Moiré Pattern Formation in Epitaxial Growth on a Covalent Substrate: Sb on InSb(111)A.

Structural moiré superstructures arising from two competing lattices may lead to unexpected electronic behavior. Sb is predicted to show thickness-dependent topological properties, providing potential applications for low-energy-consuming electronic devices. Here we successfully synthesize ultrathin Sb films on semi-insulating InSb(111)A. Despite the covalent nature of the substrate, which has dangling bonds on the surface, we prove by scanning transmission electron microscopy that the first layer of Sb atoms grows in an unstrained manner. Rather than compensating for the lattice mismatch of -6.4% by structural modifications, the Sb films form a pronounced moiré pattern as we evidence by scanning tunneling microscopy. Our model calculations assign the moiré pattern to a periodic surface corrugation. In agreement with theoretical predictions, irrespective of the moiré modulation, the topological surface state known on a thick Sb film is experimentally confirmed to persist down to small film thicknesses, and the Dirac point shifts toward lower binding energies with a decrease in Sb thickness.

Generation and Biological Evaluation of Fc Antigen Binding Fragment-Drug Conjugates as a Novel Antibody-Based Format for Targeted Drug Delivery.

Fragment crystallizable (Fc) antigen binding fragments (Fcabs) represent a novel antibody format comprising a homodimeric Fc region with an engineered antigen binding site. In contrast to their full-length antibody offspring, Fcabs combine Fc-domain-mediated and antigen binding functions at only one-third of the size. Their reduced size is accompanied by elevated tissue penetration capabilities, which is an attractive feature for the treatment of solid tumors. In the present study, we explored for the first time Fcabs as a novel scaffold for antibody-drug conjugates (ADCs). As model, various HER2-targeting Fcab variants coupled to a pH-sensitive dye were used in internalization experiments. A selective binding on HER2-expressing tumor cells and receptor-mediated endocytosis could be confirmed for selected variants, indicating that these Fcabs meet the basic prerequisite for an ADC approach. Subsequently, Fcabs were site-specifically coupled to cytotoxic monomethyl auristatin E yielding homogeneous conjugates. The conjugates retained HER2 and FcRn binding behavior of the parent Fcabs, showed a selective in vitro cell killing and conjugation site-dependent serum stability. Moreover, Fcab conjugates showed elevated penetration in a spheroid model, compared to their full-length antibody and Trastuzumab counterparts. Altogether, the presented results emphasize the potential of Fcabs as a novel scaffold for targeted drug delivery in solid cancers and pave the way for future in vivo translation.

Isolation of saturated alkylresorcinols from rye grains by countercurrent chromatography.

Alkylresorcinols (5-alkyl-1,3-dihydroxybenzenes) are amphiphilic phenolic lipid compounds that are abundant in cereals with highest contents in rye. Alkylresorcinols are suspected to show a wide range of favourable biological activities. For such and further testing, highly pure alkylresorcinol standards are required. Especially, purities >> 98% were partly difficult to obtain in the past. Here, we aimed to isolate the most abundant (saturated) alkylresorcinols from rye using countercurrent chromatography. To achieve very high purity, alkylresorcinol-containing extract (∼7.14 g) of rye grains (cold extracts with cyclohexane/ethyl acetate (46/54, w/w)) were preparatively transesterified followed by a preparative hydrogenation. Countercurrent chromatography separation of ∼1 g hydrogenated and transesterified rye grain extract using the solvent system n-hexane-ethyl acetate-methanol-water (9:1:9:1, v/v/v/v) yielded 51.8 mg AR17:0, 77.4 mg AR19:0, 57.2 mg AR21:0, 28.8 mg AR23:0 and 11.5 mg AR25:0 with purities >99% in either case. The isolated alkylresorcinol homologues can be used for subsequent bioassays.

Countercurrent chromatographic fractionation followed by gas chromatography/mass spectrometry identification of alkylresorcinols in rye.

