Search Results (1,472)

The lung–kidney axis forms an important physiologically integrated system which controls multiple essential functions of the body. An important observation of this interaction is tissue oxygenation and erythropoiesis, a vital process that involves erythropoietin (EPO) release by the kidney to bring red cell production into the bone, while pulmonary gas exchange ensures adequate oxygen delivery to the cells. Subsequently, the lung–kidney activation of the renin angiotensin system (RAS) influences vascular tone, blood pressure, and tissue perfusion, influencing the delivery of oxygen and the body’s requirement for erythropoietin. Additionally, beyond oxygen sensing, studies have evidenced the role of hypoxia-inducible factors (HIFs), inflammatory mediators, endothelial signaling pathways and iron availability. These modulate erythropoietin production, which enhances the process of erythropoiesis and arterial oxygen balance. Localized variations in renal oxygen levels together with hemodynamic control mechanisms enable the body to produce erythropoietin independently from systemic hypoxia conditions. This concept emerged to include the renal oxygen extraction fraction (OFE) and intrarenal microvascular shunting with perfusion oxygen coupling in governing EPO production. The present review refines the traditional knowledge to further expand our understanding of the lung–kidney axis regulating the process of erythropoiesis and arterial oxygen content. The integrative framework demonstrates that pulmonary arterial oxygenation and renal oxygen sensing together with bone hematopoietic responses operate as a unified system which maintains both oxygen equilibrium and hematopoietic balance throughout the body. Full article

Creating a dependable approach for identifying both the mass of a shuttle car and how material is distributed in it removes the need for equipment operators to manually engage the flight chain. The quantification of environmental and installation conditions and the extent of influence considering their combined contribution towards inaccurate or exclusive measurements are to that degree limited. This experimental study investigated how two different strain transducers—installed in a force-shunt configuration—respond to thermo-mechanical loads when used to determine load distribution and position. Initial observations indicated that thermal effects at the installation site contributed to measurement inaccuracies or exclusive readings. The investigation quantified the impact of environmental and installation variables on measurement accuracy and found this influence to be indirectly linked to the mechanical properties of the substrate to which the strain transducers were mounted. Mounting bolt torque was determined to exert a negligible effect on strain measurement accuracy for the custom-built strain transducers. Nonetheless, both transducers failed to consistently return to the selected baseline at the start of experiments since thermal dependence persisted at the balanced state following the first cycle of loading. The research indicated that the custom-built force-shunt strain transducers are an effective means for mapping the profile and location of coal in shuttle cars, provided that the systems are subjected to continuous and cyclic rebalancing to maintain accuracy. Full article

The transjugular intrahepatic portosystemic shunt (TIPS) is a cornerstone intervention for complications of portal hypertension, including variceal bleeding and refractory ascites. As the population with cirrhosis ages, clinicians increasingly face the question of whether and how to perform TIPS safely in older adults. We reviewed observational cohorts, registry analyses, and systematic reviews/meta-analyses. Existing evidence does not support chronological age as an absolute contraindication; however, multiple studies suggest that advanced age is associated with higher rates of post-TIPS hepatic encephalopathy (HE), early mortality, and readmissions. These findings underscore the need to shift from a binary “eligible vs. ineligible” paradigm to a structured, actionable framework that addresses modifiable risks and anticipates age-related vulnerabilities. Recent clinical practice guidance emphasizes comprehensive pre-TIPS assessment and vigilant post-procedure care, with specific attention to HE risk factors (e.g., prior HE, hyponatremia, renal dysfunction, sarcopenia) and cardiopulmonary reserve. In this narrative review, we propose an elderly-focused clinical pathway built around a four-domain assessment (Liver–Brain–Body–Heart/Kidney) and a traffic-light risk tiering system to guide patient selection, procedural strategy, follow-up scheduling, and triggered management of HE, cardiac decompensation, and renal dysfunction. This pathway aims to preserve the benefits of portal decompression while reducing preventable complications and improving outcomes that are meaningful to older patients, including functional status and quality of life. This narrative review emphasizes that outcomes after TIPS in older adults are determined not by chronological age alone but by multidomain physiological reserve. The proposed pathway informs patient selection, procedural planning, and early post-discharge monitoring in older adults. Full article

