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Intervallfasten (IF), also die zeitlich beschränkte Nahrungsaufnahme mit markanten Zeitphasen ohne Mahlzeiten, ist gesundheitsförderlich und hat sich bewährt zur Gewichtsreduktion und in der Therapie und Prävention von Diabetes mellitus vom Typ 2. Dieser Beitrag beschreibt die positiven Effekte, die das Intervallfasten auf die sportliche Leistungsfähigkeit haben kann – ohne das Risiko einer verringerten Mikronährstoffzufuhr.

The common human single nucleotide polymorphism rs3820282 is associated with multiple phenotypes ranging from gestational length to likelihood of endometriosis and ovarian cancer and can thus serve as a paradigm for a highly pleiotropic genetic variant. Pleiotropy makes it challenging to assign specific causal roles to particular genetic variants. Deleterious mutations in multifunctional genes may cause either the co-occurrence of multiple disorders in the same individuals (i.e., syndromes), or be repeatedly associated with a variety of disorders in a population. Moreover, the adverse effects can occur in combination with advantages in other traits, maintaining high frequencies of deleterious alleles in the population. To reveal the causal role of this specific SNP, we investigated the molecular mechanisms affected by rs3820282 in mice. We have shown previously that rs3820282 introduces a high affinity estrogen receptor 1 binding site at theWnt4locus. Having introduced this nucleotide substitution into the homologous site of the mouse genome by CRISPR/Cas 9 we show that this change causes a specific upregulation ofWnt4transcription in the endometrial stromal cells during the preovulatory estrogen peak in late proestrus. Transcriptomic analysis of the whole uterus reveals broad systemic effects on uterine gene expression, including downregulation of proliferation and induction of many progesterone-regulated pro-implantation genes. The effect on proliferation is limited to the luminal epithelium, whereas other effects involve the uterine stromal compartment. We suggest that in the uterus, these changes could contribute to increased permissiveness to embryo invasion. Yet in other estrogen-responsive tissues, the same changes potentially lead to decreased resistance to invasion by cancer cells and endometriotic foci. A single molecular effect of rs3820282 onWnt4expression may thus underlie the various associated phenotypic effects.

Counting transcripts of mRNA is a key method of observation in modern biology. With advances in counting transcripts in single cells (single-cell RNA sequencing or scRNA-seq), these data are routinely used to identify cells by their transcriptional profile, and to identify genes with differential cellular expression. Because the total number of transcripts counted per cell can vary for technical reasons, the first step of standard scRNA-seq workflows is to normalize by sequencing depth, transforming counts into proportional abundances. The primary objective of this step is to reshape the data such that cells with similar biological proportions of transcripts end up with similar transformed measurements. But there is growing concern that normalization and other transformations result in unintended distortions that hinder both analyses and the interpretation of results. This has led to an intense focus on optimizing methods for normalization and transformation of scRNA-seq data. Here we take an alternative approach, by avoiding normalization altogether. We abandon the use of distances to compare cells, and instead use a restricted algebra, motivated by measurement theory and abstract algebra, that preserves the count nature of the data. We demonstrate that this restricted algebra is sufficient to draw meaningful and practical comparisons of gene expression through the use of the dot product and other elementary operations. This approach sidesteps many of the problems with common transformations, and has the added benefit of being simpler and more intuitive. We implement our approach in the package countland, available in python and R. By explicitly considering counts in terms of their measurement process, we avoid and overcome many challenges in modern RNA-seq and open new avenues for the analysis of these data.

Eine an individuellen Schweißverlusten und der persönlichen sportlichen Zielsetzung ausgerichtete Trinkstrategie vor, während und nach der Aktivität ist ein entscheidender Faktor, um die Leistungsfähigkeit beim Sport zu unterstützen und die Regeneration zu optimieren. Konkrete Trinkempfehlungen für sportlich Aktive haben individuelle physiologische Grundbedingungen, Umgebungsfaktoren und logistische Rahmenbedingungen zu berücksichtigen.

Synopsis A review of the literature on the anatomy of the lower female genital tract in therian mammals reveals, contrary to the general perception, a large amount of inter-specific variation. Variation in females is anatomically more radical than that in the male genitalia. It includes the absence of whole anatomical units, like the cervix in many Xenarthra, or the absence of the urogenital sinus (UGS), as well as the complete spatial separation of the external clitoral parts from the genital canal (either vagina or UGS). A preliminary phylogenetic analysis shows two patterns. Some morphs are unique to early branching clades, like the absence of the cervix, while others arose multiple times independently, like the flattening out or loss of the UGS, or the extreme elongation of the clitoris. Based on available information, the ancestral eutherian configuration of the external female genitalia included a cervix, a single vaginal segment, a tubular UGS, and an unperforated clitoris close to the entrance of the genital canal. The evidence for either bilobed or unitary glandes clitorides is ambivalent. Despite the wealth of information available, many gaps in knowledge remain and will require a community-wide effort to come to a more robust model of female genital evolutionary patterns.

