Experimental measurements of orientation and rotation of dense 3D packings of spheres

Many recent advances in the study of granular media have stemmed from the improved capability to image and track individual grains in two and three dimensions. While two-dimensional systems readily yield both translational and rotational motion, a challenge in three-dimensional experiments is the tracking of rotational motion of isotropic particles. We propose an extension of the refractive index matched scanning technique as a method of measuring individual particle rotation. Initial measurements indicate that shear-driven rotational motion may stem from gear-like motion within the shear zone.     

Relationships between milking frequency, lactation persistency and milk yield in Swedish Red heifers and cows milked in a voluntary attendance automatic milking system

A large dataset comprising output from an automatic milking (AM) system between 1999 and 2006 was examined and a total of 172 cow lactation curves and 68 heifer lactation curves were identified for further analysis. Relationships between milking frequency at different stages of lactation and lactation persistency and total lactation yield were determined. Cows had higher peak and total milk yields than heifers, but heifers had higher persistency (defined as the rate of decline in milk yield between days 100 and 300 post calving). Milking frequency did not differ significantly between cows and heifers in early lactation, but thereafter decreased significantly more in cows than in heifers. The effect of milking frequency on yield characteristics was analysed by comparing the highest and lowest quartiles for milking frequency. High milking frequency in early lactation was consistently associated with increased peak yield. High milking frequency averaged across the whole lactation was associated with increased peak yield in both cows and heifers, and with improved lactation persistency in cows only. This resulted in total lactation yield that was 21% greater in the high quartile cows compared with the low.     

Internal reflection ellipsometry for real-time monitoring of polyelectrolyte multilayer growth onto tantalum pentoxide

Internal reflection ellipsometry was used for detection of the consecutive coating of two polyelectrolytes, poly(allylamine hydrochloride) (PAH) and poly(acrylic acid) (PAA), onto a tantalum pentoxide (Ta₂O₅) substrate until the 10th bilayer. The UV patterned PAH-PAA-multilayer was characterized in air via ellipsometry and atomic force microscopy. Suited optical models enabled the determination of the layer thicknesses in wet and dry states. Linear multilayer formation could be proved by Attenuated Total Reflection — Fourier Transformed Infrared Spectroscopy measurements following the increase of the ν(C=O) band depending on the adsorption of the PAA. Streaming potential measurements after each layer deposition step indicated a change in surface charge after each layer deposition due to the consecutive coating of PAH and PAA. In this article the internal reflection ellipsometry is shown to be a convenient possibility to analyze the modification of a thin transparent Ta₂O₅ substrate.     

Bücherschau

Ohne Zusammenfassung VDI     

Endogenous Modulation of Extracellular Matrix Collagen during Scar Formation after Myocardial Infarction

Myocardial infarction is remains the leading cause of death in developed countries. Recent data show that the composition of the extracellular matrix might differ despite similar heart function and infarction sizes. Because collagen is the main component of the extracellular matrix, we hypothesized that changes in inflammatory cell recruitment influence the synthesis of different collagen subtypes in myofibroblasts, thus changing the composition of the scar. We found that neutrophils sustain the proliferation of fibroblasts, remodeling, differentiation, migration and inflammation, predominantly by IL-1 and PPARγ pathways (n = 3). They also significantly inhibit the mRNA expression of fibrillar collagen, maintaining a reduced stiffness in isolated myofibroblasts (n = 4–5). Reducing the neutrophil infiltration in CCR1^−/− resulted in increased mRNA expression of collagen 11, moderate expression of collagen 19 and low expression of collagen 13 and 26 in the scar 4 weeks post infarction compared with other groups (n = 3). Mononuclear cells increased the synthesis of all collagen subtypes and upregulated the NF-kB, angiotensin II and PPARδ pathways (n = 3). They increased the synthesis of collagen subtypes 1, 3, 5, 16 and 23 but reduced the expression of collagens 5 and 16 (n = 3). CCR2^−/− scar tissue showed higher levels of collagen 13 (n = 3), in association with a significant reduction in stiffness (n = 4–5). Upregulation of the inflammation-related genes in myofibroblasts mostly modulated the fibrillar collagen subtypes, with less effect on the FACIT, network-forming and globular subtypes (n = 3). The upregulation of proliferation and differentiation genes in myofibroblasts seemed to be associated only with the fibrillar collagen subtype, whereas angiogenesis-related genes are associated with fibrillar, network-forming and multiplexin subtypes. In conclusion, although we intend for our findings to deepen the understanding of the mechanism of healing after myocardial infarction and scar formation, the process of collagen synthesis is highly complex, and further intensive investigation is needed to put together all the missing puzzle pieces in this still incipient knowledge process.     

