Prediction and observation of an antiferromagnetic topological insulator.

Magnetic topological insulators are narrow-gap semiconductor materials that combine non-trivial band topology and magnetic order1. Unlike their nonmagnetic counterparts, magnetic topological insulators may have some of the surfaces gapped, which enables a number of exotic phenomena that have potential applications in spintronics1, such as the quantum anomalous Hall effect2 and chiral Majorana fermions3. So far, magnetic topological insulators have only been created by means of doping nonmagnetic topological insulators with 3d transition-metal elements; however, such an approach leads to strongly inhomogeneous magnetic4 and electronic5 properties of these materials, restricting the observation of important effects to very low temperatures2,3. An intrinsic magnetic topological insulator-a stoichiometric well ordered magnetic compound-could be an ideal solution to these problems, but no such material has been observed so far. Here we predict by ab initio calculations and further confirm using various experimental techniques the realization of an antiferromagnetic topological insulator in the layered van der Waals compound MnBi2Te4. The antiferromagnetic ordering  that MnBi2Te4  shows makes it invariant with respect to the combination of the time-reversal and primitive-lattice translation symmetries, giving rise to a ℤ2 topological classification; ℤ2 = 1 for MnBi2Te4, confirming its topologically nontrivial nature. Our experiments indicate that the symmetry-breaking (0001) surface of MnBi2Te4 exhibits a large bandgap in the topological surface state. We expect this property to eventually enable the observation of a number of fundamental phenomena, among them quantized magnetoelectric coupling6-8 and axion electrodynamics9,10. Other exotic phenomena could become accessible at much higher temperatures than those reached so far, such as the quantum anomalous Hall effect2 and chiral Majorana fermions3.

Magnetization Process of Atacamite: A Case of Weakly Coupled S=1/2 Sawtooth Chains.

We present a combined experimental and theoretical study of the mineral atacamite Cu_{2}Cl(OH)_{3}. Density-functional theory yields a Hamiltonian describing anisotropic sawtooth chains with weak 3D connections. Experimentally, we fully characterize the antiferromagnetically ordered state. Magnetic order shows a complex evolution with the magnetic field, while, starting at 31.5 T, we observe a plateaulike magnetization at about M_{sat}/2. Based on complementary theoretical approaches, we show that the latter is unrelated to the known magnetization plateau of a sawtooth chain. Instead, we provide evidence that the magnetization process in atacamite is a field-driven canting of a 3D network of weakly coupled sawtooth chains that form giant moments.

Double-Unit Superomedio-Central (DUS) Pedicle Inverted-T Reduction Mammaplasty in Gigantomastia: A 7-year Single-Center Retrospective Study.

INTRODUCTION: Reduction mammaplasty in patients with gigantomastia is challenging. The Double-Unit technique with a Superomedio-Central pedicle and inverted-T incision is the standard technique for reduction mammaplasty in our clinic. The aim of this study was to review our approach in cases with gigantomastia in comparison with the current literature. PATIENTS AND METHODS: From 01/2011 to 12/2017, we performed 831 reduction mammaplasties in 630 patients. The Double-Unit  Superomedio-Central  (DUS) pedicle and inverted-T incision was implemented as a standard procedure for gigantomastia. Patient demographics and the outcome parameters complication rate, patient satisfaction with the aesthetic result, nipple sensibility, and surgical revision rate were obtained and retrospectively analyzed. RESULTS: In 37 patients, 55 reduction mammaplasties were performed with more than 1000 g per breast. Mean resection weight was 1311 g on right side and 1289 g on left side. Mean age was 52.5 years, mean body mass index was 32.8 kg/m2, mean sternal-notch-to-nipple distance was 38.3 cm. A free NAC graft was necessary in four breasts. Overall complication rate was 14.5%; secondary surgical revision rate was 12.7%. 91% of the patients were "very satisfied" and "satisfied" with the aesthetic result. Nipple sensibility was rated "high" and "medium" in 83%. CONCLUSION: The Double-Unit technique with a Superomedio-Central pedicle and inverted-T incision is very effective to achieve volume reduction and aesthetically pleasing reproducible results with a low complication rate in cases with gigantomastia. LEVEL OF EVIDENCE: Level of Evidence This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

New method to predict need for Rashkind procedure in fetuses with dextro-transposition of the great arteries.

