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BackgroundAttention on harmful effects of psychological interventions for adult post-traumatic stress disorder (PTSD) has increased, yet a comprehensive meta-analysis is lacking.AimsTo summarise incidences and relative risks of deterioration, adverse events (AEs) and serious adverse events (SAEs) in trials of psychological interventions for adult PTSD.MethodWe searched MEDLINE, PsycInfo, Web of Science and PTSDpubs from inception to 21 April 2022 for sufficiently large (n ≥ 20) randomised controlled trials (RCTs) reporting on the incidence of harms.ResultsWe included 56 RCTs (4230 patients). Incidences of harms were generally low (0–5%). Psychological interventions were associated with decreased risk of deterioration relative to passive (RR = 0.21, 95% CI 0.15–0.28) and active control conditions (RR = 0.36, 95% CI 0.14–0.92). Decreased risk was even more pronounced in sensitivity analyses on trials exclusively delivering treatments face to face. When compared with other psychological interventions, trauma-focused cognitive–behavioural therapy (TF-CBT) was associated with decreased risk of SAEs (RR = 0.54, 95% CI 0.31–0.95) and with no differential risk of deterioration and AEs.ConclusionsThe current evidence base suggests that psychological interventions are safe for most adults with PTSD. In none of the analyses were psychological interventions associated with an increased risk of harm compared with control conditions. TF-CBT was found at least as safe as other psychological interventions. Individual face-to-face delivery might be the safest delivery format. However, more data are needed to draw firmer conclusions. We encourage research teams to routinely and thoroughly assess and report the incidence of harms and their causes.

We present results on the search for two-neutrino double-electron capture (2νECEC) of 124Xe and neutrinoless double-β decay (0νββ) of 136Xe in XENON1T. We consider captures from the K shell up to the N shell in the 2νECEC signal model and measure a total half-life of T2νECEC1/2=(1.1±0.2stat±0.1sys)×1022yr with a 0.87kgyr isotope exposure. The statistical significance of the signal is 7.0σ. We use XENON1T data with 36.16kgyr of 136Xe exposure to search for 0νββ. We find no evidence of a signal and set a lower limit on the half-life of T0νββ1/2>1.2×1024yrat90%CL. This is the best result from a dark matter detector without an enriched target to date. We also report projections on the sensitivity of XENONnT to 0νββ. Assuming a 275kgyr 136Xe exposure, the expected sensitivity is T0νββ1/2>2.1×1025yrat90%CL, corresponding to an effective Majorana mass range of ⟨mββ⟩

Description, Membrane-based heterostructure, verified experimentally and theoretically, opens possibiliies for low-power magnetoelectrics., Strain-mediated magnetoelectric (ME) coupling in ferroelectric (FE)/ferromagnetic (FM) heterostructures offers a unique opportunity for both fundamental scientific research and low-power multifunctional devices. Relaxor-FEs, such as (1 − x)Pb(Mg1/3Nb2/3)O3-(x)PbTiO3 (PMN-xPT), are ideal FE layer candidates because of their giant piezoelectricity. However, thin films of PMN-PT suffer from substrate clamping, which substantially reduces piezoelectric in-plane strains. Here, we demonstrate low-voltage ME coupling in an all-thin-film heterostructure that uses the anisotropic strains induced by the (011) orientation of PMN-PT. We completely remove PMN-PT films from their substrate and couple with FM Ni overlayers to create membrane PMN-PT/Ni heterostructures showing 90° Ni magnetization rotation with 3 V PMN-PT bias, much less than the bulk PMN-PT ~100-V requirement. Scanning transmission electron microscopy and phase-field simulations clarify the membrane response. These results provide a crucial step toward understanding the microstructural behavior of PMN-PT thin films for use in piezo-driven ME heterostructures.

