Pinning potential in highly performant CaKFe4As4 superconductor from DC magnetic relaxation and AC multi-frequency susceptibility studies.

We have investigated the pinning potential of high-quality single crystals of superconducting material CaKFe4As4 having high critical current density and very high upper critical field using both magnetization relaxation measurements and frequency-dependent AC susceptibility. Preliminary studies of the superconducting transition and of the isothermal magnetization loops confirmed the high quality of the samples, while temperature dependence of the AC susceptibility in high magnetic fields show absolutely no dependence on the cooling conditions, hence, no magnetic history. From magnetization relaxation measurements were extracted the values of the normalized pinning potential U*, which reveals a clear crossover between elastic creep and plastic creep. The extremely high values of U*, up to 1200 K around the temperature of 20 K lead to a nearly zero value of the probability of thermally-activated flux jumps at temperatures of interest for high-field applications. The values of the creep exponents in the two creep regimes resulted from the analysis of the magnetization relaxation data are in complete agreement with theoretical models. Pinning potentials were also estimated, near the critical temperature, from AC susceptibility measurements, their values being close to those resulted (at the same temperature and DC field) from the magnetization relaxation data.

Second magnetization peak, rhombic-to-square Bragg vortex glass transition, and intersecting magnetic hysteresis curves in overdoped BaFe2(As1-xPx)2 single crystals.

The second magnetization peak (SMP) in the fourfold symmetric superconducting single crystals (such as iron pnictides and tetragonal cuprates) has been attributed to the rhombic-to-square transition (RST) of the quasi-ordered vortex solid (the Bragg vortex glass, BVG). This represents an alternative to the pinning-induced BVG disordering as the actual SMP mechanism. The analysis of the magnetic response of BaFe2(As1-xPx)2 specimens presented here shows that the SMP is not generated by the RST. However, the latter can affect the pinning-dependent SMP onset field if this is close to the (intrinsic) RST line, through the occurrence of a "shoulder" on the magnetic hysteresis curves m(H), and a maximum in the temperature variation of the DC critical current density. These features disappear in AC conditions, where the vortex system is dynamically ordered in the RST domain, emphasizing the essential role of vortex dislocations for an efficient accommodation of the vortex system to the pinning landscape and the SMP development. The m(H) shoulder is associated with a precipitous pinning-induced proliferation of dislocations at the RST, where the BVG elastic "squash" modulus softens. The DC magnetization relaxation indicates that the pinning-induced vortex system disordering continues above the RST domain, as the basic SMP mechanism.

Magnetic Phase Coexistence and Hard-Soft Exchange Coupling in FePt Nanocomposite Magnets.

With the aim of demonstrating phase coexistence of two magnetic phases in an intermediate annealing regime and obtaining highly coercive FePt nanocomposite magnets, two alloys of slightly off-equiatomic composition of a binary Fe-Pt system were prepared by dynamic rotation switching and ball milling. The alloys, with a composition Fe53Pt47 and Fe55Pt45, were subsequently annealed at 400 °C and 550 °C and structurally and magnetically characterized by means of X-ray diffraction, 57Fe Mössbauer spectrometry and Superconducting Quantum Interference Device (SQUID) magnetometry measurements. Gradual disorder-order phase transformation and temperature-dependent evolution of the phase structure were monitored using X-ray diffraction of synchrotron radiation. It was shown that for annealing temperatures as low as 400 °C, a predominant, highly ordered L10 phase is formed in both alloys, coexisting with a cubic L12 soft magnetic FePt phase. The coexistence of the two phases is evidenced through all the investigating techniques that we employed. SQUID magnetometry hysteresis loops of samples annealed at 400 °C exhibit inflection points that witness the coexistence of the soft and hard magnetic phases and high values of coercivity and remanence are obtained. For the samples annealed at 500 °C, the hysteresis loops are continuous, without inflection points, witnessing complete exchange coupling of the hard and soft magnetic phases and further enhancement of the coercive field. Maximum energy products comparable with values of current permanent magnets are found for both samples for annealing temperatures as low as 500 °C. These findings demonstrate an interesting method to obtain rare earth-free permanent nanocomposite magnets with hard-soft exchange-coupled magnetic phases.

Mn-Induced Thermal Stability of L10 Phase in Fept Magnetic Nanoscale Ribbons.

