State-of-the-art review on energy sharing and trading of resilient multi microgrids.

Independently run single microgrids (MGs) encounter difficulties with inadequate self-consumption of local renewable energy and frequent power exchange with the grid. Combining numerous MGs to form a multi-microgrid (MMG) is a viable approach to enhance smart distribution networks' operational and financial performance. However, the correlation and coordination of intermittent power generation within each MG network pose many techno-economic challenges for energy sharing and trading. This review offers a comprehensive analysis of these challenges within the framework of MMG operations. It examines state-of-the-art methodologies for optimizing multi-energy dispatch and scrutinizes contemporary strategies within energy markets that contribute to the resilience of power systems. The discourse extends to the burgeoning role of blockchain technology in revolutionizing decentralized market frameworks and the intricacies of MMG coordination for reliable and cost-effective energy distribution. Overall, this study provides ample inspiration for theoretical and practical research to the new entrants and experts alike to develop new concepts for energy markets, scheduling and novel operating models for future resilient multi-energy networked systems/MMGs.

Effect of membrane composition on cytokine production and clinical symptoms during hemodialysis: a crossover study.

BACKGROUND: Intradialytic symptoms including hypotension have been reported during dialysis and it has been suggested that these are related to the release of cytokines like IL-1beta and TNFalpha by blood mononuclear cells when they get activated either due to contact with the dialyzer membrane or by compliment activation. OBJECTIVE: To study the relationship between hemodialysis symptoms, cytokine production, and dialyzer membrane composition. METHOD: In a randomized prospective crossover study, 20 ESRD patients on maintenance hemodialysis were studied over cuprophan (CU) and polysulfone (PS) low flux dialyzer membranes for three weeks each undergoing a biweekly dialysis schedule of 4 h sessions. Serial IL-1beta and TNFalpha levels were measured over 0, 15, 240 min during the first use of the dialyzer for all patients on both membranes. Intradialytic symptoms were monitored in a total of 240 dialysis sessions. RESULTS: IL-1beta levels increased from 16.6 +/- 2.2 to 64.8 +/- 25.1 pg/mL on CU and 21.5 +/- 3.7 to 103.5 +/- 30.7 pg/mL on PS membrane over the 4-h dialysis session. Similarly TNFalpha increased from 42.8 +/- 4.5 to 354.9 +/- 80.4 pg/mL on CU and 117.1+/- 53.7 to 387.0 +/- 78.0 pg/mL on PS membrane. IL-1beta levels increased significantly with PS membrane while TNFalpha rise was significant with both the membranes. Nausea was the most common symptom occurring in 138 dialysis sessions (57.5%). Vomiting, chest pain, fever, chills, and breathlessness occurred significantly more during dialysis with CU membrane as compared with PS membrane (P < 0.01). Nausea, cramps, back pain, itching, restlessness, post dialysis fatigue, and hypotension did not differ between the two membranes. The mean rise in the cytokine levels during the first 15 min of sessions where the symptoms occurred, when compared with the mean rise in sessions where the symptoms did not occur, did not reveal any significant difference. Cytokine release did not correlate with the occurrence of intradialytic symptoms. CONCLUSION: Both CU and PS membranes increase circulating cytokine levels. More intradialytic clinical symptoms are seen in dialysis with CU as compared with PS membrane but the rise in cytokines IL-1beta and TNFalpha does not appear to be responsible for them.

Regeneration of granular activated carbon loaded with explosives.

Granular activated carbon (GAC) loaded with trinitrotoluene (TNT) and nitrobenzene (NB) were subjected to different atmospheres, such as nitrogen, oxygen, air, steam and an air-steam mixture, at varying temperatures and for different time intervals for regeneration. The air-steam mixture proved to be the best regenerating media for the explosive-loaded GACs. The regeneration of the activated carbon was found to be above 85% for TNT and above 90% for NB loaded carbons.

Left ventricular pseudoaneurysm as a complication of electrophysiologic study.

We have described a patient who developed a small submitral pseudoaneurysm of the left ventricle during electrophysiologic mapping aimed at ablating a concealed accessory pathway. The patient was asymptomatic, and the lesion was detected on a routine postprocedure echocardiographic study. Spontaneous healing occurred, and the lesion was no longer seen on a repeated echocardiographic examination performed a month later.

An unusual case of vegetative aortitis diagnosed by transesophageal echocardiography.

We report a case of Staphylococcus aureus aortitis in a 42-year-old man who had a fever, an embolus to the left upper arm, and positive blood cultures. Transesophageal echocardiography re-vealed a 3 x 1-centimeter polypoid mass attached to the intima of the medial wall of the aorta, just distal to the origin of the left subclavian artery. The clinical presentation and the transesophageal echocardiography findings led to the diagnosis of vegetative aortitis. Antibiotic therapy was begun, and 5 days later the mass was surgically excised to prevent the possible formation of an infective aortic aneurysm and embolization to the vital organs.

Age related effects of organochlorine insecticide lindane on intestinal brush border membrane in rats.