Bulk single-crystal relaxor-ferroelectrics, like Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT), are widely known for their large piezoelectricity. This is attributed to polarization rotation which is facilitated by the presence of various crystal symmetries for compositions near a morphotropic phase boundary (MPB). Relaxor-ferroelectric thin films, which are necessary for low-voltage applications, suffer a reduction in their piezoelectric response due to clamping by the passive substrate. To understand the microscopic behavior of this adverse phenomenon, we employ AC electric field driven in-operando synchrotron x-ray diffraction (XRD) on patterned device structures to investigate the piezoelectric domain behavior under an electric field for both a clamped (001) PMN-PT thin film on Si and a (001) PMN-PT membrane released from its substrate. In the clamped film, the substrate inhibits the field induced rhombohedral (R) to tetragonal (T) phase transition resulting in a reversible R to Monoclinic (M) transition with a reduced longitudinal piezoelectric coefficient d33 < 100 pm/V. Releasing the film from the substrate results in recovery of the R to T transition and results in a d33 > 1000 pm/V. Using diffraction with spatial mapping, we find that lateral constraints imposed by the boundary between active and inactive material also inhibits the R to T transition. Phase-field calculations on both clamped and released PMN-PT thin films simulate our experimental findings. Resolving the suppression of thin film piezoelectric response is critical to their application in piezo-driven technologies.

Background Heart failure (HF) is a major cause of cardiovascular morbidity and mortality. Despite recent advances in diagnosis and management of HF, the prognosis remains poor. HF and chronic kidney disease (CKD) are interlinked chronic health conditions. The availability of large volume of patient data and modern analytic techniques opens new opportunities for identification of individuals at elevated risk of HF. Purpose Develop risk prediction model for HF hospitalizations (HHF) in patients with non-diabetic CKD by applying data-driven computational intelligence techniques to a US population-based administrative claims database. Methods Individual-level data from the US Optum Clinformatics Data Mart for years 2008–2018 were analysed. To be eligible for inclusion, adult individuals were required to have non-diabetic CKD stage 3 or 4 (index event) and one year continuous insurance coverage prior to the index date (baseline period). Selection criteria and the main clinical outcome, hospitalisation for heart failure (HHF), were identified by using laboratory tests results and/or specific codes from common clinical coding systems. Risk prediction model for HHF was built on patient data in the baseline period composed to more than 6,000 variables. Computational intelligence method based on ant colony optimization was used to develop a time-to-first-event risk prediction model for HHF. Results Of the 64 million individuals in the database, 504,924 satisfied the selection criteria. Median age was 75 years, 60% were female. Among most common baseline comorbidities were hypertension (85%) and hyperlipidaemia (68%). Coronary artery disease, HF, atrial fibrillation and peripheral artery disease were recorded in 24%, 16%, 15% and 14% of individuals. Over a median follow-up of 744 days, 53,282 (11%) patients had recorded HHF, the corresponding incidence rate was 3.95 events/100 patient-years. The developed risk prediction model for HHF in non-diabetic CKD contained 20 risk factors. The five strongest risk factors were history of HF, intake of loop diuretics, severely increased albuminuria, atrial fibrillation or flutter and CKD 4 as observed “yes/no” in the baseline period. Fig. 1 depicts the final risk prediction model. To assess model performance, all patients in the cohort were stratified into five HHF risk groups. For each group, a Kaplan-Meier curve was built based on the HHF outcome data in the database. Fig. 2 shows clear separation between the curves, demonstrating high performance of the developed risk prediction model. Conclusion Despite many existing scores to predict HHF, their use is limited. Some scores rely on availability of rarely collected information, some are applicable for specific patient populations only. Risk prediction model for HHF in non-diabetic CKD is presented, which contains risk factors routinely collected by healthcare providers. Therefore, it might be applicable for HHF risk estimation in various settings. Funding Acknowledgement Type of funding sources: Other. Main funding source(s): Bayer AG Forest plot of HHF risk prediction modelKaplan-Meier plot of risk strata

Complex-oxide materials exhibit a vast range of functional properties desirable for next-generation electronic, spintronic, magnetoelectric, neuromorphic, and energy conversion storage devices1-4. Their physical functionalities can be coupled by stacking layers of such materials to create heterostructures and can be further boosted by applying strain5-7. The predominant method for heterogeneous integration and application of strain has been through heteroepitaxy, which drastically limits the possible material combinations and the ability to integrate complex oxides with mature semiconductor technologies. Moreover, key physical properties of complex-oxide thin films, such as piezoelectricity and magnetostriction, are severely reduced by the substrate clamping effect. Here we demonstrate a universal mechanical exfoliation method of producing freestanding single-crystalline membranes made from a wide range of complex-oxide materials including perovskite, spinel and garnet crystal structures with varying crystallographic orientations. In addition, we create artificial heterostructures and hybridize their physical properties by directly stacking such freestanding membranes with different crystal structures and orientations, which is not possible using conventional methods. Our results establish a platform for stacking and coupling three-dimensional structures, akin to two-dimensional material-based heterostructures, for enhancing device functionalities8,9.

