Optical modeling and computational analysis of improved daylight collector geometry for a tubular skylight.

A carefully designed daylight collector for a tubular skylight is necessary to serve the occupants' illumination needs under the dynamic trajectory of the sun. This work simulated an improved configuration of a passive daylight collector comprising parabolic and conical reflectors in a modeled room using the lighting software tool TracePro. Results indicated that the lighting performance of the proposed design configuration was significantly enhanced under low altitude sun in comparison with conventional tubular skylights (with revolved parabolic and cylindrical reflectors) [Light. Res. Technol.52, 495 (2020)10.1177/1477153519872794] and hemispherical transparent dome as daylight collectors by more than ∼30%-40% and ∼110%-130%, respectively.

Mean wavelength-based Fresnel lens solar collector for eliminating the hotpot problem in daylighting systems.

In this paper, the mean-wavelength-based Fresnel lens was designed by merging the modified edge ray principle and idea of superposition. The bottom-to-top approach optimizes the design of individual prisms according to the predetermined plastic optical fiber (POF) bundle size. The simulated optical efficiency of the collector for the sun's visible spectrum (380-740 nm) light is 82.93% with a uniformity ratio of 0.434. Based on the designed collector, the daylighting system can deliver 199.38 lumens via a 10 m long POF bundle with an efficiency of 23.78%. The thermal analysis revealed that the maximum temperature on the focus plane was 49.7°C.

Premature atrial contraction induced cardiomyopathy: A case report.

This case report describes the successful management of a 45-year-old female patient with incessant premature atrial complexes (PACs) leading to left ventricular dysfunction. Despite initial treatment with beta-blockers, the patient's PACs persisted, prompting catheter ablation. Mapping in the left atrium identified the site of earliest atrial activation near the right superior pulmonary vein, and radiofrequency energy successfully terminated the PACs. Follow-up assessments showed the patient remained asymptomatic, with normalized left ventricular function. This case highlights the efficacy of catheter ablation in resolving PAC-induced cardiomyopathy and emphasizes the need for further research in this area.

Modeling a UVC irradiation standalone system for inactivating Mycobacterium tuberculosis from indoor spaces.

After the outbreak of the COVID-19 pandemic, a rise in demand has occurred for efficient designs of disinfection systems that utilize ultraviolet-C (UVC) radiation to inactivate airborne microorganisms effectively. This paper proposes what we believe to be a novel standalone system for inactivating Mycobacterium tuberculosis (which requires a higher dosage value than SARS-CoV-2) from a medium size room of 12.5f t×12.5f t×9f t. The structure consists of a UVC source at the center and a spiral pathway guiding the air around the UVC source, thus increasing the residence time of the aerosol particle. The top and bottom louvre and a hollow cylindrical cover (comprising four external cover segments) enclose the UVC source and prevent the danger of direct exposure to indoor occupants. The whole system is modeled in SolidWorks, and flux leakage was examined using the RayViz tool in SolidWorks. Optical/radiometric analysis in ray tracing software TracePro provided the UVC flux value at different locations of the standalone system. Flow simulation carried out in SolidWorks helped calculate aerosol particles' residence time at different airflow trajectories. The designed standalone system demonstrated the capability of delivering 1.87 times more dosage than is required to inactivate Mycobacterium tuberculosis from the ambient air. The standalone system achieves a ventilation rate, i.e., air changes per hour value of 10, according to guidelines from the Council of Scientific & Industrial Research, India.

Ivabradine vs metoprolol in patients with acute inferior wall myocardial infarction-"Expanding arena for ivabradine".

BACKGROUND: Atrioventricular (AV) blocks are of concern with the use of beta blockers in inferior wall myocardial infarction (MI). Ivabradine lowers heart rate with a lesser risk of AV blocks. OBJECTIVES: To compare ivabradine with metoprolol in acute inferior wall MI in terms of feasibility, tolerability, and efficacy. METHODS: It was a prospective double-blind single-center randomized controlled study. Of 1032 patients with acute inferior wall MI, 468 eligible patients were randomized in 1:1 manner to ivabradine (group A) and metoprolol (group B). Intention to treat analysis of 426 patients (group A-232 and group B-232) was performed. The primary endpoint was 30-day incidence of major adverse cardiovascular events including death, reinfarction, complete heart block (CHB), and heart failure. Secondary endpoints included 30 days incidence of recurrent angina, readmission, first- or second-degree AV block, and tachyarrhythmias. RESULTS: Both the drugs decreased the mean heart rate to 62.22±2.95 (group A) vs 62.53±3.59 (group B) beats per minute (P=0.33). Ejection fraction improved in both the groups (5.15±1.93% in group A vs 5.52±2.18% in group B, P=0.065). The two groups did not differ significantly in their primary endpoints in terms of death (group A=1.72% vs group B=1.72%, OR=1.00, 95% CI=0.25-4.05, P=1.00), reinfarction (group A=0.86% vs group B=0.86%, OR=1.00, 95% CI=0.14-7.16, P=1.00), heart failure (group A=4.31% vs group B=2.59%, OR=1.70, 95% CI=0.61-4.75, P=0.31), or CHB (0% vs 2.59%, OR=0.07, 95% CI=0.00-1.34, P=0.08). There were no significant differences in the secondary endpoints of recurrent angina, readmission, and tachyarrhythmias except for more first- and second-degree AV blocks with metoprolol (12.93% vs 2.59%, OR=5.59, 95% CI=2.28-13.72, P=0.0002). CONCLUSIONS: Ivabradine is well tolerated and equally effective as metoprolol in acute inferior wall ST elevation myocardial infarction patients for lowering the heart rate with lesser risk of AV blocks.

