X marks the spot: Accurate energies from intersecting extrapolations of continuum quantum Monte Carlo data.

We explore the application of an extrapolative method that yields very accurate total and relative energies from variational and diffusion quantum Monte Carlo (VMC and DMC) results. For a trial wave function consisting of a small configuration interaction (CI) wave function obtained from full CI quantum Monte Carlo and reoptimized in the presence of a Jastrow factor and an optional backflow transformation, we find that the VMC and DMC energies are smooth functions of the sum of the squared coefficients of the initial CI wave function and that quadratic extrapolations of the non-backflow VMC and backflow DMC energies intersect within uncertainty of the exact total energy. With adequate statistical treatment of quasi-random fluctuations, the extrapolate and intersect with polynomials of order two method is shown to yield results in agreement with benchmark-quality total and relative energies for the C2, N2, CO2, and H2O molecules, as well as for the C2 molecule in its first electronic singlet excited state, using only small CI expansion sizes.

Evaluating CPR training: simulation vs. webinars for Iranian emergency medical technicians during COVID-19.

INTRODUCTION: The high prevalence of COVID-19 and the necessity for social distancing have impacted medical training. On the one hand, the high mortality rate following the disease led the American Heart Association (AHA) to issue guidelines in October 2020 for performing cardiopulmonary resuscitation on patients diagnosed or suspected of having COVID-19. Various methods exist for teaching these guidelines. However, the use of many of these methods is greatly challenged due to the high risk of disease transmission. Moreover, the published guidelines emphasize protection against COVID-19 infection. The present study aims to compare the impact of two educational methods, educational webinars and simulations, on the competence of performing cardiopulmonary resuscitation during the COVID-19 epidemic. METHODS: This semi-experimental study was conducted on 70 emergency medical technicians. A pre-test was administered to all participants, and then they were randomly assigned into two groups: an educational webinar group (35 people) and a simulation group (35 people). The educational webinar group received online training using Adobe Connect software version 2.6.9, while the simulation group received in-person training using a manikin simulator. The competence of performing cardiopulmonary resuscitation during the COVID-19 epidemic was compared between the two groups immediately after the training and again two months later. Data collection instruments utilized in this research included a demographic questionnaire and a competency questionnaire in performing CPR during the COVID-19 pandemic. The data were analyzed using SPSS software version 19 and statistical tests for comparison. RESULTS: The results indicated that in both the educational webinar and simulation groups, the average competence score for performing cardiopulmonary resuscitation (CPR) at the three stages under investigation showed significant differences (p < 0.001). Additionally, in both groups under study, the average competence score for performing CPR immediately and two months after training was significantly higher compared to before the training (p < 0.001); however, two months after training, it was significantly lower compared to immediately after the training (p < 0.001). CONCLUSIONS: Based on the results obtained from the current research, both educational methods (educational webinar and simulation) had a significant effect on the competence of performing CPR during the COVID-19 epidemic and were equally effective. Moreover, the recall test results (two months later) showed a decrease in the competence of performing CPR during the COVID-19 epidemic in both training methods (webinar and simulation), indicating the need for periodic CPR training.

A new approach to prediction riboflavin absorbance using imprinted polymer and ensemble machine learning algorithms.

