Improved energy efficiency using adaptive ant colony distributed intelligent based clustering in wireless sensor networks.

Optimization algorithms have come a long way in the last several decades, with the goal of reducing energy consumption and minimizing interference with primary users during data transmission over shorter distances. The adaptive ant colony distributed intelligent based clustering algorithm (AACDIC) is a key component of the cognitive radio (CR) system because of its superior performance in spectrum sensing among a group of multi-users in terms of reduced sensing errors, power conservation, and faster convergence times. This study presents the AACDIC method, which improves energy efficiency by determining the ideal cluster count using connectedness and distributed cluster-based sensing. In this study, we take into account the reality of a system with an unpredictable number of both primary users and secondary users. As a result, the proposed AACDIC method outperforms pre-existing optimization algorithms by increasing the rate at which solutions converge via the utilisation of multi-user clustered communication. Experiments show that compared to other algorithms, the AACDIC method significantly reduces node power usage by 9.646 percent. The average power of Secondary Users nodes is reduced by 24.23 percent compared to earlier versions. The AACDIC algorithm is particularly strong at reducing the Signal-to-Noise Ratio to levels as low as 2 dB, which significantly increases the likelihood of detection. When comparing AACDIC to other primary detection optimization strategies, it is clear that it has the lowest false positive rate. The proposed AACDIC algorithm optimizes network capacity performance, as shown by the results of simulations, due to its ability to solve multimodal optimization challenges. Our analysis reveals that variations in SNR significantly affect the probability of successful detection, shedding light on the intricate interplay between signal strength, noise levels, and the overall reliability of sensor data. This insight contributes to a more comprehensive understanding of the proposed scheme's performance in realistic deployment scenarios, where environmental conditions may vary dynamically. The experimental results demonstrate the effectiveness of the proposed algorithm in mitigating the identified drawback and highlight the importance of SNR considerations in optimizing detection reliability in energy-constrained WSNs.

Implementing Brief Mindfulness-Based Interventions to Reduce Compassion Fatigue.

BACKGROUND: Nurses in surgical-trauma units are susceptible to compassion fatigue due to work-related stressors. Mitigating and preventing compassion fatigue are critical to supporting the health and well-being of surgical-trauma nurses. LOCAL PROBLEM: During the COVID-19 pandemic, a surgical-trauma unit was converted to a designated COVID-19 unit. Nurses verbalized feelings of burnout and stress during the pandemic and did not have a mechanism to cope with work-related stress. This project evaluated the impact of brief mindfulness-based interventions on compassion fatigue. METHODS: From February 2021 to March 2022, mindfulness champions led 5 minutes of mindfulness-based interventions, including meditation, deep breathing, and self-compassion exercises, during shift huddles. The Professional Quality of Life, version 5, questionnaire was used to evaluate preintervention and postintervention burnout, secondary traumatic stress, and compassion satisfaction. Paired-sample t tests were used to evaluate the results. RESULTS: Twenty-nine of 34 nurses responded (85% response rate) with matched preintervention and postintervention questionnaires. All subscale scores showed significant improvement after intervention. The mean burnout subscale score decreased by 9.35% (P = .003), mean secondary traumatic stress subscale score decreased by 11.89% (P = .005), and mean compassion satisfaction subscale score increased by 6.44% (P = .03) after intervention. DISCUSSION: After implementing brief mindfulness-based interventions in shift huddles, nurses reported reductions in elements of compassion fatigue (burnout and secondary traumatic stress). Nurses reported that adding brief mindfulness-based interventions to shift huddles helped them cope with work-related stress. CONCLUSIONS: Brief mindfulness-based interventions can improve nurses' compassion satisfaction while reducing compassion fatigue measurements.

Overexpression and enhanced specific activity of aldoketo reductases (AKR1B1 & AKR1B10) in human breast cancers.

The incidence of breast cancer in India is on the rise and is rapidly becoming the primary cancer in Indian women. The aldoketo reductase (AKR) family has more than 190 proteins including aldose reductase (AKR1B1) and aldose reductase like protein (AKR1B10). Apart from liver cancer, the status of AKR1B1 and AKR1B10 with respect to their expression and activity has not been reported in other human cancers. We studied the specific activity and expression of AKR1B1 and AKR1B10 in breast non tumor and tumor tissues and in the blood. Fresh post-surgical breast cancer and non-cancer tissues and blood were collected from the subjects who were admitted for surgical therapy. Malignant, benign and pre-surgical chemotherapy samples were evaluated by histopathology scoring. Expression of AKR1B1 and AKR1B10 was carried out by immunoblotting and immunohistochemistry (IHC) while specific activity was determined spectrophotometrically. The specific activity of AKR1B1 was significantly higher in red blood cells (RBC) in all three grades of primary surgical and post-chemotherapy samples. Specific activity of both AKR1B1 and AKR1B10 increased in tumor samples compared to their corresponding non tumor samples (primary surgical and post-chemotherapy). Immunoblotting and IHC data also indicated overexpression of AKR1B1 in all grades of tumors compared to their corresponding non tumor samples. There was no change in the specific activity of AKR1B1 in benign samples compared to all grades of tumor and non-tumors.