OBJECTIVE: Prenatal congenital heart disease classification systems distinguish between critical dextro-transposition of the great arteries (d-TGA) with restriction of the foramen ovale (FO) (which requires a Rashkind procedure within the first 24 h following delivery) and d-TGA for which surgery is planned (after prostaglandin perfusion or Rashkind procedure later than 24 h after delivery). However, current prenatal diagnostic criteria for postnatal FO restriction in d-TGA are inadequate, resulting in a high false-negative rate. We aimed to identify echocardiographic features to predict the urgent need for Rashkind procedure. METHODS: We identified retrospectively 98 patients with singleton pregnancy diagnosed prenatally with fetal d-TGA at two European centers from 2006 to 2013. Two groups were compared: (1) those in whom the Rashkind procedure was performed within the first 24 h postnatally; and (2) those who did not undergo a Rashkind procedure before cardiac surgery. Exclusion criteria were: (1) no fetal echocardiography within 3 weeks prior to delivery (n = 18); (2) delivery before 37 weeks of gestation (n = 6); (3) improper or lack of measurement of pulmonary vein maximum flow velocity (n = 10); (4) lack of neonatal follow-up data (n = 9); (5) Rashkind procedure performed more than 24 h after delivery (n = 4). RESULTS: Fifty-one patients met the inclusion criteria: 29 who underwent the Rashkind procedure and 22 who did not. There were no differences between these two study groups in terms of maternal age, gestational age at time of fetal echocardiography, fetal biometric measurements, estimated fetal weight, rate of Cesarean delivery, newborn weight or Apgar score at 1 min. There were also no differences during prenatal life between the two groups in terms of fetal cardiac size (heart area/chest area ratio), rate of disproportion between left and right ventricle, FO diameter and maximum velocity of flow through the FO. However, the pulmonary vein maximum velocity was significantly higher in the group requiring a Rashkind procedure (47.62 ± 7.48 vs 32.21 ± 5.47 cm/s; P < 0.001). The cut-off value of 41 cm/s provided maximum specificity (100%) and positive predictive value (100%) at only a slight cost of sensitivity (82%) and NPV (86%). The prenatal appearance of the FO also differed between the groups, the FO valve being flat in 52% of those requiring a Rashkind procedure. CONCLUSIONS: In fetuses with d-TGA, prenatal sonographic findings of increased pulmonary venous blood flow and flattened FO valve were associated with the need for a Rashkind procedure within the first 24 h postnatally; these echocardiographic features could be used to predict prenatally a need for the procedure following delivery. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Magnetization relaxation in the single-ion magnet DySc2N@C80: quantum tunneling, magnetic dilution, and unconventional temperature dependence.

Relaxation of magnetization in endohedral metallofullerenes DySc2N@C80 is studied at different temperatures, in different magnetic fields, and in different molecular arrangements. Magnetization behavior and relaxation are analyzed for powder sample, and for DySc2N@C80 diluted in non-magnetic fullerene Lu3N@C80, adsorbed in voids of a metal-organic framework, and dispersed in a polymer. The magnetic field dependence and zero-field relaxation are also studied for single-crystals of DySc2N@C80 co-crystallized with Ni(ii) octaethylporphyrin, as well as for the single crystal diluted with Lu3N@C80. Landau-Zener theory is applied to analyze quantum tunneling of magnetization in the crystals. The field dependence of relaxation rates revealed a dramatic dependence of the zero-field tunneling resonance width on the dilution and is explained with the help of an analysis of dipolar field distributions. AC magnetometry is used then to get access to the relaxation of magnetization in a broader temperature range, from 2 to 87 K. Finally, a theoretical framework describing the spin dynamics with dissipation is proposed to study magnetization relaxation phenomena in single molecule magnets.

Evidence for a Field-Induced Quantum Spin Liquid in α-RuCl_{3}.

We report a ^{35}Cl nuclear magnetic resonance study in the honeycomb lattice α-RuCl_{3}, a material that has been suggested to potentially realize a Kitaev quantum spin liquid (QSL) ground state. Our results provide direct evidence that α-RuCl_{3} exhibits a magnetic-field-induced QSL. For fields larger than ∼10 T, a spin gap opens up while resonance lines remain sharp, evidencing that spins are quantum disordered and locally fluctuating. The spin gap increases linearly with an increasing magnetic field, reaching ∼50 K at 15 T, and is nearly isotropic with respect to the field direction. The unusual rapid increase of the spin gap with increasing field and its isotropic nature are incompatible with conventional magnetic ordering and, in particular, exclude that the ground state is a fully polarized ferromagnet. The presence of such a field-induced gapped QSL phase has indeed been predicted in the Kitaev model.

