Proposal for a correlation induced spin-current polarizer

We propose a spin polarizer device composed of a quantum dot connected to the spin polarized leads. The spin control of the current flowing through the device is entirely due to the Coulomb interactions present inside the dot. We show that the initial polarization present in the source lead can be reverted or suppressed just by manipulating the gate voltage acting on the dot, the presence of the external magnetic field is not required. The influence of the temperature and finite bias on the efficiency of the current spin switching effect is also discussed.Comment: 5 pages, 4 figures, title changed, rearranged figures, one reference added, discussion extension, accepted for Phys. Rev.

Quantum dot detects Majorana modes of both chiralities

A tunneling junction between normal electrode and a topological superconducting wire, mediated by a quantum dot, is considered theoretically. We show that the presence of the dot in the junction can be advantageous to Majorana zero modes identification. Namely, we demonstrate that for the dot strongly coupled to the wire, the Majorana mode from the upper chiral sub-band "leaks" into the dot, providing supplementary information on Majorana mode formation. Thus, both the Zeeman-split dot sub-levels detect Majorana partners of a Kramers pair, formed at the wire end. The characteristic three-peak structures in both spin sectors of the spectral density of the dot, distinguish from the trivial scenario of one Andreev resonance at Fermi energy produced exclusively by the dot's spin sub-levels.Comment: paper presented at The European Conference Physics of Magnetism 2023, Pozna\'n, Poland, accepted for J. of Magnetism and Magnetic Material

Sub-gap Fano resonances in a topological superconducting wire with on-site Coulomb interactions

We consider theoretically a $1D$-semiconducting wire with strong Rashba interaction in proximity with $s$-wave superconductor, driven into topological phase by external magnetic field. Additionally, we take into account on-site Coulomb interactions inside the wire. The system is modelled by a tight binding Hamiltonian with Rashba hopping term and induced $s$-wave superconductivity. Calculations are performed utilizing recursive Green's function method, and Coulomb interactions are treated selfconsistently within Hubbard $I$ approximation. For the Hubbard levels residing within $p$-wave superconducting gap, particle-hole symmetric four-resonance structure develops in the density of states, apart from Majorana resonance. One pair of particle-hole symmetric resonances is created by the discrete $II$-Hubbard levels of the particular site, and the second pair of Hubbard sub-bands originates from recursive summation over the sites of the wire. Quantum interference between both types of pairs of states creates in-gap charge-conjugated Fano resonances with opposite asymmetry factors. We demonstrate that when quantum interference is dominated by two-particle tunneling, the Majorana resonance is strongly diminished, while it is not altered when single-particle tunneling dominates in interference process. We also discuss some consequences for experimental distinction of true Majorana states, and show that on-site Coulomb interactions support the appearance of topological phase.Comment: 16 pages, 7 figure

Charge dynamics effects in conductance through a large semi-open quantum dot

Fano lineshapes in resonant transmission in a quantum dot imply interference between localized and extended states. The influence of the charge accumulated at the localized levels, which screens the external gate voltage acting on the conduction channel is investigated. The modified Fano q parameter and the resonant conduction is derived starting from a microscopic Hamiltonian. The latest experiments on "charge sensing" and ``Coulomb modified Fano sensing `` compare well with the results of the present model.Comment: 5 pages, 4 figures, RevTex styl

Tunnelling magnetoresistance anomalies of a Coulomb blockaded quantum dot

We consider quantum transport and tunneling magnetoresistance (TMR) through an interacting quantum dot in the Coulomb blockade regime, attached to ferromagnetic leads. We show that there exist two kinds of anomalies of TMR, which have different origin. One type, associated with TMR sign change and appearing at conductance resonances, is of single particle origin. The second type, inducing a pronounced increase of TMR value far beyond 100%, is caused by electron correlations. It is manifested in-between Coulomb blockade conductance peaks. Both types of anomalies are discussed for zero and finite bias and their robustness to the temperature increase is also demonstrated. The results are presented in the context of recent experiments on semiconductor quantum dots in which similar features of TMR have been observed.Comment: 10 pages, 7 figures, Revtex style, to appaear in Phys. Rev. B extended discussion added, some typographic errors correcte

Czy nieprawidłowe rozpoznanie zespołu Wolframa jako cukrzycy typu 1 i jej powikłań może być przyczyną rzadkiego rozpoznawania tego zespołu?

