The enigma of the 'smoker's paradox': Results from a single-center registry of patients with STEMI undergoing primary percutaneous coronary intervention.

BACKGROUND: Smoker's paradox usually refers to the observation of a favorable outcome of smoking patients in acute myocardial infarction. METHODS: From April 2006 to December 2018 a population of 2456 patients with ST segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (pPCI) were prospectively enrolled in the MATRIX registry. Ischemic time, clinical, demographics, angiographic data, and 1-year follow-up were collected. RESULTS: Among 2546 patients admitted with STEMI, 1007 (41 %) were current smokers. Smokers were 10 years younger and had lower crude in-hospital and 1-year mortality (1.5 % vs 6 %, p < 0.0001 and 5 % vs 11 %, p < 0.0001), shorter ischemic time (203 [147-299] vs 220 [154-334] minutes, p = 0.002) and shorter decision time (60 [30-135] vs 70 [36-170] minutes, p = 0.0063). Smoking habit [OR:0.37(95 % CI:0.18-0.75)-p < 0.01], younger age [OR 1.06 (95%CI:1.04-1.09)-p < 0.001] and shorter ischemic time [OR:1.01(95%CI:1.01-1.02)-p < 0.05] were associated to lower in-hospital mortality. Only smoking habit [HR:0.65(95 % CI: 0.44-0.9)-p = 0.03] and younger age [HR:1.08 (95%CI:1.06-1.09)-p < 0.001] were also independently associated to lower all-cause death at 1-year follow-up. After propensity matching, age, cardiogenic shock and TIMI flow <3 were associated with in-hospital mortality, while smoking habit was still associated with reduced mortality. Smoking was also associated with reduced mortality at 1-year follow-up (HR 0.54, 95 % CI [0.37-0.78]; p < 0.001). CONCLUSIONS: Smoking patients show better outcome after PCI for STEMI at 1-year follow-up. Although "Smoking paradox" could be explained by younger age of patients, other factors may have a role in the explanation of the phenomenon.

Heart Failure Management through Telehealth: Expanding Care and Connecting Hearts.

Heart failure (HF) is a leading cause of morbidity worldwide, imposing a significant burden on deaths, hospitalizations, and health costs. Anticipating patients' deterioration is a cornerstone of HF treatment: preventing congestion and end organ damage while titrating HF therapies is the aim of the majority of clinical trials. Anyway, real-life medicine struggles with resource optimization, often reducing the chances of providing a patient-tailored follow-up. Telehealth holds the potential to drive substantial qualitative improvement in clinical practice through the development of patient-centered care, facilitating resource optimization, leading to decreased outpatient visits, hospitalizations, and lengths of hospital stays. Different technologies are rising to offer the best possible care to many subsets of patients, facing any stage of HF, and challenging extreme scenarios such as heart transplantation and ventricular assist devices. This article aims to thoroughly examine the potential advantages and obstacles presented by both existing and emerging telehealth technologies, including artificial intelligence.

Clinical Features and Patient Outcomes in Infective Endocarditis with Surgical Indication: A Single-Centre Experience.

BACKGROUND: Infective endocarditis (IE) is marked by a heightened risk of embolic events (EEs), uncontrolled infection, or heart failure (HF). METHODS: Patients with IE and surgical indication were enrolled from October 2015 to December 2018. The primary endpoint consisted of a composite of major adverse events (MAEs) including all-cause death, hospitalizations, and IE relapses. The secondary endpoint was all-cause death. RESULTS: A total of 102 patients (66 ± 14 years) were enrolled: 50% with IE on prosthesis, 33% with IE-associated heart failure (IE-aHF), and 38.2% with EEs. IE-aHF and EEs were independently associated with MAEs (HR 1.9, 95% CI 1.1-3.4, p = 0.03 and HR 2.1, 95% CI 1.2-3.6, p = 0.01, respectively) and Kaplan-Meier survival curves confirmed a strong difference in MAE-free survival of patients with EEs and IE-aHF (p < 0.01 for both). IE-aHF (HR 4.3, 95% CI 1.4-13, p < 0.01), CRP at admission (HR 5.6, 95% CI 1.4-22.2, p = 0.01), LVEF (HR 0.9, 95% CI 0.9-1, p < 0.05), abscess (HR 3.5, 95% CI 1.2-10.6, p < 0.05), and prosthetic detachment (HR 4.6, 95% CI 1.5-14.1, p < 0.01) were independently associated with the all-cause death endpoint. CONCLUSIONS: IE-aHF and EEs were independently associated with MAEs. IE-aHF was also independently associated with the secondary endpoint.

