Unconventional magnetism in all-carbon nanofoam

We report production of nanostructured carbon foam by a high-repetition-rate, high-power laser ablation of glassy carbon in Ar atmosphere. A combination of characterization techniques revealed that the system contains both sp2 and sp3 bonded carbon atoms. The material is a novel form of carbon in which graphite-like sheets fill space at very low density due to strong hyperbolic curvature, as proposed for ?schwarzite?. The foam exhibits ferromagnetic-like behaviour up to 90 K, with a narrow hysteresis curve and a high saturation magnetization. Such magnetic properties are very unusual for a carbon allotrope. Detailed analysis excludes impurities as the origin of the magnetic signal. We postulate that localized unpaired spins occur because of topological and bonding defects associated with the sheet curvature, and that these spins are stabilized due to the steric protection offered by the convoluted sheets.Comment: 14 pages, including 2 tables and 7 figs. Submitted to Phys Rev B 10 September 200

Clinical and epidemiological characteristics of Q fever in hospitalized patients

Retrospektivno su analizirane kliničke i epidemiološke značajke Q-groznice u 25 bolesnika koji su hospitalizirani u Klinici za infektivne bolesti u Zagrebu od 1. siječnja do 31. prosinca 2004. godine. Dijagnoza Q-groznice postavljena je u svih bolesnika serološki, imunoenzimskim testom (ELISA). Bolest se pojavljivala od ožujka do srpnja. Svi bolesnici su se razboljeli sporadično, a stanovnici su grada Zagreba i njegove okolice. Trinaest (52, 0%) bolesnika s Q-groznicom inficirano je u mjestu stanovanja, 10 (40, 0%) u drugim dijelovima Hrvatske, dok su dva (8, 0%) bolesnika u inkubacijskom razdoblju boravila u Bosni i Hercegovini. Bilo je znatno više muškaraca, nego žena (22:3). Većina bolesnika (68, 0%) je bila u dobi od 21-40 godina. Vodeći simptomi bolesti bili su vrućica, glavobolja i kašalj, a najvažniji patološki laboratorijski nalazi ubrzana sedimentacija eritrocita i povišena vrijednost C-reaktivnog proteina. Rendgenskim slikanjem pluća u većine bolesnika otkriven je intersticijski infiltrat, smješten u jednom plućnom režnju (23 ili 92, 0%). Pleuralni izljev je registriran u dva (8, 0%) bolesnika. Bolesnici su liječeni azitromicinom, fluorokinolonima i doksiciklinom. Doksiciklin je pokazao najbolji klinički učinak. Svi bolesnici su izliječeni.We retrospectively analysed clinical and epidemiological characteristics of Q fever in 25 patients hospitalized at the University Hospital for Infectious Diseases in Zagreb from January 1 to December 31, 2004. The diagnosis of Q fever was confirmed by serology in all patients, by an enzyme-linked immunosorbent assay (ELISA). The disease occurred from March to July. All patients were sporadic cases, and they were inhabitants of Zagreb and its surrounding areas. Thirteen (52.0 %) patients with Q fever were infected in their place of living, 10 (40.0 %) in other parts of Croatia, while 2 (8.0 %) patients were in Bosnia and Hercegovina during the incubation period. There were significantly more males than females (22:3). Most of the patients (68.0 %) were aged 21–40 years. Main symptoms of disease were fever, headache, and cough, and most significant pathological laboratory findings were accelerated erythrocyte sedimentation rate and increased value of C- reactive protein. Chest X-ray revealed interstitial pulmonary infiltrates in the majority of patients, localized in a single pulmonary lobe (23 or 92.0 %). Pleural effusion was recorded in 2 (8.0 %) patients. The patients were treated with azithromycin, fluoroquinolone, and doxycycline. Doxycycline showed the best clinical efficacy. All patients were cured

Clinical and epidemiological characteristics of Q fever in hospitalized patients

Retrospektivno su analizirane kliničke i epidemiološke značajke Q-groznice u 25 bolesnika koji su hospitalizirani u Klinici za infektivne bolesti u Zagrebu od 1. siječnja do 31. prosinca 2004. godine. Dijagnoza Q-groznice postavljena je u svih bolesnika serološki, imunoenzimskim testom (ELISA). Bolest se pojavljivala od ožujka do srpnja. Svi bolesnici su se razboljeli sporadično, a stanovnici su grada Zagreba i njegove okolice. Trinaest (52, 0%) bolesnika s Q-groznicom inficirano je u mjestu stanovanja, 10 (40, 0%) u drugim dijelovima Hrvatske, dok su dva (8, 0%) bolesnika u inkubacijskom razdoblju boravila u Bosni i Hercegovini. Bilo je znatno više muškaraca, nego žena (22:3). Većina bolesnika (68, 0%) je bila u dobi od 21-40 godina. Vodeći simptomi bolesti bili su vrućica, glavobolja i kašalj, a najvažniji patološki laboratorijski nalazi ubrzana sedimentacija eritrocita i povišena vrijednost C-reaktivnog proteina. Rendgenskim slikanjem pluća u većine bolesnika otkriven je intersticijski infiltrat, smješten u jednom plućnom režnju (23 ili 92, 0%). Pleuralni izljev je registriran u dva (8, 0%) bolesnika. Bolesnici su liječeni azitromicinom, fluorokinolonima i doksiciklinom. Doksiciklin je pokazao najbolji klinički učinak. Svi bolesnici su izliječeni.We retrospectively analysed clinical and epidemiological characteristics of Q fever in 25 patients hospitalized at the University Hospital for Infectious Diseases in Zagreb from January 1 to December 31, 2004. The diagnosis of Q fever was confirmed by serology in all patients, by an enzyme-linked immunosorbent assay (ELISA). The disease occurred from March to July. All patients were sporadic cases, and they were inhabitants of Zagreb and its surrounding areas. Thirteen (52.0 %) patients with Q fever were infected in their place of living, 10 (40.0 %) in other parts of Croatia, while 2 (8.0 %) patients were in Bosnia and Hercegovina during the incubation period. There were significantly more males than females (22:3). Most of the patients (68.0 %) were aged 21–40 years. Main symptoms of disease were fever, headache, and cough, and most significant pathological laboratory findings were accelerated erythrocyte sedimentation rate and increased value of C- reactive protein. Chest X-ray revealed interstitial pulmonary infiltrates in the majority of patients, localized in a single pulmonary lobe (23 or 92.0 %). Pleural effusion was recorded in 2 (8.0 %) patients. The patients were treated with azithromycin, fluoroquinolone, and doxycycline. Doxycycline showed the best clinical efficacy. All patients were cured