The molecularly imprinted polymer (MIP) is useful for measuring the amount of riboflavin (vitamin B2), in various samples using UV/Vis instruments. The practical optimization of the MIP synthesis conditions has a number of drawbacks, like the need to spend money, the need to spend time, the use of the compounds that cause contamination, needing laboratory equipment and tools. Using machine learning (ML) to predict the amount of riboflavin absorbance is a creative solution to overcome the problems and shortcomings of optimizing polymer synthesis conditions. In fact, by using the model without needing real work in the laboratory, the optimum laboratory conditions are determined, and as a result the maximized absorption of the riboflavin is obtained. In this paper, MIP was synthesized for selective extraction of the riboflavin, and UV/Vis spectrophotometry was used to quantitatively measure riboflavin absorbance. Various factors affect the performance of the polymer. The effect of six important factors, including the molar ratio of the template, the molar ratio of monomer, the molar ratio of cross-linker, loading time, stirring rate, and pH, were investigated. Then, using ensemble ML algorithms, like gradient boosting (GB), extra trees (ET), random forest (RF), and Ada boost (Ada) algorithms, an accurate model was created to predict the riboflavin absorption. Also, the mutual information feature selection method was used to determine the important features. The results of using feature selection method was shown that variables such as the molar ratio of the template, the molar ratio of the monomer, and the molar ratio of the cross-linker had a high effect on riboflavin absorbance. The GB and Ada boost algorithms performed better than ET and RF algorithms. After tuning the n-estimator hyper parameter (n-estimator = 300), the GB algorithm was shown an excellent performance in predicting the absorbance of riboflavin and the maximum R2-scoring of the model was obtained at 0.965995, the minimum of the mean absolute error (MAE), and mean square error (MSE) of the model respectively were obtained -0.003711 and -0.000078. Therefore, by using the proposed model, it is possible to predict riboflavin absorbance theoretically, and with high accuracy by changing the inputs of model, and using the model instead of working in the lab saves time, money, chemical compounds, and lab ware.

Machine-learning-based predictions of imprinting quality using ensemble and non-linear regression algorithms.

The molecularly imprinted polymers are artificial polymers that, during the synthesis, create specific sites for a definite purpose. These polymers due to their characteristics such as stability, easy of synthesis, reproducibility, reusability, high accuracy, and selectivity have many applications. However, the variety of the functional monomers, templates, solvents, and synthesis conditions like pH, temperature, the rate of stirring, and time, limit the selectivity of imprinting. The Practical optimization of the synthetic conditions has many drawbacks, including chemical compound usage, equipment requirements, and time costs. The use of machine learning (ML) for the prediction of the imprinting factor (IF), which indicates the quality of imprinting is a very interesting idea to overcome these problems. The ML has many advantages, for example a lack of human error, high accuracy, high repeatability, and prediction of a large amount of data in the minimum time. In this research, ML was used to predict the IF using non-linear regression algorithms, including classification and regression tree, support vector regression, and k-nearest neighbors, and ensemble algorithms, like gradient boosting (GB), random forest, and extra trees. The data sets were obtained practically in the laboratory, and inputs, included pH, the type of the template, the type of the monomer, solvent, the distribution coefficient of the MIP (KMIP), and the distribution coefficient of the non-imprinted polymer (KNIP). The mutual information feature selection method was used to select the important features affecting the IF. The results showed that the GB algorithm had the best performance in predicting the IF, and using this algorithm, the maximum R2 value (R2 = 0.871), and the minimum mean absolute error (MAE = - 0.982), and mean square error were obtained (MSE = - 2.303).

Optimizing Jastrow factors for the transcorrelated method.

We investigate the optimization of flexible tailored real-space Jastrow factors for use in the transcorrelated (TC) method in combination with highly accurate quantum chemistry methods, such as initiator full configuration interaction quantum Monte Carlo (FCIQMC). Jastrow factors obtained by minimizing the variance of the TC reference energy are found to yield better, more consistent results than those obtained by minimizing the variational energy. We compute all-electron atomization energies for the challenging first-row molecules C2, CN, N2, and O2 and find that the TC method yields chemically accurate results using only the cc-pVTZ basis set, roughly matching the accuracy of non-TC calculations with the much larger cc-pV5Z basis set. We also investigate an approximation in which pure three-body excitations are neglected from the TC-FCIQMC dynamics, saving storage and computational costs, and show that it affects relative energies negligibly. Our results demonstrate that the combination of tailored real-space Jastrow factors with the multi-configurational TC-FCIQMC method provides a route to obtaining chemical accuracy using modest basis sets, obviating the need for basis-set extrapolation and composite techniques.

Utilization and Complications of Catheter Ablation for Atrial Fibrillation in Patients With Hypertrophic Cardiomyopathy.

