Multiparametric Characterization of the DSL-6A/C1 Pancreatic Cancer Model in Rats.

The DSL-6A/C1 murine pancreatic ductal adenocarcinoma (PDAC) tumor model was established in Lewis rats and characterized through a comprehensive multiparametric analysis to compare it to other preclinical tumor models and explore potential diagnostic and therapeutical targets. DSL-6A/C1 tumors were histologically analyzed to elucidate PDAC features. The tumor microenvironment was studied for immune cell prevalence. Multiparametric MRI and PET imaging were utilized to characterize tumors, and 68Ga-FAPI-46-targeting cancer-associated fibroblasts (CAFs), were used to validate the histological findings. The histology confirmed typical PDAC characteristics, such as malformed pancreatic ductal malignant cells and CAFs. Distinct immune landscapes were identified, revealing an increased presence of CD8+ T cells and a decreased CD4+ T cell fraction within the tumor microenvironment. PET imaging with 68Ga-FAPI tracers exhibited strong tracer uptake in tumor tissues. The MRI parameters indicated increasing intralesional necrosis over time and elevated contrast media uptake in vital tumor areas. We have demonstrated that the DSL-6A/C1 tumor model, particularly due to its high tumorigenicity, tumor size, and 68Ga-FAPI-46 sensitivity, is a suitable alternative to established small animal models for many forms of preclinical analyses and therapeutic studies of PDAC.

The driving force behind tool-stone selection in the African Middle Stone Age.

In the Stone Age, the collection of specific rocks was the first step in tool making. Very little is known about the choices made during tool-stone acquisition. Were choices governed by the knowledge of, and need for, specific properties of stones? Or were the collected raw materials a mere by-product of the way people moved through the landscape? We investigate these questions in the Middle Stone Age (MSA) of southern Africa, analyzing the mechanical properties of tool-stones used at the site Diepkloof Rock Shelter. To understand knapping quality, we measure flaking predictability and introduce a physical model that allows calculating the relative force necessary to produce flakes from different rocks. To evaluate their quality as finished tools, we investigate their resistance during repeated use activities (scraping or cutting) and their strength during projectile impacts. Our findings explain tool-stone selection in two emblematic periods of the MSA, the Still Bay and Howiesons Poort, as being the result of a deep understanding of these mechanical properties. In both cases, people chose those rocks, among many others, that allowed the most advantageous trade-off between anticipated properties of finished tools and the ease of acquiring rocks and producing tools. The implications are an understanding of African MSA toolmakers as engineers who carefully weighed their choices taking into account workability and the quality of the tools they made.

Differentiating α-moganite, silanol and α-quartz by Raman spectroscopy.

The silica phases quartz, silanol and moganite are widely prevalent and consequential in industrial applications and natural science. However, methods for differentiating these important phases are few. Using Raman spectra simulated by density function and perturbation expansion after discretization theory, representative spectra could be obtained and the comingling of diagnostic Raman Bands for the three phases identified in samples. On this basis new methods to identify moganite in Raman spectra are proposed.

Ochre-based compound adhesives at the Mousterian type-site document complex cognition and high investment.

Ancient adhesives used in multicomponent tools may be among our best material evidences of cultural evolution and cognitive processes in early humans. African Homo sapiens is known to have made compound adhesives from naturally sticky substances and ochre, a technical behavior proposed to mark the advent of elaborate cognitive processes in our species. Foragers of the European Middle Paleolithic also used glues, but evidence of ochre-based compound adhesives is unknown. Here, we present evidence of this kind. Bitumen was mixed with high loads of goethite ochre to make compound adhesives at the type-site of the Mousterian, Le Moustier (France). Ochre loads were so high that they lowered the adhesive's performance in classical hafting situations where stone implements are glued to handles. However, when used as handheld grips on cutting or scraping tools, a behavior known from Neanderthals, high-ochre adhesives present a real benefit, improving their solidity and rigidity. Our findings help understand the implications of Pleistocene adhesive making.

Inference under superspreading: Determinants of SARS-CoV-2 transmission in Germany.

