No patients were excluded from the study. Thirty-four punctures were performed. The donor vessel angiography success rate was 88.2% (30 of 34 punctures). The clinical success rate was 94.4% (17 of 18 patients). Esophageal varices in most patients disappeared or were reduced by 1 month after treatment. Adverse events related to the procedure included fever (three patients) and chest pain (one patient); however, both were resolved with conservative treatment. No respiratory deterioration due to aspiration occurred during the procedure. The results of this study demonstrate that GI-EIS is a safe, clinically feasible, and effective treatment option for prophylactic hemostasis of esophageal varices.

Assessment of upper GI motor activity and GI symptoms in patients with amyotrophic lateral sclerosis: an observational study

Background/aimsOro-pharyngeal dysfunction has been reported in Amyotrophic Lateral Sclerosis (ALS). We aimed to assess ALS patients upper gastrointestinal (GI) motor activity and GI symptoms according to bulbar and spinal onset and severity of ALS.MethodsALS bulbar (B) and spinal (S) patients with ALS Functional Rating Scale (ALSFRS-r) ≥35, bulbar sub-score ≥10, and Forced Vital Capacity (FVC) >50%, underwent to: Fiberoptic Endoscopic Evaluation of Swallowing (FEES); esophageal manometry; gastric emptying; Rome symptom questionnaire. Medical Research Council Scale for Muscle Strength (MRC) was performed for the upper and lower limbs. Mann-Whitney's U, Fisher's ranks test, Pearson's test was used.ResultsThirteen ALS patients were included (6 F; mean age 61.2 ± 13.7 years, range: 37-87), 5 with B and 8 with S onset (ALSFRS-R score 39.5 ± 4.9, MRC score 128.6 ± 23.3, disease duration 22.8 ± 17.9 months). FEES detected a high dysphagia score in 5 patients with no difference between S and B phenotype. Lower esophageal sphincter pressure was normal in all patients. Esophageal dysmotility was observed in three S and two B onset patients. Upper esophageal sphincter (UES) pressure was higher in all ALS patients. UES spasms and delayed gastric emptying were detected in two B and one S and in two B and four S patients, respectively. There was no correlation between esophagogastric motor abnormalities and clinical characteristics of ALS, nor GI symptoms.ConclusionsThe presence of UES spasm and the delayed gastric emptying in a subgroup of ALS patients may suggest the role of ANS dysfunction in ALS.