Background Atrial fibrillation (AF) is common and bears a major clinical impact in patients with hypertrophic cardiomyopathy (HCM). We aimed to investigate the use and real-world safety of catheter ablation for AF in patients with HCM. Methods and Results We drew data from the US National Inpatient Sample to identify cases of AF ablation in HCM patients between 2003 and 2015. Sociodemographic and clinical data were collected, and incidence of catheter ablation complications, mortality, and length of stay were analyzed, including trends between the early (2003-2008) and later (2009-2015) study years. Among a weighted total of 1563 catheter ablation cases in patients with HCM, the median age was 62 (interquartile range, 52-72), 832 (53.2%) were male, and 1150 (73.6%) were white. The average annual volume of AF ablations in patients with HCM doubled between the early and the later study period (79-156). At least 1 complication occurred in 16.1% of cases, and the in-hospital mortality rate was 1%. Cardiac and pericardial complications declined from 8.8% to 2.3% and from 2.8% to 0.9%, respectively, between the early and the later study years (P<0.01). Independent predictors of complications included female sex (odds ratio [OR], 4.81; 95% CI, 2.72-8.51), diabetes mellitus (OR, 6.57; 95% CI, 2.68-16.09) and obesity (OR, 3.82; 95% CI, 1.61-9.06). Conclusions Despite some decline in procedural complications over the years, catheter ablation for AF is still associated with a relatively high periprocedural morbidity and even mortality in patients with HCM. This emphasizes the importance of careful clinical consideration, by an experienced electrophysiologist, in referring patients with HCM for an AF ablation.

Safety and In-Hospital Outcomes of Transvenous Lead Extraction for Cardiac Implantable Device-Related Infections: Analysis of 13 Years of Inpatient Data in the United States.

OBJECTIVES: The aim of this study was to investigate the safety and in-hospital outcomes of transcutaneous lead extraction (TLE) associated with device-related infection (DRI) in the United States from 2003 to 2015. BACKGROUND: DRI remains the most serious complication and the most common indication for lead extraction in patients with cardiac implantable electronic devices. The rates of DRI and associated lead extraction have been growing in line with the increasing number of cardiac implantable electronic device implantations worldwide. METHODS: Data for this study were drawn from the National (Nationwide) Inpatient Sample. The International Classification of Diseases-9th Revision-Clinical Modification coding system was used to identify hospitalizations with TLE for DRI and to investigate the rates of major adverse events. RESULTS: From a total of approximately 100 million unweighted hospitalizations over the 13-year study period, 12,257 unweighted observations were identified. This represents 59,082 (95% confidence interval [CI]: 58,982 to 59,182) patients who underwent TLE for DRI during the study period. A large majority of patients (75%) were older than 60 years. Patients were predominantly male (70%) and Caucasian (76%), and 80% had at least 1 comorbidity. The median length of stay was 8 days (interquartile range 5 to 14 days). At least 1 major adverse event occurred in 10.42% of procedures. The all-cause in-hospital mortality rate was 4.11%. Independent predictors of mortality were weight loss (adjusted odds ratio [aOR]: 4.02; 95% CI: 3.13 to 5.17), congestive heart failure (aOR: 3.28; 95% CI: 2.48 to 4.34), chronic kidney disease (aOR: 2.09; 95% CI: 1.70 to 2.56), pericardial complications (aOR: 2.87; 95% CI: 1.79 to 4.61), and procedure-related pulmonary injury (aOR: 2.06; 95% CI: 1.25 to 3.40). CONCLUSIONS: These results reflect the high rate of complications and mortality for TLE due to DRI in real-world experience, highlighting the importance of comorbidities, especially congestive heart failure and chronic kidney disease, as significant predictors of mortality in these patients.

Emergency Department Visits for Atrial Fibrillation in the United States: Trends in Admission Rates and Economic Burden From 2007 to 2014.