Focal para-hisian atrial tachycardia with dual exits.

Focal atrial tachycardias (AT) in the right atrium (RA) tend to cluster around the crista terminalis, coronary sinus (CS) region, tricuspid annulus, and para-hisian region. In most cases, the AT focus can be identified by careful activation mapping, and completely eliminated by radiofrequency (RF) catheter ablation. However, RF ablation near the His bundle (HB) carries a risk of inadvertent damage to the atrioventricular (AV) conduction system. Here we describe a patient with an AT originating in the vicinity of the AV node, which was successfully ablated earlier from non-coronary aortic cusp (NCC), and recurred with an exit from para-hisian location. Respiratory excursions of the catheter were associated with migration to the area of HIs. This was successfully ablated during controlled apnoea, using 3D electroanatomic mapping.

Idiopathic right ventricular tract outflow tachycardia induced by high-frequency stimulation.

Ventricular tachycardia arising from the right ventricular outflow tract is one of the common forms of idiopathic ventricular tachycardia. One of the major challenges in mapping and ablation of idiopathic right ventricular outflow tract ventricular tachycardia is noninducibility. Direct stimulation of sympathetic nerves innervating the right ventricular outflow may provide an alternative approach to induce arrhythmia. We report a case of idiopathic right ventricular outflow tract tachycardia in whom tachycardia was noninducible by aggressive conventional stimulation protocols, which was induced by high-frequency stimulation of proximal pulmonary artery and was successfully ablated.

Three dimensional epicardial mapping and ablation of recurrent non-ischaemic ventricular tachycardia.

Radiofrequency ablation is a therapeutic option for recurrent ventricular tachycardia (VT) in both ischaemic and non-ischaemic subsets. Usually this is attempted by mapping endocardially; however, in some situations epicardial approach may be needed to access the VT circuit. We report two cases in which epicardial approach was used to successfully ablate the VT, when endocardial ablation was ineffective.

Evaluation of bachmann bundle pacing versus right atrial pacing in prevention of atrial fibrillation after coronary artery bypass surgery.

BACKGROUND: In patients undergoing coronary artery bypass surgery (CABGS), occurrence of atrial fibrillation (AF) is common in the postoperative period and is associated with increased morbidity with longer intensive unit care (ICU) and hospital stay. Prevention with antiarrhythmic drugs is of limited success and associated with significant side effects. Therefore alternative approaches, such as Bachmann Bundle pacing, are required. METHODS AND RESULTS: 154 consecutive patients, mean age 58±8.8 years, including 134 males and 20 females, were randomized to three groups; Group I : No pacing n= 54, Group II : RA pacing n= 52, Group III : Bachmann Bundle pacing n= 48. All the groups were well matched with regard to age, left atrial size, ejection fraction and use of beta blockers. Patients in Groups II and III were continually paced at a rate of 100 beats per minute (bpm) or at 10 bpm more than patients' intrinsic heart rate. All the patients were monitored for 72 hours by telemetry and occurrence of AF was noted. Incidence of AF was 0% (none of 48 patients) in Group III as compared to 16.6% in Group I (9 of 54 patients) (p 0.003) and 12.5% in Group II (5 of 52 patients) (p 0.03). There was a trend towards shorter ICU stay in Group III (3.9 days) as compared to Group II (4.5 days) and Group I (4.1 days). Among the three groups, the reduction in mean P wave duration also was greater in Bachmann bundle paced group. CONCLUSION: In patients undergoing CABGS, Bachmann bundle pacing is superior to right atrial / no pacing in the post operative period for preventing occurrence of AF and reducing ICU stay, commensurate with a reduction in mean P wave duration on surface ECG.

Patterns of ventricular dyssynchrony in congestive heart failure- comparison with controls and implications for patient selection for cardiac resynchronization therapy.