Partial Reduction in BRCA1 Gene Dose Modulates DNA Replication Stress Level and Thereby Contributes to Sensitivity or Resistance

BRCA1 is a well-known breast cancer risk gene, involved in DNA damage repair via homologous recombination (HR) and replication fork protection. Therapy resistance was linked to loss and amplification of the BRCA1 gene causing inferior survival of breast cancer patients. Most studies have focused on the analysis of complete loss or mutations in functional domains of BRCA1. How mutations in non-functional domains contribute to resistance mechanisms remains elusive and was the focus of this study. Therefore, clones of the breast cancer cell line MCF7 with indels in BRCA1 exon 9 and 14 were generated using CRISPR/Cas9. Clones with successful introduced BRCA1 mutations were evaluated regarding their capacity to perform HR, how they handle DNA replication stress (RS), and the consequences on the sensitivity to MMC, PARP1 inhibition, and ionizing radiation. Unexpectedly, BRCA1 mutations resulted in both increased sensitivity and resistance to exogenous DNA damage, despite a reduction of HR capacity in all clones. Resistance was associated with improved DNA double-strand break repair and reduction in replication stress (RS). Lower RS was accompanied by increased activation and interaction of proteins essential for the S phase-specific DNA damage response consisting of HR proteins, FANCD2, and CHK1.     

Five-year experience with setup and implementation of an integrated database system for clinical documentation and research

In radiation oncology, where treatment concepts are elaborated in interdisciplinary collaborations, handling distributed, large heterogeneous amounts of data efficiently is very important, yet challenging, for an optimal treatment of the patient as well as for research itself. This becomes a strong focus, as we step into the era of modern personalized medicine, relying on various quantitative data information, thus involving the active contribution of multiple medical specialties. Hence, combining patient data from all involved information systems is inevitable for analyses. Therefore, we introduced a documentation and data management system integrated in the clinical environment for electronic data capture. We discuss our concept and five-year experience of a precise electronic documentation system, with special focus on the challenges we encountered. We specify how such a system can be designed and implemented to plan, tailor and conduct (multicenter) clinical trials, ultimately reaching the best clinical performance, and enhancing interdisciplinary and clinical research.     

Detection of colorectal adenoma and cancer based on transthyretin and C3a-desArg serum levels

Colorectal cancer is the second leading cause of cancer death, and it develops from benign colorectal adenomas in over 95% of patients. Early detection of these cancer precursors by screening tests and their removal can potentially eradicate more than 95% of colorectal cancers before they develop. To discover sensitive and specific biomarkers for improvement of pre‐clinical diagnosis of colorectal adenoma and cancer, we analysed in two independent studies (n = 87 and n = 83 patients) serum samples from colorectal cancer (stage III), colorectal adenoma and control patients using SELDI‐TOF‐MS. Extensive statistical analysis was performed to establish homogeneous patient groups based on their clinical data. Two biomarkers that were each able to distinguish control patients from either colorectal adenoma or colorectal cancer patients (p<0.001) were identified as transthyretin (pre‐albumin) and C3a‐desArg by MS/MS and were further validated by antibody‐based assays (radial immunodiffusion, ELISA). A combination of both proteins clearly indicated the presence of colorectal adenoma or carcinoma. Using a cut‐off of <0.225 g/L for transthyretin and >1974 ng/mL for C3a‐desArg, we found a sensitivity and specificity for colorectal adenoma of 96% and 70%, respectively.