Time-reversal symmetry-breaking charge order in a kagome superconductor.

The kagome lattice1, which is the most prominent structural motif in quantum physics, benefits from inherent non-trivial geometry so that it can host diverse quantum phases, ranging from spin-liquid phases, to topological matter, to intertwined orders2-8 and, most rarely, to unconventional superconductivity6,9. Recently, charge sensitive probes have indicated that the kagome superconductors AV3Sb5 (A = K, Rb, Cs)9-11 exhibit unconventional chiral charge order12-19, which is analogous to the long-sought-after quantum order in the Haldane model20 or Varma model21. However, direct evidence for the time-reversal symmetry breaking of the charge order remains elusive. Here we use muon spin relaxation to probe the kagome charge order and superconductivity in KV3Sb5. We observe a noticeable enhancement of the internal field width sensed by the muon ensemble, which takes place just below the charge ordering temperature and persists into the superconducting state. Notably, the muon spin relaxation rate below the charge ordering temperature is substantially enhanced by applying an external magnetic field. We further show the multigap nature of superconductivity in KV3Sb5 and that the [Formula: see text] ratio (where Tc is the superconducting transition temperature and λab is the magnetic penetration depth in the kagome plane) is comparable to those of unconventional high-temperature superconductors. Our results point to time-reversal symmetry-breaking charge order intertwining with unconventional superconductivity in the correlated kagome lattice.

Extended Magnetic Dome Induced by Low Pressures in Superconducting FeSe_{1-x}S_{x}.

We report muon spin rotation and magnetization measurements under pressure on Fe_{1+δ}Se_{1-x}S_{x} with x≈0.11. Above p≈0.6 GPa we find a microscopic coexistence of superconductivity with an extended dome of long range magnetic order that spans a pressure range between previously reported separated magnetic phases. The magnetism initially competes on an atomic scale with the coexisting superconductivity leading to a local maximum and minimum of the superconducting T_{c}(p). The maximum of T_{c} corresponds to the onset of magnetism while the minimum coincides with the pressure of strongest competition. A shift of the maximum of T_{c}(p) for a series of single crystals with x up to 0.14 roughly extrapolates to a putative magnetic and superconducting state at ambient pressure for x≥0.2.

Breakdown of Magnetic Order in the Pressurized Kitaev Iridate ß-Li_{2}IrO_{3}.

Temperature-pressure phase diagram of the Kitaev hyperhoneycomb iridate ß-Li_{2}IrO_{3} is explored using magnetization, thermal expansion, magnetostriction, and muon spin rotation measurements, as well as single-crystal x-ray diffraction under pressure and ab initio calculations. The Néel temperature of ß-Li_{2}IrO_{3} increases with the slope of 0.9 K/GPa upon initial compression, but the reduction in the polarization field H_{c} reflects a growing instability of the incommensurate order. At 1.4 GPa, the ordered state breaks down upon a first-order transition, giving way to a new ground state marked by the coexistence of dynamically correlated and frozen spins. This partial freezing in the absence of any conspicuous structural defects may indicate the classical nature of the resulting pressure-induced spin liquid, an observation paralleled to the increase in the nearest-neighbor off-diagonal exchange Γ under pressure.

Complementary Response of Static Spin-Stripe Order and Superconductivity to Nonmagnetic Impurities in Cuprates.

We report muon-spin rotation and neutron-scattering experiments on nonmagnetic Zn impurity effects on the static spin-stripe order and superconductivity of the La214 cuprates. Remarkably, it was found that, for samples with hole doping x≈1/8, the spin-stripe ordering temperature T_{so} decreases linearly with Zn doping y and disappears at y≈4%, demonstrating a high sensitivity of static spin-stripe order to impurities within a CuO_{2} plane. Moreover, T_{so} is suppressed by Zn in the same manner as the superconducting transition temperature T_{c} for samples near optimal hole doping. This surprisingly similar sensitivity suggests that the spin-stripe order is dependent on intertwining with superconducting correlations.

[Laryngeal paraganglioma]. / Paraganglioma gortani.

The paper describes a clinical case of laryngeal paraganglioma, a rare tumor. It provides the detailed characteristics of current diagnostic techniques.

[The role of small intestine length in the development of short bowel syndrome]. / Rol' dliny tonkoi kishki v razvitii sindroma korotkoi kishki (s kommentariem).

