Understanding the EKG changes in methemoglobinemia.

Methemoglobin is a form of hemoglobin that has been oxidized, changing its heme iron configuration from the ferrous to the ferric state. Unlike normal hemoglobin, methemoglobin does not bind oxygen and as a result, cannot deliver oxygen to the tissues. At the presentation in the emergency department, an electrocardiogram (EKG) is usually performed as a reflex for patients admitted for shortness of breath to rule out acute coronary syndrome. Very limited data is available on EKG abnormalities in patients with methemoglobinemia. In this study, we retrospectively analyzed the pattern of EKG changes in patients with methemoglobinemia.

Correction to: Molecular revolution in the diagnosis of microbial brain abscesses.

An erratum to this paper has been published: https://doi.org/10.1007/s10096-020-04047-8.

Evidence for Superconductivity above 260 K in Lanthanum Superhydride at Megabar Pressures.

Recent predictions and experimental observations of high T_{c} superconductivity in hydrogen-rich materials at very high pressures are driving the search for superconductivity in the vicinity of room temperature. We have developed a novel preparation technique that is optimally suited for megabar pressure syntheses of superhydrides using modulated laser heating while maintaining the integrity of sample-probe contacts for electrical transport measurements to 200 GPa. We detail the synthesis and characterization of lanthanum superhydride samples, including four-probe electrical transport measurements that display significant drops in resistivity on cooling up to 260 K and 180-200 GPa, and resistivity transitions at both lower and higher temperatures in other experiments. Additional current-voltage measurements, critical current estimates, and low-temperature x-ray diffraction are also obtained. We suggest that the transitions represent signatures of superconductivity to near room temperature in phases of lanthanum superhydride, in good agreement with density functional structure search and BCS theory calculations.

Synthesis and Stability of Lanthanum Superhydrides.

Recent theoretical calculations predict that megabar pressure stabilizes very hydrogen-rich simple compounds having new clathrate-like structures and remarkable electronic properties including room-temperature superconductivity. X-ray diffraction and optical studies demonstrate that superhydrides of lanthanum can be synthesized with La atoms in an fcc lattice at 170 GPa upon heating to about 1000 K. The results match the predicted cubic metallic phase of LaH10 having cages of thirty-two hydrogen atoms surrounding each La atom. Upon decompression, the fcc-based structure undergoes a rhombohedral distortion of the La sublattice. The superhydride phases consist of an atomic hydrogen sublattice with H-H distances of about 1.1 Å, which are close to predictions for solid atomic metallic hydrogen at these pressures. With stability below 200 GPa, the superhydride is thus the closest analogue to solid atomic metallic hydrogen yet to be synthesized and characterized.

Novel ground state structures of N-doped LuH3.

Ab-initiocrystal structure searches have played a pivotal role in recent discoveries of high-Tc hydride superconductors under high pressure. Using evolutionary crystal searches, we predict novel ground state structures of N-doped LuH3at ambient conditions. We find an insulating ground state structure for LuN0.125H2.875(∼1.0 wt.% N), contrary to earlier studies where assumed structures were all metallic. This insulating behavior of ground state was found to persist up to ∼45 GPa. However our crystal structure searches revealed a metallic state for an H-deficient variant of LuN0.125H2.875. We study bonding characteristics of important structures by calculating electronic density of states, electronic-localization functions and Bader charges. Our Bader charge analysis shows that insulators have both H+and H-ions whereas metals have only H-ions. We find that H+ions are bonded to N atomsviaa very short covalent bond. Thus we identify a clear relationship between formation of N-H bonds and insulating behavior of materials. Besides this, we perform crystal structure searches for three more compositions with higher N-content (>1.0 wt.%). Analysis of electronic properties shows that the ground states of these compositions are insulator.

Atrioventricular Synchrony Restoration Aided by a Temporary Permanent Pacemaker in Right Ventricular Infarction and Complete Heart Block.

