5,328 research outputs found
A CACNA1D mutation in a patient with persistent hyperinsulinaemic hypoglycaemia, heart defects, and severe hypotonia.
Congenital hyperinsulinaemic hypoglycaemia (HH) can occur in isolation or it may present as part of a wider syndrome. For approximately 40%-50% of individuals with this condition, sequence analysis of the known HH genes identifies a causative mutation. Identifying the underlying genetic aetiology in the remaining cases is important as a genetic diagnosis will inform on recurrence risk, may guide medical management and will provide valuable insights into β-cell physiology. We sequenced the exome of a child with persistent diazoxide-responsive HH, mild aortic insufficiency, severe hypotonia, and developmental delay as well as the unaffected parents. This analysis identified a de novo mutation, p.G403D, in the proband's CACNA1D gene. CACNA1D encodes the main L-type voltage-gated calcium channel in the pancreatic β-cell, a key component of the insulin secretion pathway. The p.G403D mutation had been reported previously as an activating mutation in an individual with primary hyper-aldosteronism, neuromuscular abnormalities, and transient hypoglycaemia. Sequence analysis of the CACNA1D gene in 60 further cases with HH did not identify a pathogenic mutation. Identification of an activating CACNA1D mutation in a second patient with congenital HH confirms the aetiological role of CACNA1D mutations in this disorder. A genetic diagnosis is important as treatment with a calcium channel blocker may be an option for the medical management of this patient
A case of malignant hyperthermia during anesthesia induction with sevoflurane -A case report-
We experienced a case of malignant hyperthermia (MH) in 6-year-old boy during anesthesia induction for strabismus surgery. It has been generally reported that sevoflurane can induce the delayed onset of MH in the absence of succinylcholine. Our case of MH was elicited after about 2-3 min of sevoflurane administration with N2O, O2 and rocuronium. However, we successfully treated the patient by early recognition of his condition and administering symptomatic treatment and dantrolene
Milling plant and soil material in plastic tubes over-estimates carbon and under-estimates nitrogen concentrations
Peer reviewedPostprin
A Multi-factor Authentication Method for Security of Online Examinations
Security of online examinations is the key to success of remote online learning. However, it faces many conventional and non-conventional security threats. Impersonation and abetting are rising non-conventional security threats, when a student invites a third party to impersonate or abet in a remote exam. This work proposed dynamic profile questions authentication to identify that the person taking an online test is the same who completed the course work. This is combined with remote proctoring to prevent students from taking help from a third party during exam. This research simulated impersonation and abetting attacks in remote online course and laboratory based control simulation to analyse the impact of dynamic profile questions and proctoring. The study also evaluated effectiveness of the proposed method. The findings indicate that dynamic profile questions are highly effective. The security analysis shows that impersonation attack was not successful
Thermal conductivity measurement of liquids in a microfluidic device
A new microfluidic-based approach to measuring liquid thermal conductivity is developed to address the requirement in many practical applications for measurements using small (microlitre) sample size and integration into a compact device. The approach also gives the possibility of high-throughput testing. A resistance heater and temperature sensor are incorporated into a glass microfluidic chip to allow transmission and detection of a planar thermal wave crossing a thin layer of the sample. The device is designed so that heat transfer is locally one-dimensional during a short initial time period. This allows the detected temperature transient to be separated into two distinct components: a short-time, purely one-dimensional part from which sample thermal conductivity can be determined and a remaining long-time part containing the effects of three-dimensionality and of the finite size of surrounding thermal reservoirs. Identification of the one-dimensional component yields a steady temperature difference from which sample thermal conductivity can be determined. Calibration is required to give correct representation of changing heater resistance, system layer thicknesses and solid material thermal conductivities with temperature. In this preliminary study, methanol/water mixtures are measured at atmospheric pressure over the temperature range 30–50°C. The results show that the device has produced a measurement accuracy of within 2.5% over the range of thermal conductivity and temperature of the tests. A relation between measurement uncertainty and the geometric and thermal properties of the system is derived and this is used to identify ways that error could be further reduced
Nitrogen and phosphorus availability interact to modulate leaf trait scaling relationships across six plant functional types in a controlled-environment study