The effect of oral administration of lindane (gamma-HCH) has been studied on the intestine in 10-day, 20-day and 100-day old rats. In 10 day-old suckling pups exposed to lindane, there was a significant decrease in the activities of sucrase (29%), lactase (20%) and that of alkaline phosphatase (24%) compared to control. Sialic acid content of the brush borders was significantly decreased (29%) in 10-day old as well as in 20- and 100-day old rats (20 and 25% respectively), while fucose content of the membranes was significantly enhanced in all the age groups upon pesticide treatment. Among the brush border lipids, cholesterol content was significantly increased in all the age groups studied, the maximum increase of 35% being observed in 10-day-old rats. Membrane phospholipids were also increased in 20- and 100-day old animals (22% each) on lindane exposure. The present studies indicated that brush border membranes of suckling rat intestine were more susceptible to pesticide induced changes compared to older animals.

Effects of endosulfan on intestinal functions in protein-malnourished rats.

In rats fed 18% protein diet, administration of endosulfan (2mg/kg body weight daily for 7 days) significantly decreased the brush border sialic acid and increased the hexoses contents. The intestinal uptake of glucose was increased while that of glycine and calcium was reduced. Brush border enzymes and lipids were not affected. However, in protein malnourished rats (fed 8% protein) exposed to endosulfan, brush border sucrase and peptidase activities were enhanced, while alkaline phosphatase activity was decreased compared to untreated malnourished animals. Membrane sialic acid content was low while fucose and cholesterol levels were augmented in endosulfan fed malnourished animals. The uptake of glucose and glycine was elevated under these conditions. These results Suggest that the nutritional status of the animals has an important bearing on thc susceptibility of intestinal tissue to endosulfan toxicity in rats.

Repair of acute descending aortic dissection complicated by visceral ischemia.

Visceral ischemia is a rare but lethal complication of type III aortic dissection. We report a Marfan patient with such a complication who had a complete resolution of profound visceral ischemia despite a delay in repair of over 48 hours.

Percutaneous closure of a left ventricular perforation post balloon mitral valvotomy.

The risk of left ventricular perforation is a rare but well-recognized complication of percutaneous double balloon mitral valvuloplasty that usually requires surgical bailout. We describe a case of left ventricular perforation with cardiac tamponade, caused by the propulsion of the balloons during balloon mitral valvotomy on an 86-year-old female with previous thoracotomies that was resolved using percutaneous coil embolization of the perforation. This approach to these types of complications, although unlikely to be of extensive use, will serve to expand the horizon of options in the field of interventions. Cathet. Cardiovasc. Intervent. 48:78-83, 1999.

Echocardiographic recognition of iatrogenic aortic valve leaflet perforation.

BACKGROUND: There is a paucity of literature regarding iatrogenic aortic valve perforation after cardiac operations performed in the vicinity of the aortic valve. This report describes the echocardiographic recognition of iatrogenic aortic valve perforation. METHODS: Among 6 patients who had previously under-gone non-aortic valve cardiac operations, a diagnosis of iatrogenic aortic regurgitation was made by transthoracic two-dimensional echocardiography and Doppler color flow imaging. RESULTS: The location of the aortic valve leaflet perforation varied and depended on the site of the previous intracardiac lesion repair. Repeat operations in 5 patients confirmed the echocardiographic findings. Aortic valve repair was confirmed in 2 patients by transesophageal echocardiography, whereas aortic valve replacement became necessary in 2 other patients. A fifth patient with acquired cardiomyopathy underwent orthotopic heart transplantation. CONCLUSIONS: A detailed two-dimensional echocardiographic examination, along with color flow imaging, should be done to evaluate iatrogenic aortic valve perforation in patients with a new murmur of aortic regurgitation after cardiac operations in proximity to the aortic valve. Precise preoperative diagnosis of this lesion allows optimal surgical planning and treatment.

Angiography in blunt thoracic aortic injury.

PURPOSE: Recent studies have suggested that transesophageal echocardiography (TEE) can be used as the primary imaging method in patients suspected of traumatic rupture of the thoracic aorta. A segment of the aorta and the aortic arch branches cannot be adequately evaluated in all patients by TEE. To assess the impact of these limitations of TEE, this retrospective study examined the aortographic features of traumatic aortic or great vessel injuries in a large number of patients. MATERIALS AND METHODS: We retrospectively reviewed clinical and imaging features of 89 patients with a history of blunt chest trauma and angiographic evidence of traumatic injury to the thoracic aorta or to its branches. RESULTS: Of these 89 patients, 72 had aortic rupture alone. One (1%) of these ruptures occurred at the distal ascending aorta, a potential blind spot for TEE. Seventeen patients (19%) had 24 injuries to the aortic arch branches: in 14 of these 17 patients, the aorta was intact, whereas three patients also had aortic rupture. Seventy percent of the injuries to the aortic arch branches were not suspected on physical examination. CONCLUSION: Twenty percent of patients in our retrospective series had traumatic involvement of aortic arch branches or the distal ascending aorta. These vascular injuries may be suboptimally assessed or overlooked if TEE is used as the sole imaging modality in the evaluation of patients with blunt chest trauma.