AIM: To define the the role of small bowel length in development of SBS. MATERIAL AND METHODS: Seventeen patients with SBS after small bowel resection in neonatal period were included into the study. Total small bowel length ranged from 5 to 55 cm (11.8±5.59% from normal length for certain age). RESULTS: Described small bowel length has high risk of SBS/IF development irrespective to other factors (specific segment of small bowel that was resected, preserved intestinal segment state, absence of colon and/or ileocecal valve). CONCLUSION: It is required to perform further studies with greater amount of patients to discover exact small bowel length which is associated with SBS and other factors affecting small bowel state.

[On the training of the expert and pedagogical personnel for the forensic medical services of the Republic of Kazakhstan]. / O podgotovke ekspertnykh i nauchno-pedagogicheskikh kadrov dlya sudebno-meditsinskoi sluzhby Respubliki Kazakhstan.

We undertook the analysis of the legislative acts currently in force in the Republic of Kazakhstan pertinent to the training of the expert and pedagogical personnel for the forensic medical services with special reference to their advantages and disadvantages from the standpoint of legal regulation of the activities in this sphere. The problems of staffing support of expert practice are illustrated on the example of activities of the Almaty branch of the Centre of Forensic Medicine of the Kazakh Ministry of Justice. The approaches to the solution of these problems are proposed.

Mutual Independence of Critical Temperature and Superfluid Density under Pressure in Optimally Electron-Doped Superconducting LaFeAsO(1-x)F(x).

The superconducting properties of LaFeAsO(1-x)F(x) under conditions of optimal electron doping are investigated upon the application of external pressure up to ∼23 kbar. Measurements of muon-spin spectroscopy and dc magnetometry evidence a clear mutual independence between the critical temperature T(c) and the low-temperature saturation value for the ratio n(s)/m(*) (superfluid density over effective band mass of Cooper pairs). Remarkably, a dramatic increase of ∼30% is reported for n(s)/m(*) at the maximum pressure value while T(c) is substantially unaffected in the whole accessed experimental window. We argue and demonstrate that the explanation for the observed results must take the effect of nonmagnetic impurities on multiband superconductivity into account. In particular, the unique possibility to modify the ratio between intraband and interband scattering rates by acting on structural parameters while keeping the amount of chemical disorder constant is a striking result of our proposed model.

Negative oxygen isotope effect on the static spin stripe order in superconducting La(2-x)Ba(x)CuO(4) (x=1/8) observed by muon-spin rotation.

Large negative oxygen-isotope (^{16}O and ^{18}O) effects (OIEs) on the static spin-stripe-ordering temperature T_{so} and the magnetic volume fraction V_{m} were observed in La_{2-x}Ba_{x}CuO_{4}(x=1/8) by means of muon-spin-rotation experiments. The corresponding OIE exponents were found to be α_{T_{so}}=-0.57(6) and α_{V_{m}}=-0.71(9), which are sign reversed to α_{T_{c}}=0.46(6) measured for the superconducting transition temperature T_{c}. This indicates that the electron-lattice interaction is involved in the stripe formation and plays an important role in the competition between bulk superconductivity and static stripe order in the cuprates.

Two-dimensional superfluid density in an alkali metal-organic solvent intercalated iron selenide superconductor Li(C5H5N)0.2Fe2Se2.

We report the low-temperature electronic and magnetic properties of the alkali metal-organic solvent intercalated iron selenide superconductor Li(C5H5N)0.2Fe2Se2 using muon-spin-spectroscopy measurements. The zero-field muon spin relaxation (µSR) results indicate that nearly half of the sample is magnetically ordered and spatially phase separated from the superconducting region. The transverse-field µSR results reveal that the superfluid density of Li(C5H5N)0.2Fe2Se2 is two dimensional in nature. The temperature dependence of the penetration depth λ(T) can be explained using a two-gap s-wave model. This implies that, despite the 2D nature of the superfluid density, the symmetry of the superconducting gap remains unaltered to the parent compound FeSe.

Tunable unconventional kagome superconductivity in charge ordered RbV3Sb5 and KV3Sb5.