Wolfram syndrome (WS), also known as DIDMOAD (Diabetes Insipidus, Diabetes Mellitus, Optic Atrophy and Deafness), is a rare autosomal recessive syndrome (1/770,000 in the United Kingdom), characterised by juvenile onset of diabetes mellitus, optic nerve atrophy, diabetes insipidus, sensorineural deafness, renal tract and neurological abnormalities, and primary gonadal atrophy. WS is caused mainly by biallelic mutations in the WFS1 gene, which encodes wolframin. Wide tissue distribution of wolframin and many mutations in the wolframin gene resulting in Wolfram syndrome may contribute to different phenotypes and the unusual combinations of clinical features. We describe a female patient with Wolfram syndrome diagnosed at the age of 25, with a previous false diagnosis of type 1 diabetes mellitus and misdiagnosed diabetic complications. The patient was found to be a compound heterozygote for two novel mutations in exon 8 of WFS1 gene: a 2-bp deletion AT at nt 1539 leading to a frameshift (Y513fs) and a single-base substitution 1174C > T resulting in a stop codon (Q392X). A detailed analysis of the patient’s medical history and a review of the literature suggest that many cases of Wolfram syndrome may remain undiagnosed due to misdiagnosis as type 1 diabetes mellitus and incorrect interpretation of clinical symptoms of neurodegenerative abnormalities, especially in their early stages. (Endokrynol Pol 2014; 65 (5): 398–400)Zespół Wolframa (WS), znany również jako DIDMOAD (moczówka prosta, cukrzyca, atrofia nerwu wzrokowego i głuchota), jest rzadkim zespołem dziedziczonym autosomalnie recesywnie (1/770000 w Wielkiej Brytanii), charakteryzującym się wystąpieniem cukrzycy w wieku młodzieńczym, zanikiem nerwu wzrokowego, moczówką prostą, głuchotą, niewydolnością oddechową i zaburzeniami neurologicznymi oraz pierwotną atrofią gonad. WS jest spowodowany głównie mutacją w genie WFS1, który koduje wolframinę. Obecność wolframiny w wielu tkankach organizmu oraz wiele różnych mutacji w genie wolframiny, których skutkiem jest wystąpienie zespołu Wolframa, może stanowić przyczynę różnych fenotypów tego zespołu oraz różnych kombinacji cech klinicznych. W poniższej publikacji opisano przypadek pacjentki z zespołem Wolframa, której choroba początkowo była błędnie zdiagnozowana jako cukrzyca typu 1 i jej powikłania. W badaniach genetycznych wykazano, że pacjentka była heterozygotą w zakresie dwóch nowych mutacji w egzonie 8 genu WFS1: 2-bp delecji AT w regionie nt 1539, prowadzącej do mutacji zmiany ramki odczytu (Y513fs) oraz substytucji pojedynczej zasady 1174 C > T, czego skutkiem był stop kodon (Q392X). Ze szczegółowej analizy historii medycznej pacjentki oraz przeglądu piśmiennictwa wynika, że duża liczba przypadków zespołu Wolframa może zostać niewłaściwie rozpoznana jako cukrzyca typu 1 lub zaburzenia neurodegeneracyjne, zwłaszcza w początkowej fazie ich rozwoju. (Endokrynol Pol 2014; 65 (5): 398–400

Efficacy and safety of a vaginal medicinal product containing three strains of probiotic bacteria : a multicenter, randomized, double-blind, and placebo-controlled trial