Superspreading, under-reporting, reporting delay, and confounding complicate statistical inference on determinants of disease transmission. A model that accounts for these factors within a Bayesian framework is estimated using German Covid-19 surveillance data. Compartments based on date of symptom onset, location, and age group allow to identify age-specific changes in transmission, adjusting for weather, reported prevalence, and testing and tracing. Several factors were associated with a reduction in transmission: public awareness rising, information on local prevalence, testing and tracing, high temperature, stay-at-home orders, and restaurant closures. However, substantial uncertainty remains for other interventions including school closures and mandatory face coverings. The challenge of disentangling the effects of different determinants is discussed and examined through a simulation study. On a broader perspective, the study illustrates the potential of surveillance data with demographic information and date of symptom onset to improve inference in the presence of under-reporting and reporting delay.

Production method of the Königsaue birch tar documents cumulative culture in Neanderthals.

Birch tar is the oldest synthetic substance made by early humans. The earliest such artefacts are associated with Neanderthals. According to traditional interpretations, their study allows understanding Neanderthal tool behaviours, skills and cultural evolution. However, recent work has found that birch tar can also be produced with simple processes, or even result from fortuitous accidents. Even though these findings suggest that birch tar per se is not a proxy for cognition, they do not shed light on the process by which Neanderthals produced it, and, therefore, cannot evaluate the implications of that behaviour. Here, we address the question of how tar was made by Neanderthals. Through a comparative chemical analysis of the two exceptional birch tar pieces from Königsaue (Germany) and a large reference birch tar collection made with Stone Age techniques, we found that Neanderthals did not use the simplest method to make tar. Rather, they distilled tar in an intentionally created underground environment that restricted oxygen flow and remained invisible during the process. This degree of complexity is unlikely to have been invented spontaneously. Our results suggest that Neanderthals invented or developed this process based on previous simpler methods and constitute one of the clearest indicators of cumulative cultural evolution in the European Middle Palaeolithic. Supplementary information: The online version contains supplementary material available at 10.1007/s12520-023-01789-2.

MediMer: a versatile do-it-yourself peptide-receptive MHC class I multimer platform for tumor neoantigen-specific T cell detection.

Peptide-loaded MHC class I (pMHC-I) multimers have revolutionized our capabilities to monitor disease-associated T cell responses with high sensitivity and specificity. To improve the discovery of T cell receptors (TCR) targeting neoantigens of individual tumor patients with recombinant MHC molecules, we developed a peptide-loadable MHC class I platform termed MediMer. MediMers are based on soluble disulfide-stabilized ß2-microglobulin/heavy chain ectodomain single-chain dimers (dsSCD) that can be easily produced in large quantities in eukaryotic cells and tailored to individual patients' HLA allotypes with only little hands-on time. Upon transient expression in CHO-S cells together with ER-targeted BirA biotin ligase, biotinylated dsSCD are purified from the cell supernatant and are ready to use. We show that CHO-produced dsSCD are free of endogenous peptide ligands. Empty dsSCD from more than 30 different HLA-A,B,C allotypes, that were produced and validated so far, can be loaded with synthetic peptides matching the known binding criteria of the respective allotypes, and stored at low temperature without loss of binding activity. We demonstrate the usability of peptide-loaded dsSCD multimers for the detection of human antigen-specific T cells with comparable sensitivities as multimers generated with peptide-tethered ß2m-HLA heavy chain single-chain trimers (SCT) and wild-type peptide-MHC-I complexes prior formed in small-scale refolding reactions. Using allotype-specific, fluorophore-labeled competitor peptides, we present a novel dsSCD-based peptide binding assay capable of interrogating large libraries of in silico predicted neoepitope peptides by flow cytometry in a high-throughput and rapid format. We discovered rare T cell populations with specificity for tumor neoepitopes and epitopes from shared tumor-associated antigens in peripheral blood of a melanoma patient including a so far unreported HLA-C*08:02-restricted NY-ESO-1-specific CD8+ T cell population. Two representative TCR of this T cell population, which could be of potential value for a broader spectrum of patients, were identified by dsSCD-guided single-cell sequencing and were validated by cognate pMHC-I multimer staining and functional responses to autologous peptide-pulsed antigen presenting cells. By deploying the technically accessible dsSCD MHC-I MediMer platform, we hope to significantly improve success rates for the discovery of personalized neoepitope-specific TCR in the future by being able to also cover rare HLA allotypes.