Unconventional superconductors often feature competing orders, small superfluid density, and nodal electronic pairing. While unusual superconductivity has been proposed in the kagome metals AV3Sb5, key spectroscopic evidence has remained elusive. Here we utilize pressure-tuned and ultra-low temperature muon spin spectroscopy to uncover the unconventional nature of superconductivity in RbV3Sb5 and KV3Sb5. At ambient pressure, we observed time-reversal symmetry breaking charge order below [Formula: see text] 110 K in RbV3Sb5 with an additional transition at [Formula: see text] 50 K. Remarkably, the superconducting state displays a nodal energy gap and a reduced superfluid density, which can be attributed to the competition with the charge order. Upon applying pressure, the charge-order transitions are suppressed, the superfluid density increases, and the superconducting state progressively evolves from nodal to nodeless. Once optimal superconductivity is achieved, we find a superconducting pairing state that is not only fully gapped, but also spontaneously breaks time-reversal symmetry. Our results point to unprecedented tunable nodal kagome superconductivity competing with time-reversal symmetry-breaking charge order and offer unique insights into the nature of the pairing state.

Hidden magnetism uncovered in a charge ordered bilayer kagome material ScV6Sn6.

Charge ordered kagome lattices have been demonstrated to be intriguing platforms for studying the intertwining of topology, correlation, and magnetism. The recently discovered charge ordered kagome material ScV6Sn6 does not feature a magnetic groundstate or excitations, thus it is often regarded as a conventional paramagnet. Here, using advanced muon-spin rotation spectroscopy, we uncover an unexpected hidden magnetism of the charge order. We observe an enhancement of the internal field width sensed by the muon ensemble, which takes place within the charge ordered state. More importantly, the muon spin relaxation rate below the charge ordering temperature is substantially enhanced by applying an external magnetic field. Taken together with the hidden magnetism found in AV3Sb5 (A = K, Rb, Cs) and FeGe kagome systems, our results suggest ubiqitous time-reversal symmetry-breaking in charge ordered kagome lattices.

Direct observation of the quantum critical point in heavy fermion CeRhSi3.

We report on muon spin rotation studies of the noncentrosymmetric heavy fermion antiferromagnet CeRhSi3. A drastic and monotonic suppression of the internal fields, at the lowest measured temperature, was observed upon an increase of external pressure. Our data suggest that the ordered moments are gradually quenched with increasing pressure, in a manner different from the pressure dependence of the Néel temperature. At 23.6 kbar, the ordered magnetic moments are fully suppressed via a second-order phase transition, and T(N) is zero. Thus, we directly observed the quantum critical point at 23.6 kbar hidden inside the superconducting phase of CeRhSi3.

[Microbiological evaluation of chicken meal "shaverma" as a factor for Salmonella transmission].

It has been established that the dish shawarma may be a factor for Salmonella transmission, by involving in sporadic and outbreak cases of Salmonella infection. Chicken fillet grilling when cooking the dish shawarma has been found to ensure its guaranteed freedom from Salmonella only in a piece less than 2 cm thick. Deeper layers of chicken and its juice that accumulates in the grill tray may remain be Salmonella-contaminated throughout the heat treatment. Obviously, for the epidemiological safety of the dish shawarma, it is necessary to cut a not more than 2-cm piece of fillet every time the latter is ready-made, i.e. a white color and a clear juice are produced. At the time one should not use the chicken juice as sauce to the ready-made fillet and to gather and crumble the latter in a separate container rather than in the tray.

Local spectroscopic evidence for a nodeless magnetic kagome superconductor CeRu2.

We report muon spin rotation (µSR) experiments on the microscopic properties of superconductivity and magnetism in the kagome superconductor CeRu2withTc≃5 K. From the measurements of the temperature-dependent magnetic penetration depthλ, the superconducting order parameter exhibits nodeless pairing, which fits best to an anisotropics-wave gap symmetry. We further show that theTc/λ-2ratio is comparable to that of unconventional superconductors. Furthermore, the powerful combination of zero-field (ZF)-µSR and high-fieldµSR has been used to uncover magnetic responses across three characteristic temperatures, identified asT1∗≃110 K,T2∗≃65 K, andT3∗≃40 K. Our experiments classify CeRu2as an exceedingly rare nodeless magnetic kagome superconductor.

Coexistence of magnetism and superconductivity in the iron-based compound Cs0.8(FeSe0.98)2.

We report on muon-spin rotation and relaxation (µSR), electrical resistivity, magnetization and differential scanning calorimetry measurements performed on a high-quality single crystal of Cs(0.8)(FeSe(0.98))(2). Whereas our transport and magnetization data confirm the bulk character of the superconducting state below T(c)=29.6(2) K, the µSR data indicate that the system is magnetic below T(N)=478.5(3) K, where a first-order transition occurs. The first-order character of the magnetic transition is confirmed by differential scanning calorimetry data. Taken all together, these data indicate in Cs(0.8)(FeSe(0.98))(2) a microscopic coexistence between the superconducting phase and a strong magnetic phase. The observed T(N) is the highest reported to date for a magnetic superconductor.

