Flexible and wearable e-skin sensors are attracting a great interest for their smart sensing applications in next-generation electronics. However, implant ability, sensitivity, and biosignal ...detection capability in a self-powered manner are the prime concerns in embedded devices. In particular, electrode compatibility and imperishability have become challenging issues in wearable sensors due to the poor compatibility and fragileness of metal electrodes. In this context, we report on a skin-interactive metal-free spongy electrode in a piezoelectric sensor where highly aligned poly(vinylidene fluoride) (PVDF) nanofibers (NFs) arrays are introduced as the piezoelectric active component and conducting polyaniline- (PANI-) coated PVDF (PANI–PVDF) NFs mats served as flexible electrodes. Notably, a 99% yield of piezoelectric phases of the aligned PVDF arrays is the key factor to exhibit promising mechano-sensitivity (0.8 V/kPa) performance that in turn helps in human-health monitoring. The sensor shows excellent mechanical to electrical energy conversion that enable to sense human finger touch (10 V under 10 kPa) with energy conversion efficiency of 53%. Most importantly, due to the compatible electrodes excellent mechanical stability has been found showing negligible degradation over 12,000 periodic cycles. Furthermore, under mechanical stimuli, it is also possible to charge up a capacitor (1 μF) to 4 V within 60 s confirming the possibility to use the device as a self-powered piezo-organic-e-skin sensor (POESS). This type of structural design enables to trace elusive movement of muscles and the operation in several conditions such as bending, compression and stretching. We demonstrated various human gestures monitoring, such as wrist bending, neck stretching, and arm compressions, throat movements during drinking water, coughing actions, and swallowing. In addition, diverse specific phonation recognition, heart-pulse measurement and its respective short-time Fourier transform (STFT) analysis indicate an efficient and convenient way of monitoring human-health status particularly in hospital-free mode.
Cerium(III)-N,N-dimethylformamide-bisulfate Ce(DMF)(HSO4)3 complex is doped into poly(vinylidene fluoride) (PVDF) to induce a higher yield (99%) of the electroactive phases (β- and γ-phases) of ...PVDF. A remarkable enhancement of the output voltage (∼32 V) of a nanogenerator (NG) based on a nonelectrically poled cerium(III) complex containing PVDF composite film is achieved by simple repeated human finger imparting, whereas neat PVDF does not show this kind of behavior. This high electrical output resembles the generation of self-poled electroactive β-phase in PVDF due to the electrostatic interactions between the fluoride of PVDF and the surface-active positive charge cloud of the cerium complex via H-bonding and/or bipolar interaction among the opposite poles of cerium complex and PVDF, respectively. The capacitor charging capability of the flexible NG promises its applicability as piezoelectric-based energy harvester. The cerium(III) complex doped PVDF composite film exhibit an intense photoluminescence in the UV region, which might be due to a participation of electron cloud from negative pole of bipolarized PVDF. This fact may open a new area for prospective development of high-performance energy-saving flexible solid-state UV light emitters.
Silicon is one of the most promising materials to be used for tandem‐cell water‐splitting devices. However, the electrochemical instability of bare Si makes it difficult to be used for stable ...devices. Besides that, the photovoltage loss in Si, caused by several factors (e.g., metal oxide protection layer and/or SiO2/Si or catalyst/Si interface), limits its use in these devices. In this work, we present that an optimized open circuit potential (OCP) of Si can be obtained by controlling the SiOx thickness in sub‐nanometer range. It can be done by means of a simple and cost‐effective way using the combination of a wet chemical etching and the low temperature atomic layer deposition (ALD) of TiO2. We have found that a certain thickness of the native SiOx is necessary to prevent further oxidation of the Si photocathode during the ALD growth of TiO2. Moreover, covering the Si photocathode with an ALD TiO2 layer enhances its stability.
OCP optimized: The effect of the interfacial SiOx thickness on the open circuit potential of Si photocathode is studied. The SiOx interfacial thickness is controlled by combining wet chemical etching and low temperature atomic layer deposition (ALD) of metal oxide. It has been observed that a SiOx thickness of around 0.6 nm provides optimized open circuit potential.
Even today, patients with schizophrenia often have an unfavorable outcome. Negative symptoms and cognitive deficits are common features in many patients and prevent recovery. In recent years, aerobic ...endurance training has emerged as a therapeutic approach with positive effects on several domains of patients’ health. However, appropriately sized, multicenter randomized controlled trials that would allow better generalization of results are lacking. The exercise study presented here is a multicenter, rater-blind, two-armed, parallel-group randomized clinical trial in patients with clinically stable schizophrenia being conducted at five German tertiary hospitals. The intervention group performs aerobic endurance training on bicycle ergometers three times per week for 40–50 min/session (depending on the intervention week) for a total of 26 weeks, and the control group performs balance and tone training for the same amount of time. Participants are subsequently followed up for 26 weeks. The primary endpoint is
all-cause discontinuation
; secondary endpoints include psychopathology, cognition, daily functioning, cardiovascular risk factors, and explorative biological measures regarding the underlying mechanisms of exercise. A total of 180 patients will be randomized. With currently 162 randomized participants, our study is the largest trial to date to investigate endurance training in patients with schizophrenia. We hypothesize that aerobic endurance training has beneficial effects on patients’ mental and physical health, leading to lower treatment discontinuation rates and improving disease outcomes. The study results will provide a basis for recommending exercise interventions as an add-on therapy in patients with schizophrenia.The study is registered in the International Clinical Trials Database (ClinicalTrials.gov identifier NCT number: NCT03466112) and in the German Clinical Trials Register (DRKS-ID: DRKS00009804).