Strain-coupled magnetoelectric (ME) phenomena in piezoelectric / ferromagnetic thin-film bilayers are a promising paradigm for sensors and information storage devices, where strain is utilized to manipulate the magnetization of the ferromagnetic film. In-plane magnetization rotation with an electric field across the film thickness has been challenging due to the virtual elimination of in-plane piezoelectric strain by substrate clamping, and to the requirement of anisotropic in-plane strain in two-terminal devices. We have overcome both of these limitations by fabricating lithographically patterned devices with a piezoelectric membrane on a soft substrate platform, in which in-plane strain is freely generated, and a patterned edge constraint that transforms the nominally isotropic piezoelectric strain into the required uniaxial strain. We fabricated 500 nm thick, (001) oriented [Pb(Mg$_{1/3}$Nb$_{2/3}$)O$_3$]$_{0.7}$-[PbTiO$_3$]$_{0.3}$ (PMN-PT) unclamped piezoelectric membranes with ferromagnetic Ni overlayers. Guided by analytical and numerical continuum elastic calculations, we designed and fabricated two-terminal devices exhibiting Ni magnetization rotation in response to an electric field across the PMN-PT. Similar membrane heterostructures could be used to apply designed strain patterns to many other materials systems to control properties such as superconductivity, band topology, conductivity, and optical response.

Understanding magnetic domain structures and their responses to electric fields in multiferroic heterostructures is critical to the design of electric-field-driven spintronic devices. High-throughput finite-element and phase-field simulations are performed to probe the piezoelectric strain anisotropy and its relaxation, magnetic domain structures and their responses to applied voltages as function of the in-plane dimensions and thickness of the magnetic Ni nanoislands grown on a Pb(Mg 1/3 Nb 2/3 )O 3 -PbTiO 3 (PMN-PT) membrane. The piezoelectric strain anisotropy is found to increase with the in-plane aspect ratio, but it can be significantly relaxed, as large as >80%, in nanoislands of thickness larger than >15 nm. Magnetic domain diagrams are established to identify the domain structures for Ni nanoislands of different lengths of in-plane major and minor axis, as well as thickness. When a voltage is applied to the multiferroic heterostructure, the single-domain magnetic domain can be switched by the piezoelectric strain, whereas the vortex domain is not switched. However, for a multiferroic heterostructure with a thick nanoisland wherein most of the piezoelectric strain is relaxed, the single-domain magnetic domain shows a weak response to the voltage and cannot be switched. The effect of thickness variation in real magnets on the switching is also discussed. The present results are expected to provide guidance to the understanding and design of multiferroic nanostructures for achieving electric-field-modulated magnetic properties.

The control of the in-plane domain evolution in ferroelectric thin films is not only critical to understanding ferroelectric phenomena but also to enabling functional device fabrication. However, in-plane polarized ferroelectric thin films typically exhibit complicated multi-domain states, not desirable for optoelectronic device performance. Here we report a strategy combining interfacial symmetry engineering and anisotropic strain to design single-domain, in-plane polarized ferroelectric BaTiO3 thin films. Theoretical calculations predict the key role of the BaTiO3/PrScO3 \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${({{{{{\boldsymbol{110}}}}}})}_{{{{{{\bf{O}}}}}}}$$\end{document}(110)O substrate interfacial environment, where anisotropic strain, monoclinic distortions, and interfacial electrostatic potential stabilize a single-variant spontaneous polarization. A combination of scanning transmission electron microscopy, piezoresponse force microscopy, ferroelectric hysteresis loop measurements, and second harmonic generation measurements directly reveals the stabilization of the in-plane quasi-single-domain polarization state. This work offers design principles for engineering in-plane domains of ferroelectric oxide thin films, which is a prerequisite for high performance optoelectronic devices., In-plane polarized ferroelectric thin films typically exhibit complicated multidomain states, not desirable for optoelectronic device performance. Here, the authors combine interfacial symmetry engineering and anisotropic strain to design single-domain in-plane polarized ferroelectric BaTiO3 films.