Pacemakers are effective treatments for a variety of bradyarrhythmias. Cardiac pacemakers generally consist of a pulse generator and one or more leads. The conventional temporary transvenous ventricular cardiac pacemaker utilizing a passive fixation lead is commonly associated with multiple complications such as increased infection rate, lead dislodgement, venous thrombosis, longer duration of hospital stay, and atrioventricular (AV) dyssynchrony. On the other hand, temporary permanent pacemakers (TPPM) utilize active fixation leads; hence, they provide lower capture thresholds, reliable pacing, lower rates of displacement, and fewer pacemaker-related infections. Here, we present a case of TPPM aiding AV synchrony restoration in complete heart block accompanying right ventricular (RV) infarction with refractory cardiogenic shock. Pacemakers are effective treatments for a variety of bradyarrhythmias. Cardiac pacemakers generally consist of a pulse generator and one or more leads. We present a case of TPPM aiding AV synchrony restoration in complete heart block accompanying RV infarction with refractory cardiogenic shock. TPPM pacing is a safe and effective technique for temporary bridge pacing to prevent AV dyssynchrony in hemodynamically unstable patients with cardiogenic shock from RV infarction and complete heart block. It also hastens recovery compared to a traditional single-chamber temporary pacemaker.

Sofosbuvir/Velpatasvir/Voxilaprevir for Hepatitis C Virus Retreatment in Difficult-to-treat Patients: A Real-life Observational Study from India.

Background and aim: Hepatitis C virus (HCV) treatment fails to achieve sustained virological response at 12 weeks (SVR12) in 5-10 % and requires retreatment with second-line drugs. We report our experience of sofosbuvir/velpatasvir/voxilaprevir use for HCV retreatment in a small cohort of difficult-to-treat Indian patients. Methods: We reviewed our HCV databases to identify the patients who had failed to achieve SVR12 after treatment with sofosbuvir in combination with either daclatasvir, ledipasvir, or velpatasvir with/without ribavirin on one or more occasions. Participants were excluded if they had (i) decompensated cirrhosis, (ii) HIV coinfection or (iii) chronic kidney disease, or (iv) prior organ transplantation. All the participants were treated with sofosbuvir/velpatasvir/voxilaprevir plus ribavirin for 12 weeks. Treatment outcome was categorized as successful or failure if HCV RNA was undetectable or detectable at SVR12, respectively. Results: Fifteen patients (male 67 %; genotype-3 80 %) were included in the analysis. Ten (67 %) had cirrhosis. Five, eight, and two participants had previously failed one, two, and three courses of pegylated-interferon free, sofosbuvir containing direct acting antiviral (DAA) regimens respectively. Fourteen participants had failed to at least one course of the sofosbuvir/velpatasvir combination. Fourteen patients achieved SVR12, and one patient was lost to follow-up. Treatment was successful in 100 % and 93.3 % of per-protocol (PP) and intention to treat (ITT) analyses, respectively. Conclusion: Sofosbuvir/velpatasvir/voxilaprevir combination is an effective second-line therapy in India for difficult-to-treat HCV patients.

Comparison of a Novel Score "NOD-ACLF" to Other Established Prognostic Scores for Prediction of Mortality in APASL-ACLF Patients: A Cohort Study from a Tertiary Care Center of North India.