Complex Field-Induced States in Linarite PbCuSO4(OH)2 with a Variety of High-Order Exotic Spin-Density Wave States.

Low-temperature neutron diffraction and NMR studies of field-induced phases in linarite are presented for magnetic fields H∥b axis. A two-step spin-flop transition is observed, as well as a transition transforming a helical magnetic ground state into an unusual magnetic phase with sine-wave-modulated moments ∥H. An effective J[over ˜]_{1}-J[over ˜]_{2} single-chain model with a magnetization-dependent frustration ratio α_{eff}=-J[over ˜]_{2}/J[over ˜]_{1} is proposed. The latter is governed by skew interchain couplings and shifted to the vicinity of the ferromagnetic critical point. It explains qualitatively the observation of a rich variety of exotic longitudinal collinear spin-density wave, SDW_{p}, states (9≥p≥2).

Evaluation of right ventricular function in fetal hypoplastic left heart syndrome by color tissue Doppler imaging.

OBJECTIVE: Postnatal outcome of fetuses with hypoplastic left heart syndrome (HLHS) is determined mainly by right ventricular function. Our study examines whether there are differences in right ventricular function during gestation of fetuses with HLHS compared with healthy fetuses. METHODS: A prospective study was conducted including 20 fetuses with HLHS and 20 gestational age-matched controls. Peak systolic and diastolic right ventricular free wall velocities were assessed using color tissue Doppler imaging (c-TDI). Subsequently, isovolumic time intervals, ejection time (ET'), E'/A' ratio and tissue Doppler-derived myocardial performance index (MPI') were calculated. Possible changes to c-TDI indices during the course of pregnancy in both the HLHS group and the control group were investigated. RESULTS: Examination of right ventricular function revealed significantly lower E' velocities (13.6 vs 21.0 cm/s; P = 0.017) and E'/A' ratios (0.55 vs 0.76; P = 0.012) and prolonged isovolumic contraction time (ICT') (57.0 vs 45.7 ms; P = 0.008) in the HLHS group compared with healthy fetuses. Furthermore, isovolumic relaxation time and MPI' increased significantly with gestational age in HLHS fetuses but not in controls. Values for systolic and diastolic peak velocities (E', A', S'), ET' and ICT' did not change significantly during gestation in either group. CONCLUSION: Right ventricular function in HLHS is altered as early as in fetal life, well before palliative surgery is performed. Future research should provide further insight into ventricular remodeling during gestation in cases of HLHS. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

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.

Evaluation of exopolysaccharide producing Weissella cibaria MG1 strain for the production of sourdough from various flours.

This study determined exopolysaccharide (EPS) production by Weissella cibaria MG1 in sourdoughs prepared from gluten-free flours (buckwheat, oat, quinoa and teff), as well as wheat flour. Sourdoughs (SD) were fermented without sucrose, or by replacing 10% flour with sucrose to support EPS production. The amount of EPS depended on the substrate: high amounts of EPS corresponding to low amounts of oligosaccharides were found in buckwheat (4.2 g EPS/kg SD) and quinoa sourdoughs (3.2 g EPS/kg SD); in contrast, no EPS but panose-series oligosaccharides (PSO) were detected in wheat sourdoughs. Organic acid production, carbohydrates and rheological changes during fermentation were compared to the EPS negative control without added sucrose. Corresponding to the higher mineral content of the flours, sourdoughs from quinoa, teff and buckwheat had higher buffering capacity than wheat. Fermentable carbohydrates in buckwheat, teff and quinoa flours promoted W. cibaria growth; indicating why W. cibaria failed to grow in oat sourdoughs. Endogenous proteolytic activity was highest in quinoa flour; α-amylase activity was highest in wheat and teff flours. Protein degradation during fermentation was most extensive in quinoa and teff SD reducing protein peaks 18-29, 30-41 and 43-55 kDa extensively. Rheological analyses revealed decreased dough strength (AF) after fermentation, especially in sucrose-supplemented buckwheat sourdoughs correlating with amounts of EPS. High EPS production correlated with high protein, fermentable sugars (glucose, maltose, fructose), and mineral contents in quinoa flour. In conclusion, W. cibaria MG1 is a suitable starter culture for sourdough fermentation of buckwheat, quinoa and teff flour.

