Ultracool Field Brown Dwarf Candidates Selected at 4.5 microns

We have identified a sample of cool field brown dwarf candidates using IRAC data from the Spitzer Deep, Wide-Field Survey (SDWFS). The candidates were selected from 400,000 SDWFS sources with [4.5] <= 18.5 mag and required to have [3.6]-[4.5] >= 1.5 and [4.5] - [8.0] <= 2.0 on the Vega system. The first color requirement selects objects redder than all but a handful of presently known brown dwarfs with spectral classes later than T7, while the second eliminates 14 probable reddened AGN. Optical detection of 4 of the remaining 18 sources implies they are likely also AGN, leaving 14 brown dwarf candidates. For two of the brightest candidates (SDWFS J143524.44+335334.6 and SDWFS J143222.82+323746.5), the spectral energy distributions including near-infrared detections suggest a spectral class of ~ T8. The proper motion is < 0.25 "/yr, consistent with expectations for a luminosity inferred distance of >70 pc. The reddest brown dwarf candidate (SDWFS J143356.62+351849.2) has [3.6] - [4.5]=2.24 and H - [4.5] > 5.7, redder than any published brown dwarf in these colors, and may be the first example of the elusive Y-dwarf spectral class. Models from Burrows et al. (2003) predict larger numbers of cool brown dwarfs should be found for a Chabrier (2003) mass function. Suppressing the model [4.5] flux by a factor of two, as indicated by previous work, brings the Burrows models and observations into reasonable agreement. The recently launched Wide-field Infrared Survey Explorer (WISE) will probe a volume ~40x larger and should find hundreds of brown dwarfs cooler than T7.Comment: 13 pages, 6 figures, accepted for publication in the June 2010 issue of The Astronomical Journa

Identification and Validation of Novel Cerebrospinal Fluid Biomarkers for Staging Early Alzheimer's Disease

Ideally, disease modifying therapies for Alzheimer disease (AD) will be applied during the 'preclinical' stage (pathology present with cognition intact) before severe neuronal damage occurs, or upon recognizing very mild cognitive impairment. Developing and judiciously administering such therapies will require biomarker panels to identify early AD pathology, classify disease stage, monitor pathological progression, and predict cognitive decline. To discover such biomarkers, we measured AD-associated changes in the cerebrospinal fluid (CSF) proteome.CSF samples from individuals with mild AD (Clinical Dementia Rating [CDR] 1) (n = 24) and cognitively normal controls (CDR 0) (n = 24) were subjected to two-dimensional difference-in-gel electrophoresis. Within 119 differentially-abundant gel features, mass spectrometry (LC-MS/MS) identified 47 proteins. For validation, eleven proteins were re-evaluated by enzyme-linked immunosorbent assays (ELISA). Six of these assays (NrCAM, YKL-40, chromogranin A, carnosinase I, transthyretin, cystatin C) distinguished CDR 1 and CDR 0 groups and were subsequently applied (with tau, p-tau181 and Aβ42 ELISAs) to a larger independent cohort (n = 292) that included individuals with very mild dementia (CDR 0.5). Receiver-operating characteristic curve analyses using stepwise logistic regression yielded optimal biomarker combinations to distinguish CDR 0 from CDR>0 (tau, YKL-40, NrCAM) and CDR 1 from CDR<1 (tau, chromogranin A, carnosinase I) with areas under the curve of 0.90 (0.85-0.94 95% confidence interval [CI]) and 0.88 (0.81-0.94 CI), respectively.Four novel CSF biomarkers for AD (NrCAM, YKL-40, chromogranin A, carnosinase I) can improve the diagnostic accuracy of Aβ42 and tau. Together, these six markers describe six clinicopathological stages from cognitive normalcy to mild dementia, including stages defined by increased risk of cognitive decline. Such a panel might improve clinical trial efficiency by guiding subject enrollment and monitoring disease progression. Further studies will be required to validate this panel and evaluate its potential for distinguishing AD from other dementing conditions

Identification of Independent Risk Factors for Skin Complications in a Multifactorial Logistic Regression Analysis of Simultaneous Immediate Autologous Breast Reconstruction and Skin Reduction Mastectomy in Large and Ptotic Breasts Using an Inferiorly Based Deepithelialized Dermal Breast Flap

Autologous immediate breast reconstruction in large and ptotic breasts remains challenging. We aimed to identify independent risk factors for impaired wound healing and nipple necrosis after skin reducing wise pattern mastectomy in autologous reconstruction with an auxiliary deepithelialized inferiorly based dermal flap (IBDF). Methods. This retrospective study examined patients with wise pattern mastectomy with autologous immediate breast reconstruction (IBR) between 2017 and 2019. All cases of large and ptotic breasts were included. Demographic, oncologic, reconstructive, and surgical data were compiled, and multifactorial binary logistic regression models identified independent predictors for skin complications and nipple areolar complex (NAC) necrosis. Results. Of 591 autologous breast reconstructions, 62 (11%) met the inclusion criteria. Overall wound complication rate was 32% (n = 20, DIEP 11, thigh 9, p = 0.99), including 26% minor (n = 16, non-surgically treated) and 7% major complications (n = 4, surgically treated). Complete NAC necrosis occurred in one case. Nipple sparing mastectomy (NSM) (p = 0.003), high BMI (p = 0.019), longer operation time (p = 0.044) and higher patient age (p = 0.045) were independent risk factors for skin complications. Using internal mammary artery perforators (IMAP) as recipient vessels did not result in increased complication rates (p = 0.59). Conclusion. Higher patient age, BMI, and operation time (OT) significantly increase the risk for skin complications in combined reduction wise pattern mastectomies with autologous IBR. In this context, IBDFs help preserve the inframammary fold, providing vasculature to the T-junction and the mastectomy skin flaps. Acceptable complication rates can be achieved in large and ptotic breasts, regardless of preoperative chemotherapy or radiation. Gentle tissue handling with minimal thermal trauma preserves internal mammary artery perforators (IMAPs) as recipient vessels. In cases of flap failure and alloplastic conversion, the IBDF can serve as an autoderm, protecting the implant from exposur

Die chimäre DIEP- und Lymphknoten-Lappenplastik als kombinierte Therapie zur Brustrekonstruktion und Behandlung von Lymphödemen der oberen Extremität

Manufacturing of parts by laser cutting is widely accepted in industry. In the market there are systems which are highly focused on special applications like robot based 3D cutting but there are also general purpose machines which cut a variety of metal sheets at different thicknesses. Most of these machines use a melt based cutting process where the material is molten and ejected by an assist gas. Quality of the laser cut part is determined by a dross free cut with minimal roughness on the cut faces after all standardized properties have to be fulfilled. To ensure this level of quality, several process parameters have to be kept at the right values and within defined tolerances. The most important one is the focal position which cannot be detected during processing. In this context, the transient behavior of the focal position due to thermal heating of optical elements is a challenging problem. In this paper, a process model is developed which allows the determination of the focal position by an experimentally accessible surrogate criterion. The theoretical predictions are compared with experimental results and a concept for an active focus control is discussed

Modularität von EDM-Systemen

This article discusses the problems of modularity of EDM systems. EDM functionalities can already be found in existing system environments specific of companies, so that an EDM technology with individual expansions of functions would be desirable. The technical prerequisites which may be expected from present EDM systems are listed in a summary