Alkylresorcinols (5-alkyl-1,3-dihydroxybenzenes, ARs) are bioactive phenolic lipid compounds which are particularly abundant in rye and partly other cereals. In this study on ARs, whole rye grain extracts were gained with cyclohexane/ethyl acetate (46/54, w/w). Silylated extracts were used to develop a gas chromatography with mass spectrometry method in the selected ion monitoring mode (GC/MS-SIM) for the sensitive detection of conventional ARs along with keto-substituted (oxo-AR) and ring-methylated ARs (mAR) with 5-alkyl chain lengths of 14 to 27 carbon atoms and 0 to 4 double bonds in one run. Analysis was performed by countercurrent chromatographic (CCC) fractionation using the solvent system n-hexane/ethyl acetate/methanol/water (9/1/9/1, v/v/v/v). Subsequent GC/MS-(SIM) analysis of 80 silylated CCC fractions enabled the detection of 74 ARs in the sample. The CCC elution of the ARs followed the equivalent chain length (ECL) rule in which one double bond compensated the effect of two (additional) carbon atoms. Novel or rarely reported ARs were detected in virtually all classes, i.e. saturated AR (AR14:0), even-numbered monounsaturated AR isomers (AR16:1-AR26:1), triunsaturated ARs (AR25:3), oxo-ARs (AR17:0 oxo, AR19:1 oxo, AR21:2 oxo, AR23:2 oxo) and odd-numbered methyl-ARs (mAR15:0-mAR23:0). Positions of the double bonds of monounsaturated ARs and oxo-ARs were determined with the help of dimethyl disulfide (DMDS) derivatives. Graphical abstract.

Impact of brain tissue filtering on neurostimulation fields: a modeling study.

Electrical neurostimulation techniques, such as deep brain stimulation (DBS) and transcranial magnetic stimulation (TMS), are increasingly used in the neurosciences, e.g., for studying brain function, and for neurotherapeutics, e.g., for treating depression, epilepsy, and Parkinson's disease. The characterization of electrical properties of brain tissue has guided our fundamental understanding and application of these methods, from electrophysiologic theory to clinical dosing-metrics. Nonetheless, prior computational models have primarily relied on ex-vivo impedance measurements. We recorded the in-vivo impedances of brain tissues during neurosurgical procedures and used these results to construct MRI guided computational models of TMS and DBS neurostimulatory fields and conductance-based models of neurons exposed to stimulation. We demonstrated that tissues carry neurostimulation currents through frequency dependent resistive and capacitive properties not typically accounted for by past neurostimulation modeling work. We show that these fundamental brain tissue properties can have significant effects on the neurostimulatory-fields (capacitive and resistive current composition and spatial/temporal dynamics) and neural responses (stimulation threshold, ionic currents, and membrane dynamics). These findings highlight the importance of tissue impedance properties on neurostimulation and impact our understanding of the biological mechanisms and technological potential of neurostimulatory methods.

Production of a Cheese-Like Aroma via Fermentation of Plant Proteins and Coconut Oil with the Basidiomycetes Cyclocybe aegerita and Trametes versicolor.

Cheese is one of the most common dairy products and is characterized by its complex aroma. However, in times of climate change and resource scarcity, the possibility to mimic the characteristic cheese-like aroma from plant-based sources is in demand to offer alternatives to cheese. Accordingly, the production of a natural cheese-like aroma via fermentation of four plant-based proteins and coconut oil with basidiomycetes has been addressed. Mixtures of soy and sunflower protein with coconut oil (15 g/L) have shown the formation of a cheese-like aroma after 72 and 56 h after fermentation with Cyclocybe aegerita and Trametes versicolor, respectively. Isovaleric acid, butanoic acid, ethyl butanoate, 1-octen-3-ol, and various ketones were identified as the key odorants. Similarities to typical cheeses were observed by the principal component analysis. Overall, the finding offered an approach to a sustainable production of a natural cheese-like aroma from a plant source, thus contributing to the development of cheese alternatives.

Female Patients Show a Larger Reduction in Suicidal Ideation in Inpatient Addiction Treatment Than Male Patients: Results of a Single-Center Observational Study.

Background: Substance use disorders (SUD) are prevalent disorders worldwide. Among other associated health problems, patients with SUD are at an increased risk of dying of suicide, with females displaying an even higher risk than males. Therefore, the aim of this study was to conduct a gender-sensitive evaluation of changes in suicidal ideation during multimodal inpatient treatment at a hospital facility specialized in treating addiction. Methods: A total of 694 patients (68.2% male) completed routine assessment including suicidal ideation, abstinence confidence, impulsivity, emotion regulation, self-efficacy and autonomy and joy both before (T1) and at the end (T2) of treatment. Mean changes were evaluated with repeated measures MANOVAs. Results: Before treatment, a total of n=127 (18.3%) of the respondents reported suicidal ideation, which was reduced to n=72 (10.4%) by the end of treatment. Among female patients, the change in reported suicidal ideation compared from T1 to T2 (21.7% vs 7.7%) was significantly higher than among male patients (T1: 16.7%%, T2: 11.6%; p=0.040). Generally, females reported worse symptoms scores and slightly higher numbers of suicidal thoughts at baseline (effect sizes ranging from η²=.008 - 0.044). While both genders significantly profited from the treatment, female patients generally showed larger improvements than male. Discussion: Our study underscores the beneficial effect of addiction-specialized inpatient treatment on suicidal ideation. Additionally, we found a substantial gender effect: while female patients generally were more distressed before treatment, they also reported higher symptom reduction during the treatment. This result highlights the need to perform more gender-sensitive research and develop more gender-sensitive treatment programs.