The large-scale integration of distributed energy resources poses numerous challenges to distribution networks. At present, multi-terminal flexible interconnection has become a key development trend for active distribution networks integrated with high-penetration distributed energy resources. Conventional unified power flow controllers (UPFCs) are mainly designed for high-voltage transmission networks and lack distribution-adapted control strategies, making it difficult for them to meet the networking requirements for multi-terminal interconnection. Moreover, most existing studies still focus on two-terminal devices, soft open points and improved UPFC topologies for transmission networks. Existing multi-port schemes mostly adopt only shunt-side structures without series compensation branches, which fail to regulate voltage magnitude and phase difference, thus failing to suppress closing inrush currents and mitigate busbar voltage sags. Meanwhile, such schemes struggle with three-phase imbalance, feeder load imbalance and bidirectional power flow fluctuations in distribution networks, and lack adaptive power allocation capability among multiple ports. To solve the above problems, this paper proposes a VSC-based series–shunt hybrid multi-terminal flexible interconnection converter. The proposed topology consists of one series-side VSC and n − 1 shunt-side VSCs connected through a common DC capacitor; it removes the shunt-side transformer, and effectively reduces cost and volume, while achieving phase shifting, voltage regulation and power flow control. Meanwhile, dual closed-loop PI cross-decoupling control and a flexible closing strategy are adopted to independently regulate the active and reactive power of each feeder, adapt to three-phase imbalance and load imbalance conditions, suppress inrush currents, and realize flexible power mutual support among multiple ports, thereby significantly enhancing adaptability to distribution networks. Full article

Background: Ventricular septal rupture (VSR) following acute myocardial infarction (AMI) creates an abrupt left-to-right shunt that can progress to cardiogenic shock (CS). Once CS develops, mortality increases dramatically and delayed repair becomes less feasible. Intra-aortic balloon pumps (IABPs) are widely used to facilitate delayed repair; however, whether initiating IABP before CS onset improves survival remains unclear. Methods: We retrospectively analyzed 124 patients with AMI-related VSR (2009–2024), categorized by IABP timing relative to CS onset (defined as first catecholamine administration) into pre-CS, post-CS, and no-IABP groups. The primary outcome was all-cause mortality within 90 days after AMI onset. Kaplan–Meier curves and Cox proportional hazards models were applied, with subgroup analyses by CS status. Results: The 90-day survival rate was 68.2% in the pre-CS IABP group, 14.3% in the post-CS group, and 35.1% in the no-IABP group. Pre-CS IABP was associated with significantly lower mortality compared with no-IABP (adjusted HR = 0.401, 95% CI 0.174–0.925, p = 0.032) and post-CS IABP (adjusted HR = 0.369, 95% CI 0.149–0.910, p = 0.030). In the CS subgroup, IABP use did not improve survival (19.4% vs. 17.6%, p = 0.365). Among non-CS patients, IABP use was independently associated with lower mortality (85.7% vs. 50.0%, p = 0.027; adjusted HR = 0.178, 95% CI 0.040–0.801, p = 0.025). Conclusions: Given the retrospective design and limited sample size, these findings are hypothesis-generating. Early IABP use was associated with improved short-term survival, an effect not observed once CS had developed. These findings support early risk stratification to identify high-risk patients who may benefit from timely hemodynamic support. Full article

Excessive acidity restricts the utilization of citrus pulp, a major by-product of the dried tangerine peel industry. To overcome this bottleneck, a functional microbial consortium (BsHpMrF) comprising Bacillus subtilis L4, Hanseniaspora pseudoguilliermondii B4, and Monascus ruber CGMCC 10910 was constructed for efficient biological deacidification. The consortium exhibited a synergistic effect, achieving an 88.23% reduction in total acidity and converting the acidic pulp into a neutral, bio-stabilized substrate. Untargeted metabolomics analysis revealed that this efficiency was driven by the concurrent activation of the TCA cycle and glyoxylate shunt for organic acid mineralization, coupled with membrane lipid remodeling (increased unsaturation) to enhance acid tolerance. Notably, the fermentation process functioned as a “metabolic factory”, significantly enriching the matrix with bioactive lipids (e.g., 10-HDA, nervonic acid) and indole-3-acetic acid (IAA, 414.28 mg/L). Application assays demonstrated that the fermentation products acted as a potent biostimulant for soybean sprouts, significantly promoting lateral roots and eliciting the accumulation of antioxidant phenolics and flavonoids. This study provides a sustainable “waste-to-treasure” strategy, valorizing acidic citrus pulp into a functional biostimulant for high-quality edible sprout production, thereby achieving a sustainable “waste-to-food” circular loop. Full article