Lateral $\beta $ -Ga2O3 MOSFET for power switching applications with a 1.8 kV breakdown voltage and a record power figure of merit of 155 MW/cm2 are demonstrated. Sub- $\mu \text{m}$ gate length combined with gate recess was used to achieve low ON-state resistances with reasonable threshold voltages above −24 V. The combination of compensation-doped high-quality crystals, implantation-based inter-device isolation, and SiN x -passivation yielded in consistently high average breakdown field strengths of 1.8–2.2 MV/cm for gate–drain spacings between 2 and 10 $\mu \text{m}$ . These values outperform the results of more established wide-bandgap device technologies, such as SiC or GaN, and the major Ga2O3 material promise—a higher breakdown strength—is well demonstrated.

Jörg Thierfelder, Hans Norbert Janowski und Günter Wagner: Kirche – Sozialismus – Demokratie. Gotthilf Schenkel. Pfarrer, Religiöser Sozialist, Politiker. W. Kohlhammer Verlag Stuttgart 2020. 278 Seiten. Fester Einband € 28,–. ISBN 978-3-17-033593-6

Monoclinic β-Ga2O3 (bandgap = 4.85 eV) is a transparent semiconducting oxide with very promising perspectives especially in solar blind UV photodetectors and high power device applications. In particular, for high power switching β-Ga2O3 is predicted to outperform the leading technology based on SiC and GaN, due to a much higher calculated critical field strength. Another significant advantage of β-Ga2O3, especially in view of large-scale production, is that large bulk crystals can be grown from the melt by standard techniques, making available reasonably-priced native substrates for the growth of high quality homoepitaxial layers, which is essential for the fabrication of high performance power devices. This review article focuses on the growth of bulk and homoepitaxial β-Ga2O3, summarizing the research work carried out in this field and pointing out the strengths and the main challenges of different growth techniques. The impressive material development already achieved for both bulk and epitaxial β-Ga2O3 crystals has enabled the fabrication of prototype devices with very promising performances, demonstrating the outstanding potential of β-Ga2O3 for power electronics applications.

$\beta $ -Ga2O3 thin-channel MOSFETs were evaluated using both dc and pulsed ${I}$ – ${V}$ measurements. The reported pulsed ${I}$ – ${V}$ technique was used to study self-heating effects in the MOSFET channel. The device was analyzed over a large temperature range of 23 °C–200 °C. A relationship between dissipated power and channel temperature was established, and it was found that the MOSFET channel was heating up to 208 °C when dissipating 2.5 W/mm of power. The thermal resistance of the channel was found to be 73 °C-mm/W. The results are supported with the experimental Raman nanothermography and thermal simulations and are in reasonable agreement with pulsed ${I}$ – ${V}$ findings. The high thermal resistance underpins the importance of optimizing thermal management in future Ga2O3 devices.

Thin films of the wide band gap semiconductor β-Ga2O3 have a high potential for applications in transparent electronics and high power devices. However, the role of interfaces remains to be explored. Here, we report on fundamental limits of transport properties in thin films. The conductivities, Hall densities and mobilities in thin homoepitaxially MOVPE grown (100)-orientated β-Ga2O3 films were measured as a function of temperature and film thickness. At room temperature, the electron mobilities ((115 ± 10) cm2/Vs) in thicker films (>150 nm) are comparable to the best of bulk. However, the mobility is strongly reduced by more than two orders of magnitude with decreasing film thickness ((5.5 ± 0.5) cm2/Vs for a 28 nm thin film). We find that the commonly applied classical Fuchs-Sondheimer model does not explain sufficiently the contribution of electron scattering at the film surfaces. Instead, by applying an electron wave model by Bergmann, a contribution to the mobility suppression due to the large de Broglie wavelength in β-Ga2O3 is proposed as a limiting quantum mechanical size effect.

The influence of substrate miscut on the surface morphology and Hall mobility at optimized growth conditions of $\beta$ -Ga 2 O 3 layers was investigated. The results demonstrate that the surface morphology and the Hall mobility are impacted by the miscut angle of $\beta$ -Ga 2 O 3 substrates. For substrates with miscut angle of 6° and a growth rate of about 4 nm/min, a morphology with step bunches was observed and a Hall mobility of the layer of $115\pm 10$ cm2/(Vs) was obtained. Using substrates with 4° miscut, step-flow growth mode and an enhancement of the Hall mobility about $135\pm 10\ \mathrm{cm}^{2}/(\mathrm{Vs})$ was achieved.