BACKGROUND: Assessment of ventricular dyssynchrony by Tissue Doppler Imaging (TDI) is being increasingly used in patient selection for Cardiac Resynchronization Therapy (CRT). Regional distribution of dyssynchrony has been sparingly addressed in dyssynchrony studies in heart failure population. METHODS: TDI was used to assess prevalence and regional distribution patterns of ventricular dyssynchrony in heart failure (HF) patients with systolic LVdysfunction (LVEF equal or less than 40%) in sinus rhythm. Inter-ventricular dyssynchrony (IVD) and left ventricular dyssynchrony (LVD) equal or greater than 40 msec were considered significant and LVD equal or greater than 65 m sec indicated severe dyssynchrony. RESULTS: 100 HF patients (Wide QRS, Gp I, N =70 & Normal QRS Gp II, N=30, and 25 normal individuals with complete LBBB (n=14) or RBBB (n=11) underwent TDI. IVD was seen in 35 (35%) patients (74% LV delay & 26% RV delay) and LVD in 68 patients (68%). The relative prevalence of lVD and LVD respectively in Group land Group II HF patients was47% vs. 7% (p < 0.001) and 70% vs. 67%. (p=ns) while LVD in Groups A (LBBB, n=41) & B (RBBB, n=26) was 76% and 58%, p=ns. The prevalence ofsevere LVD was similar in Gp I & II (37% and 57%, p=ns), and in Gp A & B (46% & 26%, p=ns). Regional distribution patterns of LVD in normal individuals with bundle branch block showed septal delay in 20%, a prevalence of similar to heart failure population (23%, Gp I, and 21% Gp II, p=ns). Lateral wall delay was demonstrated only in the HF population seen in 33% of Gp I and 47% of Gp II patients, p=ns. CONCLUSIONS: LVD is distributed amongst HF patients with narrow or wide QRS and with LBBB or RBBB with a similar regional distribution. Dyssynchrony in normal individuals with bundle branch block is in the form of septal delay. These findings may have implications for patient selection for CRT and site of LV pacing.

Brugada syndrome unmasked by sodium channel blockade.

We report the case of a 29-year-old male suffering from recurrent syncope and palpitations. He had a structurally normal heart and his baseline electrocardiogram was normal. His electrophysiologic study revealed an inducible, nonsustained polymorphic ventricular tachycardia on programmed electrical stimulation. With the administration of intravenous Flecainide, there was typical ST-segment elevation in leads V2 and V3, indicative of the Brugada syndrome. He underwent an implantable cardioverter defibrillator implantation. The cardioverter defibrillator delivered an appropriate shock when the patient suffered ventricular fibrillation during follow-up one year later. This report illustrates the role of pharmacologic challenge in the diagnosis of the Brugada syndrome.

Successful radiofrequency catheter ablation of recurrent atrial fibrillation due to left inferior pulmonary vein tachycardia.

This report illustrates the case of a young lady evaluated for drug-refractory symptomatic paroxysmal atrial fibrillation. Successful isolation of left inferior pulmonary vein was achieved by segmental ostial ablation and circumferential Lasso mapping catheter. Patient is now free of symptoms and is off all anti-arrhythmic drugs.

Non-surgical transpericardial catheter ablation of post-infarction ventricular tachycardia.

Non-surgical transpericardial approach for catheter-based epicardial radiofrequency ablation of post-infarction left ventricular tachycardia has been described as an alternative and additive procedure to standard endocardial technique for delivery of radiofrequency energy in difficult situations. We report our initial experience with this approach in three patients of post-infarction recurrent ventricular tachycardia, refactory to multiple antiarrhythmic drugs. Ablation was successful in terminating the tachycardia in two and in modifying the circuit to be amenable for control with single antiarrhythmic drug in one patient. There were no serious acute or long-term complications related to the procedure. Epicardial approach is an effective and safe adjunct to standard endocardial ablative technique for patients of post-infarction ventricular tachycardia.

Refractory adenosine-sensitive congenital His bundle tachycardia: response to calcium-channel blockers.

The congenital form of His bundle tachycardia is an uncommon pediatric arrhythmia. We report the case of a 7-year-old child with tachycardiomyopathy. The incessant arrhythmia, detected in infancy, was resistant to amiodarone and beta-blockers. During electrophysiologic study, the tachycardia converted to sinus rhythm with intravenous adenosine and diltiazem. Subsequently, the child is maintaining sinus rhythm on oral verapamil. Calcium-channel blockers should be considered for the treatment of this arrhythmia, which is often resistant to multiple antiarrhythmic drugs.

Common supraventricular arrhythmias in Indian population and their management.

Supraventricular tachycardias (SVTs) present as recurrent palpitations. Unlike ventricular tachycardias, these arrhythmias usually carry a benign prognosis. It is important to exclude structural heart disease in these patients. Though vagal manoeuvres and drug therapy are useful for acute termination of SVTs, recurrences are common. Catheter ablation is safe, highly effective and has a curative potential. It obviates the need for long-term medical therapy as it eliminates the arrhythmia in these patients.