[Management documentation of therapeutic units on inpatient treatment for people with dementia--does it allow conclusion to be drawn them about inpatient services? An exploratory analysis]. / Leistungsdokumentation durch Therapieeinheiten bei stationär behandelten Menschen mit dementieller Erkrankung--erlauben sie Rückschlüsse auf das Leistungsgeschehen? Eine explorative Analyse.

BACKGROUND: Against the background of the continuously growing incidence rates of gerontopsychiatric disorders, their economic dimen-sions, and the effects on persons affected as well as their social environments, the present study focuses on an analysis of the services provided in acute psychiatric care settings for patients with dementia. RESULTS are based on secondary data. AIM OF THE STUDY: We aim to compare therapeutic service units of different clusters of occupational groups (physicians/psychologists, nurses/special therapists) for the ICD-10 diagnostic groups F00-F03 and G30 in the years 2010 (starting with July) and 2011. Main research question is how many patients are mappable with 'therapeutic units' (Therapieeinheiten, TE) of the operation and procedures catalogue (OPS). METHODS: The present study is based on an analysis of the §21 KHEntgG data record of 35 acute psychiatric facilities. Data collection took place within the project "Versorgungsindikatoren für die Psychiatrie und Psychosomatik (VIPP)", "Supply indicators for psychiatric and psychosomatic settings". The data record implies statewide data of specialised hospitals, university hospitals and departments of psychiatry of the Federal Republic of Germany. RESULTS: In total, 5 111 cases were included in the analysis. Nurses and special therapists carried out significantly more therapeutic units in the main diagnoses groups (F01, F03 and G30) and the care groups (regular vs. intensive) than physicians and psychologists (p<0.05). It was not possible to map all patients with the use of therapeutic units (G30 78.8%, F01 83.4%, F03 81.2%). Mapping of patients was significantly higher in the intensive care compared to regular care in both occupational clusters (p<0.05). CONCLUSIONS: We demonstrated that the "therapeutic units" of the OPS codes are now used in the routine data (§21 KHEntgG), and that they are able to portray relevant aspects of non-medication therapeutic service. The present study provides a preliminary/exploratory overview on the services provided, mapped by therapeutic units. Future research should focus on the overlap between the category "therapeutic" units and the services actually provided.

Secondary solution for breast reconstruction following total DIEP flap loss: A single-center experience after 3270 DIEP flaps.

BACKGROUND: Total deep inferior epigastric perforator (DIEP) flap failure is a significant concern in autologous breast reconstruction. Literature on secondary reconstruction options following total flap failure is limited. This study outlines the outcomes of patients who underwent reconstruction post-DIEP flap failure at our institution. METHODS: We conducted a retrospective analysis of patients receiving autologous breast reconstruction between 2004 and 2021. We aimed to identify causes of total DIEP flap failure, outcomes of revision surgery, and outcomes of secondary breast reconstruction procedures. RESULTS: From 2004 to 2021, 3456 free flaps for breast reconstruction were performed, with 3270 being DIEP flaps for 2756 patients. DIEP flap failure was observed in 40 cases (1.22%). Bilateral reconstructions had a higher failure rate (2.31%) than unilateral (0.72%). The primary cause was intraoperative complications during flap harvest (18 cases), followed by insufficient arterial perfusion (seven cases). Other causes included postoperative hematoma (seven cases), venous congestion (six cases), and late-onset fat necrosis (two cases). Post-failure, five patients received a second free flap with three cases of repeated flap failure. Twenty patients received implant-based reconstruction with two cases of reconstruction failure, while seven patients received a pedicled latissimus dorsi (LD) flap reconstructions with no cases of reconstruction failure. Eight patients declined further reconstruction. CONCLUSION: A second free flap post-DIEP failure was associated with a high risk of reconstruction failure, suggesting the need for careful patient selection. Implant-based and pedicled LD flap seem to be reliable secondary reconstruction options.