BACKGROUND: Atrial fibrillation (AF) is an increasingly prevalent public health problem and one of the most common causes of emergency department (ED) visits. We aimed to investigate the trends in ED visits and hospital admissions for AF. METHODS AND RESULTS: This is a repeated cross-sectional analysis of ED visit-level data from the Nationwide Emergency Department Sample for 2007 to 2014. We identified adults who visited EDs in the United States, with a principal diagnosis of AF. A sample of 864 759 ED visits for AF, representing a weighted total of 3 886 520 ED visits, were analyzed. The annual ED visits for AF increased by 30.7% from 411 406 in 2007 (95% confidence interval, 389 819-432 993) to 537 801 (95% confidence interval, 506 747-568 855) in 2014. Patient demographics remained consistent, with an average age of 69 to 70 years and slight female predominance (51%-53%) throughout the study period. Hospital admission rates were stable at ≈70% between 2007 and 2010, after which they gradually declined to 62% in 2014 (Ptrend=0.017). Despite the decline in hospital admission rates, AF hospitalizations increased from 288 225 in 2007 to 333 570 in 2014 because of the increase in total annual ED visits during the study. The adjusted annual charges for admitted AF patients increased by 37% from $7.39 billion in 2007 to $10.1 billion in 2014. CONCLUSIONS: Annual ED visits and hospital admissions for AF increased significantly between 2007 and 2014, despite a reduction in admission rates. These data emphasize the need for widespread implementation of effective strategies aimed at improving the management of patients with AF to reduce hospital admissions and the economic burden of AF.

Diagnostic Accuracy of a Novel Mobile Phone Application for the Detection and Monitoring of Atrial Fibrillation.

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in adults, associated with significant morbidity, increased mortality, and rising health-care costs. Simple and available tools for the accurate detection of arrhythmia recurrence in patients after electrical cardioversion (CV) or ablation procedures for AF can help to guide therapeutic decisions. We conducted a prospective, single-center study to evaluate the accuracy of Cardiio Rhythm Mobile Application (CRMA) for AF detection. Patients >18 years of age who were scheduled for elective CV for AF were enrolled in the study. CRMA finger pulse recordings, utilizing an iPhone camera, were obtained before (pre-CV) and after (post-CV) the CV. The findings were validated against surface electrocardiograms. Ninety-eight patients (75.5% men), mean age of 67.7 ± 10.5 years, were enrolled. No electrocardiogram for validation was available in 1 case. Pre-CV CRMA readings were analyzed in 97 of the 98 patients. Post-CV CRMA readings were analyzed for 92 of 93 patients who underwent CV. One patient left before the recording was obtained. The Cardiio Rhythm Mobile Application correctly identified 94 of 101 AF recordings (93.1%) as AF and 80 of 88 non-AF recordings (90.1%) as non-AF. The sensitivity was 93.1% (95% confidence interval [CI] = 86.9% to 97.2%) and the specificity was 90.9% (95% CI = 82.9% to 96.0%). The positive predictive value was 92.2% (95% CI = 85.8% to 95.8%) and the negative predictive value was 92.0% (95% CI = 94.8% to 95.9%). In conclusion, the CRMA demonstrates promising potential in accurate detection and discrimination of AF from normal sinus rhythm in patients with a history of AF.

Utilization and in-hospital complications of cardiac resynchronization therapy: trends in the United States from 2003 to 2013.

Aims: Cardiac resynchronization therapy (CRT) device implantation has been shown to reduce morbidity and mortality in selected patients with heart failure. We sought to investigate the utilization and in-hospital complications of cardiac resynchronization therapy defibrillator (CRT-D) and pacemaker (CRT-P) implantations in the United States from 2003 to 2013. Methods and results: Patients receiving CRT-D or CRT-P were identified in the National Inpatient Sample database (NIS), using the International Classification of Diseases-Ninth Revision-Clinical Modification procedure codes. Annual implantation rates, patient demographics, co-morbidities, in-hospital complications, and length of stay were analysed. From 2003 to 2013, an estimated total of 439 010 (95% CI: 406 723-471 296) inpatient CRT implantations were performed in the U.S. The median age of patients was 72 and 71% were male. Overall, 6.1% had at least one complication. During the study period, comorbidity index and overall complication rate increased (P = 0.002 and P = 0.01, respectively). Mortality and length of stay showed no significant trend. Predictors of complications included: age 65 and older, female sex (OR: 1.19; 95% CI: 1.12-1.27), Deyo-Charlson Comorbidity Index, and elective admission (OR: 0.61; 95% CI: 0.57-0.66). Conclusion: From 2003 to 2013, the severity of comorbid conditions increased and a rising trend was observed in the rate of periprocedural complications among patients undergoing CRT in the United States. In-hospital mortality and length of stay showed no uniform trend.

A Model for settlement of health insurance organizations' debt to health service delivery institutions.

