SCC characterization of AL-Li-Cu-x Alloys

In the past several decades many Al-Li-X alloys have been studied to understand the fracture properties due to its superior specific strength and modulus over the currently dominated 2024 & 7075 type aircraft structural alloys. It is also observed that their stress corrosion resistance is also good in the peak aged condition depending on the (Li/Cu) ratio. To understand its behavior with respect to its heat treatment, a systematic collection of data is required from the published literature. We have collected such systematic data for three alloys from the early 1980’s on Al-3Li, Al-2Li-3Cu and Al-1.5Li-4.5Cu, all with 0.12Zr to keep the grain structure predominantly un-recrystalized. Such alloys were tested in the S-T direction in 3.5%NaCl solution to obtain the plateau velocities (da/dt) and threshold KIscc. It is observed that in all the alloys, (da/dt) decreased with aging heat treatment time, the decrease increased with (Li/Cu) ratio. This decrease is interpreted in terms of the degree of anodic dissolution of the grain boundary precipitates. The results are compared with theSCCbehavior of 7050 and 2024 alloys. Additional data where reversion aging treatment was given shows that grain boundary precipitates play an important role in theSCCbehavior. The overall trend in theSCCbehavior is discussed in light of the current understanding of the aluminum alloy behavior in terms of anodic dissolution and the role of hydrogen

Scrub Typhus and Myocarditis: A Rare Complication

Scrub typhus, also called bush typhus, is a zoonotic disease a Gram-negative bacterium. Its presentation may range from nonspecific febrile illness to severe disease, with cardiovascular, renal, hepatic and neurological involvement. Myocarditis is one of the rare complications of scrub typhus. Hence, we are reporting a case of a 50-year-old male, farmer by occupation, presenting to us in multiorgan dysfunction syndrome who developed myocarditis during second week of his illness

Free volume study of poly(chlorotrifluoroethylene) using positron annihilation spectroscopy as a microanalytical tool

Positron lifetimes and X-ray diffraction measurements were carried out on poly(chlorotrifluoroethylene) films annealed between 25 and 215 degrees C. The positron lifetime results were used to determine the free volume and XRD data were used to determine the apparent crystallite size and crystallinity. The glass transition temperature (T-g) of 52 degrees C obtained from positron results is in agreement with that obtained by thermal analysis. The average free volume cell size is 74 Angstrom(3) in films annealed below T-g, and increases to 84 Angstrom(3) in samples annealed above T-g. Although the observed changes in positron lifetime parameters as a function of annealing temperature are small, they are significant for the kind of material investigated. Our observations are explained in terms of thermally activated chain mobility, local relaxations and long-range motions. We further estimate, for the first time, the activation energies in the amorphous and crystalline regions of the polymer using the Goldanskii kinetic relations. Copyright (C) 1996 Elsevier Science Ltd

A Study of Erectile Dysfunction in Male Diabetes Patients and its Correlation with Platelet-Lymphocyte Ratio

Introduction: Erectile dysfunction (ED) constitutes a large burden on society given its high prevalence and impact on quality of life. Diabetes is a common cause of organic ED. Prevalence of ED in diabetes ranges from 35% to 85% depending on the study, versus 26% in general population. Platelet-lymphocyte ratio (PLR) has been detected as an important marker for inflammation. Some studies have identified its role in ED but more research is needed. Material and methods: It was a hospital-based prospective observational study. According to International Index of Erectile Function (IIEF)-5 questionnaire, patients were divided into 4 categories: mild ED with score 17 to 21, mild-to-moderate ED with score 12 to 16, moderate ED with score 8 to 11 and severe ED with score 1 to 7. Presence of ED and its severity was correlated with age, residence, duration of diabetes, glycemic status, lipid profile, PLR, complications, body mass index (BMI), etc. Results: Prevalence of ED in male diabetes patients was found to be 72.4%. Among 110 cases with ED, 8 had mild ED (7.2%), 27 had mild-to-moderate (24.5%), 27 had moderate ED (24.5%) and 48 had severe ED (43.6%). Prevalence of ED was found to be proportional to age. Majority of cases in ED group were those with long-standing diabetes. Correlation of ED with complication of diabetes, like nephropathy and retinopathy, was significant, whereas it was not significant with neuropathy. Significant correlation of ED was found with BMI and PLR. Conclusion: ED prevalence was high among the diabetes patients and it increased with age and duration of the disease. Presence of diabetic complications was significantly associated with ED. BMI was significantly associated with development of ED. PLR was significantly higher in ED group and closely related to severity of ED

