Methodische und statistische Untersuchungen zur Anwendbarkeit ausgewählter sequentieller Extraktionsverfahren auf bergbautypische Gesteins- und Bodenmaterialien

Der Gegenstand der vorliegenden Arbeit bilden Untersuchungen zur Anwendbarkeit ausgewählter sequentieller Extraktionsverfahren auf verschiedene Gesteinsmaterialien aus Regionen des Uranerz- sowie des Blei- und Zinkerzbergbaus. Neben der Erprobung der generellen Anwendbarkeit sowie der Selektivität modifizierter Extraktionssequenzen nach Tessier und Förstner stand vor allem die Auflösung von Unsicherheiten aus dem Extraktionsprozess und der analytischen Bestimmung im Vordergrund der Untersuchungen

Frauenerwerbstätigkeit, Qualifikation und Entlohnung in fünf Betrieben des Kreises Freiberg/Sachsen in den Jahren 1945 bis 1980

Die Autorin bezieht sich auf eine Analyse, die Mitte der achtziger Jahre in Sachsen durchgeführt wurde. Untersucht wurden zwei Betriebe der metallverarbeitenden und drei Betriebe der Leichtindustrie. Skizziert werden Technik, Arbeitsorganisation, die geschlechtstypische Zuweisung von Arbeitsplätzen, Entwicklung der Struktur und Qualifikation der Beschäftigten sowie die Entwicklung der Löhne. Die ökonomische Gleichstellung der Frau mit dem Mann in industriellen Arbeitsprozessen konnte in den untersuchten Betrieben, so ein Fazit der Autorin, nicht verwirklicht werden. So wurden etwa Frauen bei gleicher Qualifikation an minderwertigeren Arbeitsplätzen eingesetzt, die Familienarbeit zwang Frauen häufiger zu einem Wechsel des Arbeitsplatzes mit Lohnminderung an der neuen Arbeitsstelle etc. (rk

A new BIST scheme for low-power and high-resolution DAC testing

A BIST scheme for testing on chip DAC is presented in this paper. We discuss the generation of on chip testing stimuli and the measurement of digital signals with a narrow-band digital filter. We validate the scheme with software simulation and point out the possibility of ADC BIST with verified DACicus-journals

Dry transfer of CVD graphene using MoS2_2-based stamps

Recently, a contamination-free dry transfer method for graphene grown by chemical vapor deposition (CVD) has been reported that allows to directly pick-up graphene from the copper growth substrate using a flake of hexagonal boron nitride (hBN), resulting in ultrahigh charge carrier mobility and low overall doping. Here, we report that not only hBN, but also flakes of molybdenum disulfide (MoS$_2$) can be used to dry transfer graphene. This, on one hand, allows for the fabrication of complex van-der-Waals heterostructures using CVD graphene combined with different two-dimensional materials and, on the other hand, can be a route towards a scalable dry transfer of CVD graphene. The resulting heterostructures are studied using low temperature transport measurements revealing a strong charge carrier density dependence of the carrier mobilities (up to values of 12,000 cm$^2$/(Vs)) and the residual charge carrier density fluctuations near the charge neutrality point when changing the carrier density in the MoS$_2$ by applying a top gate voltage.Comment: 5 pages, 3 figure

Atomically Thin Resonant Tunnel Diodes built from Synthetic van der Waals Heterostructures

Vertical integration of two-dimensional van der Waals materials is predicted to lead to novel electronic and optical properties not found in the constituent layers. Here, we present the direct synthesis of two unique, atomically thin, multi-junction heterostructures by combining graphene with the monolayer transition-metal dichalocogenides: MoS2, MoSe2, and WSe2.The realization of MoS2-WSe2-Graphene and WSe2-MoSe2-Graphene heterostructures leads toresonant tunneling in an atomically thin stack with spectrally narrow room temperature negative differential resistance characteristics

Therapeutic options to prevent recurrence of an aggressive aneurysmatic bone cyst of the cervical spine of a 16 year old boy - a case report