Eptifibatide in post-infarction angina patients who refused intervention: Ajmer postmyocardial infarction angina eptifibatide research (AJMER) study: a pilot study.

BACKGROUND: Early intervention is certainly a preferred strategy over conservative management in patients with post-infarction angina (PIA). But at times, it may not be feasible to intervene, especially if patient refuses for intervention. In a pilot study, we analyzed whether the addition of eptifibatide to intensified antianginal therapy would be of added benefit, in patients with PIA not willing to undergo intervention. METHODS: A total of 461 patients with PIA who refused intervention were randomized in a 1:1 manner to receive either eptifibatide along with intensification of antianginal therapy (group A; n = 229) or intensified antianginal therapy alone (group B; n = 232). The primary endpoints were composite of all-cause death and nonfatal myocardial infarction at 30 days. RESULTS: Primary composite endpoint did not differ between the two groups (16.2% vs. 18.9% in group A and group B, odds ratio [OR], 0.82; 95% CI, 0.5-1.30; P-value = 0.43). Significant earlier relief of angina (complete relief of angina within 12 h: 76% of patients in group A vs. 40.5% in group B; P-value <0.0001) was achieved in group A compared to group B. Although on Bleeding Academic Research Consortium (BARC) scale, type 1 and 2 bleeding was higher in group A (OR, 3.18; 95% CI, 1.76-5.74; P-value = 0.0001), the more serious (composite of type 3 and 5) bleeds did not show any difference (OR, 1.73; 95% CI, 0.7-4.08; P-value = 0.21). CONCLUSION: In patients with PIA who refused intervention, eptifibatide infusion resulted in earlier relief of angina albeit at the cost of increased non-life-threatening bleeding. Further, this effect was achieved in significantly higher number of patients receiving eptifibatide infusion when compared to patients not receiving it. Primary composite endpoints, however, did not differ in two groups, but being a pilot study, this needs to be confirmed by larger study of adequate sample size.

Warning leak of intracranial aneurysm masquerading as sinus node dysfunction: A case report.

We describe the successful endovascular repair of an intracranial aneurysm causing subarachnoid hemorrhage in a 62-year-old man, who was initially diagnosed and treated as a case of symptomatic sinus bradycardia. The aim of this report and following discussion is to discuss the subtle warning signs of intracranial aneurysm that may masquerade as sinus node dysfunction.

Coronary sinus anatomy: Ajmer Working Group Classification.

BACKGROUND: Coronary sinus (CS) anatomy is a major predictor of successful implantation of left ventricular (LV) lead and procedural outcome. We therefore made an attempt to look at the CS anatomy and possible feasibility to classify them into categories depending upon their size, branching pattern, location of posterolateral vein (PLV), and other parameters in order to guide the cardiologist for successful cannulation of the CS and LV lead implantation. METHODS: We analyzed the levophase angiograms of patients (n = 100) undergoing routine coronary angiography in the right anterior oblique view. We have made an attempt to classify these observations on the basis of predetermined parameters and a working classification was brought out for the ease of the operator and to predict the bottlenecks of the procedure. OBSERVATIONS: On the basis of predetermined parameters, venograms obtained from 100 patients were analyzed and findings were divided into three groups depending upon the ease of cannulation of posterolateral vein for LV lead placement. These 3 groups were further classified as type I, type II, and type III coronary sinuses. CONCLUSIONS: This observational study proposes a new anatomical working classification for CS for purposes of successful LV lead placement and optimal operative success.

A study of coronary artery patency in relation to the index event in patients with myocardial infarction thrombolysed with streptokinase.

BACKGROUND: Restoration of infarct vessel patency is the key treatment for acute ST-elevation myocardial infarction. OBJECTIVE: The purpose of the study was to confirm the effectiveness of streptokinase (STK) for successful thrombolysis of the infarct-related artery (IRA) in patients with acute myocardial infarction (AMI), in relation to the time of the index event and age compared with newer thrombolytic agents, in a tertiary care centre. METHODS: 100 patients (77% male) thrombolysed with STK underwent coronary angiography within 48 h of presentation. Patency of the IRA was used to assess successful thrombolysis. RESULTS: The mean pain-to-needle time was 3.24 h. 76 patients (76%) treated with thrombolysis had patent arteries with thrombolysis in myocardial infarction (TIMI) 2 or 3 flow. In subgroup analysis of time from the index event, patency rates were 83.3%, 77.5%, 68.7% and 40% in patients presenting within 0-2, 2-4, 4-6 and 6-12 h, respectively. In subgroup analysis, all patients less than 30 years of age had patent arteries with TIMI 2 or 3 flow. Coronary angiography showed the IRA was the left anterior descending artery (LAD) in 55%, the right coronary artery (RCA) in 33% and the left circumflex artery (LCX) in 12%. The patency rates of the LAD, RCA and LCX were 74.5%, 69.6% and 100%, respectively. CONCLUSIONS: We found STK to be as effective as newer thrombolytic agents reported in other studies. In patients with AMI thrombolysed within 4 h, STK results in higher patency in young compared to older patients.