Understanding magnetic domain structures and their responses to electric fields in multiferroic heterostructures is critical to the design of electric-field-driven spintronic devices. High-throughput finite-element and phase-field simulations are performed to probe the piezoelectric strain anisotropy and its relaxation, magnetic domain structures and their responses to applied voltages as function of the in-plane dimensions and thickness of the magnetic Ni nanoislands grown on a Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) membrane. The piezoelectric strain anisotropy is found to increase with the in-plane aspect ratio, but it can be significantly relaxed, as large as >80%, in nanoislands of thickness larger than >15 nm. Magnetic domain diagrams are established to identify the domain structures for Ni nanoislands of different lengths of in-plane major and minor axis, as well as thickness. For Ni nanoislands with a circular in-plane geometry, an analytical function describing the relationship between the critical thickness hcritical and the in-plane diameter is obtained based on high-throughput calculations. When a voltage is applied to the multiferroic heterostructure, the single-domain magnetic domain can be switched by the piezoelectric strain, whereas the vortex domain is not switched. However, for a multiferroic heterostructure with a thick nanoisland wherein most of the piezoelectric strain is relaxed, the single-domain magnetic domain shows a weak response to the voltage and cannot be switched by the voltage. The present results are expected to provide guidance to the understanding and design of multiferroic nanostructures for achieving electric-field-modulated magnetic properties.

The XENON1T liquid xenon time projection chamber is the most sensitive detector built to date for the measurement of direct interactions of weakly interacting massive particles with normal matter. The data acquisition system (DAQ) is constructed from commercial, open source, and custom components to digitize signals from the detector and store them for later analysis. The system achieves an extremely low signal threshold below a tenth of a photoelectron using a parallelized readout with the global trigger deferred to a later, software stage. The event identification is based on MongoDB database queries and has over 97% efficiency at recognizing interactions at the analysis energy threshold. A readout bandwidth over 300 MB/s is reached in calibration modes and is further expandable via parallelization. This DAQ system was successfully used during three years of operation of XENON1T., 14 pages, 6 figures, submitted to JINST; Version 2 with minor updates to text

Coronary restenosis is the answer of the arterial wall to a mechanical violation through balloon angioplasty, bare-metal (BM) stent implantation or rotational atherectomy through repeated narrowing. It has great clinical and prognostic relevance and occurs in approximately 30% of non-coated stents and in 10% of coated coronary stents. The wound healing process that precedes restenosis includes inflammatory reactions, cellular proliferation and remodeling of the arterial wall, where protein synthesis of the extracellular matrix is initiated. The inflammatory reaction activates platelets, leucocytes and monocytes and stimulates smooth muscle cells. The medications on the drug-eluting stents (rapamycin, paclitaxel, sirolimus, evarolimus and zotarolimus) inhibit cell division, are cytotoxic and only these sustainably influence restenosis. Whether they play a role in neoatherosclerosis needs to be determined. The mechanism of restenosis with implantation of drug-eluting stents is heterogeneous and associated with the deposition of T‑lymphocytes and fibrin. Risk factors for the development of restenosis include mechanical factors, such as incorrect apposition and expansion of stents, inflammation, diabetes mellitus, genetic factors, bypass operations, stent length and stent diameter. The restenosis rate is lower with drug-eluting stents and must be considered differently between the drug-eluting stents. Drug-eluting stents of the latest generation and drug-coated balloons (DCB) showed the best clinical and angiographic results for in-stent restenosis in randomized trials. The BM and older first-generation drug-eluting stents should be avoided. Further randomized studies are needed.

Extreme climatic events and their hazards have strong impact on society. Urban areas in Brazil are especially vulnerable to the impact of such events due to their rapid growth and inappropriate infrastructure. Viçosa is a mid-sized city in Southeastern Brazil that has been experiencing issues associated with urban expansion and population growth since the 1960s. Thus, this study aims to identify patterns of extreme climate events in Viçosa based on daily temperature and precipitation time series (1968-2017). Homogeneity tests were carried out in order to identify breaking points in these climate variables. Climate trends were analyzed through Mann-Kendall test and their magnitude was checked based on Sen’s slope. Results have evidenced statistically significant and increasing trends in annual minimum temperature since the 1990s. Moreover, statistically significant breaking points in extreme temperature indices have shown increasing number of warm days, and decreasing number of cold nights, in both annual and seasonal analyses. Extreme climatic events have been observed more often in recent years, mainly in the number of consecutive dry days and maximum and heavy precipitation days. Based on results, Viçosa experiences warmer conditions throughout the year, whereas more (less) torrential rainfall events have been occurring during Summer (Winter).