We describe the case of a 26-year-old man who presented with acute chest pain and was found to have single-vessel coronary occlusion most consistent with probable paradoxical embolism. Coronary angiography demonstrated complete occlusion of the ramus intermedius artery. Aspiration thrombectomy restored flow without stent implantation. Intravascular ultrasound showed no plaque rupture, atherosclerosis, or coronary dissection, supporting but not definitively confirming an embolic etiology. Transthoracic and transesophageal echocardiography subsequently identified a large patent foramen ovale with bidirectional shunting. Lower-extremity Doppler studies and an extensive hypercoagulable evaluation were negative. The patient later underwent successful percutaneous closure of the patent foramen ovale. This case highlights probable paradoxical coronary embolism as a rare cause of acute myocardial infarction in a young patient without significant atherosclerotic disease and underscores the value of multimodality imaging in supporting the diagnosis and guiding management. Full article

In this work, the impact of hydrogen plasma treatment on the electrical and electronic quality of multicrystalline silicon (mc-Si) was systematically investigated using plasma-enhanced chemical vapor deposition (PE-CVD). Hydrogen radicals generated in the plasma effectively passivate dangling bonds, reducing electrically active defects and enhancing material quality. Optimized PE-CVD conditions were applied to promote efficient hydrogen incorporation and surface modification. Optical characterization, including reflectivity measurements and FT-IR spectroscopy, confirms the formation of Si–H bonds and a significant reduction in surface reflectivity of up to 66% at 600 nm. Electrical and optoelectronic analyses reveal pronounced improvements in carrier lifetime and diffusion length, increased by 200% and 79%, respectively. In addition, dark current–voltage (I–V) measurements show a 32% decrease in series resistance and a 51% increase in shunt resistance, indicating enhanced charge transport and suppressed leakage currents. These macroscopic electrical improvements are supported by light beam-induced current (LBIC) measurements, which demonstrate a 14% increase in grain boundary current, confirming effective hydrogen passivation and reduced recombination. Overall, hydrogen plasma PE-CVD treatment is shown to significantly improve the electronic quality and photovoltaic performance of mc-Si solar cells. Full article

The expansion and ongoing refinement of control solutions for three-phase microgrids are key enablers in the transition from conventional distribution networks to smart microgrids. By integrating distributed generation, a microgrid can operate in either grid-connected or island mode. One of the major technical challenges in microgrid operation is mitigating or eliminating phase power unbalances. Unbalanced single-phase loads, combined with unbalanced and intermittent single-phase generation, can produce adverse effects on both energy efficiency and power quality. Unlike conventional distribution networks, microgrids may exhibit bidirectional power flows, which can occur simultaneously on all phases or differ from phase to phase. This paper introduces new analytical expressions for sizing a balancing capacitive compensator (BCC) for three-phase four-wire systems and derives a simplified sizing algorithm. The approach is validated through a numerical study using a Matlab/Simulink model of a low-voltage three-phase microgrid with high penetration of single-phase loads and single-phase distributed sources. The BCC is installed at the point of common coupling (PCC) between the microgrid and the main grid. Three operating regimes (cases) of the microgrid were analyzed, considering three compensation scenarios (sub-cases) for each: 1—without compensation, 2—with balanced capacitive compensation (classical), and 3—with unbalanced capacitive compensation (with BCC). For each of the three regimes (cases), the use of the BCC determines, at the PCC, in addition to the cancellation of the reactive component of the positive sequence current, the cancellation of the negative- and zero-sequence currents. In other words, the BCC–microgrid assembly is seen from the main grid either as a perfectly balanced active power load or as a perfectly balanced active power source. Thus, the BCC prevents the propagation of the unbalance disturbance in the main grid; in the considered case study, this also results from the cancellation of the negative- and zero-sequence components of the phase voltages measured at the PCC. The results show that the load-balancing capability of the BCC can be extended to power-flow balancing in any network section, including cases where the phase power directions differ. Implemented as a BCC-type SVC or as an automatically adjustable variant (ABCC), the proposed unbalanced shunt capacitive compensation method is effective for mitigating or eliminating bidirectional phase power-flow unbalances. Full article