Magnetic nanoscale materials exhibiting the L10 tetragonal phase such as FePt or ternary alloys derived from FePt show most promising magnetic properties as a novel class of rare earth free permanent magnets with high operating temperature. A granular alloy derived from binary FePt with low Pt content and the addition of Mn with the nominal composition Fe57Mn8Pt35 has been synthesized in the shape of melt-spun ribbons and subsequently annealed at 600 °C and 700 °C for promoting the formation of single phase, L10 tetragonal, hard magnetic phase. Proton-induced X-ray emission spectroscopy PIXE has been utilized for checking the compositional effect of Mn addition. Structural properties were analyzed using X-ray diffraction and diffractograms were analyzed using full profile Rietveld-type analysis with MAUD (Materials Analysis Using Diffraction) software. By using temperature-dependent synchrotron X-ray diffraction, the disorder-order phase transformation and the stability of the hard magnetic L10 phase were monitored over a large temperature range (50-800 °C). A large interval of structural stability of the L10 phase was observed and this stability was interpreted in terms of higher ordering of the L10 phase promoted by the Mn addition. It was moreover found that both crystal growth and unit cell expansion are inhibited, up to the highest temperature investigated (800 °C), proving thus that the Mn addition stabilizes the formed L10 structure further. Magnetic hysteresis loops confirmed structural data, revealing a strong coercive field for a sample wherein single phase, hard, magnetic tetragonal L10 exists. These findings open good perspectives for use as nanocomposite, rare earth free magnets, working in extreme operation conditions.

The burden and epidemiology of community-acquired central nervous system infections: a multinational study.

Risk assessment of central nervous system (CNS) infection patients is of key importance in predicting likely pathogens. However, data are lacking on the epidemiology globally. We performed a multicenter study to understand the burden of community-acquired CNS (CA-CNS) infections between 2012 and 2014. A total of 2583 patients with CA-CNS infections were included from 37 referral centers in 20 countries. Of these, 477 (18.5%) patients survived with sequelae and 227 (8.8%) died, and 1879 (72.7%) patients were discharged with complete cure. The most frequent infecting pathogens in this study were Streptococcus pneumoniae (n = 206, 8%) and Mycobacterium tuberculosis (n = 152, 5.9%). Varicella zoster virus and Listeria were other common pathogens in the elderly. Although staphylococci and Listeria resulted in frequent infections in immunocompromised patients, cryptococci were leading pathogens in human immunodeficiency virus (HIV)-positive individuals. Among the patients with any proven etiology, 96 (8.9%) patients presented with clinical features of a chronic CNS disease. Neurosyphilis, neurobrucellosis, neuroborreliosis, and CNS tuberculosis had a predilection to present chronic courses. Listeria monocytogenes, Staphylococcus aureus, M. tuberculosis, and S. pneumoniae were the most fatal forms, while sequelae were significantly higher for herpes simplex virus type 1 (p < 0.05 for all). Tackling the high burden of CNS infections globally can only be achieved with effective pneumococcal immunization and strategies to eliminate tuberculosis, and more must be done to improve diagnostic capacity.

Harnessing spin precession with dissipation.

Non-collinear spin transport is at the heart of spin or magnetization control in spintronics devices. The use of nanoscale conductors exhibiting quantum effects in transport could provide new paths for that purpose. Here we study non-collinear spin transport in a quantum dot. We use a device made out of a single-wall carbon nanotube connected to orthogonal ferromagnetic electrodes. In the spin transport signals, we observe signatures of out of equilibrium spin precession that are electrically tunable through dissipation. This could provide a new path to harness spin precession in nanoscale conductors.

Clinical, Histological and Prognosis Correlations in Diagnosis and Treatment of Gastric Cancer.

Purpose The study authors have proposed to highlight the main epidemiologic and prognostic aspects of digestive malignancies in the Dolj county population, justifying the need for permanent and detailed estimate of this phenomenon. Methods The authors of the study have proposed to outline a descriptive epidemiological panel, characteristic for the population groups at risk of developing gastric cancers and establishing clinical factors (tumor location, disease stage, type of surgery) and histological factors (histopathological type, degree of tumor differentiation) with prognostic significance having as landmark, survival rate at 5 years or disease-free survival of 5 years. Results The study was conducted on a sample of 458 patients with gastric tumors endoscopically detected, histologically confirmed and treated between 2000-2010. The epidemiological study allowed us to outline the descriptive epidemiological panel characteristic for the group of patients at risk of developing gastric cancer. Analysis of correlation between clinical parameters and histopathological parameters reached statistical threshold in multivariate statistical analysis of the localization of tumor, disease stage and histological type (p <0.0001) and the degree of differentiation of gastric carcinomas (p <0.005). Multivariate statistical analysis has detected statistically significant differences in terms of survival rate at 5 years (p> 0.001) and free interval of disease at 5 years (p> 0.001), depending on the location of the tumor, correlated with other clinical factors (disease stage, type of surgery) and histological factors (histopathological type, tumor differentiation grade), which allowed us to outline clinical, histological and prognostic groups. Conclusions Defining the clinical, histological and prognostic groups, allows an accurate assessment of patient prognosis from the time of randomization and initiation of treatment, type of surgery in advanced loco-regional, reconverted to operability, after neoadjuvant polychemotherapy being dictated by the location of the tumor (1/3 superior vs. 1 / 3 medium vs. 1/3 lower stomach).