Knapping force as a function of stone heat treatment.

We propose a quantitative framework for understanding the knapping force requirements imposed by different raw materials in their unheated and heat-treated states. Our model interprets stone tool knapping as being the result of cracks formed during the first impact with a hammer stone, followed by continued stressing of these cracks that eventually leads to flake detachment. We combine bending strength, indentation fracture resistance and "Griffith" crack lengths of flint and silcrete to obtain functions identifying critical forces for flaking without or after heat treatment. We argue that these forces are a key factor for understanding the "knappability" of different raw materials, because only forces with 100N or less can be used for very precise strike control. Our model explains for the first time why experimental knappers frequently observe that flint (a stronger material, which, in our case, has a strength above 100 MPa) is easier to knap than silcretes (which is relatively weaker with strength values at or below 60 MPa). Our findings allow for understanding the differences between heat-treated and untreated flint and silcrete in terms of knapping quality, and they allow to compare the qualities of different raw materials.

Archaeological adhesives made from Podocarpus document innovative potential in the African Middle Stone Age.

Studying the earliest archaeological adhesives has implications for our understanding of human cognition. In southern Africa, the oldest adhesives were made by Homo sapiens in the Middle Stone Age. Chemical studies have shown that these adhesives were made from a local conifer of the Podocarpaceae family. However, Podocarpus does not exude resin, nor any other substance that could have been recognized as having adhesive properties. Therefore, it remains unknown how these adhesives were made. This study investigates how Podocarpus adhesives can be made, comparing their mechanical properties with other naturally available adhesives. We found that Podocarpus tar can only be made by dry distillation of leaves, requiring innovative potential, skill, and knowledge. This contrasts with our finding that the Middle Stone Age environment was rich in substances that can be used as adhesives without such transformation. The apparent preference for Podocarpus tar may be explained by its mechanical properties. We found it to be superior to all other substances in terms of its adhesive properties. In addition, the condensation method that allows producing it can be recognized accidentally, as the processes take place above ground and can be triggered accidentally. Our findings have implications for establishing a link between technology and cognition in the Middle Stone Age.

The origin of chert in the Aurignacian of Vogelherd Cave investigated by infrared spectroscopy.

The analyses of raw material provenance offers the possibility of tracing short and long-distance raw material transport. So far, most studies of raw material of flint and chert in Europe have been based on macroscopic analyses. We apply infrared spectroscopy to Aurignacian assemblages from Vogelherd cave and to the Magdalenian site Randecker Maar in southwestern Germany. We compare raw material samples from three chert-bearing areas in Germany with archaeological samples from Vogelherd. Our results show that infrared spectroscopy can distinguish between different raw materials. Our archaeological samples from Vogelherd correspond to the sampled geological cherts in terms of their spectral signature. Our comparison of reference samples and archaeological samples highlights problems in commonly used macroscopic identifications of chert raw materials.

Mechanical properties of lithic raw materials from Kazakhstan: Comparing chert, shale, and porphyry.