Electronic structure of the muonium center as a shallow donor in ZnO

The electronic structure and the location of muonium centers (Mu) in single-crystalline ZnO were determined for the first time. Two species of Mu centers with extremely small hyperfine parameters have been observed below 40 K. Both Mu centers have an axial-symmetric hyperfine structure along with a [0001] axis, indicating that they are located at the AB_{O,//} and BC_{//} sites. It is inferred from their small ionization energy (~6 meV and 50 meV) and hyperfine parameters (~10^{-4} times the vacuum value) that these centers behave as shallow donors, strongly suggesting that hydrogen is one of the primary origins of n type conductivity in as-grown ZnO.Comment: 4 pages, 4 figures, submitted to PR

Spin relaxation of conduction electrons in bulk III-V semiconductors

Spin relaxation time of conduction electrons through the Elliot-Yafet, D'yakonov-Perel and Bir-Aronov-Pikus mechanisms is calculated theoretically for bulk GaAs, GaSb, InAs and InSb of both $n$- and $p$-type. Relative importance of each spin relaxation mechanism is compared and the diagrams showing the dominant mechanism are constructed as a function of temperature and impurity concentrations. Our approach is based upon theoretical calculation of the momentum relaxation rate and allows understanding of the interplay between various factors affecting the spin relaxation over a broad range of temperature and impurity concentration.Comment: an error in earlier version correcte

Photoluminescence from voids created by femtosecond-laser pulses inside cubic-BN

Photoluminescence (PL) from femtosecond-laser-modified regions inside cubic-boron nitride (c-BN) was measured under UV and visible light excitation. Bright PL at the red spectral range was observed, with a typical excited state lifetime of ∼4  ns. Sharp emission lines are consistent with PL of intrinsic vibronic defects linked to the nitrogen vacancy formation (via Frenkel pair) observed earlier in high-energy electron-irradiated and ion-implanted c-BN. These, formerly known as the radiation centers, RC1, RC2, and RC3, have been identified at the locus of the voids formed by a single femtosecond-laser pulse. The method is promising to engineer color centers in c-BN for photonic applications

The motor function measure to study limitation of activity in children and adults with Charcot-Marie-Tooth disease

AbstractObjectiveTo study the applicability and responsiveness of the motor function measure (total score and sub-scores D1, D2 and D3) in patients with Charcot-Marie-Tooth disease.Patients and methodsTwo hundred and thirty-three patients aged 4–86 years were included in the descriptive study. Scores and sub-scores were analyzed by age and by disease subtypes. Sensitivity to change (responsiveness) was estimated in patients having had at least two evaluations with at least six months between the first and the second.ResultsMotor function measure scores decrease with age, especially sub-scores D1 and D3. There were no significant differences between the scores according to type of Charcot-Marie-Tooth disease. The scores were significantly higher for ambulatory than for non-ambulatory patients. Significant responsiveness was demonstrated only in type 2 Charcot-Marie-Tooth disease.Discussion/conclusionsOur results suggest that, especially for D1 and D3 sub-scores, the motor function measure is a reliable and valid outcome measure that can be usefully applied in longitudinal follow-up. Studies of longer duration could demonstrate its responsiveness in other Charcot-Marie-Tooth disease subtypes

Clinical Performance of the Automated LIAISON® Meridian H. pylori SA Stool Antigen Test

Background. Antigens derived from Helicobacter pylori can be used as stool biomarkers to assist in the diagnosis of H. pylori infection. Since current assays have variable performance, we assessed the clinical performance of the automated LIAISON® Meridian H. pylori SA chemiluminescent immunoassay against more invasive biopsy tests that are considered to be the "gold standard" (Composite Reference Method). Methods. This prospective multisite study enrolled patients undergoing an esophagogastroduodenoscopy with collection of biopsy and stool specimens. Adult patients (≥22 years) participated in the study from February 2017 to August 2018. Specimens of the stomach were tested by three methods, known as the Composite Reference Method: (1) histological evaluation, (2) culture of the organism, and (3) rapid urease detection test. H. pylori in stool was detected using the automated LIAISON® Meridian H. pylori SA assay, a chemiluminescent immunoassay. Statistical analyses were performed using MedCalc 18.11.6. Results. 277 patients (63% female) were included in the study. The prevalence of infected subjects was 24.2% in this study cohort. Clinical performance assessed against the Composite Reference Method showed very good agreement (Cohen's kappa=0.922), with good sensitivity (95.5%) and specificity (97.6%). Reproducibility study results showed total imprecision ranging from 3.1% to 13.9% CV. Conclusion. The automated LIAISON® Meridian H. pylori SA assay brings reliable noninvasive testing for H. pylori to the laboratory that is in very good agreement with the current, more invasive biopsy-based methods such as histology, culture, or rapid urease test. The clinical trial identifiers are NCT03060746 (pretherapy) and NCT03060733 (posttherapy)