A Sn-doped (100) $\beta $ -Ga2O3 epitaxial layer was grown via metal–organic vapor phase epitaxy onto a single-crystal, Mg-doped semi-insulating (100) $\beta $ -Ga2O3 substrate. Ga2O3-based metal–oxide–semiconductor field-effect transistors with a 2- $\mu \text{m}$ gate length ( $L_{G})$ , 3.4- $\mu \text{m}$ source–drain spacing ( $L_{\textrm {SD}})$ , and 0.6- $\mu \text{m}$ gate–drain spacing ( $L_{\textrm {GD}})$ were fabricated and characterized. Devices were observed to hold a gate-to-drain voltage of 230 V in the OFF-state. The gate-to-drain electric field corresponds to 3.8 MV/cm, which is the highest reported for any transistor and surpassing bulk GaN and SiC theoretical limits. Further performance projections are made based on layout, process, and material optimizations to be considered in future iterations.

We have applied positron annihilation spectroscopy to study vacancy-type defects in unintentionally doped and Si and Sn doped β-Ga 2 O 3 homoepitaxial thin films grown by metal-organic chemical vapor deposition (MOCVD). We detect Ga vacancy related defects at high concentrations in semi-insulating and highly resistive material, while conductive (ntype) material exhibits very low Ga vacancy concentrations. These findings show that Ga vacancies can act as efficient electrical compensators for n-type conductivity, but their concentrations can be suppressed by controlling the growth environment, leading to efficient n-type doping. We also note the strong anisotropy of the positron annihilation signals and give recommendation for presenting positron data obtained in β-Ga 2 O 3 .

Thin films of the wide band gap semiconductor β-Ga2O3 have a high potential for applications in transparent electronics and high power devices. However, the role of interfaces remains to be explored. Here, we report on fundamental limits of transport properties in thin films. The conductivities, Hall densities and mobilities in thin homoepitaxially MOVPE grown (100)-orientated β-Ga2O3 films were measured as a function of temperature and film thickness. At room temperature, the electron mobilities ((115 ± 10) cm2/Vs) in thicker films (>150 nm) are comparable to the best of bulk. However, the mobility is strongly reduced by more than two orders of magnitude with decreasing film thickness ((5.5 ± 0.5) cm2/Vs for a 28 nm thin film). We find that the commonly applied classical Fuchs-Sondheimer model does not explain sufficiently the contribution of electron scattering at the film surfaces. Instead, by applying an electron wave model by Bergmann, a contribution to the mobility suppression due to the large de Broglie wavelength in β-Ga2O3 is proposed as a limiting quantum mechanical size effect.

Sn-doped β-Ga2O3 epitaxial layers have been grown on (100) β-Ga2O3 substrates by metal organic vapour-phase epitaxy. Triethylgallium (TEGa), molecular oxygen (O2) and tetraethyltin (TESn) were used as Ga, O and Sn precursors, respectively. Layers grown at optimized temperature and chamber pressure, i.e. 850 °C and 5 mbar, had flat surfaces with a rms roughness of about 600 pm. Structural analysis by transmission electron microscopy revealed that the main defects in the layers were stacking faults and twin lamella. The incoherent boundaries of these defects are supposed to act as compensation and scattering centres, limiting the carrier mobility. Sn was homogeneously incorporated with a flat profile throughout the whole layer at concentration levels ranging from 2 × 1017 to 3 × 1019 cm−3 proportionally to the used TESn flux. All layers were electrically conductive. However, an unambiguous Hall effect was measurable only for Sn concentrations higher than 1 × 1018 cm−3, resulting in electron concentrations from 5 × 1017 to 2 × 1018 cm−3 at room temperature. For increasing free carrier concentrations, the electron mobility showed the tendency to increase from 10 to 30 cm2/Vs. The maximum mobility of 41 cm2/Vs, measured in a sample with free carrier concentration of 1 × 1018 cm−3, represents the highest value reported for β-Ga2O3 layers grown by MOVPE so far.

We report the first demonstration of self-aligned gate (SAG) β-Ga2O3 metal-oxide-semiconductor field-effect transistors (MOSFETs) as a path toward eliminating source access resistance for low-loss power applications. The SAG process is implemented with a subtractively defined and etched refractory metal, such as Tungsten, combined with ion-implantation. We report experimental and modeled DC performance of a representative SAG device that achieved a maximum transconductance of 35 mS mm−1 and an on-resistance of ∼30 Ω mm with a 2.5 μm gate length. These results highlight the advantage of implant technology for SAG β-Ga2O3 MOSFETs enabling future power switching and RF devices with low parasitic resistance.