The aneurysmatic bone cyst (ABC) is a benign primary bone tumour. If located in the cervical spine, its expansive growth and destructive behaviour may lead to instability and serious neurological impairment. We report a case of a 16-year-old boy with an aggressive ABC in the 7th cervical vertebra. Computertomographic and magnetic resonance imaging revealed the envelopment of the left 7th and 8th spinal nerve along with the anterior displacement of the left vertebral artery. The interdisciplinary surgical strategy consisted of a partially incomplete cyst resection, subtotal spondylectomy with posterior screw-and-rod fixation from C6-Th1, iliac crest bone grafting and anterior plating from C6-Th1. With regard to the high rate of recurrence after incomplete resection published in the recent literature, the patient was postoperatively treated by megavoltage radiotherapy with a total dose of 30Gy (daily dose of 1.8 Gy for 3 weeks). The clinical and radiographic follow-up showed complete recovery of all neurologic impairments and no signs of tumour recurrence at 3, 6 and 12 months after surgery. This case highlights diverse treatment regimens and shall outline the challenge and the problems of the interdisciplinary decision-making in adolescents presenting with ABC in high-demanding anatomical regions

TIE2-expressing monocytes and M2-polarized macrophages impact survival and correlate with angiogenesis in adenocarcinoma of the pancreas

Introduction: M2-polarized tumor-associated macrophages (TAMs) and TIE2- expressing monocytes (TEMs) are associated with angiogenesis and have been identified as a potential prognostic marker in several solid tumors, including hepatobiliary malignancies. However, little is known regarding their influence on tumor progression and patient survival in pancreatic ductal adenocarcinoma (PDAC). Results: Patients with tumors characterized by the presence of CD163+ TAMs or TEMs in TCA or TIF, respectively, showed a significantly decreased 1-, 3- and 5-year overall and recurrence-free survival compared to patients without CD163+ TAMs or TEMs (all ρ < 0.05). Patients with TEMs in TCA showed a higher incidence of tumor recurrence (ρ < 0.05). Furthermore, the presence of CD163+ TAMs was associated with a higher tumor MVD (ρ < 0.05). Conclusions: Presence of M2-polarized TAMs and TEMs is associated with a decreased overall and recurrence-free survival of patients with PDAC. Materials and methods: The localization and density of CD163+ M2-polarized TAMs and TEMs were quantified in the tumor central area (TCA) and tumor-infiltrating front (TIF) in human PDAC tissue (n = 106) and correlated to clinicopathological characteristics, tumor recurrence rates and patient survival. In parallel, tumor microvascular density (MVD) and the density of angiopoietin-positive tumor cells were quantified. Statistical analysis was performed using SPSS software

Prognostic Factors for Iatrogenic Tracheal Rupture: A Single-Center Retrospective Cohort Study

Iatrogenic tracheal ruptures are rare but severe complications of medical interventions. The main goal of this study was to explore prognostic factors for all-cause mortality and rupture-related (adjusted) mortality. We retrospectively analyzed patients admitted to an academic referral center over a 15-year period (2004–2018). Fifty-four patients met the inclusion criteria, of whom 36 patients underwent surgical repair and 18 patients were treated conservatively. In a 90-day follow-up, the all-cause mortality was 50%, while the adjusted mortality was 13%. Rupture length was identified as a predictor for all-cause mortality (area under the curve, 0.84; 95% confidence interval (CI) 0.74–0.94) with a cutoff rupture length of 4.5 cm (sensitivity, 0.70; specificity, 0.81). Multivariate analysis confirmed rupture length as a prognostic factor for all-cause mortality (adjusted hazard ratio (HR) 1.5; 95% CI 1.2–1.9; p = 0.001), but not for adjusted mortality (HR 1.5; 95% CI 0.97–2.3; p = 0.068), while mediastinitis predicted adjusted mortality (HR 5.8; 95% CI 1.1–31.7; p = 0.042), but not all-cause mortality (HR 1.6; 95% CI 0.7–3.5; p = 0.243). The extent of iatrogenic tracheal rupture and mediastinitis might be relevant prognostic factors for all-cause mortality and adjusted mortality, respectively