Nitrogen (N) and phosphorus (P) have key roles in leaf metabolism, resulting in a strong coupling of chemical composition traits to metabolic rates in field-based studies. However, in such studies, it is difficult to disentangle the effects of nutrient supply per se on trait-trait relationships. Our study assessed how high and low N (5 mM and 0.4 mM, respectively) and P (1 mM and 2 μM, respectively) supply in 37 species from six plant functional types (PTFs) affected photosynthesis (A) and respiration (R) (in darkness and light) in a controlled environment. Low P supply increased scaling exponents (slopes) of area-based log-log A-N or R-N relationships when N supply was not limiting, whereas there was no P effect under low N supply. By contrast, scaling exponents of A-P and R-P relationships were altered by P and N supply. Neither R : A nor light inhibition of leaf R was affected by nutrient supply. Light inhibition was 26% across nutrient treatments; herbaceous species exhibited a lower degree of light inhibition than woody species. Because N and P supply modulates leaf trait-trait relationships, the next generation of terrestrial biosphere models may need to consider how limitations in N and P availability affect trait-trait relationships when predicting carbon exchange
A Case of Intramuscular Hemangioma Presenting with Large-angle Hypertropia
Purpose: To report the case of a patient with large-angle hypertropia of an intramuscular hemangioma of the right superior rectus muscle (SR). Methods: A 63-year-old man with progressive vertical deviation of the right eye for the past 6 months visited our strabismus department; his condition was not painful. An examination indicated that he had 60PD of right hypertropia at distance and near in primary gaze. Additionally, a significant limitation of his downgaze was noted. The right eye appeared mildly proptotic, and the upper and lower eyelids were slightly edematous. Corrected vision was 20/20 in both eyes. Results: Orbital magnetic resonance imaging (MRI) studies revealed fusiform enlargement of the right superior rectus muscle, with prominent but irregular enhancement following gadolinium administration. Incisional biopsy revealed an intramuscular hemangioma in the superior rectus muscle with cavernous-type vessels. Conclusions: This case demonstrates that intramuscular hemangioma should be considered in the differ-ential diagnosis of isolated extraocular muscle enlargement and unusual strabismus. Korean Journal o
Computational and experimental investigation of the strain rate sensitivity of small punch testing of the high-entropy alloy CoCrFeMnNi
The suitability of determining the strain rate sensitivity (SRS) of the CoCrFeMnNi high-entropy alloy (HEA) by small punch (SP) testing has been assessed at displacement rates ranging from 0.2 to 2 mm∙min−1. The stress was found to increase as the displacement rate was raised from 0.2 to 2 mm∙min−1, whereas the plastic strain distributions were similar in all cases. However, for a higher displacement rate of 10 mm∙min−1, the sample was found to exhibit a drop in strength and ductility attributed to casting defects. The strain-rate sensitivity exponent (m) was found to be 0.1387 whilst the Finite Element Analysis (FEA) simulations predicted a slightly smaller value of 0.1313. This latter value is closer to m = 0.091 obtained from nanoindentation strain rate jump tests since the results are insensitive to the presence of small casting defects. The relationship between the experimental and the empirically derived predicted properties from the SP tests revealed a high level of agreement for maximum stress properties. The properties predicted at 2 mm∙min−1 (R2 = 0.96) offered a stronger fit than at 0.5 mm∙min−1 (R2 = 0.92)
Inflammatory cytokines and biofilm production sustain Staphylococcus aureus outgrowth and persistence: A pivotal interplay in the pathogenesis of Atopic Dermatitis
Individuals with Atopic dermatitis (AD) are highly susceptible to Staphylococcus aureus colonization. However, the mechanisms driving this process as well as the impact of S. aureus in AD pathogenesis are still incompletely understood. In this study, we analysed the role of biofilm in sustaining S. aureus chronic persistence and its impact on AD severity. Further we explored whether key inflammatory cytokines overexpressed in AD might provide a selective advantage to S. aureus. Results show that the strength of biofilm production by S. aureus correlated with the severity of the skin lesion, being significantly higher (P < 0.01) in patients with a more severe form of the disease as compared to those individuals with mild AD. Additionally, interleukin (IL)-β and interferon γ (IFN-γ), but not interleukin (IL)-6, induced a concentration-dependent increase of S. aureus growth. This effect was not observed with coagulase-negative staphylococci isolated from the skin of AD patients. These findings indicate that inflammatory cytokines such as IL1-β and IFN-γ, can selectively promote S. aureus outgrowth, thus subverting the composition of the healthy skin microbiome. Moreover, biofilm production by S. aureus plays a relevant role in further supporting chronic colonization and disease severity, while providing an increased tolerance to antimicrobials
Identifying metabolites by integrating metabolome databases with mass spectrometry cheminformatics.
Novel metabolites distinct from canonical pathways can be identified through the integration of three cheminformatics tools: BinVestigate, which queries the BinBase gas chromatography-mass spectrometry (GC-MS) metabolome database to match unknowns with biological metadata across over 110,000 samples; MS-DIAL 2.0, a software tool for chromatographic deconvolution of high-resolution GC-MS or liquid chromatography-mass spectrometry (LC-MS); and MS-FINDER 2.0, a structure-elucidation program that uses a combination of 14 metabolome databases in addition to an enzyme promiscuity library. We showcase our workflow by annotating N-methyl-uridine monophosphate (UMP), lysomonogalactosyl-monopalmitin, N-methylalanine, and two propofol derivatives
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