3D Magneto-Hydrodynamic Simulations of Parker Instability with Cosmic Rays

This study investigates Parker instability in an interstellar medium (ISM) near the Galactic plane using three-dimensional magneto-hydrodynamic simulations. Parker instability arises from the presence of a magnetic field in a plasma, wherein the magnetic buoyant pressure expels the gas and cause the gas to move along the field lines. The process is thought to induce the formation of giant molecular clouds in the Galaxy. In this study, the effects of cosmic-ray (CR) diffusion are examined. The ISM at equilibrium is assumed to comprise a plasma fluid and a CR fluid at various temperatures, with a uniform magnetic field passing through it in the azimuthal direction of the Galactic disk. After a small perturbation, the unstable gas aggregates at the footpoint of the magnetic fields and forms dense blobs. The growth rate of the instability increases with the strength of the CR diffusion. The formation of dense clouds is enhanced by the effect of cosmic rays (CRs), whereas the shape of the clouds depends sensitively on the initial conditions of perturbation.Comment: 4 pages, Computer Physics Communications 2011, 182, p177-17

Is clopidogrel better than aspirin following breakthrough strokes while on aspirin? A retrospective cohort study.

ObjectiveThere is insufficient evidence on which to base a recommendation for optimal antiplatelet therapy following a stroke while on aspirin. The objective was to compare clopidogrel initiation vs aspirin reinitiation for vascular risk reduction among patients with ischaemic stroke on aspirin at the time of their index stroke.DesignRetrospective.SettingWe conducted a nationwide cohort study by retrieving all hospitalised patients (≥18 years) with a primary diagnosis of ischaemic stroke between 2003 and 2009 from Taiwan National Health Insurance Research Database.ParticipantsAmong 3862 patients receiving aspirin before the index ischaemic stroke and receiving either aspirin or clopidogrel after index stroke during follow-up period, 1623 were excluded due to a medication possession ratio <80%. Also, 355 were excluded due to history of atrial fibrillation, valvular heart disease or coagulopathy. Therefore, 1884 patients were included in our final analysis.InterventionsPatients were categorised into two groups based on whether clopidogrel or aspirin was prescribed during the follow-up period. Follow-up was from time of the index stroke to admission for recurrent stroke or myocardial infarction, death or the end of 2010.Primary and secondary outcome measuresThe primary end point was hospitalisation due to a new-onset major adverse cardiovascular event (MACE: composite of any stroke or myocardial infarction). The leading secondary end point was any recurrent stroke.ResultsCompared to aspirin, clopidogrel was associated with a lower occurrence of future MACE (HR=0.54, 95% CI 0.43 to 0.68, p<0.001, number needed to treat: 8) and recurrent stroke (HR=0.54, 95% CI 0.42 to 0.69, p<0.001, number needed to treat: 9) after adjustment of relevant covariates.ConclusionsAmong patients with an ischaemic stroke while taking aspirin, clopidogrel initiation was associated with fewer recurrent vascular events than aspirin reinitiation

Acute immune thrombocytopenic purpura in an adolescent with 2009 novel H1N1 influenza A virus infection

AbstractAlthough both leukopenia and thrombocytopenia are not uncommon hematological findings among patients with novel 2009 H1N1 influenza virus infection, immune thrombocytopenic purpura has rarely been shown to be associated with this novel influenza A infection. Here, we describe a previously healthy adolescent who presented with fever, influenza-like symptoms and acute onset of generalized petechiae and active oral mucosa bleeding on the third day of his illness. Severe leukopenia and thrombocytopenia were found. There was neither malignancy nor blast cells found by bone marrow aspiration. Real-time reverse transcriptase polymerase chain reaction was positive for novel 2009 H1N1 influenza infection. Novel influenza-associated atypical immune thrombocytopenic purpura was diagnosed. The patient recovered uneventfully after oseltamivir and methylprednisolone therapy