Objective: The main objective of this study was to evaluate whether vaginal administration of probiotic Lactobacillus results in their colonization and persistence in the vagina and whether Lactobacillus colonization promotes normalization and maintenance of pH and Nugent score. Patients and methods: The study was a multicenter, randomized, double-blind, and placebocontrolled trial. Altogether, 376 women were assessed for eligibility, and signed informed consent. One hundred and sixty eligible women with abnormal, also called intermediate, vaginal microflora, as indicated by a Nugent score of 4-6 and pH >4.5 and zero or low Lactobacillus count, were randomized. Each participant was examined four times during the study. Women were randomly allocated to receive either the probiotic preparation inVag®, or a placebo (one capsule for seven consecutive days vaginally). The product inVag includes the probiotic strains Lactobacillus fermentum 57A, Lactobacillus plantarum 57B, and Lactobacillus gasseri 57C. We took vaginal swabs during visits I, III, and IV to determine the presence and abundance of bacteria from the Lactobacillus genus, measure the pH, and estimate the Nugent score. Drug safety evaluation was based on analysis of the types and occurrence of adverse events. Results: Administration of inVag contributed to a significant decrease (between visits) in both vaginal pH (P<0.05) and Nugent score (P<0.05), and a significant increase in the abundance of Lactobacillus between visit I and visits III and IV (P<0.05). Molecular typing revealed the presence of Lactobacillus strains originating from inVag in 82% of women taking the drug at visit III, and 47.5% at visit IV. There was no serious adverse event related to inVag administration during the study. Conclusion: The probiotic inVag is safe for administration to sustainably restore the healthy vaginal microbiota, as demonstrated by predominance of the Lactobacillus bacteria in vaginal microbiota

Management of diabetes mellitus in patients with type 2 diabetes residing in a rural district of westpomeranian province

WSTĘP. Zdecydowana większość chorych na cukrzycę typu 2 (ok. 95% wszystkich przypadków cukrzycy) pozostaje, zwłaszcza na terenach wiejskich, pod wyłączną opieką lekarzy rodzinnych. W badaniu UKPDS udowodniono, że lepsze wyrównanie cukrzycy typu 2 istotnie zmniejsza ryzyko rozwoju przewlekłych powikłań cukrzycowych. Celem przedstawionego badania była ocena wyrównania metabolicznego chorych na cukrzycę typu 2, zamieszkujących gminę rolniczą w województwie zachodniopomorskim. MATERIAŁ I METODY. Badanie przeprowadzono w Poradni Lekarza Rodzinnego NZOZ &#8222;Asklepios&#8221; w Bobolicach, pod opieką której pozostaje 279 pacjentów chorych na cukrzycę stanowiących 3,3% zarejestrowanych tam osób. Na badanie zaproszono wszystkich chorych, spośród których zgłosiło się 249 osób (89%). Wiek badanych wynosił 32-91 lat (śr. 66,5 &#177; &#177; 12,4 roku). Wskaźnik masy ciała (BMI) oznaczony u 174 chorych wynosił 32,3 &#177; 6,4 kg/m2. U wszystkich badanych rano, na czczo pobrano krew żylną w celu oznaczenia stężeń HbA1c oraz glukozy. WYNIKI. Średnie stężenie HbA1c w badanej próbie wynosiło 7,82 &#177; 1,95%, średnie stężenie glukozy na czczo - 156 &#177; 66 mg/dl. Stężenie HbA1c wynoszące maksymalnie 6,5% stwierdzono u 31% osób uczestniczących w badaniu. Pożądaną glikemię na czczo wynoszącą maksymalnie 110 mg/dl, stwierdzono u 25% chorych. Jedynie u 17% badanych oba parametry, HbA1c oraz glikemia na czczo, spełniały kryteria wyrównania wyznaczone przez PTD 2007. Stężenie HbA1c poniżej 7%, zalecane przez ADA, osiągnęło 38% uczestników badania, zaś glikemię na czczo w przedziale 90-130 mg/dl zaobserwowano u 37% badanych. Oba zalecane przez ADA kryteria wyrównania spełniło 22% chorych. Uzyskane wyniki porównano z danymi pochodzącymi z innych ośrodków, w których oceniano chorych zamieszkujących miasta. WNIOSKI. Wyrównanie metaboliczne chorych na cukrzycę typu 2 zamieszkujących tereny wiejskie jest niezadowalające i wydaje się gorsze niż u pacjentów mieszkających w miastach. Być może wpływa na to większy stopień otyłości i nadwagi obserwowany u tych chorych, a także mniejsza dostępność opieki specjalistycznej.INTRODUCTION. The great majority of patients with type 2 diabetes, which accounts for 95% of all dia betic subjects, are treated only by general practitioners, especially in rural areas. The UKPDS study demonstrated that a better control of type 2 diabetes considerably reduces the risk of chronic diabetic complications. The main goal of the study was to assess metabolic control in type 2 diabetes patients, residents of a rural district of Westpomeranian Province. MATERIAL AND METHODS. The study was conducted in the General Practitioner&#8217;s Clinic NZOZ &#8222;Asklepios&#8221; in Bobolice, who provides medical care for 279 diabetics who account for 3.3% of all registered subjects. All diabetic patients were invited to participate in the study, and 249 subjects volunteered (89%). The age of investigated subjects ranged from 32 to 91 years (mean 66.5 &#177; 12.4 years). The mean body mass index (BMI), calculated for 174 patients, was 32.3 &#177; 6.4 kg/m&#178;. In the morning after an overnight fast, in all participants venous blood samples were taken for measurement of HbA1c and serum glucose level. RESULTS. The mean HbA1c level was 7.82 &#177; 1.95% and mean fasting serum glucose 156 &#177; 66 mg/dl. Values of HbA1c &#8805; 6.5% were observed in 31% of participants. Recommended glucose level &#163; 110 mg/dl was observed in 25% patients. Only in 17% of subjects both parameters, HbA1c and fasting glycaemia met the criteria recommended by Polish Diabetes Association 2007. Values of HbA1c < 7%, recommended by the American Diabetes Association (ADA) were observed in 38% of subjects while fasting glycaemia 90-130 mg/dl in 37% of cases. Both criteria, recommended by the ADA were met in 22% of diabetic patients. Obtained results were compared with the published data concerning outpatients&#8217; clinics from urban areas. CONCLUSION. Metabolic control of type 2 diabetic subjects, residents of the rural area in North-West part of Poland, is unsatisfactory and seems to be worse than in the patients from urban areas. This may be a result of higher degree of obesity and overweight of these patients as well as worse access to specialist care