Achieving environmental stability in an atomically thin quantum spin Hall insulator via graphene intercalation.

Atomic monolayers on semiconductor surfaces represent an emerging class of functional quantum materials in the two-dimensional limit - ranging from superconductors and Mott insulators to ferroelectrics and quantum spin Hall insulators. Indenene, a triangular monolayer of indium with a gap of ~ 120 meV is a quantum spin Hall insulator whose micron-scale epitaxial growth on SiC(0001) makes it technologically relevant. However, its suitability for room-temperature spintronics is challenged by the instability of its topological character in air. It is imperative to develop a strategy to protect the topological nature of indenene during ex situ processing and device fabrication. Here we show that intercalation of indenene into epitaxial graphene provides effective protection from the oxidising environment, while preserving an intact topological character. Our approach opens a rich realm of ex situ experimental opportunities, priming monolayer quantum spin Hall insulators for realistic device fabrication and access to topologically protected edge channels.

Isolation of plastochromanol-8 from flaxseed oil by countercurrent separation methods.

The naturally occurring antioxidant plastochromanol-8 (PC-8) is a member of the tocochromanol (vitamin E) family which features eight unsaturated isoprene units in the side chain compared to three in the case of γ-tocotrienol. Due to the lack of a commercially available PC-8 standard, we developed a route to gain relevant amounts of highly pure PC-8. Specifically, ∼320 g flaxseed oil was saponified and the bulky PC-8 was enriched by gel permeation chromatography. It followed countercurrent chromatography using the solvent system n-hexane/benzotrifluoride/acetonitrile (20:7:13, v/v/v). The final purification was achieved by centrifugal partition chromatography using the novel solvent system hexamethyldisiloxane/acetonitrile (1:1, v/v). This step provided ∼26 mg PC-8 (>99.5 %, according to HPLC, GC and NMR analysis). Two further, hitherto unknown minor tocochromanols (<1 % of PC-8) were detected and could be identified to be plastochromanol-7 (PC-7) and plastochromanol-9 (PC-9), i.e. tocochromanols with seven and nine unsaturated isoprene units, respectively, in the side chain.

Characterization of hay-like off-odor in basil samples after various processing and strategies for reducing the off-odor.

Hay-like off-odor present in dried basil products results in low consumer acceptance. To understand the hay-like off-odor formation in processing of basil products, identification of hay-like off-odor in thawed, air-dried and spray-dried basil samples was investigated by means of a trained human panel (n = 10) and gas chromatography-mass spectrometry-olfactometry. 3-Methylnonane-2,4-dione (3-MND) was identified in all basil samples to be responsible for the hay-like off-odor. To reduce the hay-like off-odor in dried basil products, the effect of light, oxygen, and temperature on the 3-MND formation was studied during thawing, air drying and spray drying processes. In the thawing process, darkness and nitrogen protection significantly reduced the 3-MND formation. With extending thawing time, no significant increase on the concentration of 3-MND was observed after 60 min in the darkness and under nitrogen. In the designed spray-drying setup, nitrogen protection could further alleviate the 3-MND formation whereas the elevated drying temperature (40-100 °C) boosted the 3-MND formation in air-drying processing. Collectively, these findings indicated that darkness, nitrogen protection and low temperature were considered as critical processing parameters to minimize the generation of hay-like compound 3-MND in dried basil products.

Efficient DNA Repair Mitigates Replication Stress Resulting in Less Immunogenic Cytosolic DNA in Radioresistant Breast Cancer Stem Cells.

Cancer stem cells (CSCs) are a major cause of tumor therapy failure. This is mainly attributed to increased DNA repair capacity and immune escape. Recent studies have shown that functional DNA repair via homologous recombination (HR) prevents radiation-induced accumulation of DNA in the cytoplasm, thereby inhibiting the intracellular immune response. However, it is unclear whether CSCs can suppress radiation-induced cytoplasmic dsDNA formation. Here, we show that the increased radioresistance of ALDH1-positive breast cancer stem cells (BCSCs) in S phase is mediated by both enhanced DNA double-strand break repair and improved replication fork protection due to HR. Both HR-mediated processes lead to suppression of radiation-induced replication stress and consequently reduction of cytoplasmic dsDNA. The amount of cytoplasmic dsDNA correlated significantly with BCSC content (p=0.0002). This clearly indicates that HR-dependent avoidance of radiation-induced replication stress mediates radioresistance and contributes to its immune evasion. Consistent with this, enhancement of replication stress by inhibition of ataxia telangiectasia and RAD3 related (ATR) resulted in significant radiosensitization (SER37 increase 1.7-2.8 Gy, p<0.0001). Therefore, disruption of HR-mediated processes, particularly in replication, opens a CSC-specific radiosensitization option by enhancing their intracellular immune response.