Absent coronary venous sinus: a rare anomaly.

A 42-year-old man, presenting with dyspnea on exertion and ST segment depression on treadmill test, was found to have absent coronary venous sinus on coronary angiography. We report this case of isolated congenital absence of coronary venous sinus because of its rarity.

Significance of tumour markers in colorectal carcinoma associated with Schistosomiasis.

Schistosomiasis as well as Colorectal Carcinoma are equally prevalent in Egypt. However, the role of Schistosomiasis as a risk factor for Colorectal Carcinoma is not well established. Three tumour markers have been assessed in 69 patients with large bowel disease. They were classified into five groups. Group 1 (A) included 21 cases with Schistosomal hepatic fibrosis. Group 2 (B) included 6 cases of ulcerative colitis. Group 3 (C) included 10 cases of adenomatous polypi of which 12 cases had Schistosomiasis. Group 4 (D) consisted of 21 cases of colorectal carcinoma, 12 cases had schistosomiasis in association with colorectal carcinoma constituting group 5 (E). Elevated CEA was observed in benign tumours but showed non significant difference in G4 and G5. Significantly increased AFP levels were evident in G1, G4, and G5. Significant increase of B-HCG was observed only in G4 and G5 indicating its significance as diagnostic index in case of malignancy. It has been observed that Schistosomal hepatic fibrosis induced increased levels of some of the tumour markers. Therefore, the factor of Schistosomal hepatic fibrosis should be considered during the assessment of tumour markers in colorectal carcinoma cases.

Proton stopping powers in some low-Z elements.

For some calculations, the proton stopping power in tissue must be known accurately. The composition of tissue was assumed to be constituted of 11 elements; the proton stopping powers were available for hydrogen, carbon, nitrogen, and oxygen. Those for the remaining 7 elements for the energy range 0.5 to 10 MeV at intervals of 0.5 MeV are evaluated and presented in this paper. Corrections such as the Barkas effect correction, Bloch's correction, and shell correction are evaluated and used in the calculation of proton stopping powers. Corrections for the Bethe formula for heavy ions were suggested by Barkas et al. (Phys. Rev. Lett. 11, 26, 1963) when they observed that the stopping powers for positive ions were larger than those for the negative ions with identical velocities. They suggested that a charge-dependent correction term be incorporated in the Bethe formula. Theoretical estimates of this correction derived by Ashley et al. (Phys. Rev. 85, 2392-2397, 1972) were used in the calculation of the Barkas effect. The Barkas effect correction depends on projectile velocity and Z. It decreases with energy. To account for the discrepancy between the classical and the quantum mechanical treatment of the Bethe formula, Bloch (Ann. Phys. 285, Chap. 18, 1933) suggested a correction to the stopping-power formula; this correction is also evaluated in this paper. Bloch's correction also decreases with energy. The shell correction needed for the binding of the electrons in the target atom is also calculated using Walske's asymptotic formula taking into account the screening effect of the atomic electrons of the K and L shells of the target atom. A computer program was written to calculate the stopping powers of protons with all these corrections for seven low-Z elements which are part of the tissue composition. These values are compared with those of other authors, and fairly good agreement is found. The lack of sufficient experimental information and uncertainty in the mean excitation energy values and shell corrections area are some of the causes for the differences in the evaluation of stopping power by the different authors.

Energy response of CaSO4:Dy teflon TLD disk dosimeters to photons and electrons.

The photon energy response of CaSO4:Dy teflon disk dosimeters used widely in radiation dosimetry is computed using the energy absorption coefficient values for calcium, sulfur, oxygen, and carbon taken from J. H. Hubbell's tables. For fluorine, the energy absorption coefficients were obtained from the values given by F. H. Attix for CaF2 and Ca. The energy response of the radiation-monitoring disk for the range of 10 keV to 10 MeV, relative to air, is computed and plotted. The response is maximum between 20 and 30 keV and then gradually falls to a constant at 200 keV to 10 MeV. This computed response for different energies is compared with the experimental TL response of the dosimeter. The electron energy response of these TLD disks is computed using the stopping-power values for the different component elements. The electron stopping power for sulfur and calcium from 10 keV to 10 MeV is computed using the Bethe-Bloch formula. Those for oxygen and carbon are taken from the tables given by M. J. Berger and S. M. Seltzer. For fluorine, the values are computed from those for Li and LiF given in the same tables. This calculated response is compared with the experimental beta response of the TL dosimeter.