Transient Left Ventricular Dysfunction from Cardiomyopathies to Myocardial Viability: When and Why Cardiac Function Recovers.

Transient left ventricular dysfunction (TLVD), a temporary condition marked by reversible impairment of ventricular function, remains an underdiagnosed yet significant contributor to morbidity and mortality in clinical practice. Unlike the well-explored atherosclerotic disease of the epicardial coronary arteries, the diverse etiologies of TLVD require greater attention for proper diagnosis and management. The spectrum of disorders associated with TLVD includes stress-induced cardiomyopathy, central nervous system injuries, histaminergic syndromes, various inflammatory diseases, pregnancy-related conditions, and genetically determined syndromes. Furthermore, myocardial infarction with non-obstructive coronary arteries (MINOCA) origins such as coronary artery spasm, coronary thromboembolism, and spontaneous coronary artery dissection (SCAD) may also manifest as TLVD, eventually showing recovery. This review highlights the range of ischemic and non-ischemic clinical situations that lead to TLVD, gathering conditions like Tako-Tsubo Syndrome (TTS), Kounis syndrome (KS), Myocarditis, Peripartum Cardiomyopathy (PPCM), and Tachycardia-induced cardiomyopathy (TIC). Differentiation amongst these causes is crucial, as they involve distinct clinical, instrumental, and genetic predictors that bode different outcomes and recovery potential for left ventricular function. The purpose of this review is to improve everyday clinical approaches to treating these diseases by providing an extensive survey of conditions linked with TLVD and the elements impacting prognosis and outcomes.

Pericardial agenesis: a case report of a rare congenital heart disease.

Background: Pericardial agenesis is a rare congenital heart disease characterized by a variable clinical presentation. Case summary: A 32-year-old man was sent by an occupational health physician to our health care centre because of pathological electrocardiogram (ECG). On transthoracic echocardiogram, we had some difficulty to obtain a good quality of four-chamber apical view that was shifted upper and laterally towards the left anterior axillary line. Nonetheless, an abnormal diastolic expansion of the apex of the left ventricle (LV) that had an otherwise normal systolic function was detected. A chest X-ray confirmed the leftward shift of the heart, with the elongation of the left border of cardiac silhouette and cardiac MRI, finally revealed the absence of left-sided pericardium associated with a leftward dislocation of the heart and a dysmorphism of the LV apex that appeared rounded and curved. The non-invasive work-up was completed with 48 h long Holter ECG that was unremarkable. The exercise test was also negative for both inducible myocardial ischaemia and arrhythmias. Patient was scheduled for loop-recorder implantation, and a 6-month clinical follow-up was advised. Discussion: Pericardial agenesis is a rare congenital heart disease associated with an increased risk of cardiac arrhythmias and type A aortic dissection, however its clinical course could be also completely unremarkable. The diagnosis is challenging, and cardiac MRI remains the gold standard imaging modality. In complete left-sided and asymptomatic forms, no treatment is needed. Prognosis is not well established due to both the rarity of disease and extreme variability of clinical presentation.

Systemic Vascular Resistance and Myocardial Work Analysis in Hypertrophic Cardiomyopathy and Transthyretin Cardiac Amyloidosis with Preserved Left Ventricular Ejection Fraction.