Isatin (2,3-dioxoindole): a competitive inhibitor of Na(+)-dependent lysine uptake in rat instestine.

Isatin (2,3-dioxoindole) competitively inhibited (27-40%) Na(+)-dependent L-lysine uptake in rat intestine. The value of Kt was increased from 3.04 mM in control to 5.88 mM in presence of 10 mM isatin. Effect of isatin on the Na(+)-independent amino acid uptake was insignificant (12-18%). The inhibitory constant (Ki) was 2.8 mM under these conditions. The observed inhibition was unaffected by -SH group reacting agents. Isatin (1-10 mM) inhibited Na+, K(+)-ATPase activity in intestine in vitro, the maximum inhibition (66%) being at 10 mM isatin concentration. But the drug had no effect on enzyme activity under in vivo conditions.

Transesophageal echocardiographic diagnosis of eustachian valve endocarditis.

A 33-year-old man with a history of intravenous drug abuse was seen with fever, septic pulmonary embolization, and Staphylococcus aureus bacteremia. Transthoracic echocardiography was nondiagnostic. Transesophageal echocardiography showed a large, pedunculated, and highly mobile vegetation attached to the eustachian valve.

Infective endocarditis.

IE is a fascinating disease that continues to challenge the clinicians. Over the last several decades, there have been marked changes in its presentation. The morbidity and mortality have markedly improved by early diagnosis and prompt treatment using highly effective antibiotic regimens and early valve replacement surgery whenever necessary. Early diagnosis is possible by improvement in blood culture techniques and advances in transthoracic and transesophageal echocardiographic approaches. This article has reviewed the pathogenesis, microbiology, clinical presentation, diagnostic methodology, treatment, and prevention of IE.

Frequency and explanation of false negative diagnosis of aortic dissection by aortography and transesophageal echocardiography.

OBJECTIVES: This study was designed to define the frequency and explanation of false negative diagnosis of aortic dissection by aortography and transesophageal echocardiography. BACKGROUND: Aortography and transesophageal echocardiography have been widely utilized to diagnose aortic dissection. Previous reports have not fully addressed the reasons why these studies yield false negative results in a large number of patients with aortic dissection. METHODS: Sixty-five consecutive patients with aortic dissection underwent aortography and transesophageal echocardiography. Diagnosis of aortic dissection was confirmed at operation or by computed tomography in all patients. RESULTS: Biplane transesophageal echocardiograms yielded false negative results in two patients (sensitivity 97% [63 of 65]). Both patients had well localized DeBakey type II aortic dissection. The diagnosis was probably missed because of image interference from the air-filled trachea and mainstem bronchi. In both patients, the dissection was readily identified by aortography. Aortograms yielded false negative results in 15 patients (sensitivity 77% [50 of 65]); the aortic dissection was type I in 7 patients, type II in 1 and type III in 7. The dissection in all 15 patients was readily identified by transesophageal echocardiography. The missed diagnosis was probably due to a completely thrombosed false lumen or intramural hematoma with noncommunicating dissection in 13 patients and to a large ascending aortic aneurysm with nearly equal flow on both sides of the intimal flap in 2. In no patient was the diagnosis missed by both aortography and transesophageal echocardiography. CONCLUSION: Transesophageal echocardiography is an excellent screening tool for aortic dissection. However, it may miss small type II aortic dissections localized to the upper portion of the ascending aorta because of image interference from the air-filled trachea. An intramural hematoma cannot be easily visualized by aortography, and this lesion is the principal reason for false negative aortographic findings.

In vivo effects of isatin on certain enzymes, lipids & serotonergic system of rat brain.

Isatin (10 microM) strongly inhibited the activity of rat brain monoamine oxidase-B (MAO-B) in vitro. At millimolar concentrations (1-10 mM) it inhibited brain acetylcholinesterase (AChE) and sodium, potassium-adenosine triphosphatase (Na+, K(+)-ATPase) activity also. However, isatin did not affect these enzymes after both acute and chronic treatments in vivo. Administration of isatin to rats at 300 mg/kg body weight for 2 and 6 h significantly raised brain serotonin levels. Chronic treatment for 20 days resulted in enhanced brain glycolipids and plasmalogen levels. There was no change in the levels of 5-hydroxy indole acetic acid (5 HIAA), phospholipids, cholesterol and gangliosides under these conditions.

Inhibition of glucose transport in human erythrocytes by 2,3-dioxoindole (isatin).

10 mM isatin (2,3-dioxoindole) inhibited glucose influx into human erythrocytes by over 30%. The inhibition is of the competitive type, where the affinity constant (Kt) was increased from 5.71 (control) to 11.11 mM in the presence of isatin with no change in Vmax (130 nmol/min/ml packed cells). The observed inhibition of sugar transport by isatin was not mediated through membrane -SH groups accessible to iodoacetate, iodoacetamide, DTNB, DNP or sodium arsenite. Isatin inhibited sugar transport in the presence of 2 mM harmaline, an alkaloid inhibitor of Na+, K(+)-ATPase activity. The inhibition was non additive which suggests that these two compounds interact with the same or a similar site on the erythrocyte membrane.