[Does the resident care assessment instrument improve long-term home care? - results of a nation-wide study in Germany]. / Verbessert das Resident Assessment Instrument die ambulante Pflege? - Ergebnisse einer bundesweiten Studie.

BACKGROUND: Effective and efficient instruments for care planning and controlling are required to optimise the nursing process and improve outcome quality despite of various lacks of quality and precarious circumstances. METHODS: A cluster randomised controlled trial was conducted to assess whether the implementation of the Resident Assessment Instrument (RAI) into home care service providers can help to improve or stabilise functional abilities (ADL, IADL) and cognitive skills (MMST), improve quality of life (EQ-5D), reduce institutionalisation and thereby increase outcome quality. RESULTS: A comparison of mean differences between the treatment and control group showed no significant effects. Although the multilevel regression results show that clients in the treatment group fared better in terms of ADL and IADL (smaller decline) and were less likely to move to nursing homes and be hospitalised, none of these effects are significant. CONCLUSIONS: The lack of significance might be due to the fact that RAI was not fully implemented and even the partial implementation lasted much longer than expected. Moreover, the number of clients included in the study was smaller than originally planned.

Magnetic frustration in a quantum spin chain: the case of linarite PbCuSO4(OH)2.

We present a combined neutron diffraction and bulk thermodynamic study of the natural mineral linarite PbCuSO4(OH)2, this way establishing the nature of the ground-state magnetic order. An incommensurate magnetic ordering with a propagation vector k=(0,0.186,1/2) was found below T(N)=2.8 K in a zero magnetic field. The analysis of the neutron diffraction data yields an elliptical helical structure, where one component (0.638µ(B)) is in the monoclinic ac plane forming an angle with the a axis of 27(2)°, while the other component (0.833µ(B)) points along the b axis. From a detailed thermodynamic study of bulk linarite in magnetic fields up to 12 T, applied along the chain direction, a very rich magnetic phase diagram is established, with multiple field-induced phases, and possibly short-range-order effects occurring in high fields. Our data establish linarite as a model compound of the frustrated one-dimensional spin chain, with ferromagnetic nearest-neighbor and antiferromagnetic next-nearest-neighbor interactions. Long-range magnetic order is brought about by interchain coupling 1 order of magnitude smaller than the intrachain coupling.

Hypercapnic coma due to spontaneous pneumothorax: case report and review of the literature.

BACKGROUND: Hypercapnic coma is a rare differential diagnosis in the unconscious patient. One underlying mechanism may be hypoventilation due to spontaneous pneumothorax. Although hypercapnia is not a typical finding in spontaneous pneumothorax in patients with otherwise healthy lungs, under certain circumstances, hypercapnia may readily develop. OBJECTIVES: We report a rare case of profound hypercapnic coma due to spontaneous pneumothorax after contralateral pneumonectomy. In addition, we review other causes of hypercapnic coma and its outcome and discuss the relationship between arterial carbon dioxide partial pressure and level of consciousness. CASE REPORT: An 85-year-old man without evidence of trauma or intoxication presented unconscious to our Emergency Department. The physical examination and X-ray study revealed a left-sided spontaneous pneumothorax. A right-sided pneumonectomy 25 years earlier had promoted the development of profound hypercapnic coma. After insertion of a thoracic drain, the coma rapidly resolved without any neurological deficit. CONCLUSIONS: Although severe hypercapnia is usually due to decompensation of chronic lung disease, pneumothorax potentially may cause hypercapnic coma. Review of the literature suggests that there is no close correlation between arterial pCO(2) (partial pressure of CO(2)) levels and the degree of impairment of consciousness; however, levels exceeding 80 mm Hg are likely associated with significantly impaired consciousness. Hypercapnic coma usually resolves without neurological deficit as arterial pCO(2) tensions decline.

[Cutaneous and pulmonary sarcoidosis. Successful therapy with fumaric acid esters]. / Kutane und pulmonale Sarkoidose. Erfolgreiche Therapie mit Fumarsäureestern.

A 43-year-old man with cutaneous and pulmonary sarcoidosis was treated with fumaric acid esters (Fumaderm®) for 11 months because of the cutaneous lesions. During the treatment the cutaneous lesions and pulmonary changes vanished completely. In addition, serum angiotensin converting enzyme (ACE) levels normalized after end of therapy. This case report is one of a few examples of the successful treatment of cutaneous and pulmonary sarcoidosis with fumaric acid esters (Fumaderm®).