Background: The pathophysiological impact of systemic vascular resistance (SVR) and pressure-strain loop-derived global myocardial work index (GWI) in hypertrophic cardiomyopathy (HCM) and transthyretin cardiac amyloidosis (ATTR) has been randomly investigated. Methods: Both SVR and GWI were assessed in outpatients consecutively referred at two Italian cardiology departments for heart failure with preserved left ventricular ejection fraction (LVEF), affected by either nonobstructive HCM or wild-type ATTR. Based on relevant cross-tabulations, the patients were gathered into 4 functional classes according to cut-off values of 1440 dyne/s/cm-5 for SVR, and 1576 mm Hg% for GWI, as suggested by previous studies. Results: A total of 60 patients, 30 in each group, aged 61 ± 16 years, with 78% males, were studied. HCM patients were younger than those with ATTR and in a better clinical condition (23% HCM vs. 77% ATTR were NYHA class II-III, p < 0.001). Overall, 51 patients (85%) showed a high SVR, 21/30 HCM (70%), and 30 ATTR (100%) (p < 0.005). Both SVR and GWI (expressions of ventricular-arterial coupling) were impaired in 43% of HCM patients (showing greater LV concentric hypertrophy) and 93% of ATTR patients (in advanced NYHA functional class) (p < 0.001). Conclusions: A substantial percentage of present study population showed impaired SVR and/or GWI, despite preserved LVEF. The proposed classification may shed further light on the pathophysiological and clinical characteristics of such hypertrophic phenotypes.

Kissing shockwave balloon in a case of extensive calcified abdominal aorta during transfemoral TAVI.

An 84-year-old man with extensive calcified atherosclerosis of the infrarenal abdominal aorta was diagnosed with severe aortic valve stenosis, presenting with dyspnea. To facilitate transfemoral approach during the TAVI procedure, IVUS-guided intravascular lithotripsy was successfully performed using Kissing Shockwave Balloon Technique.

Patient-reported outcome measures for transthyretin cardiac amyloidosis: the ITALY study.

BACKGROUND: Transthyretin cardiac amyloidosis (ATTR-CA) has a deep impact on the quality of life (QoL), yet no specific patient-reported outcome measures (PROMs) for ATTR-CA exist. METHODS: The ITALY study involved 5 Italian referral centres (Pisa, Pavia, Ferrara, Florence, Messina) enrolling consecutive outpatients with ATTR-CA. RESULTS: Two 30-item questionnaires were created for wild-type (wt) and variant (v) ATTR-CA. Scores ranged from 100 (best condition) to 0 (worst condition). Out of 140 patients enrolled (77% with ATTRwt-CA), 115 repeated the re-evaluation at 6 months. At baseline, only 30% of patients needed help to fill out the questionnaires. Among baseline variables, all KCCQ and SF-36 domains were univariate predictors of ITALY scores in ATTRwt-CA patients, with the KCCQ Symptom Summary score (beta coefficient 0.759), Social Limitations (0.781), and Overall summary score (0.786) being the strongest predictors. The SF-36 Emotional well-being score (0.608), the KCCQ Overall summary score (0.656), and the SF-36 Energy/fatigue score (0.669) were the strongest univariate predictors of ITALY scores in ATTRv-CA. Similar results were found at 6 months. CONCLUSIONS: The ITALY questionnaires are the first specific PROMs for ATTRwt- and ATTRv-CA. Questionnaire completion is feasible. ITALY scores display close relationships with non-ATTR-specific measures of QoL.

Preliminary Outcomes of Zone 2 Thoracic Endovascular Aortic Repair Using Castor Single-Branched Stent Grafts: A Single-Center Experience.