The genome sequence of Salmonella enterica serovar Choleraesuis, a highly invasive and resistant zoonotic pathogen

Salmonella enterica serovar Choleraesuis (S.Choleraesuis), a highly invasive serovar among non-typhoidal Salmonella, usually causes sepsis or extra-intestinal focal infections in humans. S.Choleraesuis infections have now become particularly difficult to treat because of the emergence of resistance to multiple antimicrobial agents. The 4.7 Mb genome sequence of a multidrug-resistant S.Choleraesuis strain SC-B67 was determined. Genome wide comparison of three sequenced Salmonella genomes revealed that more deletion events occurred in S.Choleraesuis SC-B67 and S.Typhi CT18 relative to S.Typhimurium LT2. S.Choleraesuis has 151 pseudogenes, which, among the three Salmonella genomes, include the highest percentage of pseudogenes arising from the genes involved in bacterial chemotaxis signal-transduction pathways. Mutations in these genes may increase smooth swimming of the bacteria, potentially allowing more effective interactions with and invasion of host cells to occur. A key regulatory gene of TetR/AcrR family, acrR, was inactivated through the introduction of an internal stop codon resulting in overexpression of AcrAB that appears to be associated with ciprofloxacin resistance. While lateral gene transfer providing basic functions to allow niche expansion in the host and environment is maintained during the evolution of different serovars of Salmonella, genes providing little overall selective benefit may be lost rapidly. Our findings suggest that the formation of pseudogenes may provide a simple evolutionary pathway that complements gene acquisition to enhance virulence and antimicrobial resistance in S.Choleraesuis

Inhibitory Effects of Ketamine on Lipopolysaccharide-Induced Microglial Activation

Microglia activated in response to brain injury release neurotoxic factors including nitric oxide (NO) and proinflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). Ketamine, an anesthetic induction agent, is generally reserved for use in patients with severe hypotension or respiratory depression. In this study, we found that ketamine (100 and 250 μM) concentration-dependently inhibited lipopolysaccharide (LPS)-induced NO and IL-1β release in primary cultured microglia. However, ketamine (100 and 250 μM) did not significantly inhibit the LPS-induced TNF-α production in microglia, except at the higher concentration (500 μM). Further study of the molecular mechanisms revealed that ketamine markedly inhibited extracellular signal-regulated kinase (ERK1/2) phosphorylation but not c-Jun N-terminal kinase or p38 mitogen-activated protein kinase stimulated by LPS in microglia. These results suggest that microglial inactivation by ketamine is at least partially due to inhibition of ERK1/2 phosphorylation

Polythiophenes comprising conjugated pendantstoward long-term air-stable inverted polymer solar cellswith high open circuit voltages

A series of polythiophenes (PTs) functionalized with bulky conjugated side chains comprising tert-butylsubstituted carbazole (tCz) as an electron donor pendant and bisbenzothiazolylvinyl (DBT) as anelectron acceptor pendant were synthesized via Stille copolymerization for polymer solar cell (PSC)applications. We use the descriptors PTtCz, PT(tCz)0.9(DBT)0.1, PT(tCz)0.64(DBT)0.36, PT(tCz)0.45(DBT)0.55,and PTDBT to identify each of these conjugated polymers, with the names denoting the compositionsof the bulky pendants. The tunable energy levels of the PTs were accomplished by incorporating bothtCz as a donor pendant and DBT as an acceptor pendant, while retaining the low-lying HOMO levels( 5.26 to 5.39 eV). Furthermore, lower bandgaps were observed for the DBT-derived PTs because ofstronger donor–p–acceptor characteristics and more efficient intramolecular charge transfer.Conventional PSCs were fabricated by spin-coating the blend of each PT and the fullerene derivative(PC71BM). The conventional PSC devices exhibited high open circuit voltages (Voc) of around 0.79–0.91 V. The power conversion efficiency (PCE) of the PSCs based on PTtCz : PC71BM (w/w ¼ 1 : 2.5)reached 2.48% with a Voc of 0.91 V, short circuit current (Jsc) of 6.58 (mA cm 2) and fill factor (FF) of41% under the illumination of AM1.5, 100 mW cm 2. Furthermore, a PTtCz/PC71BM-based inverted PSCwith ZnOx and MoO3 as an electron extraction layer and a hole extraction layer respectively was capableof retaining ca. 80% of its original efficiency after storage under ambient conditions (withoutencapsulation) for 1032 h, according to the ISOS-D-1 shelf protocol. The highly durable inverted PSCaccompanied by a large Voc value was achieved for the PT-type polymers