In southern New England forests, small mammals provide essential contributions to ecosystem functioning via food-web interactions and seed dispersal. This region has been exposed to extensive habitat fragmentation due to residential and agricultural development, resulting in a considerable amount of edge habitat, in addition to naturally occurring landscape heterogeneity. Limited research has been conducted relating small-mammal species richness and abundance to different types of edge habitat in this region. Studies incorporating an analysis of variation in both fine-scale vegetation and coarse-scale landscape variation are even more limited. We compared small-mammal richness, total abundance, and abundance of Peromyscus maniculatus (Deer Mouse), Peromyscus leucopus (White-footed Mouse), Myodes gapperi (Red-backed Vole), Tamias striatus (Eastern Chipmunk), and Tamiasciurus hudsonicus (Eastern Red Squirrel) at developed-edge, wetland-edge, and forest-interior sites. We also measured vegetation and landscape variables to understand how variation in characteristics at different scales affected small-mammal measures. We selected 4 sites of each edge type and used Sherman live-traps during the summers of 2009–2010 to survey small-mammal populations (75 traps for 4 nights at 12 sites for 2 y = 7200 trap-nights). We did not find differences among edge types and interior forest for total abundance, richness, and abundance of the 5 small-mammal species with sufficient data for analysis. However, vegetation variables and landscape variables were significantly associated with small-mammal populations. Step-wise linear regression included vegetation variables for 4 of the 5 species, and various landscape scales were included in all analyses except abundance of Peromyscus adults. Patch size was included in 4 analyses (positive for total abundance, White-footed Mouse, and Red-backed Vole; negative for Eastern Chipmunk). We found conifer basal area to have a positive relationship with abundance of Peromyscus adults and Red-backed Voles, but a negative relationship with abundance of Peromyscus juveniles and Eastern Red Squirrels. Species abundance and richness of small-mammal communities and populations in northeastern Massachusetts were related to both fine-scale vegetation differences and coarse-scale landscape metrics, but these relationships were complex and scale-dependent.

Background: Sagopilone (ZK-EPO) is a fully synthetic microtubule-stabilizing agent that has demonstrated high antitumor activity in preclinical models. This first-in-human phase I study aimed to determine the maximum tolerated dose (MTD) and dose-limiting toxic effects (DLTs) of 3-weekly sagopilone treatment. Patients and methods: A total of 52 patients with advanced solid tumors received a 30-min infusion of escalating doses of sagopilone (0.6-29.4 mg/m(2)) every 3 weeks. Nine additional patients were recruited to a 3-h infusion arm (16.53-or 22.0-mg/m(2) dose) to assess the incidence of neuropathy with prolonged infusion. Results: The MTD was established as 22.0 mg/m(2). DLTs comprised peripheral sensory neuropathy (PNP), infection, hyponatremia, diarrhea, and central ataxia. PNP was the most common grade 3 event, with a similar incidence in the 30-min and 3-h arms. Hematologic adverse events were rare and of low intensity. One confirmed partial response (PR) and one unconfirmed PR were reported in the 30-min arm, and a further unconfirmed PR was observed in the 3-h arm. Eleven patients achieved disease stabilization. Sagopilone showed high levels of tissue binding and no obvious serum accumulation in both arms. Conclusions: These data demonstrate that sagopilone therapy is feasible and well tolerated. The recommended dose for phase II studies is 16.53 mg/m(2), once every 3 weeks.

Background: Epothilones are a novel class of microtubule-stabilising agents, and sagopilone is a fully synthetic epothilone that has shown marked in vivo and in vitro preclinical activity. Methods: This phase I, open-label study investigated the maximum tolerated dose (MTD) and dose-limiting toxicities (DLTs) of weekly sagopilone. Twenty-three patients with malignancy resistant or refractory to standard treatment were enrolled into this study evaluating sagopilone doses from 0.6 to 7.0 mg m−2. Results: The incidence of drug-related haematological adverse events (AEs) was low, with two grade 3 events observed. Nonhaematological AEs were generally mild and reversible; increased γ-GT was the only grade 4 event and grade 3 events comprised peripheral neuropathy (n=2), diarrhoea (n=1) and fatigue (n=1). Two grade 3 events were DLTs (diarrhoea and peripheral neuropathy at 7.0 mg m−2). The MTD of weekly sagopilone was therefore established as 5.3 mg m−2. Stable disease was the best overall response (n=3). Microtubule bundle formation in peripheral blood mononuclear cells increased post-treatment, peaking after 1 h. Sagopilone disposition was similar across treatment courses and showed rapidly decreasing serum concentrations after infusion end and a long terminal disposition phase with no obvious accumulation in the serum, probably reflecting a fast uptake into tissues followed by a slow release. Conclusion: Weekly administration of sagopilone could represent an alternative to the 3-weekly administration currently evaluated in phase II trials.