Background: Sukuk is a type of financial instrument backed by balance sheet and physical assets. This applied and descriptive study aimed at providing solutions to the problems faced by insurance companies in the health sector. Methods: In this study, we achieved operational models by reviewing the release nature and mechanism of any of the securities and combining them. Results: According to the model presented in this study, 2 problems could be solved: settling the past debts and avoiding future debts. This model was deigned based on asset backed securities. Conclusion: Utilizing financing instruments (such as Sukuk), creating investment funds, and finding a solution to this problem, this study was conducted in 2 aspects: (1) models that are settling old debts of the organization, and (2) models that prevent debts in the future.

Catheter Ablation for Cardiac Arrhythmias: Utilization and In-Hospital Complications, 2000 to 2013.

OBJECTIVES: This study sought to investigate the utilization of and in-hospital complications in patients undergoing catheter ablation in the United States from 2000 to 2013 by using the National Inpatient Sample and Nationwide Inpatient Sample. BACKGROUND: Catheter ablation has become a mainstay in the treatment of a wide range of cardiac arrhythmias. METHODS: This study identified patients 18 years of age and older who underwent inpatient catheter ablation from 2000 to 2013 and had 1 primary diagnosis of any of the following arrhythmias: atrial fibrillation, atrial flutter, supraventricular tachycardia, or ventricular tachycardia. RESULTS: An estimated total of 519,951 (95% confidence interval: 475,702 to 564,200) inpatient ablations were performed in the United States between 2000 and 2013. The median age was 62 years (interquartile range: 51 to 72 years), and 59.3% of the patients were male. The following parameters showed increasing trends during the study period: annual volume of ablations, number of hospitals performing ablations, mean age and comorbidity index of patients, rate of ≥1 complication, and length of stay (p < 0.001 for each). Substantial proportions (27.5%) of inpatient ablation procedures were performed in low-volume hospitals and were associated with an increased risk for complications (odds ratio: 1.26; 95% confidence interval: 1.12 to 1.42; p < 0.001). Older age, greater numbers of comorbidities, and complex ablations for atrial fibrillation and ventricular tachycardia were independent predictors of in-hospital complications and in-hospital mortality. In addition, female sex and lower hospital volumes were independent predictors of complications. CONCLUSIONS: From 2000 to 2013, there was a substantial increase in the annual number of in-hospital catheter ablation procedures, as well as the rate of periprocedural complications nationwide. Low-volume centers had a significantly higher rate of complications.

Heat-Induced Radiolabeling of Nanoparticles for Monocyte Tracking by PET.

Heat-induced radiolabeling (HIR) yielded (89) Zr-Feraheme (FH) nanoparticles (NPs) that were used to determine NP pharmacokinetics (PK) by positron emission tomography (PET). Standard uptake values indicated a fast hepatic uptake that corresponded to blood clearance, and a second, slow uptake process by lymph nodes and spleen. By cytometry, NPs were internalized by circulating monocytes and monocytes in vitro. Using an IV injection of HIR (89) Zr-FH (rather than in vitro cell labeling), PET/PK provided a view of monocyte trafficking, a key component of the immune response.

From a simple chronic headache to neurobrucellosis: a case report.

Brucellosis is an infectious disease with high incidence in Iran. Neurobrucellosis is a focal complication of brucellosis affecting both central and peripheral nervous system presenting with a varieties of signs and symptoms. The most reported manifestations are meningitis and meningoencephalitis. In this report, we will describe a case of a young woman affected by neurobrucellosis presenting with chronic progressive headache and papilledema.

Sudden hearing loss subsequent to diarrhea: what is the missing link?

Sudden sensorineural hearing loss (SSNHL) is a debilitating condition with an incidence of nearly 20 per 100,000 in populations. Metronidazole-induced ototoxicity is an extremely rare etiology of SSNHL. In this report, we describe a young female with bilateral SSNHL due to oral use of metronidazole. A 23 years old female presented to the emergency department with acute bilateral hearing loss. We found out that her hearing loss had started 4 days after initiation of metronidazole which was administered for treatment of diarrhea. This case report shows that physicians should be aware of the uncommon side effects while prescribing metronidazole to patients in order to manage the possible adverse events on time.