Seizure Detection, Seizure Prediction, and Closed-Loop Warning Systems in Epilepsy

Nearly one-third of patients with epilepsy continue to have seizures despite optimal medication management. Systems employed to detect seizures may have the potential to improve outcomes in these patients by allowing more tailored therapies and might, additionally, have a role in accident and SUDEP prevention. Automated seizure detection and prediction require algorithms which employ feature computation and subsequent classification. Over the last few decades, methods have been developed to detect seizures utilizing scalp and intracranial EEG, electrocardiography, accelerometry and motion sensors, electrodermal activity, and audio/video captures. To date, it is unclear which combination of detection technologies yields the best results, and approaches may ultimately need to be individualized. This review presents an overview of seizure detection and related prediction methods and discusses their potential uses in closed-loop warning systems in epilepsy

Predicting Hemolytic Uremic Syndrome and Renal Replacement Therapy in Shiga Toxin-producing Escherichia coli-infected Children.

BACKGROUND: Shiga toxin-producing Escherichia coli (STEC) infections are leading causes of pediatric acute renal failure. Identifying hemolytic uremic syndrome (HUS) risk factors is needed to guide care. METHODS: We conducted a multicenter, historical cohort study to identify features associated with development of HUS (primary outcome) and need for renal replacement therapy (RRT) (secondary outcome) in STEC-infected children without HUS at initial presentation. Children agedeligible. RESULTS: Of 927 STEC-infected children, 41 (4.4%) had HUS at presentation; of the remaining 886, 126 (14.2%) developed HUS. Predictors (all shown as odds ratio [OR] with 95% confidence interval [CI]) of HUS included younger age (0.77 [.69-.85] per year), leukocyte count ≥13.0 × 103/μL (2.54 [1.42-4.54]), higher hematocrit (1.83 [1.21-2.77] per 5% increase) and serum creatinine (10.82 [1.49-78.69] per 1 mg/dL increase), platelet count \u3c250 \u3e× 103/μL (1.92 [1.02-3.60]), lower serum sodium (1.12 [1.02-1.23 per 1 mmol/L decrease), and intravenous fluid administration initiated ≥4 days following diarrhea onset (2.50 [1.14-5.46]). A longer interval from diarrhea onset to index visit was associated with reduced HUS risk (OR, 0.70 [95% CI, .54-.90]). RRT predictors (all shown as OR [95% CI]) included female sex (2.27 [1.14-4.50]), younger age (0.83 [.74-.92] per year), lower serum sodium (1.15 [1.04-1.27] per mmol/L decrease), higher leukocyte count ≥13.0 × 103/μL (2.35 [1.17-4.72]) and creatinine (7.75 [1.20-50.16] per 1 mg/dL increase) concentrations, and initial intravenous fluid administration ≥4 days following diarrhea onset (2.71 [1.18-6.21]). CONCLUSIONS: The complex nature of STEC infection renders predicting its course a challenge. Risk factors we identified highlight the importance of avoiding dehydration and performing close clinical and laboratory monitoring

Three-Dimensional Structure of N-Terminal Domain of DnaB Helicase and Helicase-Primase Interactions in Helicobacter pylori

Replication initiation is a crucial step in genome duplication and homohexameric DnaB helicase plays a central role in the replication initiation process by unwinding the duplex DNA and interacting with several other proteins during the process of replication. N-terminal domain of DnaB is critical for helicase activity and for DnaG primase interactions. We present here the crystal structure of the N-terminal domain (NTD) of H. pylori DnaB (HpDnaB) helicase at 2.2 Å resolution and compare the structural differences among helicases and correlate with the functional differences. The structural details of NTD suggest that the linker region between NTD and C-terminal helicase domain plays a vital role in accurate assembly of NTD dimers. The sequence analysis of the linker regions from several helicases reveals that they should form four helix bundles. We also report the characterization of H. pylori DnaG primase and study the helicase-primase interactions, where HpDnaG primase stimulates DNA unwinding activity of HpDnaB suggesting presence of helicase-primase cohort at the replication fork. The protein-protein interaction study of C-terminal domain of primase and different deletion constructs of helicase suggests that linker is essential for proper conformation of NTD to interact strongly with HpDnaG. The surface charge distribution on the primase binding surface of NTDs of various helicases suggests that DnaB-DnaG interaction and stability of the complex is most probably charge dependent. Structure of the linker and helicase-primase interactions indicate that HpDnaB differs greatly from E.coli DnaB despite both belong to gram negative bacteria