586 research outputs found
Pressure dependence of upper critical fields in FeSe single crystals
We investigate the pressure dependence of the upper critical fields
({\mu}) for FeSe single crystals with pressure up to 2.57 GPa.
The superconducting (SC) properties show a disparate behavior across a critical
pressure where the pressure-induced antiferromagnetic phase coexists with
superconductivity. The magnetoresistance for and is very
different: for , magnetic field induces and enhances a hump in the
resistivity close to the for pressures higher than 1.2 GPa, while it is
absent for . Since the measured {\mu} for FeSe samples is
smaller than the orbital limited upper critical field ()
estimated by the Werthamer Helfand and Hohenberg (WHH) model, the Maki
parameter ({\alpha}) related to Pauli spin-paramagnetic effects is additionally
considered to describe the temperature dependence of {\mu}().
Interestingly, the {\alpha} value is hardly affected by pressure for ,
while it strongly increases with pressure for . The pressure evolution of
the {\mu}(0)s for the FeSe single crystals is found to be almost
similar to that of (), suggesting that the pressure-induced magnetic
order adversely affects the upper critical fields as well as the SC transition
temperature.Comment: 23 pages, 6 figures, 1 tabl
Immunoglobulin G Subclass Deficiency is the Major Phenotype of Primary Immunodeficiency in a Korean Adult Cohort
Primary immunodeficiency disease (PID) is a rare disorder in adults. Most often, serious forms are detected during infancy or childhood. However, mild forms of PID may not be diagnosed until later in life, and some types of humoral immunodeficiency may occur in adulthood. The purpose of this study was to identify clinical features of PID in Korean adults. A retrospective study was performed on 55 adult patients who were diagnosed as PID between January 1998 and January 2009 at a single tertiary medical center in Korea. IgG subclass deficiency was the most common phenotype (67%, 37/55), followed by total IgG deficiency (20%, 11/55), IgM deficiency (7%, 4/55), common variable immunodeficiency (2%, 1/55), and X-linked agammaglobulinemia (2%, 1/55). IgG3 and IgG4 were the most affected subclasses. Upper and lower respiratory tract infections (76%) were the most frequently observed symptoms, followed by multiple site infection (11%), urinary tract infection, and colitis. Bronchial asthma, rhinitis, and several autoimmune diseases were common associated diseases. IgG and IgG subclass deficiency should be considered in adult patients presenting with recurrent upper and lower respiratory infections, particularly in those with respiratory allergies or autoimmune diseases
Enhanced critical current density in the pressure-induced magnetic state of the high-temperature superconductor FeSe
We investigate the relation of the critical current density (Jc) and the
remarkably increased superconducting transition temperature (Tc) for the FeSe
single crystals under pressures up to 2.43 GPa, where the Tc is increased by ~8
K/GPa. The critical current density corresponding to the free flux flow is
monotonically enhanced by pressure which is due to the increase in Tc, whereas
the depinning critical current density at which the vortex starts to move is
more influenced by the pressure-induced magnetic state compared to the increase
of Tc. Unlike other high-Tc superconductors, FeSe is not magnetic, but
superconducting at ambient pressure. Above a critical pressure where magnetic
state is induced and coexists with superconductivity, the depinning Jc abruptly
increases even though the increase of the zero-resistivity Tc is negligible,
directly indicating that the flux pinning property compared to the Tc
enhancement is a more crucial factor for an achievement of a large Jc. In
addition, the sharp increase in Jc in the coexisting superconducting phase of
FeSe demonstrates that vortices can be effectively trapped by the competing
antiferromagnetic order, even though its antagonistic nature against
superconductivity is well documented. These results provide new guidance toward
technological applications of high-temperature superconductors.Comment: 24pages, 8 figure
Acute urticaria caused by the injection of goat-derived hyaluronidase
Hyaluronidase is a goat testicular protein that hydrolyzes hyaluronic acid, a structural component of the intercellular matrix. It is commonly used as a spreading factor to improve the diffusion of drugs, including local anesthetics and chemotherapeutics. We experienced a 55-yr-old female with generalized urticaria that developed within 1 hr after the epidural injection of hyaluronidase. She had a history of allergic rhinitis, and had suffered from post-herpetic neuralgia and a herniated disc for several years. To relieve her pain, she had been given epidural injections consisting of mepivacaine hydrochloride, triamcinolone acetonide, and morphine sulfate biweekly for one year. Hyaluronidase had been administered several times with these drugs before this episode of generalized urticaria. Skin prick testing showed a positive response to 1,500 IU/mL of hyaluronidase extract, as compared to histamine. The patient's serum hyaluronidase-specific IgE level, determined using an enzyme-linked immunosorbent assay (ELISA), was markedly elevated, as compared to unexposed healthy controls. An IgE immunoblot analysis using hyaluronidase extract and the patient's serum showed IgE binding components at 31 and 21 kDa, whereas no corresponding IgE binding component was found in healthy controls. An ELISA inhibition test showed significant, dose-dependent inhibition with the serial addition of hyaluronidase extract. This is the first case of an IgE-medicated allergic reaction to goat (Naemorhedus goral raddenus) hyaluronidase, demonstrated by skin testing and a specific IgE and immunoblot assay
Unilateral Pulmonary Edema: A Rare Initial Presentation of Cardiogenic Shock due to Acute Myocardial Infarction
Cardiogenic unilateral pulmonary edema (UPE) is a rare clinical entity that is often misdiagnosed at first. Most cases of cardiogenic UPE occur in the right upper lobe and are caused by severe mitral regurgitation (MR). We present an unusual case of right-sided UPE in a patient with cardiogenic shock due to acute myocardial infarction (AMI) without severe MR. The patient was successfully treated by percutaneous coronary intervention and medical therapy for heart failure. Follow-up chest Radiography showed complete resolution of the UPE. This case reminds us that AMI can present as UPE even in patients without severe MR or any preexisting pulmonary disease affecting the vasculature or parenchyma of the lung
Occupational asthma caused by inhalation of bovine serum albumin powder
Bovine serum albumin (BSA), which is present in bovine plasma, is one of the major allergens affecting patients with food allergies induced by milk and meat. It is also commonly used in research laboratories. Although some reports have documented food allergies associated with BSA, BSA-induced occupational asthma has not been reported. We report a case of occupational asthma and rhinitis in a laboratory worker caused by the inhalation of BSA powder, in which an IgE-mediated response was suggested as the pathogenic mechanism
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