Background: Commonly used prognostic scores for acute on-chronic liver failure (ACLF) have complex calculations. We tried to compare the simple counting of numbers and types of organ dysfunction to these scores, to predict mortality in ACLF patients. Methods: In this prospective cohort study, ACLF patients diagnosed on the basis of Asia Pacific Association for Study of the Liver (APASL) definition were included. Severity scores were calculated. Prognostic factors for outcome were analysed. A new score, the Number of Organ Dysfunctions in Acute-on-Chronic Liver Failure (NOD-ACLF) score was developed. Results: Among 80 ACLF patients, 74 (92.5%) were male, and 6 were female (7.5%). The mean age was 41.0±10.7 (18-70) years. Profile of acute insult was; alcohol 48 (60%), sepsis 30 (37.5%), variceal bleeding 22 (27.5%), viral 8 (10%), and drug-induced 3 (3.8%). Profiles of chronic insults were alcohol 61 (76.3%), viral 20 (25%), autoimmune 3 (3.8%), and non-alcoholic steatohepatitis 2 (2.5%). Thirty-eight (47.5%) were discharged, and 42 (52.5%) expired. The mean number of organ dysfunction (NOD-ACLF score) was ->4.5, simple organ failure count (SOFC) score was >2.5, APASL ACLF Research Consortium score was >11.5, Model for End-Stage Liver Disease-Lactate (MELD-LA) score was >21.5, and presence of cardiovascular and respiratory dysfunctions were significantly associated with mortality. NOD-ACLF and SOFC scores had the highest area under the receiver operating characteristic to predict mortality among all these. Conclusion: The NOD-ACLF score is easy to calculate bedside and is a good predictor of mortality in ACLF patients performing similar or better to other scores.

Metal doped nanosized titania used for the photocatalytic degradation of rhodamine B dye under visible-light.

Metal-doped anatase nanosized titania photocatalysts were successfully synthesized using a sol-gel process. Different amounts of the dopants (0.2, 0.4, 0.6, 0.8 and 1.0%) of the metals (Ag, Ni, Co and Pd) were utilized. The UV-Vis spectra (solid state diffuse reflectance spectra) of the doped nanoparticles exhibited a red shift in the absorption edge as a result of metal doping. The metal-doped nanoparticles were investigated for their photocatalytic activity under visible-light irradiation using Rhodamine B (Rh B) as a control pollutant. The results obtained indicate that the metal-doped titania had the highest activity at 0.4% metal loading. The kinetic models revealed that the photodegradation of Rh B followed a pseudo first order reaction. From ion chromatography (IC) analysis the degradation by-products Rhodamine B fragments were found to be acetate, chloride, nitrite, carbonate and nitrate ions.

Neurosarcoidosis Presenting as Normal Pressure Hydrocephalus in a Patient with Pulmonary Sarcoidosis.

A gentleman in his early 50's with past medical history significant for biopsy confirmed pulmonary sarcoidosis presented with acute onset confusion, gait disturbance and bowel/urinary incontinence. Brain imaging was consistent with normal pressure hydrocephalus and CSF studies supported the suspicion of neurosarcoidosis. He received treatment with a prolonged course of steroids with good effect. We discuss a rare case of normal pressure hydrocephalus as a presenting feature of neurosarcoidosis and the rationale of starting empiric treatment for probable diagnosis of the same.

Fluorescence sensing and adsorption kinetics of Gd-doped AgInS2 I-III-VI quantum dots - A case study of Ag+ ions interactions.

The poor fluorescence properties of magneto-fluorescent paramagnetic-ion (Gd, Mn, or Co) doped I-III-VI quantum dots (QDs) at higher paramagnetic-ion doping concentrations have limited their use in magnetic-driven water-based applications. This work presents, for the first time, the use of stable magneto-fluorescent Gd-doped AgInS2 QDs at high Gd mole ratios of 16, 20, and 30 for the fluorescence detection and adsorption of Ag+ ions in water environments. The effect of pH, initial concentration, contact time, and adsorbent dosage were systematically evaluated. The AgInS2 QDs with the least Gd mole ratio (16) exhibited the best fluorescence characteristics (LOD = 0.88, R2 = 0.9549) while all materials showed good adsorption properties under optimized conditions (pH of 2, initial concentration of 30 ppm, contact time of 10 min and adsorbent dosage of 0.02 g) and a pseudo 2nd order reaction was followed. The adsorption mechanism was proposed to be a combination of ion-exchange, electrostatic interaction, complexation, and diffusion processes. Application in environmental wastewater samples revealed complete removal of Ag + ions alongside Ti2+ Pb2+, Ni2+, Cr3+, and Zn2+ ions.

Takotsubo cardiomyopathy following envenomation: An updated review.