IgE type multiple myeloma exhibits hypermutated phenotype and tumor reactive T cells.

Multiple myeloma (MM) is a hematological malignancy originating from malignant and clonally expanding plasma cells. MM can be molecularly stratified, and its clonal evolution deciphered based on the Ig heavy and light chains of the respective malignant plasma cell clone. Of all MM subtypes, IgE type MM accounts for only <0.1% of cases and is associated with an aggressive clinical course and consequentially dismal prognosis. In such malignancies, adoptive transfer of autologous lymphocytes specifically targeting presented (neo)epitopes encoded by either somatically mutated or specifically overexpressed genes has resulted in substantial objective clinical regressions even in relapsed/refractory disease. However, there are no data on the genetic and immunological characteristics of this rare and aggressive entity. Here, we comprehensively profiled IgE type kappa MM on a genomic and immune repertoire level by integrating DNA- and single-cell RNA sequencing and comparative profiling against non-IgE type MM samples. We demonstrate distinct pathophysiological mechanisms as well as novel opportunities for targeting IgE type MM. Our data further provides the rationale for patient-individualized neoepitope-targeting cell therapy in high tumor mutation burden MM.

Transcranial magnetic stimulation and brain atrophy: a computer-based human brain model study.

This paper is aimed at exploring the effect of cortical brain atrophy on the currents induced by transcranial magnetic stimulation (TMS). We compared the currents induced by various TMS conditions on several different MRI derived finite element head models of brain atrophy, incorporating both decreasing cortical volume and widened sulci. The current densities induced in the cortex were dependent upon the degree and type of cortical atrophy and were altered in magnitude, location, and orientation when compared to healthy head models. Predictive models of the degree of current density attenuation as a function of the scalp-to-cortex distance were analyzed, concluding that those which ignore the electromagnetic field-tissue interactions lead to inaccurate conclusions. Ultimately, the precise site and population of neural elements stimulated by TMS in an atrophic brain cannot be predicted based on healthy head models which ignore the effects of the altered cortex on the stimulating currents. Clinical applications of TMS should be carefully considered in light of these findings.

Investigating molecular recognition and biological function at interfaces using piscidins, antimicrobial peptides from fish.

We studied amidated and non-amidated piscidins 1 and 3, amphipathic cationic antimicrobial peptides from fish, to characterize functional and structural similarities and differences between these peptides and better understand the structural motifs involved in biological activity and functional diversity among amidated and non-amidated isoforms. Antimicrobial and hemolytic assays were carried out to assess their potency and toxicity, respectively. Site-specific high-resolution solid-state NMR orientational restraints were obtained from (15)N-labeled amidated and non-amidated piscidins 1 and 3 in the presence of hydrated oriented lipid bilayers. Solid-state NMR and circular dichroism results indicate that the peptides are alpha-helical and oriented parallel to the membrane surface. This orientation was expected since peptide-lipid interactions are enhanced at the water-bilayer interface for amphipathic cationic antimicrobial peptides. (15)N solid-state NMR performed on oriented samples demonstrate that piscidin experiences fast, large amplitude backbone motions around an axis parallel to the bilayer normal. Under the conditions tested here, piscidin 1 was confirmed to be more antimicrobially potent than piscidin 3 and antimicrobial activity was not affected by amidation. In light of functional and structural similarities between piscidins 1 and 3, we propose that their topology and fast dynamics are related to their mechanism of action.

A sham-controlled trial of a 5-day course of repetitive transcranial magnetic stimulation of the unaffected hemisphere in stroke patients.