Supplementation of standard antibiotic therapy with oral probiotics for bacterial vaginosis and aerobic vaginitis : a randomised, double-blind, placebo-controlled trial

BACKGROUND: This multicentre, randomised, double-blind, placebo-controlled trial was performed to determine whether the use of oral probiotic preparation (prOVag®) containing three Lactobacillus strains together with standard metronidazole treatment and also targeted antibiotic treatment (following the failure of metronidazole therapy) could reduce the recurrence rates of bacterial vaginosis (BV) and aerobic vaginitis (AV). METHODS: Patients at private gynaecological clinics in Poland with histories of recurrent BV/AV and current symptoms were randomly allocated to receive metronidazole and probiotic or placebo, and assessed monthly on visits II and III-V. The total number of study visits was 5–6 (I, II, II bis – if applicable, III, IV, V). One probiotic or placebo capsule was administered with metronidazole/targeted antibiotic twice daily for 10 days; during follow up, patients took one capsule daily for 10 days perimenstrually. Clinical examination and vaginal swabbing were performed at each visit. Primary outcomes were clinical or microbiological BV/AV recurrence and probiotic safety. Secondary outcomes were vaginal pH, Nugent score, and Lactobacillus counts in the vaginal microbiota. Safety analysis was performed in 578 (probiotic, n = 285; placebo, n = 293) 18–50-year-old women who were randomised. RESULTS: BV/AV was confirmed microbiologically in 241 (probiotic, n = 118; placebo, n = 123) participants, who continued the trial. Data from 154 (probiotic, n = 73; placebo, n = 81) participants who completed the study were analysed to determine the efficacy of prOVag. Additional analyses included 37 (probiotic, n = 22; placebo, n = 15) participants who received targeted antibiotics and probiotics or placebo. prOVag lengthened the time to clinical relapse of BV/AV symptoms up to 51 % (p < 0.05) compared with placebo; AV relapse was delayed by up to 76 % (p < 0.05). Probiotic use also reduced and maintained low vaginal pH and Nugent score, and increased vaginal Lactobacillus counts following standard treatment. CONCLUSION: This study demonstrated that oral probiotics lengthened remission in patients with recurrent BV/AV and improved clinical and microbiological parameters. TRIAL REGISTRATION: NCT01993524; 20 November 2013. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12905-015-0246-6) contains supplementary material, which is available to authorized users