The study of lithic raw material quality has become one of the major interpretive tools to investigate the raw material selection behaviour and its influence to the knapping technology. In order to make objective assessments of raw material quality, we need to measure their mechanical properties (e.g., fracture resistance, hardness, modulus of elasticity). However, such comprehensive investigations are lacking for the Palaeolithic of Kazakhstan. In this work, we investigate geological and archaeological lithic raw material samples of chert, porphyry, and shale collected from the Inner Asian Mountain Corridor (henceforth IAMC). Selected samples of aforementioned rocks were tested by means of Vickers and Knoop indentation methods to determine the main aspect of their mechanical properties: their indentation fracture resistance (a value closely related to fracture toughness). These tests were complemented by traditional petrographic studies to characterise the mineralogical composition and evaluate the level of impurities that could have potentially affected the mechanical properties. The results show that materials, such as porphyry possess fracture toughness values that can be compared to those of chert. Previously, porphyry was thought to be of lower quality due to the anisotropic composition and coarse feldspar and quartz phenocrysts embedded in a silica rich matrix. However, our analysis suggests that different raw materials are not different in terms of indentation fracture resistance. This work also offers first insight into the quality of archaeological porphyry that was utilised as a primary raw material at various Upper Palaeolithic sites in the Inner Asian Mountain Corridor from 47-21 ka cal BP.

Hyperthermia-induced doxorubicin delivery from thermosensitive liposomes via MR-HIFU in a pig model.

PURPOSE: Encapsulation of cytotoxic drugs for a localized release is an effective way to increase the therapeutic window of such agents. In this article we present the localized release of doxorubicin (DOX) from phosphatidyldiglycerol (DPPG2) based thermosensitive liposomes using MR-HIFU mediated hyperthermia in a swine model. MATERIALS AND METHODS: German landrace pigs of weights between 37.5 and 53.5 kg received a 30-min infusion of DOX containing thermosensitive liposomes (50 mg DOX/m2). The pigs' biceps femoris was treated locally in two separate target areas with mild hyperthermia using magnetic resonance guided high intensity focused ultrasound, starting 10 min and 60 min after initiation of the infusion, respectively. The pharmacokinetics and biodistribution of DOX were determined and an analysis of the treatment parameters' influence was performed. RESULTS: Compared to untreated tissue, we found a 15-fold and a 7-fold increase in DOX concentration in the muscle volumes that had undergone hyperthermia starting 10 min and 60 min after the beginning of the infusion, respectively. The pharmacokinetic analysis showed a prolonged circulation time of DOX and a correlation between the AUC of extra-liposomal DOX in the bloodstream and the amount of DOX accumulated in the target tissue. CONCLUSIONS: We have demonstrated a workflow for MR-HIFU hyperthermia drug delivery that can be adapted to a clinical setting, showing that HIFU-hyperthermia is a suitable method for local drug release of DOX using DPPG2 based thermosensitive liposomes in stationary targets. Using the developed pharmacokinetic model, an optimization of the drug quantity deposited in the target via the timing of infusion and hyperthermia should be possible.

A new method for birch tar making with materials available in the Stone Age.

The use of birch tar can be traced back to the European Middle Palaeolithic and is relevant for our understanding of the technical skills and cognitive abilities of Neanderthals. Due to the lack of archaeological evidence, it remains unknown what techniques were used for birch tar making. Efficiency was recently used as a proxy to determine the method most likely used in the Middle Palaeolithic. Todtenhaupt et al. have proposed a technique employing a groove-like structure that is comparable with the recently presented condensation method. The groove method resulted in higher tar yields compared to other experimental aceramic production processes. However, the implications for Palaeolithic tar making remain unclear because some of the materials used in the experiment were not available then (polished granite slabs). To approach this problem, we replicated the groove with river cobbles and, in a second experiment with flint fragments, to evaluate whether similar results can be obtained. We were successful in producing birch tar in multiple runs with the cobble- and flint-grooves, which, in addition, proved to be more efficient than the condensation method in terms of tar yield per bark input. Our experimental study provides an additional possibility to make prehistoric birch tar.

Visualization of thermal washout due to spatiotemporally heterogenous perfusion in the application of a model-based control algorithm for MR-HIFU mediated hyperthermia.