BACKGROUND AND PURPOSE: It has been recently shown that a single session of repetitive transcranial magnetic stimulation (rTMS) of the unaffected hemisphere can improve motor function in stroke patients; however, this improvement is short-lasting. We therefore conducted a randomized, sham-controlled, phase II trial to evaluate whether five sessions of low-frequency rTMS can increase the magnitude and duration of these effects and whether this approach is safe. METHODS: Fifteen patients with chronic stroke were randomized to receive active or sham rTMS of the unaffected hemisphere. A blinded rater assessed motor function and corticospinal excitability at baseline, during and after 2 weeks of treatment. Safety was assessed using a neuropsychologic battery and electroencephalogram. RESULTS: Active rTMS resulted in a significant improvement of the motor function performance in the affected hand that lasted for 2 weeks. These effects were not observed in the sham rTMS group (affected and unaffected hand) and in the unaffected hand in the active rTMS group. Corticospinal excitability decreased in the stimulated, unaffected hemisphere and increased in the affected hemisphere. There was a significant correlation between motor function improvement and corticospinal excitability change in the affected hemisphere. Cognitive performance and electroencephalogram were not changed significantly throughout the trial in both groups of treatment. CONCLUSIONS: These results support and extend the findings of previous studies on rTMS in stroke patients because five consecutive sessions of rTMS increased the magnitude and duration of the motor effects. Furthermore, this increased dose of rTMS is not associated with cognitive adverse effects and/or epileptogenic activity.

Transcranial direct current stimulation of the unaffected hemisphere in stroke patients.

Recovery of function after a stroke is determined by a balance of activity in the neural network involving both the affected and the unaffected brain hemispheres. Increased activity in the affected hemisphere can promote recovery, while excessive activity in the unaffected hemisphere may represent a maladaptive strategy. We therefore investigated whether reduction of the excitability in the unaffected hemisphere by cathodal transcranial direct current stimulation could result in motor performance improvement in stroke patients. We compared these results with excitability-enhancing anodal transcranial direct current stimulation of the affected hemisphere and sham transcranial direct current stimulation. Both cathodal stimulation of the unaffected hemisphere and anodal stimulation of the affected hemisphere (but not sham transcranial direct current stimulation) improved motor performance significantly. These results suggest that the appropriate modulation of bihemispheric brain structures can promote motor function recovery.

Intracardiac migration and knotting of a ventriculoperitoneal shunt.

We report a patient with delayed migration of the distal ventriculoperitoneal shunt catheter from the peritoneum to the right atrium with associated knotting of the catheter complicating removal. We also review the literature on this topic.

Modulation of right motor cortex excitability without awareness following presentation of masked self-images.

The neural substrates of self-awareness have been studied with a variety of neurophysiological and behavioral tools. In the present study, unconscious modulation of corticospinal excitability following presentation of self-images was probed with transcranial magnetic stimulation (TMS). TMS-induced motor evoked potentials (MEP) were collected from the contralateral first dorsal interosseus (FDI) muscle while subjects viewed masked pictures of their own face. MEP amplitudes were compared to those obtained when pictures of strangers were masked. Masked self-images induced a relative increase in corticospinal excitability when TMS was applied to the right primary motor cortex. These results demonstrate the utility of TMS to probe unconscious processing and support the notion of hemispheric asymmetry in the processing of self-images.

Intracranial measurement of current densities induced by transcranial magnetic stimulation in the human brain.

Transcranial magnetic stimulation (TMS) is a non-invasive technique that uses the principle of electromagnetic induction to generate currents in the brain via pulsed magnetic fields. The magnitude of such induced currents is unknown. In this study we measured the TMS induced current densities in a patient with implanted depth electrodes for epilepsy monitoring. A maximum current density of 12 microA/cm2 was recorded at a depth of 1 cm from scalp surface with the optimum stimulation orientation used in the experiment and an intensity of 7% of the maximal stimulator output. During TMS we recorded relative current variations under different stimulating coil orientations and at different points in the subject's brain. The results were in accordance with current theoretical models. The induced currents decayed with distance form the coil and varied with alterations in coil orientations. These results provide novel insight into the physical and neurophysiological processes of TMS.

Three-dimensional head model simulation of transcranial magnetic stimulation.

This paper presents a finite element method used to evaluate the induced current density in a realistic model of the human head exposed to a time varying magnetic field. The tissue electric properties were varied to ascertain their influence on the induced currents. Current density magnitude and vector plots were generated throughout the tissue layers to determine the effects of tissue boundaries on the field. The current density magnitude correlated to the conductivity of the tissue in all the cases tested except where the tissue permittivity was raised to a level to allow for displacement currents. In this case, the permittivity of the tissue was the dominant factor. Current density components normal to the tissue interface were shown to exist in all solutions within the cortex contrary to the predictions of present models that rely on symmetrical geometries. Additionally, modifications in the cortical geometry were shown to perturb the field so that the site of activation could be altered in diseased patient populations. Finally, by varying the tissue permittivity values and the source frequency, we tested the effects of alpha dispersion theories on transcranial magnetic stimulation.