Therapeutical Attitude and Analysis of Results in Brain Metastases.

Objectives - The aim of this study is to assess therapeutic outcomes in patients presenting with brain metastases as the first manifestation of malignancies either as a final stage in the evolution of malignancies. Materials and methods - We've performed a complex retrospective study on a total of 81 patients with brain metastases treated in Medical Oncology Clinic of the Emergency County Hospital Craiova between 1 January 2005-31 December 2010. Results - The average age of women (55 years) was statistically significantly low compared to men (64 years) (p = 0.000). The most affected age group was 51-60 years in women with maximum frequency of breast cancer and 61-70 years for men, with predominance of lung cancer. Most cases were presented with multiple metastases (90.12%) and the average latency-free interval from primary tumor detection to onset of symptoms was 29.8 months. Clinical manifestations, in most cases, occurred in less than 6 months after diagnosis of the primary tumor being a consequence of the evolution of disease at distance (36 patients / 62 patients in oncological evidence 58.06%) and 12 months after diagnosis survival rate was low being detected in patients with a controlled primary tumor and distant resumption of the disease (14 patients / 62 patients in oncological evidence-22.58%).Median survival in patients with irradiated brain metastases was 7 months. Multivariate statistical analysis of the survival rate has detected statistically significant differences depending on the type of the primary tumor (p = 0.000) and the manner of the onset of brain metastases as the first manifestation or evolution of neoplastic disease (p = 0.000).Survival was affected, without statistical significance threshold, by the number of metastases, patient gender and the loco-regional status of the primary tumor.

The impact of additional cytogenetic abnormalities at diagnosis and during therapy with tyrosine kinase inhibitors in Chronic Myeloid Leukaemia.

BACKGROUND: Chronic Myeloid Leukemia's (CML) treatment was optimized since the development of tyrosine kinase inhibitors (TKI) and an increased overall survival during TKI was noticed. During the TKI era, protocols for assessing response and resistance to treatment were developed. Additional chromosomal abnormalities (ACAs) are strongly associated with disease progression but their prognostic impact and influence on treatment response are yet to be defined. The aim of this study was to analyze the impact of ACAs on time to achieve complete cytogenetic response (CCyR), treatment and overall survival. MATERIALS AND METHODS: Since 2005 until 2013, the data from the Hematology and Bone Marrow Transplantation Department of Fundeni Clinical Institute was collected. In this observational retrospective single centre study, 28 CML patients with ACAs at diagnosis and during TKI treatment were included. RESULTS: From ACAs at diagnosis group, the most frequent major route ACAs were trisomy 8, trisomy 19 and second Philadelphia (Ph) chromosome and the most frequent minor route ACAs were monosomies and structural abnormalities (inversions and translocations). From the ACAs during the TKI group, the most frequent major route cytogenetic abnormalities in Ph positive and negative cells were trisomy 8, trisomy 19 and second Ph chromosome and the most frequent minor route cytogenetic abnormalities in Ph positive and negative cells were marker chromosomes and structural abnormalities (inversions, translocations and dicentric chromosomes). CONCLUSIONS: In both groups, the time to CCyR was longer and long-term results were inferior in comparison with standard patients but the differences were not significant and in accordance to published data. The 12 months follow-up after the study's end showed that 26 patients were alive and in long-term CCyR and 2 deaths were reported. ABBREVIATIONS: CML = Chronic Myeloid Leukemia, BCR-ABL1 = Break Cluster Region - Abelson gene, TKI = tyrosine kinase inhibitor treatment, ACAs = additional cytogenetic abnormalities, CCyR = complete cytogenetic response, PCyR = partial cytogenetic response, mCyR = minor cytogenetic response, MMR = major molecular response, HSCT = hematopoietic stem cell transplant, HLA = human leukocyte antigens, CP = chronic phase, AP = accelerated phase, BP = blast phase, OS = overall survival, CBA = chromosome banding analysis, +8 = trisomy 8, i(17q) = isochromosome (17q), +Ph = second Philadelphia chromosome, -7 = monosomy 7, -17 = monosomy 17, +17 = trisomy 17, -21 = monosomy 21, +21 = trisomy 21, -Y = loss of Y chromosome, ELN = European LeukemiaNet, IMA600 = Imatinib 600 mg daily, IMA400 = Imatinib 400 mg daily, NILO600 = Nilotinib 600 mg daily, DASA100 = Dasatinib 100mg daily, DASA140 = Dasatinib 140 mg daily.