BACKGROUND: Takotsubo cardiomyopathy (TTC) can be diagnosed in patients presenting with clinical features of acute coronary syndrome (ACS) by using Mayo clinic criteria. Multiple precipitators have been attributed to causing TTC. Rarely it has been reported to occur following an acute envenomation. AIM: This review describes the various patterns, mechanisms, and outcomes of envenomation induced TTC. METHODS: In this review, we included all studies on "TTC" and "envenomation "published in the various databases before June 2022. To be included in the review articles had to have a distinct diagnosis of TTC and an envenomation. RESULTS: A total of 20 patients with envenomation induced TTC were identified. Most episodes of envenomation induced TTC were reported following a bee sting, scorpion sting, and snake envenomation. Fear and anxiety related to the sting, direct catecholamine toxicity and administration of exogenous beta-adrenergic agents have been commonly postulated to precipitate TTC in these patients. 95% of these patients presented with a clinical picture of ACS. Most of these patients also fulfill at least 3 out of 4 criteria of Mayo clinic criteria for TTC. Echocardiographic evidence of Apical TTC was noted in 72% of patients. 94% of these patients had clinical improvement following optimal management and 35% of these patients were treated with guideline directed medications for heart failure. CONCLUSION: Envenomation following multiple insect stings and reptile bites can precipitate TTC. Most reported envenomation related TTC has been due to bee stings and scorpion bites. Common mechanisms causing TTC were fear, anxiety, and stress of envenomation. Most of these patients present with clinical presentation of ACS, ST elevation, and elevated troponin. The most common type of TTC in these patients is Apical, which improved following medical management.

Cardiovascular complications following medical termination of pregnancy: An updated review.

BACKGROUND: Around 1 million cases of medical termination of pregnancy (MTP) take place yearly in the United States of America with around 2 percent of this population developing complications. The cardiovascular (CVD) complications occurring post MTP or after stillbirth is not very well described. AIM: To help the reader better understand, prepare, and manage these complications by reviewing various cardiac comorbidities seen after MTP. METHODS: We performed a literature search in PubMed, Medline, RCA, and google scholar, using the search terms "abortions" or "medical/legal termination of pregnancy" and "cardiac complications" or "cardiovascular complications". RESULTS: The most common complications described in the literature following MTP were infective endocarditis (IE) (n = 16), takotsubo cardiomyopathy (TTC) (n = 7), arrhythmias (n = 5), and sudden coronary artery dissection (SCAD) (n = 4). The most common valve involved in IE was the tricuspid valve in 69% (n = 10). The most observed causative organism was group B Streptococcus in 81% (n = 12). The most common type of TTC was apical type in 57% (n = 4). Out of five patients developing arrhythmia, bradycardia was the most common and was seen in 60% (3/5) of the patients. All four cases of SCAD-P type presented as acute coronary syndrome 10-14 d post termination of pregnancy with predominant involvement of the right coronary artery. Mortality was only reported following IE in 6.25%. Clinical recovery was reported consistently after optimal medical management following all these complications. CONCLUSION: In conclusion, the occurrence of CVD complications following pregnancy termination is infrequently documented in the existing literature. In this review, the most common CVD complication following MTP was noted to be IE and TTC.

Dilated Cardiomyopathy: Beware of Diet Drugs Slimming the Heart.

There have been rare reports of dilated cardiomyopathy from chronic use of phentermine/topiramate, although very limited data are available. Phentermine is an atypical amphetamine analog that has been contraindicated in patients with a history of cardiovascular disease. We present a case of nonischemic dilated cardiomyopathy in the setting of chronic phentermine/topiramate use, which is the most likely cause of her dilated cardiomyopathy.

Yamaguchi syndrome - An updated review article of electrocardiographic and echocardiographic findings.

Apical hypertrophic cardiomyopathy (ApHCM) is thought to be an uncommon variant of hypertrophic cardiomyopathy (HCM). This article is a literature review focusing on the characteristic electrocardiogram (EKG) and 2D echocardiogram findings as currently there are no specific ACC/AHA/ESC guidelines set as diagnostic criteria for ApHCM.