Background and Clinical Significance: Hepatic encephalopathy (HE) is a reversible brain dysfunction typically associated with cirrhosis and portal hypertension. In these patients, portosystemic shunts allow ammonia and other toxins to bypass hepatic metabolism, leading to neurological symptoms. However, HE can also occur in non-cirrhotic patients through congenital shunts or, less commonly, through iatrogenic shunts following abdominal trauma or surgery. This case is clinically significant as it illustrates a rare presentation of recurrent HE caused by a de novo portosystemic shunt following major abdominal surgery in a patient without underlying liver disease. Case Presentation: A 76-year-old male was admitted with confusion, lethargy, and flapping tremors. His medical history included a total pancreatectomy for pancreatic adenocarcinoma six months prior. Laboratory tests revealed hyperammonemia and altered liver enzymes likely related to ongoing chemotherapy, but no signs of hepatic insufficiency or cirrhosis. A review of recent CT imaging identified a new portosystemic shunt between the portal territory and the azygous vein that was absent prior to his pancreatectomy. This iatrogenic shunt likely formed via the re-vascularization of vestigial vessels following surgical de-vascularization. The patient was successfully managed with lactulose and rifaximin. At 3-month follow-up, no further HE episodes had occurred. Conclusions: This case highlights that HE should be considered in patients without cirrhosis presenting with altered mental status and hyperammonemia, especially following abdominal surgery. It underscores the importance of a multidisciplinary approach and meticulous re-evaluation of imaging to identify iatrogenic vascular shunts that may be amenable to medical or interventional management. Full article

Background: Non-invasive scoring systems for predicting the hepatic venous pressure gradient (HVPG) and, thus, clinically significant portal hypertension (CSPH) have been proposed; the aim of this study was to evaluate the accuracy of these scores in a cohort of patients undergoing transjugular intrahepatic portosystemic shunt (TIPS) placement and to further analyze patients without a markedly elevated portosystemic gradient (PSG) at the time of the procedure. Methods: We retrospectively analyzed 314 patients who underwent TIPS implantation at our tertiary care center between 2010 and 2022. The diagnostic performance of CT-based scoring systems by Iranmanesh (Score 1) and Kihira (Score 2), as well as laboratory-based scores including MELD (Score 3), FIB-4 (Score 4), and APRI (Score 5), was assessed for detecting a markedly elevated PSG (PSG > 10 mmHg). Additionally, we evaluated whether incorporating the inferior vena cava (IVC) diameter as a surrogate marker of central venous pressure (CVP) improves the accuracy of CT-based scores. Results: Both Scores 1 and 2 showed high sensitivity (89–87%) but low specificity (33–27%). ROC analysis revealed AUC values between 0.65 and 0.62. Laboratory-based scores (Score 3–5) performed poorly with AUCs of 0.57–0.54. Adding IVC diameter as an estimator for CVP to Scores 1 and 2 significantly increased the AUC to 0.74 and 0.76. In Lasso regression, IVC diameter was selected as a significant variable for PSG estimation. Conclusions: CT-based scoring systems showed promise in assessing markedly elevated PSG, but their specificity was low. Including the IVC diameter improved accuracy in detecting elevated PSG in TIPS patients. Future scoring systems should incorporate CVP estimators like the IVC diameter. Full article

Background: Aneurysmal subarachnoid hemorrhage (SAH) during pregnancy is rare, occurring in approximately 0.01–0.05% of pregnancies, most commonly in the third trimester. Its management is particularly challenging, requiring careful consideration of both maternal and fetal outcomes. Methods: We report the case of a 32-year-old woman at 31 weeks of gestation who presented with severe headache and left third cranial nerve palsy. Imaging revealed diffuse SAH with significant obstructive hydrocephalus and a 5 mm left posterior communicating artery aneurysm. Following multidisciplinary discussion, surgical clipping was performed while preserving the pregnancy to allow for fetal lung maturation. On postoperative day 8, the patient developed right-sided weakness and aphasia secondary to severe vasospasm. Initial management with catecholamine-induced hypertension resulted in increased uterine contractions and fetal distress. Subsequent intra-arterial administration of nimodipine effectively resolved the vasospasm, enabling cessation of vasopressor therapy. After achieving fetal lung maturity, cesarean section was performed at 34 weeks, followed by ventriculo-peritoneal shunt placement for communicating hydrocephalus. Due to sustained shunt failure, the distal catheter was finally inserted into the superior vena cava at the junction of the atrium. Results: The patient showed gradual neurological recovery with complete resolution of third cranial nerve palsy, and both mother and infant were discharged without complications. Conclusions: This case highlights that while standard vasospasm therapies can be implemented during pregnancy, hemodynamic approaches may provoke maternal and fetal complications. Endovascular rescue strategies should be promptly considered for severe vasospasm, and ventriculo-atrial shunting for complex communicating hydrocephalus may serve as a viable alternative option in post-cesarean patients. Full article