Mucormycosis during Imatinib treatment: case report.

UNLABELLED: Philadelphia chromosome positive acute lymphoblastic leukemia is classified as a very high-risk group and it requires an intensive chemotherapy regimen associated with tyrosine-kinase inhibitors and allogeneic hematopoietic stem cell transplant from related or unrelated HLA matched donor. Most times, intensive chemotherapy regimens are associated with prolonged and profound pancytopenia when the risk of invasive fungal infection increases. After Candida and Aspergillus species, Mucormycosis is the third frequent fungal infection in hematology patients and it is associated with a reduced overall survival. When suspected, immediate treatment is needed. We present the case of 24-year-old patient diagnosed with Philadelphia chromosome positive acute lymphoblastic leukemia who developed right rhino-sino-orbital fungal infection with a favorable response to systemic antifungal treatment and noninvasive surgery. Later, patient refused consolidation and allogeneic hematopoietic stem cell transplant from an unrelated HLA matched donor but accepted the first generation tyrosine kinase inhibitor (Imatinib) and maintained a complete hematological and molecular response. ABBREVIATIONS: ENT = ear nose throat; BMB = bone marrow biopsy; ALL = acute lymphoblastic leukemia; TKI = tyrosine kinase inhibitor; IFI = invasive fungal infection; BMB = bone marrow biopsy; HE = hematoxylin and eosin; IHC = immunohistochemistry; CD = cluster of differentiation; ob = objective; Tdt = terminal deoxynucleotidyl transferase.

Spatio-temporal analysis of tuberculous infection risk among clients of a homeless shelter during an outbreak.

SETTING: British Columbia (BC) has a low incidence of tuberculosis (TB), with the burden of endogenously acquired disease concentrated among vulnerable populations, including the homeless. In May 2008, a TB outbreak began in a BC homeless shelter, with a single index case seeding multiple secondary cases within the shelter. OBJECTIVE: To use nightly shelter records to quantify the risk of latent tuberculous infection (LTBI) among shelter clients as a function of their sleeping distance from and duration of exposure to the index case. DESIGN: Distance and duration of exposure were visualised and assessed using logistic regression with LTBI status as outcome. We used a novel machine learning approach to establish exposure thresholds that optimally separated infected and non-infected individuals. RESULTS: Of 161 exposed shelter clients, 58 had a recorded outcome of infected (n = 39) or non-infected (n = 19). Only duration of exposure to the index was associated with increased odds of infection (OR 1.26); stays of ⩾ 5 nights put shelter clients at higher odds of infection (OR 4.97). CONCLUSION: The unique data set and analytical approach suggested that, in a shelter environment, long-term clients are at highest risk of LTBI and should be prioritised for screening during an outbreak investigation.

The microbiological diagnosis of tuberculous meningitis: results of Haydarpasa-1 study.

We aimed to provide data on the diagnosis of tuberculous meningitis (TBM) in this largest case series ever reported. The Haydarpasa-1 study involved patients with microbiologically confirmed TBM in Albania, Croatia, Denmark, Egypt, France, Hungary, Iraq, Italy, Macedonia, Romania, Serbia, Slovenia, Syria and Turkey between 2000 and 2012. A positive culture, PCR or Ehrlich-Ziehl-Neelsen staining (EZNs) from the cerebrospinal fluid (CSF) was mandatory for inclusion of meningitis patients. A total of 506 TBM patients were included. The sensitivities of the tests were as follows: interferon-γ release assay (Quantiferon TB gold in tube) 90.2%, automated culture systems (ACS) 81.8%, Löwenstein Jensen medium (L-J) 72.7%, adenosine deaminase (ADA) 29.9% and EZNs 27.3%. CSF-ACS was superior to CSF L-J culture and CSF-PCR (p <0.05 for both). Accordingly, CSF L-J culture was superior to CSF-PCR (p <0.05). Combination of L-J and ACS was superior to using these tests alone (p <0.05). There were poor and inverse agreements between EZNs and L-J culture (κ = -0.189); ACS and L-J culture (κ = -0.172) (p <0.05 for both). Fair and inverse agreement was detected for CSF-ADA and CSF-PCR (κ = -0.299, p <0.05). Diagnostic accuracy of TBM was increased when both ACS and L-J cultures were used together. Non-culture tests contributed to TBM diagnosis to a degree. However, due to the delays in the diagnosis with any of the cultures, combined use of non-culture tests appears to contribute early diagnosis. Hence, the diagnostic approach to TBM should be individualized according to the technical capacities of medical institutions particularly in those with poor resources.