Prevalence of obstructive sleep apnea in patients with squamous cell carcinoma of the tongue following ablation surgery

AbstractBackground/purposeThe purpose of this study was to determine the prevalence of obstructive sleep apnea (OSA) in patients with squamous cell carcinoma (SSC) of the tongue after primary surgical resection and to correlate the presence of OSA with the occurrence of obstructive apnea in this patient population.Materials and methodsThis was a retrospective study of 26 Taiwanese patients, 24 males and two females, aged 37–71 years, after surgical resection of SSC of the tongue. Patients who had a follow-up after treatment of 6 months to 11 years were eligible for inclusion. During the post-treatment period, the occurrence of OSA was determined in these patients. Overnight polysomnography (PSG) was used to determine the apnea–hypopnea index (AHI). Patients were considered to have OSA if the AHI value was >5.ResultsPatients with an AHI value of <5 showed a mean body mass index (BMI) of 22.8 kg/m2, while those with an AHI value of >5 showed a mean BMI of 28.3 kg/m2. The BMI distribution between patients with AHI value of <5 and those with AHI values of >5 was statistically significant (P = 0.018). Using the definition of clinically significant sleep apnea as AHI > 5, 14 of 26 patients (53.85%) had clinical OSA. The OSA and non-OSA groups showed no statistical significance in terms of age, tumor size, tongue ablation, neck dissection [method?], or wound reconstruction methods.ConclusionIncidence of OSA in the patient population with SSC of the tongue was found to be significantly higher than that in the general population. The limitations of this study were the relatively small patient sample size and no presurgical PSG record being obtained from the patients to compare the sleep quality before and after cancer therapy

Using the computer-based feedback (CBF) system to investigate the juniorphysicians’s and clinical-instructors perceptions for the benefits of general medicine clinical-instructors training program

Background: The purpose of this study is to examine the clinical-instructors and junior-physicians (residents and interns) perceptions for the general-medicine training program by using bi-directional interactive and self-assessments computer-based feedback (CBF) and paper-based multisource feedback assessment (PBMFA) systems for the efficiency and benefit evaluation.Methods: Between 2011 January to 2013 December, junior-physicians and their clinical-instructors in the same medical team were enrolled consecutively for monitoring the CBF scores gave by each other after each clinical course. A total of 321 residents, 298 interns and 110 clinical-instructors who participated in the core competency general-medicine training program in 6-months period were included in the study. The CBF and PBMFA evaluations are undergone paralleled to gather the suggested information in different levels of Kirkpatrick evolutional theory.Results: The results showed that lecturers, being 5-10 years as attending physicians, internal medicine sub-specialty clinical-instructors are most benefit from the general medicine training program. Accordingly, the CBF scores of junior-physicians was positively correlated with the times (&gt; 3-times) of exposure to the medical teams that leaded by qualified clinical-instructors. Both clinical-instructors and junior-physicians have positive attitude to the value of the general-medicine training program. Interestingly, a good consistency was existed between residents CBF scores and PBMFA grades for their core-competency performance. Comparatively, the overall perception of clinical-instructors and junior-physicians for the general-medicine training was very positive.Conclusions: Clinical-instructors and junior-physicians had positive perception of CBF and PBMFA systems which could give us different information to improve and strength the further core-competency general-medicine training program by appropriate utilization