PURPOSE: This article will report results from the in-vivo application of a previously published model-predictive control algorithm for MR-HIFU hyperthermia. The purpose of the investigation was to test the controller's in-vivo performance and behavior in the presence of heterogeneous perfusion. MATERIALS AND METHODS: Hyperthermia at 42°C was induced and maintained for up to 30 min in a circular section of a thermometry slice in the biceps femoris of German landrace pigs (n=5) using a commercial MR-HIFU system and a recently developed MPC algorithm. The heating power allocation was correlated with heat sink maps and contrast-enhanced MRI images. The temporal change in perfusion was estimated based on the power required to maintain hyperthermia. RESULTS: The controller performed well throughout the treatments with an absolute average tracking error of 0.27 ± 0.15 °C and an average difference of 1.25 ± 0.22 °C between T10 and T90. The MPC algorithm allocates additional heating power to sub-volumes with elevated heat sink effects, which are colocalized with blood vessels visible on contrast-enhanced MRI. The perfusion appeared to have increased by at least a factor of ∼1.86 on average. CONCLUSIONS: The MPC controller generates temperature distributions with a narrow spectrum of voxel temperatures inside the target ROI despite the presence of spatiotemporally heterogeneous perfusion due to the rapid thermometry feedback available with MR-HIFU and the flexible allocation of heating power. The visualization of spatiotemporally heterogeneous perfusion presents new research opportunities for the investigation of stimulated perfusion in hypoxic tumor regions.

Rational Design of Thermoresponsive Microgel Templates with Polydopamine Surface Coating for Microtissue Applications.

Functional microgels provide a versatile basis for synthetic in vitro platforms as alternatives to animal experiments. The tuning of the physical, chemical, and biological properties of synthetic microgels can be achieved by blending suitable polymers and formulating them such to reflect the heterogenous and complex nature of biological tissues. Based on this premise, this paper introduces the development of volume-switchable core-shell microgels as 3D templates to enable cell growth for microtissue applications, using a systematic approach to tune the microgel properties based on a deep conceptual and practical understanding. Microscopic microgel design, such as the tailoring of the microgel size and spherical shape, is achieved by droplet-based microfluidics, while on a nanoscopic scale, a thermoresponsive polymer basis, poly(N-isopropylacrylamide) (PNIPAAm), is used to provide the microgel volume switchability. Since PNIPAAm has only limited cell-growth promoting properties, the cell adhesion on the microgel is further improved by surface modification with polydopamine, which only slightly affects the microgel properties, thereby simplifying the system. To further tune the microgel thermoresponsiveness, different amounts of N-hydroxyethylacrylamide are incorporated into the PNIPAAm network. In a final step, cell growth on the microgel surface is investigated, both at a single microgel platform and in spheroidal cell structures.

A nonviral, nonintegrating DNA nanovector platform for the safe, rapid, and persistent manufacture of recombinant T cells.

The compelling need to provide adoptive cell therapy (ACT) to an increasing number of oncology patients within a meaningful therapeutic window makes the development of an efficient, fast, versatile, and safe genetic tool for creating recombinant T cells indispensable. In this study, we used nonintegrating minimally sized DNA vectors with an enhanced capability of generating genetically modified cells, and we demonstrate that they can be efficiently used to engineer human T lymphocytes. This vector platform contains no viral components and is capable of replicating extrachromosomally in the nucleus of dividing cells, providing persistent transgene expression in human T cells without affecting their behavior and molecular integrity. We use this technology to provide a manufacturing protocol to quickly generate chimeric antigen receptor (CAR)-T cells at clinical scale in a closed system and demonstrate their enhanced anti-tumor activity in vitro and in vivo in comparison to previously described integrating vectors.

Reversible Iodine Intercalation into Tungsten Ditelluride.

The new compound WTe2I was prepared by a reaction of WTe2 with iodine in a fused silica ampule at temperatures between 40 and 200 °C. Iodine atoms are intercalated into the van der Waals gap between tungsten ditelluride layers. As a result, the WTe2 layer separation is significantly increased. Iodine atoms form planar layers between each tungsten ditelluride layer. Due to oxidation by iodine the semimetallic nature of WTe2 is changed, as shown by comparative band structure calculations for WTe2 and WTe2I based on density functional theory. The calculated phonon band structure of WTe2I indicates the presence of phonon instabilities related to charge density waves, leading to an observed incommensurate modulation of the iodine position within the layers.