ZusammenfassungThrombozyten spielen die zentrale Rolle bei der Entstehung koronarer Thrombosen. Eine gesteigerte systemische Thrombozytenaktivierung trägt maßgeblich zur Pathophysiologie des akuten Koronarsyndroms bei. Trotz fortschrittlicher interventioneller Techniken und zunehmend besserer pharmakologischer Begleittherapie bleibt das Ausmaß der Thrombozytenaktivierung ein Faktor, der die Gesamtprognose signifikant beeinflusst. Eine residuelle Thrombozytenaktivierung nach Stentimplantation hängt oft mit einer gesteigerten initialen Thrombozytenaktivierung zusammen. Eine wirksame antithrombozytäre Therapie ist entscheidend in der Akuttherapie und in der Sekundärprophylaxe bei Patienten nach koronaren Interventionen oder akutem Koronarsyndrom. Die Effizienz der antithrombotischen Therapie beeinflusst entscheidend die Langzeitprognose bei diesen Patienten.

The release of the antibiotic pradofloxacin from a new ocular insert called the OphthaCoil was evaluated. The ocular insert consists of a drug-loaded adherent hydrogel on a thin wire, which is coiled. The inner lumen of the coil was filled with a polymer rod made from a poly(2-hydroxyethyl methacrylate) hydrogel and loaded with the same drug. The in vitro release of pradofloxacin and its pharmacokinetics in dog tear fluid was evaluated over a 72-h time interval. The results show that in vitro release is faster than in vivo release, probably because the refresh time for tear fluid in the eye is slower than in the in vitro experiments. In vivo, the drug level in the tear fluid remained within the concentration range during the entire 72 h, which is when pradofloxacin is expected to be active against the most relevant bacteria species involved in canine conjunctival infections. These results are quite promising for the future application of the OphthaCoil in veterinary or human ophthalmology.

Laterally de2ned quantum dot structures have been fabricated on the basis of AlxGa1−xAs parabolic quantum wells which allow the occupation of more than one subband in growth direction. Magneto-Coulomb oscillations allow the determination of a gate parameter regime where the states of the secondsubbandare occupiedin the quantum d The occupation of the secondsubbandin the d ot comes along with 5uctuations in the cond uctance peaks at zero magnetic 2eldwhich we characterize with time dependent measurements. We discuss the possibility that the 5uctuations are an intrinsic property of the d ot at the threshholdto two occupiedsubband s. ? 2002 Elsevier Science B.V. All rights reserved.

Native potato starch has been processed without the use of any additive. Moldings of initial high strength and ductility have been achieved. However, mechanical properties change with time. Thermogravimetric experiments at different temperatures show that aging takes place in three different steps. The first is characterized by a strong formation of double helices (as revealed by wide-angle X-ray scattering [WAXS]) in parallel with strong water loss. Hardness, strength, and elongation at break increase in this time range: Double helices act as reinforcing elements. When the yield elongation is surpassed, double helices are unraveled, providing a higher elongation at break. With further aging (drying), due to a shrinking process, a temporary reduction of double helices, causing a resoftening, seems to take place. In a third step, the starch moldings become quite brittle due to the lack of molecular mobility. At room conditions, it takes approximately 1 year (beginning of range 3) to lose the good mechanica...

The temperature dependence of the conductance of a quantum point contact has been measured. The conductance as a function of the Fermi energy shows temperature-independent fixed points, located at roughly multiple integers of $e^{2}/h$. Around the first fixed point at e$^{2}$/h, the experimental data for different temperatures can been scaled onto a single curve. For pure thermal smearing of the conductance steps, a scaling parameter of one is expected. The measured scaling parameter, however, is significantly larger than 1. The deviations are interpreted as a signature of the potential landscape of the quantum point contact, and of the source-drain bias voltage. We relate our results phenomenologically to the metal-insulator transition in two dimensions., Comment: 5 pages, 3 figures