We report on results on the preparation of thin (<100 nm) aluminum oxide (Al2O3) films on silicon substrates using thermal atomic layer deposition (T-ALD) and plasma enhanced atomic layer deposition ...(PE-ALD) in the SENTECH SI ALD LL system. The T-ALD Al2O3 layers were deposited at 200 °C, for the PE-ALD films we varied the substrate temperature range between room temperature (rt) and 200 °C. We show data from spectroscopic ellipsometry (thickness, refractive index, growth rate) over 4" wafers and correlate them to X-ray photoelectron spectroscopy (XPS) results. The 200 °C T-ALD and PE-ALD processes yield films with similar refractive indices and with oxygen to aluminum elemental ratios very close to the stoichiometric value of 1.5. However, in both also fragments of the precursor are integrated into the film. The PE-ALD films show an increased growth rate and lower carbon contaminations. Reducing the deposition temperature down to rt leads to a higher content of carbon and CH-species. We also find a decrease of the refractive index and of the oxygen to aluminum elemental ratio as well as an increase of the growth rate whereas the homogeneity of the film growth is not influenced significantly. Initial state energy shifts in all PE-ALD samples are observed which we attribute to a net negative charge within the films.
Cerebral dopamine (DA) transmission is thought to be an important modulator for the development and occurrence of aggressive behavior. However, the link between aggression and DA transmission in ...humans has not been investigated using molecular imaging and standardized behavioral tasks. We investigated aggression as a function of DA transmission in a group of (N = 21) healthy male volunteers undergoing 6-18F-fluoro-L-DOPA (FDOPA)-positron emission tomography (PET) and a modified version of the Point Subtraction Aggression Paradigm (PSAP). This task measures aggressive behavior during a monetary reward-related paradigm, where a putative adversary habitually tries to cheat. The participant can react in three ways (i.e., money substraction of the putative opponent aggressive punishment, pressing a defense button, or continuing his money-making behavior). FDOPA-PET was analyzed using a steady-state model yielding estimates of the DA-synthesis capacity (K), the turnover of tracer DA formed in living brain (kloss), and the tracer distribution volume (Vd), which is an index of DA storage capacity. Significant negative correlations between PSAP aggressive responses and the DA-synthesis capacity were present in several regions, most prominently in the midbrain (r = -0.640; p = 0.002). Lower degrees of aggressive responses were associated with higher DA storage capacity in the striatum and midbrain. Additionally, there was a significant positive correlation between the investment into monetary incentive responses on the PSAP and DA-synthesis capacity, notably in the midbrain (r = +0.618, p = 0.003). The results suggest that individuals with low DA transmission capacity are more vulnerable to reactive/impulsive aggression in response to provocation.
A comparative study of thin titanium oxynitride (TiOxNy) films prepared by plasma enhanced atomic layer deposition using tetrakis(dimethylamino)titanium (TDMAT) and N2 plasma as well as ...titanium(IV)isopropoxide and NH3 plasma is reported. The comparison is based on the combination of Ti2p core level and valence band spectroscopy and current-voltage measurements. The TDMAT/N2 process delivers generally higher fractions of TiN and TiON within the Ti2p spectra of the films and stronger photoemissions within the bandgap as resolved in detail by high energy resolution synchrotron-based spectroscopy. In particular, it is shown that higher TiN contributions and in-gap emission intensities correlate strongly with increased leakage currents within the films and might be modified by the process parameters and precursor selection.
•Titanium oxynitride PEALD processes using TDMAT/N2 or TTIP/NH3 are compared.•Influence of ALD parameters on film composition and leakage current is shown.•Strong photo-emissions within the bandgap are observed in the valence band spectra.•TiN bonded nitrogen and in-gap states correlate strongly with leakage current.•TDMAT/N2 process delivers higher TiN and in-gap state contributions.
Titanium oxynitride films are prepared by plasma enhanced atomic layer deposition method using two different precursors and nitrogen sources. Synchrotron radiation-based X-ray photoelectron ...spectroscopy and X-ray absorption spectroscopy are used to characterize the nitrogen species incorporated within these films depending on the deposition parameters. It is found that nitrogen atoms in these films are differently bonded. In particular, it can be distinguished between TiON and TiN bonding configurations and molecular nitrogen species caused by precursor fragments.
The treatment of mental disorders in older adults is often restricted by limitations in efficacy and tolerability of pharmacologically dominated standard therapeutic strategies. Therefore, ...nonpharmacological therapeutic alternatives and supplements play a crucial role in these patients. Structured exercise and training are interventions that are associated with a high level of evidence in prevention and treatment of mental and cognitive disorders. This article is based on a selective search of the literature and provides an overview of the current scientific evidence with respect to the mechanisms of action, the effects on frequently occurring clinical disorders and modalities of the exercise interventions.
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