The temperature dependence of the Seebeck coefficient of homoepitaxial metal organic vapor phase grown, silicon doped β-Ga2O3 thin films was measured relative to aluminum. For room temperature, we found the relative Seebeck coefficient of Sβ-Ga2O3-Al=(−300±20) µV/K. At high bath temperatures T > 240 K, the scattering is determined by electron-phonon-interaction. At lower bath temperatures between T = 100 K and T = 300 K, an increase in the magnitude of the Seebeck coefficient is explained in the frame of Stratton’s formula. The influence of different scattering mechanisms on the magnitude of the Seebeck coefficient is discussed and compared with Hall measurement results.

In this paper we present a concept on the defect generation and annihilation during the homoepitaxial growth step of cubic silicon carbide by sublimation epitaxy on templates grown by chemical vapor deposition on silicon substrates. Several structural defects like stacking faults, twins and star defects show opposite evolution from the template layer into the sublimation grown material. While single planar defects tend to annihilate with increasing layer thickness, the defect clusters assigned to the star defects are enlarging. These issues contribute to a balance of how to achieve the best possible quality on thick layers.

The evolutionary explanation of female orgasm has been difficult to come by. The orgasm in women does not obviously contribute to the reproductive success, and surprisingly unreliably accompanies heterosexual intercourse. Two types of explanations have been proposed: one insisting on extant adaptive roles in reproduction, another explaining female orgasm as a byproduct of selection on male orgasm, which is crucial for sperm transfer. We emphasize that these explanations tend to focus on evidence from human biology and thus address the modification of a trait rather than its evolutionary origin. To trace the trait through evolution requires identifying its homologue in other species, which may have limited similarity with the human trait. Human female orgasm is associated with an endocrine surge similar to the copulatory surges in species with induced ovulation. We suggest that the homolog of human orgasm is the reflex that, ancestrally, induced ovulation. This reflex became superfluous with the evolution of spontaneous ovulation, potentially freeing female orgasm for other roles. This is supported by phylogenetic evidence showing that induced ovulation is ancestral, while spontaneous ovulation is derived within eutherians. In addition, the comparative anatomy of female reproductive tract shows that evolution of spontaneous ovulation is correlated with increasing distance of clitoris from the copulatory canal. In summary, we suggest that the female orgasm-like trait may have been adaptive, however for a different role, namely for inducing ovulation. With the evolution of spontaneous ovulation, orgasm was freed to gain secondary roles, which may explain its maintenance, but not its origin.

In this work a new approach for the production of freestanding cubic silicon carbide (3C SiC) in (001) orientation is presented which is based on the combination of chemical vapor deposition (CVD) and the fast sublimation growth process (FSGP). Fast homoepitaxial growth of 3C SiC using sublimation epitaxy on a template created by CVD growth on silicon substrates allows to obtain thick freestanding material with low defect densities. Using standard silicon wafers as substrate material permits a cost efficient process and the applying of wafers with different orientations. The (001) orientation used in this work will potentially allow further heteroepitaxial growth of other cubic semiconductors, like e.g. gallium nitride (GaN).

Charge induced in 6H–SiC diodes by heavy ions, oxygen (O), silicon (Si), nickel (Ni), and gold (Au), at energies from 6 to 18 MeV was evaluated using a Transient Ion Beam Induced Current (TIBIC) measurement system. In the case of heavy ions with relatively light mass, such as O and Si, the high Charge Collection Efficiency (CCE) was obtained, although the CCE decreased with increasing atomic numbers. The CCE of 6H–SiC n + p diodes irradiated with Au ions was approximately 40%. From the calculation using the modified Kobetich and Katz (KK) model, it is found that dense electron–hole (e–h) pairs were generated in SiC by irradiation of ions with heavy mass, such as Ni and Au, and the density was much higher than that in SiC irradiated with O ions. The decrease in the CCE due to ion irradiation with heavy mass, such as Ni and Au can be interpreted in terms of the annihilation of e–h pairs in plasma due to the Auger recombination.

In this study, we report on the application of multiple energy nitrogen ion implantation for the electrical isolation of electronic devices on monoclinic β-Ga2O3. By the introduction of uniformly distributed midgap damage-related levels in the Ga2O3 crystal lattice, we are able to increase the sheet resistances by more than 9 orders of magnitude to ≥1013 Ω/sq which remains stable up to annealing temperatures of 600 °C carried out for 60 s under a nitrogen atmosphere. At higher annealing temperatures, the damage-related trap levels are being removed causing a significant drop of the sheet resistance down to 4 × 105 Ω/sq for annealing temperatures of 800 °C. This effect is preceded by a structural recovery of the implantation damages via the recrystallization of the crystal lattice at already 400 °C as verified by x-ray diffraction measurements. The extracted activation energies of the deep states controlling the high resistivity of Ga2O3 after implantation are in the range of 0.7 eV, showing a strong correlation with the annealing temperature dependence of the sheet resistance and thus supporting the theory of a damage-induced isolation mechanism.