A genomic classifier predicting metastatic disease progression in men with biochemical recurrence after prostatectomy.

BACKGROUND: Due to their varied outcomes, men with biochemical recurrence (BCR) following radical prostatectomy (RP) present a management dilemma. Here, we evaluate Decipher, a genomic classifier (GC), for its ability to predict metastasis following BCR. METHODS: The study population included 85 clinically high-risk patients who developed BCR after RP. Time-dependent receiver operating characteristic (ROC) curves, weighted Cox proportional hazard models and decision curves were used to compare GC scores to Gleason score (GS), PSA doubling time (PSAdT), time to BCR (ttBCR), the Stephenson nomogram and CAPRA-S for predicting metastatic disease progression. All tests were two-sided with a type I error probability of 5%. RESULTS: GC scores stratified men with BCR into those who would or would not develop metastasis (8% of patients with low versus 40% with high scores developed metastasis, P<0.001). The area under the curve for predicting metastasis after BCR was 0.82 (95% CI, 0.76-0.86) for GC, compared to GS 0.64 (0.58-0.70), PSAdT 0.69 (0.61-0.77) and ttBCR 0.52 (0.46-0.59). Decision curve analysis showed that GC scores had a higher overall net benefit compared to models based solely on clinicopathologic features. In multivariable modeling with clinicopathologic variables, GC score was the only significant predictor of metastasis (P=0.003). CONCLUSIONS: When compared to clinicopathologic variables, GC better predicted metastatic progression among this cohort of men with BCR following RP. While confirmatory studies are needed, these results suggest that use of GC may allow for better selection of men requiring earlier initiation of treatment at the time of BCR.

[Hepatic tuberculosis presenting as prolonged fever]. / Tuberculoza hepatica manifestare a sindromului febril prelungit.

In our country prolonged fever is frequently caused by tuberculosis infection, that is recrudescent. Localized hepatic tuberculosis is a rare clinical form of this specific infection. The authors present the case of a 26 year old man who developed prolonged fever, highly elevated liver enzymes and meningitis syndrome and was admitted to Clinical Hospital of Infectious Diseases and Pneumophtisiology Dr. V. Babes Timisoara during 24.03 - 16.05.2008. Diagnosis of hepatobiliary tuberculosis, acute bacillary meningitis and miliary tuberculosis were established by clinical, laboratory criteria and sustained by imaging techniques. Dynamics of biological features, diagnostic pitfalls, differential diagnosis difficulties, therapeutic schedules and peculiar aspects of evolution are presented. Liver involvement can be the only manifest form of miliary tuberculosis and when it is associated with prolonged fever obligates to begin quadruple specific therapy, especially in communities where tuberculosis is prevalent. Bacteriological findings are belated and antituberculous therapy can not be started early. Quadruple association of antituberculous drugs with corticotherapy and liver protective medication showed utility in favorable resolving of this case.

[Distribution of a hypoxic gas mixture by retro-pollution of a medical gas distribution system]. / Distribution d'un mélange gazeux hypoxique par rétropollution d'un circuit de distribution d'oxygène par de l'air médical.

The authors report a case of retropollution through the defective gas mixer of a Logic O4T-IMV ventilator (Ohmeda) located in the recovery room. Due to a defective check valve inside the mixer, medical air entered into the oxygen pipeline when the O2 pressure decreased below the pressure inside the medical air pipeline. This incident resulted in episodes of hypoxic gas mixture delivery in the operating theatre, when nitrous oxide was associated with oxygen polluted with medical air. The occurrence of such an incident, rarely described so far, requires the association of several factors. It can be recognized without delay with the continuous use of an oxygen analyser.