In the context of thoracic endovascular aortic repair (TEVAR), the reconstruction of the left subclavian artery (LSA) has emerged as a crucial component in establishing a sufficient proximal landing zone. However, the technical difficulty of these procedures raises the possibility of endoleaks and neurological consequences. Single-branched stent grafts offer good anchoring and LSA flow for these patients. This study evaluates the feasibility of utilizing novel single-branched stent grafts in the treatment of distal aortic arch disease, identifying good results in the short and medium term. From September 2019 to March 2023, TEVAR and revascularized LSA were performed on ten patients at the Ospedale del Cuore-FTGM in Massa, Italy, using Castor single-branched thoracic aortic stent grafts (Microport Medical, Shanghai, China). The authors' first findings demonstrated that, after an average follow-up of one year, the Castor branching aortic stent graft system was safe and achieving an appropriate proximal landing zone and maintaining sufficient LSA perfusion was possible. With regard to the endovascular treatment of distal aortic arch diseases, this product offers a compelling substitute for surgery. For the purpose of assessing the long-term effectiveness of this approach, the follow-up period should be extended.

Myocardial Work Appraisal in Transthyretin Cardiac Amyloidosis and Nonobstructive Hypertrophic Cardiomyopathy.

Global left ventricular (LV) myocardial work (MW) indexes can be recognized at ultrasound imaging from the LV pressure/global longitudinal strain (GLS) loop analysis. A total of 4 indexes, global work index (GWI), global constructive work (GCW), global wasted work (GWW), and global work efficiency (GWE), have been demonstrated to overcome the methodological limitations of GLS and provide useful information on myocardial dysfunction in some clinical settings. Although impaired MW indexes have been demonstrated in patients with transthyretin cardiac amyloidosis (ATTR) or with nonobstructive hypertrophic cardiomyopathy (HCM), there are no comparative studies at present. This study aimed to describe the characteristics of MW in both these clinical settings compared with patients with well-controlled hypertension (HTN). A total of 83 patients, 32 with ATTR (aged 70 ± 11 years, 32% mutated, 68% wild-type, 72% men), 29 with HCM (aged 57 ± 17 years), and 22 HTN controls (aged 56 ± 5.6 years, 59% men) were prospectively enrolled at 2 clinical centers. All participants had New York Heart Association class I or II. Overall, the LV mass index was greater in both study groups than in HTN, whereas the LV ejection fraction (EF) was significantly lower in ATTR compared with other groups. Based on this finding, patients with ATTR were further divided into 2 subgroups: ATTR1 (LVEF ≤0.50), n = 14 (44%) and ATTR2 (LVEF >0.50), n = 18 (56%). Overall, the GWI and GCW were lower in all ATTR patients (mostly in ATTR1) than in the other groups (p <0.001), whereas only small differences in GWE and none in GWW were found among the groups. Of interest, the pairwise comparison and receiver operating characteristic analysis in preserved LVEF patients showed that GWI was a better discriminator of ATTR2 from HCM patients than GLS, with the cut-off value ≤1,419 mm Hg% (89% sensitivity; 55% specificity; p = 0.013). In conclusion, MW analysis was confirmed to be a modern way to investigate myocardial function in patients with hypertrophic phenocopies. GWI and GCW were more impaired in patients with ATTR compared with HCM and HTN controls. Furthermore, this study likely revealed an additional discriminative value of GWI over GLS alone in preserved LVEF settings.

Left Atrial Strain Imaging by Speckle Tracking Echocardiography: The Supportive Diagnostic Value in Cardiac Amyloidosis and Hypertrophic Cardiomyopathy.

