Rapid Detection of Staphylococcus aureus Using Graphene Oxide Coated Screen-Printed Sensor Strips

340–343Staphylococcus aureus (S. aureus) is the most common reason behind bacterial infections in humans. They cause a wide array of infections on skin, bone and joint medical implants and blood stream. In order to mitigate these infections, detecting the presence of this bacterium is of prime importance. This paper explores a new rapid detection technique to identify S aureus bacteria. A screen-printed sensor coated with graphene oxide was used as an identification platform. Graphene oxide was synthesized using modified Hummer’s method and was characterized using X-ray Diffractometer and Scanning Electron Microscope. The developed sensors showed significant decrease in the bulk resistance with the increase in bacterial concentrations. The developed sensors were subjected to selectivity, repeatability and reusability tests and showed good results

Rapid Detection of Staphylococcus aureus Using Graphene Oxide Coated Screen-Printed Sensor Strips

Staphylococcus aureus (S. aureus) is the most common reason behind bacterial infections in humans. They cause a wide array of infections on skin, bone and joint medical implants and blood stream. In order to mitigate these infections, detecting the presence of this bacterium is of prime importance. This paper explores a new rapid detection technique to identify S aureus bacteria. A screen-printed sensor coated with graphene oxide was used as an identification platform. Graphene oxide was synthesized using modified Hummer’s method and was characterized using X-ray Diffractometer and Scanning Electron Microscope. The developed sensors showed significant decrease in the bulk resistance with the increase in bacterial concentrations. The developed sensors were subjected to selectivity, repeatability and reusability tests and showed good results

Clinical spectrum of stiff person syndrome associated with glutamic acid decarboxylase antibodies

Objective: The aim of this study was to examine the clinical characteristics and associated diagnosis of the SPS. Background: Stiff person syndrome (SPS) is an immune-mediated neurological disorder that can cause rigidity of the axial and limb muscles. About 80% of patient with SPS have had high-titer antibodies against glutamic acid decarboxylase (GAD), and 15% have antibodies to glycine receptors. Design/Methods: Retrospective chart review of patients with SPS and positive GAD antibody who were seen over 5 years was performed. Demographics, detailed clinical information, and diagnostic data were recorded. Coexisting autoimmune diseases and serologies were reviewed. Results: Nine patients were included in this study, 7 women and 2 men. The median age at symptom onset was 47 years. Six patients had positive Gad antibody and 3 were negative. Primary diagnosis was stiff person syndrome (n=4), cerebellar ataxia (n=2), PERM (n=2) and sensory neuropathy/neuronopathy (n=1). Commonly associated antibodies were islet cell antibody and neuronal voltage-gated potassium channel. Type 1 diabetes, seizures, and thyroid disease were commonly associated with the diagnosis. Three patients had an EMG finding suggestive of SPS and two of these patients had negative GAD antibody. Conclusions: Women are commonly affected by the disease. There is a phenotypic variation of the disease as previously reported in the literature. EMG is helpful in the diagnosis of negative GAD antibody patients where clinical suspicion for SPS is high

Ustekinumab related CIDP in a patient with psoriatic arthritis

Objective: To describe a case of ustekinumab related CIDP. Background: Ustekinumab is an IL- 12/23 monoclonal antibody recently approved for psoriatic arthritis, plaque psoriasis and Crohn\u27s disease. There are several reports of association between anti-TNF-alpha antagonists and a variety of cases of PNS demyelination. However, none have been yet documented with ustekinumab. Design/Methods: Case report. Results: A 52 year-old man with history of psoriatic arthritis presented with subacute onset of ascending quadriparesis and paresthesias of the arms and legs two weeks after starting ustekinumab, rendering him nonambulatory without assistance. Examination showed moderate quadriparesis, diffuse areflexia, and decreased pinprick in the arms and legs. CSF showed albuminocytologic dissociation and was otherwise unremarkable. EMG showed evidence for non-length dependent diffuse demyelinating sensorimotor neuropathy of the arms and legs. Workup including ANA, RF, cryoglobulin, DNA, SSA, SSB, cANCA, pANCA, Scl-70, HIV, GM1 Ab, thiamine, B6, vitamin B12, hepatitis B/C, TSH, complement, C. jejuni, porphyrin, Lyme Ab, vitamin E, and copper was negative or normal. Patient received 5 PLEX sessions with dramatic improvement in strength with residual numbness of lower extremities. Nine days later he had recurrence of ascending weakness with numbness to the point that he could not ambulate without a walker. Repeat EMG was consistent with diagnosis of CIDP. He received 5 additional PLEX sessions with improvement of his symptoms except for residual numbness of his hands and legs. He continued outpatient PLEX weekly then every 2 weeks after which he had another relapse with similar presentation of marked weakness. He remained PLEX dependent for 6 months after onset of symptoms and was gradually weaned off. He has remained minimally symptomatic with normal strength, mild recrudescence of reflexes and stable residual numbness on mycophenolate monotherapy. Conclusions: This is the first known case report of ustekinumab related CIDP. More research is needed to establish a causal relationship

Using local GND density to study SCC initiation

Strain and geometric necessary dislocations (GNDs) have been mapped with nm-resolution around grain boundaries affected by stress corrosion cracking (SCC) or intergranular oxidation with the aim of clarifying which local conditions that trigger SCC initiation of Alloy 600 in primary water reactor (PWR) water environment. Regions studied included the cracked and uncracked portion of the same SCC-affected grain boundaries and a comparable grain boundary in the as-received condition. High-resolution “on-axis” Transmission Kikuchi Diffraction (TKD) was used to generate strain and GND density based on the cross-correlation image processing method to probe shifts of specific zone axis in the TKD patterns from all regions. All cracked boundaries analyzed had local GND densities higher than 1 × 1016 m-2. Similar grain boundaries, from as-received samples had GNDs of 5 × 1014 m-2, while an intermediate level was found in the oxidized but uncracked portion of the same GB. Results, together with a discussion on the advantages and limitations of the approach, will be presented

Using local GND density to study SCC initiation

In this work, strain and geometric necessary dislocations (GNDs) have been mapped with nm-resolution around grain boundaries affected by stress corrosion cracking (SCC) or intergranular oxidation with the aim of clarifying which local conditions trigger SCC initiation.Comment: 36 pages, 19 figure