Effects of the Resident Assessment Instrument in home care settings: results of a cluster randomized controlled trial.

Deficits in quality, a lack of professional process management and, most importantly, neglect of outcome quality are criticized in long-term care. A cluster randomized, controlled trial was conducted to assess whether the Resident Assessment Instrument (RAI) can help to improve or stabilize functional abilities (ADL, IADL) and cognitive skills (MMST), improve quality of life (EQ-5D), and reduce institutionalization, thereby, increasing outcome quality. A total of 69 home care services throughout Germany were included and randomized. The treatment group (n = 36) received training in RAI and was supported by the research team during the study (13 months). Comparison of mean differences between the treatment and control groups (n = 33) showed no significant effect. Although the multilevel regression results show that clients in the treatment group fared better in terms of ADLs and IADLs (smaller decline) and were less likely to move to nursing homes and be hospitalized, none of these effects is significant. The lack of significance might result from the small number of clients included in the study. Moreover, RAI was not fully implemented and even partial implementation required more time than expected.

[Influence of nosocomial infections on resection of tracheal stenosis after tracheotomy]. / Bedeutung nosokomialer Infektionen bei derResektion trachealer Stenosen nach Tracheotomie.

BACKGROUND: Complications located at the tracheostoma often occur in combination with nosocomial infections. We posed the question: how is the surgical result in tracheal resections influenced by bacterial contamination with multiresistant germs? PATIENTS AND METHODS: Between 2005 and 2009 we performed a primary end-to-end-resection of the trachea after tracheotomy in 30 patients. The demographic basic data, the diagnostic data on tracheal stenosis after decanullation and type of tracheotomy were documented. Preoperatively all patients underwent a flexible bronchoscopy with bronchial lavage. All patients received an antibiotic inhalation therapy postoperatively. RESULTS: 16 patients presented a status post-permanent tracheotomy (PT), in 14 cases after percutaneous dilatative tracheotomy (PDT). In 64 % of all cases the preoperative bronchial lavage was positive for bacterial contamination. The major pathogen was with 23 % a multiresistant Pseudomonas aeruginosa (MR). In three cases long-term-complications occurred, all of which were bacterially contaminated. CONCLUSION: After long-term intubation a bacterial contamination is very common and presents a negative predictor for the outcome of primary tracheal end-to-end resections. A prophylactic postoperative antibiotic therapy can improve the short- and long-term results.

Spin gap in the zigzag spin-1/2 chain cuprate Sr(0.9)Ca(0.1)CuO(2).

We report a comparative study of (63)Cu nuclear magnetic resonance spin lattice relaxation rates T(1)(-1) on undoped SrCuO(2) and Ca-doped Sr(0.9)Ca(0.1)CuO(2) spin chain compounds. A temperature independent T(1)(-1) is observed for SrCuO(2) as expected for an S=1/2 Heisenberg chain. Surprisingly, we observe an exponential decrease of T(1)(-1) for T<90 K in the Ca-doped sample evidencing the opening of a spin gap. The data analysis within the J(1)-J(2) Heisenberg model employing density-matrix renormalization group calculations suggests an impurity driven small alternation of the J(2)-exchange coupling as a possible cause of the spin gap.

[Response and remission in schizophrenic subjects]. / Response und Remission bei an Schizophrenie erkrankten Patienten.

BACKGROUND: This naturalistic study investigates in detail symptom reduction during acute inpatient treatment (response), long-term symptom improvement in the post-acute phase (remission) and the rate of re-hospitalisations. MATERIAL AND METHODS: A total of 183 patients were enrolled. Criteria for response were PANSS total score and syndrome reductions of 20, 30, 40 and 50%. Remission criteria employed were based on recommendations from Andreasen et al. RESULTS: The average length of stay was 45.6 days (SD 42.7). PANSS total score response rates were found to be 63.9% for the 20% level and were reduced in the following consecutive levels by approximately 15%. Only 10.3% of the patients remitted during a 1-year follow-up period. At least one re-hospitalisation was reported for 43.9% of the subjects. CONCLUSION: Compared to previous randomised and controlled trials, the rates of response and remission are significantly lower. In daily inpatient care, the chronic course of schizophrenia is far commoner than expected from previous reports.