Background: Left atrial (LA) function is crucial for assessing left ventricular filling in various cardiovascular conditions. Cardiac Amyloidosis (CA) is characterized by atrial myopathy and LA function impairment, with diastolic dysfunction up to restrictive filling pattern, leading to progressive heart failure and arrhythmias. This study evaluates LA function and deformation using speckle tracking echocardiography (STE) in patients with CA compared to a cohort of patients with sarcomeric Hypertrophic Cardiomyopathy (HCM) and a control group. Methods: We conducted a retrospective, observational study (from January 2019 to December 2022) including a total of 100 patients: 33 with ATTR-CA, 34 with HCMs, and 33 controls. Clinical evaluation, electrocardiograms, and transthoracic echocardiography were performed. Echocardiogram images were analyzed in post-processing using EchoPac software for LA strain quantification, including LA-reservoir, LA-conduit, and LA-contraction strain. Results: The CA group exhibited significantly impaired LA function compared to HCMs and control groups, with LA-reservoir median values of -9%, LA-conduit -6.7%, and LA-contraction -3%; this impairment was consistent even in the CA subgroup with preserved ejection fraction. LA strain parameters correlated with LV mass index, LA volume index, E/e', and LV-global longitudinal strain and were found to be associated with atrial fibrillation and exertional dyspnea. Conclusions: LA function assessed by STE is significantly impaired in CA patients compared to HCMs patients and healthy controls. These findings highlight the potential supportive role of STE in the early detection and management of the disease.

Cardiac Magnetic Resonance in HCM Phenocopies: From Diagnosis to Risk Stratification and Therapeutic Management.

Hypertrophic cardiomyopathy (HCM) is a genetic heart disease characterized by the thickening of the heart muscle, which can lead to symptoms such as chest pain, shortness of breath, and an increased risk of sudden cardiac death. However, not all patients with HCM have the same underlying genetic mutations, and some have conditions that resemble HCM but have different genetic or pathophysiological mechanisms, referred to as phenocopies. Cardiac magnetic resonance (CMR) imaging has emerged as a powerful tool for the non-invasive assessment of HCM and its phenocopies. CMR can accurately quantify the extent and distribution of hypertrophy, assess the presence and severity of myocardial fibrosis, and detect associated abnormalities. In the context of phenocopies, CMR can aid in the differentiation between HCM and other diseases that present with HCM-like features, such as cardiac amyloidosis (CA), Anderson-Fabry disease (AFD), and mitochondrial cardiomyopathies. CMR can provide important diagnostic and prognostic information that can guide clinical decision-making and management strategies. This review aims to describe the available evidence of the role of CMR in the assessment of hypertrophic phenotype and its diagnostic and prognostic implications.

Kounis syndrome in a patient with multivessel coronary artery disease and DRESS.

A 68-year-old man was admitted with ST-elevation myocardial infarction and intense rash. He was diagnosed with type 2 Kounis syndrome elicited by drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome and received complete revascularization with percutaneous coronary intervention. This case highlights the complex pathophysiology of acute coronary syndrome, and the elusive link between coronary occlusion and ST-segment deviations at ECG.

A Case of Type B Aortic Dissection: The Role of Transesophageal Ultrasound Guidance in Thoracic Endovascular Aortic Repair.

Thoracic endovascular aortic repair (TEVAR) plays a central role in managing acute and chronic aortic pathologies. With the advancement of transcatheter structural heart procedures, echocardiography has become a key in procedural guidance. Despite consensus on its use for cardiac interventions, ultrasound assistance in aortic procedures is not widely standardized. A 71-year-old obese man with chronic type B aortic dissection underwent a TEVAR procedure, using a single-branched aortic stent graft (Endovastec™ Castor™) and with transesophageal ultrasound guidance. The preprocedural assessment confirmed the presence of aortic dissection of the descending thoracic aorta with a posterior true lumen (TL) and an anterior false lumen (FL), normal aortic valve anatomy and function, normal left ventricular function, absence of intracavity thrombus, and absence of aortic plaques that could prevent the optimal implantation of the stent graft. During the procedure, a transesophageal echocardiogram (TEE) monitored the positioning of the guide wires, the arrival of the catheter of the thoracic endoprosthesis, and then the implantation of this at the level of the aortic arch and the descending thoracic aorta. Postprocedure TEE evaluation underlined full stent-graft deployment without leaks and successful exclusion of FL with the beginning of thrombosis. Angiography confirms the exclusion of the aneurysm and the absence of endoleaks. This clinical case demonstrates how transesophageal echocardiographic guidance can improve the TEVAR procedure by minimizing fluoroscopy time, contrast medium use, and enabling a better assessment of the dissection anatomy with real-time monitoring of both the TL and the FL. In conclusion, TEE can serve as an auxiliary intraoperative imaging tool to provide good information before, during, and after the procedure, increasing the success and safety of the TEVAR.