Synthesis and crystal growth of Cs(0.8)(FeSe(0.98))(2): a new iron-based superconductor with T(c) = 27 K.

We report on the synthesis of large single crystals of a new FeSe layer superconductor Cs(0.8)(FeSe(0.98))(2). X-ray powder diffraction, neutron powder diffraction and magnetization measurements have been used to compare the crystal structure and the magnetic properties of Cs(0.8)(FeSe(0.98))(2) with those of the recently discovered potassium intercalated system K(x)Fe(2)Se(2). The new compound, Cs(0.8)(FeSe(0.98))(2), shows a slightly lower superconducting transition temperature (T(c) = 27.4 K) in comparison to 29.5 in (K(0.8)(FeSe(0.98))(2)). The volume of the crystal unit cell increases by replacing K by Cs-the c parameter grows from 14.1353(13) to 15.2846(11) Å. For the alkali metal intercalated layered compounds known so far, (K(0.8)Fe(2)Se(2) and Cs(0.8)(FeSe(0.98))(2)), the T(c) dependence on the anion height (distance between Fe layers and Se layers) was found to be analogous to those reported for As-containing Fe superconductors and Fe(Se(1 - x)Ch(x)), where Ch = Te, S.

Study on possibilities of reconstructive--plastic surgery in patients with stage III breast cancer.

BACKGROUND: This population based study aimed to use reconstructive-plastic surgery with autologous tissue as a treatment of patients with stage III breast cancer. PATIENTS AND METHODS: We identified women (374) diagnosed with stage III breast cancer between 2000 and 2009 years. We compared radical operations with and without a plastic step, where 29 patients underwent the surgery in combination with an immediate radical resection with LD-flap replacement, mastectomy concurrently to TRAM-flap reconstruction in 103 patients. RESULTS: We examined the immediate and remote results of therapy. In data analysis, there were higher summarized indices of physical and mental health rates in patients who underwent the reconstruction plastic surgery compared to patients with mastectomy. All treated women 5 -year survival rate was 77.4+3.6 %, 63.5+3.2% and 40.1+3.1 % in stages IIIa, IIIb, IIIc respectively. In the control group, the rates were 78.6+3.4 %, 64.0+3.3 %, and 39.3+3.1 % (p<0.05) respectively. CONCLUSION: Our results showed that women with stage III breast cancer who underwent reconstructive-plastic surgeries had a chance to improve their quality of life, and did not increase the frequency, neither did reduce 5 year survival (Tab. 2, Fig. 4, Ref. 19). Full Text in free PDF www.bmj.sk.

[Use of fluorescent in situ hybridization in the cytogenetic diagnosis of urinary bladder urothelial carcinoma].

Our study was concerned with assessing the results of FISH analysis as a procedure to detect occult features of tumor and contribute to individualizing treatment strategies. It included a cohort of 50 patients with primary bladder tumors who had undergone transurethral resection. Washings from all patients were tested using UroVysion protocol immediately prior to surgery. Patients were divided into groups according to stage and grade of tumor. The sensitivities were 81.5%, 91.7% and 100% for Ta, T1 and T2 groups, respectively. In G1, G2 and G3 groups, the sensitivities were 70%, 100% and 100%, respectively. Besides, the rate of detecting genetically abnormal cells was significantly higher at stage T2 as compared with Ta and Ta+T1 groups. It was also higher in G3 group as compared with G1 for Ta and G2. No significant differences in the mean number of signals from each chromosome was reported. Frequency rates of abnormal cells of less than 40% correlated with absence of invasion into the muscular layer and poorly-differentiated cell status. They rose insignificantly in proportion to stage and grade. Detection of less than 40% of genetically abnormal cells correlated with absence of mascular invasion and G3 tumor (90% credibility). FISH diagnostic procedure showed high sensitivity of detecting even at incipient stage of bladder carcinoma and was instrumental in preoperative predicting type of tumor.

[Emergency prosthetic repair of a ruptured abdominal aortic aneurysm].

Presented herein is a case report regarding successful endovascular prosthetic repair of an abdominal aortic aneurysm in its retroperitoneal rupture in a 56-year-old male patient treated by implantation of the unilateral stent-graft «Aorfix¼, cross femoro-femoral bypass grafting, and ligation of the contralateral common iliac artery.