Ferromagnetically coupled single-chain magnets exhibiting a magnetic hysteresis of 0.42 Tesla in cyano-bridged FeIII2MII (M = Ni, Fe) coordination polymers.

The synthesis, single-crystal structures and magnetic properties of two new double-zigzag-chain cyano-bridged heterobimetallic {[MII(Py-NOH)2][FeIII(Tp*)(CN)3]2}·H2O ([FeIII2MII]) (Py-NOH = 4-pyridinealdoxime, Tp* = tris(3,5-dimethylpyrazol-1-yl)borohydride, M = Ni (1), Fe (2)) compounds are reported. The crystal structures of both compounds were determined by single-crystal X-ray diffraction. Complexes 1 and 2 are isostructural, with the crystal structure comprising neutral double-zigzag (4,2-ribbon-like) bimetallic chains. The FeIII ion is coordinated by three cyanide carbon atoms and three nitrogen atoms of Tp* anions. However, the MII ion is surrounded by four cyanide nitrogen atoms and two nitrogen atoms from two Py-NOH ligands. The crystal structures and magnetic studies demonstrate that both complexes behave as single-chain magnetics (SCMs) with intrachain ferromagnetic coupling. Furthermore, [FeIII2NiII] exhibits an excellent coercive field of 0.42 T at 1.8 K, among cyano-bridged 3d transition-metal-based SCMs reported thus far. Preliminary theoretical calculations provide a deep understanding of the magnetic properties of [FeIII2NiII].

Acquired Long QT Syndrome: Ventricular Fibrillation in an Otherwise Healthy Young Female.

Long QT syndrome (LQTS) occurs when there is an abnormality of myocardial repolarization characterized specifically by a prolonged QT interval on an electrocardiogram (ECG). This can be particularly dangerous as it is associated with an increased risk of polymorphic ventricular tachycardia and a life-threatening arrhythmia otherwise known as torsades de pointes (TdP). We present a case of a 40-year-old Indian female whose medical history was significant only for anemia and depression/anxiety that presented in a ventricular fibrillation cardiac arrest after becoming dyspneic and light-headed while dancing. Of relevance, she was taking sertraline 50mg once daily, a class of medications known to prolong the QT interval as well as having low serum calcium on presentation. Both her initial and subsequent electrocardiograms illuminated significantly prolonged QTc intervals. She subsequently sustained a ventricular tachycardia cardiac arrest, which degenerated into ventricular fibrillation in the cardiac intensive care unit two days later. Ultimately, the patient was pronounced brain-dead by the end of the week. We concluded this to be a case of LQTS predisposing to TdP, which then would degenerate into ventricular fibrillation. This case highlights multiple risk factors that are known to predispose to the aforementioned etiology. Further research is needed not only on common medications and their dose-dependent relationship on the QT interval across different ethnic groups but also on educating providers regarding multiple risk factors they may or may not have the power to control.

Simulation of Depth of Wear of Eco-Friendly Concrete Using Machine Learning Based Computational Approaches.

To avoid time-consuming, costly, and laborious experimental tests that require skilled personnel, an effort has been made to formulate the depth of wear of fly-ash concrete using a comparative study of machine learning techniques, namely random forest regression (RFR) and gene expression programming (GEP). A widespread database comprising 216 experimental records was constructed from available research. The database includes depth of wear as a response parameter and nine different explanatory variables, i.e., cement content, fly ash, water content, fine and coarse aggregate, plasticizer, air-entraining agent, age of concrete, and time of testing. The performance of the models was judged via statistical metrics. The GEP model gives better performance with R2 and ρ equals 0.9667 and 0.0501 respectively and meet with the external validation criterion suggested in the previous literature. The k-fold cross-validation also verifies the accurateness of the model by evaluating R2, RSE, MAE, and RMSE. The sensitivity analysis of GEP equation indicated that the time of testing is the influential parameter. The results of this research can help the designers, practitioners, and researchers to quickly estimate the depth of wear of fly-ash concrete thus shortening its ecological susceptibilities that push to sustainable and faster construction from the viewpoint of environmentally friendly waste management.

Frequency of osteoporosis in patients with cirrhosis due to hepatitis B and hepatitis C: a study of 100 cases.

BACKGROUND: Osteoporosis is the disease of bone that affected King David of Israel 3000 years ago. This condition is no longer considered to be due to aging alone and is increasingly recognised as a major health concern and accounts for about 1.5 million fractures annually in United States. Objective of this study was to see the frequency of osteoporosis in patients with cirrhosis due to Hepatitis B and C, and any correlation between the Bone Mineral Density (BMD) and duration and stage of the liver disease. METHODS: The study was conducted in the Department of Gastroenterology, Postgraduate Medical Institute, Hayatabad Medical Complex, Peshawar, from January 2008 to December 2008. All patients from the OPD or Ward fulfilling the criteria and consenting were included. Physical examination, with special emphasis on any signs of chronic liver disease was performed. Full blood count, platelet count, prothrombin time and INR, liver function tests including serum albumin, and renal function tests were done on all patients. Viral serology was checked for those patients who were either newly diagnosed as cirrhotic or were cirrhotic but not screened for viral markers. Abdominal sonogram was recorded on all patients. The Child's score was calculated for each patient using the clinical and lab parameters. The BMD was calculated for all patients using computer based ultrasound probe. Calcaneum was used for evaluation of BMD. The information collected was entered on structured data collection sheets and was analysed using SPSS version 11. RESULTS: Osteoporosis was found in 26% of subject and osteopenia in 42%, while 32% had BMD in the normal range. The mean T score was -1.483 (+/- 1.29). The mean duration of liver disease was 3.77 (+/- 1.56) year. Majority of the patients (81%) were in Child's Class C, followed by Class B and A (16% and 3% respectively). Fifty-nine percent of the patients were males with a mean age of 37.65 years, while 41% were females with mean age of 37.76 years. CONCLUSION: Osteoporosis is a common finding in patients with cirrhosis due to Hepatitis B and C. Osteoporosis is more frequent in patients with long duration of liver disease but there is no significant correlation between the aetiology or severity of liver disease and osteoporosis.

Calcium Channel Blockers and the Gastrointestinal Tract.

Calcium ions play an important role in the normal functioning of the gastrointestinal system. The calcium channel blockers appear to affect all the organs of the gastrointestinal tract and may have therapeutic efficacy on esophageal spasm, irritable bowel syndrome, mesenteric vascular insufficiency, dyskinesis of the Sphincter of Oddi, and insulinoma. Adverse effects are limited predominantly to constipation and some aggravation of ethanol-induced ulcer disease. In addition, the drugs continue to serve as important biologic probes for understanding the normal and abnormal functioning of the gastrointestinal tract.