Usefulness of a smartphone application for the diagnosis of epilepsy: Validation study in high-income and rural low-income countries.

INTRODUCTION: In low- and middle-income countries (LMIC), the diagnosis of epilepsy should be made by Non-Physician Health Workers (NPHW) who are widely available in these settings. Recently a smartphone app (Epilepsy Diagnosis Aid) has been developed and validated to be used by NPHW, in order to confirm the diagnosis of epilepsy. The aim of our study was to perform a validation of the app in two different contexts: a hospital-based setting of a high-income country (HIC) and a population-based setting of the rural communities of a LMIC. MATERIAL AND METHODS: For the hospital-based setting, the app was administered to a sample of patients with epilepsy (PWE) and to a sample of subjects affected by syncope attending the epilepsy center of the University of Catania. For the population-based setting, performed in the rural communities of the Gran Chaco region in Bolivia,the app was administered by NPHW to a sample of PWE previously identified. Sensitivity and specificity were calculated for the diagnosis of epilepsy. RESULTS: In the hospital-setting, the app was administered to 100 PWE and 20 syncopes. A probability score > 80 showed a sensitivity of 76% (95%CI 66.4-84) and a specificity of 100% (95%CI 83.2-100) for the diagnosis of epilepsy; higher values were found for active epilepsy with tonic-clonic seizures. In the rural-setting, the app was administered to 38 PWE, giving a sensitivity of 92.1% (95%CI 78.6-98.3). CONCLUSION: The app for epilepsy could represent a valuable instrument, which can be easily employed by trained NPHW to diagnose epilepsy in primary health-care settings of LMIC.

Publisher Correction: Direct thermal neutron detection by the 2D semiconductor 6LiInP2Se6.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Direct thermal neutron detection by the 2D semiconductor 6LiInP2Se6.

Highly efficient neutron detectors are critical in many sectors, including national security1,2, medicine3, crystallography4 and astronomy5. The main neutron detection technologies currently used involve 3He-gas-filled proportional counters6 and light scintillators7 for thermalized neutrons. Semiconductors could provide the next generation of neutron detectors because their advantages could make them competitive with or superior to existing detectors. In particular, solids with a high concentration of high-neutron-capture nuclides (such as 6Li, 10B) could be used to develop smaller detectors with high intrinsic efficiencies. However, no promising materials have been reported so far for the construction of direct-conversion semiconductor detectors. Here we report on the semiconductor LiInP2Se6 and demonstrate its potential as a candidate material for the direct detection of thermal neutrons at room temperature. This compound has a good thermal-neutron-capture cross-section, a suitable bandgap (2.06 electronvolts) and a favourable electronic band structure for efficient electron charge transport. We used α particles from an 241Am source as a proxy for the neutron-capture reaction and determined that the compact two-dimensional (2D) LiInP2Se6 detectors resolved the full-energy peak with an energy resolution of 13.9 per cent. Direct neutron detection from a moderated Pu-Be source was achieved using 6Li-enriched (95 per cent) LiInP2Se6 detectors with full-peak resolution. We anticipate that these results will spark interest in this field and enable the replacement of 3He counters by semiconductor-based neutron detectors.

Cs2PbI2Cl2, All-Inorganic Two-Dimensional Ruddlesden-Popper Mixed Halide Perovskite with Optoelectronic Response.