There has been no experimental work on CuCrO₂-ZnSnN₂ heterojunctions (HJs), though theoretical work shows that their photoelectric conversion efficiency is around 20%. Here, CuCrO₂ thin films and p CuCrO₂-n ZnSnN₂ HJs are prepared by varying the sputtering power of the Cu-Cr alloy target while the other parameters are held constant. The as-deposited Cu_xCr_yO_z thin films are amorphous, with CuCrO₂ as the major phase. The CuCrO₂ thin films are p-type conductive, with an optical band gap of about 3.64–3.84 eV. The ZnSnN₂ thin films are wurtzite and n-type conductive. The dark current density J versus voltage V curve measurements show that all the HJs showed rectification, while only the samples deposited at 40 and 50 W had a photo-induced current. Further analysis shows the HJs deposited at 40 W have the lowest shunt conductance, saturation current density, and trap density, implying an effect of fabrication conditions on the properties of HJs. Full article

Emergent tracheal intubation in critically ill patients is a common, yet high-risk, intervention. It is frequently complicated by peri-intubation hypoxemia, hemodynamic instability, and metabolic derangements that increase the risk of arrhythmias, hypotension, cardiac arrest, and death. Because the highest-risk interval often occurs in the minutes surrounding induction, when apnea, derecruitment, and abrupt cardiopulmonary shifts converge, oxygenation failure frequently reflects a mismatch between preoxygenation strategy and the underlying physiology rather than inadequate oxygen delivery alone. This review proposes a phenotype-based approach to peri-intubation oxygenation and focuses on four high-risk phenotypes in whom standard preoxygenation strategies commonly fail: obesity, neuromuscular disease, right ventricular dysfunction or pulmonary hypertension, and post-operative respiratory failure with altered respiratory mechanics or airway anatomy. We summarize the key mechanisms that shorten safe apnea time, including reduced functional residual capacity, intrapulmonary shunt, elevated oxygen consumption, rapid derecruitment after induction, and impaired oxygenation–hemodynamics coupling. We then compare preoxygenation modalities as physiologic tools, including facemask oxygen, high-flow nasal cannula (HFNC), noninvasive ventilation (NIV), and controlled bag-mask ventilation (BMV), and integrate contemporary randomized trial evidence that informs bedside selection and combination of these approaches. Finally, we synthesize these concepts into a practical, physiology-informed framework to guide clinicians in choosing and troubleshooting preoxygenation strategies in high-risk patients undergoing emergent intubation. Full article

Postattenuation neurologic signs (PANS) are serious complications following surgical ligation of congenital portosystemic shunts (cPSS) in dogs, but their pathogenesis remains incompletely understood. We hypothesized that surgical ligation alters hepatic tryptophan metabolism through increased substrate delivery and inflammation, leading to changes in kynurenine pathway metabolites that may contribute to PANS. Ten dogs diagnosed with cPSS between April 2019 and December 2023 underwent surgical ligation. Serum samples were collected preoperatively and on postoperative days 1, 2, and 3. Serum concentrations of quinolinic acid (QA) and 3-hydroxykynurenine (3OHKYN) were measured using ELISA in this retrospective observational study. Dogs exhibiting neurological signs within 3 days postoperatively were classified as having PANS. Serum QA concentrations showed no significant postoperative changes and did not differ between dogs with and without PANS. In contrast, serum 3OHKYN concentrations decreased significantly after surgery (p = 0.002). Dogs that developed PANS had significantly lower serum 3OHKYN concentrations on postoperative day 1 (p = 0.048) and exhibited greater reductions from baseline on postoperative days 1 and 3 (p = 0.024 and 0.017, respectively). These preliminary findings suggest that postoperative reductions in 3OHKYN, rather than increases in QA, are associated with PANS development, indicating that altered tryptophan metabolism may play a role in its pathogenesis and warrant further investigation in larger studies. Full article