The two-dimensional Ruddlesden-Popper (RP) phases are an important class of halide perovskites with versatile optoelectronic properties. So far, only organic-inorganic hybrid RP phases involving long organic spacers were reported in this class. Here, we report an all-inorganic RP phase lead halide perovskite, Cs2PbI2Cl2 (1, I4/ mmm space group; a = 5.6385(8) Å, c = 18.879(4) Å), synthesized by a solid-state method. The compound exhibits a band gap of Eg ∼ 3.04 eV and photoconductivity. We find an anomalous band gap evolution in Cs2Pb1- xSn xI2Cl2 solid solutions. Our combined density functional theory and experimental study supports the thermodynamically stable nature of 1 as a unique ordered phase in the Cs2PbX4 (X = Cl, Br, I) system. The calculations suggest that 1 is a direct bandgap semiconductor with relatively small effective carrier mass along the in-plane direction, consistent with the experimentally observed in-plane UV-light photoresponse. We also demonstrate that 1 is promising for radiation detection capable of α-particle counting. Moreover, 1 shows markedly ambient and thermal stability.

Multistates and Polyamorphism in Phase-Change K2Sb8Se13.

The phase-change (PC) materials in the majority of optical data storage media in use today exhibit a fast, reversible crystal → amorphous phase transition that allows them to be switched between on (1) and off (0) binary states. Solid-state inorganic materials with this property are relatively common, but those exhibiting an amorphous → amorphous transition called polyamorphism are exceptionally rare. K2Sb8Se13 (KSS) reported here is the first example of a material that has both amorphous → amorphous polyamorphic transition and amorphous → crystal transition at easily accessible temperatures (227 and 263 °C, respectively). The transitions are associated with the atomic coordinative preferences of the atoms, and all three states of K2Sb8Se13 are stable in air at 25 °C and 1 atm. All three states of K2Sb8Se13 exhibit distinct optical bandgaps, Eg = 1.25, 1.0, and 0.74 eV, for the amorphous-II, amorphous-I, and crystalline versions, respectively. The room-temperature electrical conductivity increases by more than 2 orders of magnitude from amorphous-I to -II and by another 2 orders of magnitude from amorphous-II to the crystalline state. This extraordinary behavior suggests that a new class of materials exist which could provide multistate level systems to enable higher-order computing logic circuits, reconfigurable logic devices, and optical switches.

Defect Antiperovskite Compounds Hg3Q2I2 (Q = S, Se, and Te) for Room-Temperature Hard Radiation Detection.

The high Z chalcohalides Hg3Q2I2 (Q = S, Se, and Te) can be regarded as of antiperovskite structure with ordered vacancies and are demonstrated to be very promising candidates for X- and γ-ray semiconductor detectors. Depending on Q, the ordering of the Hg vacancies in these defect antiperovskites varies and yields a rich family of distinct crystal structures ranging from zero-dimensional to three-dimensional, with a dramatic effect on the properties of each compound. All three Hg3Q2I2 compounds show very suitable optical, electrical, and good mechanical properties required for radiation detection at room temperature. These compounds possess a high density (>7 g/cm3) and wide bandgaps (>1.9 eV), showing great stopping power for hard radiation and high intrinsic electrical resistivity, over 1011 Ω cm. Large single crystals are grown using the vapor transport method, and each material shows excellent photo sensitivity under energetic photons. Detectors made from thin Hg3Q2I2 crystals show reasonable response under a series of radiation sources, including 241Am and 57Co radiation. The dimensionality of Hg-Q motifs (in terms of ordering patterns of Hg vacancies) has a strong influence on the conduction band structure, which gives the quasi one-dimensional Hg3Se2I2 a more prominently dispersive conduction band structure and leads to a low electron effective mass (0.20 m0). For Hg3Se2I2 detectors, spectroscopic resolution is achieved for both 241Am α particles (5.49 MeV) and 241Am γ-rays (59.5 keV), with full widths at half-maximum (FWHM, in percentage) of 19% and 50%, respectively. The carrier mobility-lifetime µτ product for Hg3Q2I2 detectors is achieved as 10-5-10-6 cm2/V. The electron mobility for Hg3Se2I2 is estimated as 104 ± 12 cm2/(V·s). On the basis of these results, Hg3Se2I2 is the most promising for room-temperature radiation detection.