Publications by authors named "Siebert G"

This work describes the design and implementation of optics for EXCLAIM, the EXperiment for Cryogenic Large-Aperture Intensity Mapping. EXCLAIM is a balloon-borne telescope that will measure integrated line emission from carbon monoxide at redshifts z < 1 and ionized carbon ([CII]) at redshifts z = 2.5 - 3.

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Approximately 4% to 35% of pediatric patients undergoing treatment for acute lymphoblastic leukemia (ALL) and lymphoblastic lymphoma (LLy) develop drug-induced hyperglycemia. Though hyperglycemia is associated with poor outcomes, no guidelines for identifying drug-induced hyperglycemia currently exist, and the time course for developing hyperglycemia remains relatively uncharacterized after induction therapy. The present study evaluated a hyperglycemia screening protocol that was implemented to identify hyperglycemia more promptly, examined predictors of hyperglycemia during ALL and LLy therapy, and described the timeline for developing hyperglycemia.

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In fiber-reinforced polymer (FRP) composite laminate structures operating under fluctuating stresses, interface delamination is seen as one of the significant damage mechanisms. The constant degradation of their relatively low interlaminar strength and stiffness are the primary reasons for delamination. This study develops an interlaminar fatigue damage model to quantify the mechanics of the damage process and address the reliability of composite structures.

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The enhancement of fuel economy and the emission of greenhouse gases are the key growing challenges around the globe that drive automobile manufacturers to produce lightweight vehicles. Additionally, the reduction in the weight of the vehicle could contribute to its recyclability and performance (for example crashworthiness and impact resistance). One of the strategies is to develop high-performance lightweight materials by the replacement of conventional materials such as steel and cast iron with lightweight materials.

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Phosphatidylinositol-transfer proteins (PITPs) regulate phosphoinositide signaling in eukaryotic cells. The defining feature of PITPs is their ability to exchange phosphatidylinositol (PtdIns) molecules between membranes, and this property is central to PITP-mediated regulation of lipid signaling. However, the details of the PITP-mediated lipid exchange cycle remain entirely obscure.

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Background: The results of studies of ocular blood flow (BF) regulation of patients with primary open-angle glaucoma (POAG), normal-tension glaucoma (NTG) and ocular hypertension (OH) are presented.

Methods And Patients: Examinations were carried out with the "OPFA", a newly developed ocular pressure flow analyzer (producer: tpm Lüneburg) on 92 patients with newly diagnosed glaucomas, among whom 48 patients had POAG, 22 NTG and 22 OH, and compared with age-matched groups of healthy subjects. The OPFA uses pneumatic coupling through special scleral suction cups to record ocular pulses with highly sensitive transducers and a suction pump for simultaneously increasing intraocular pressure (IOP).

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Objective: Increased subcutaneous adipose tissue is a well known characteristic of diabetic fetopathy. Prenatal estimation of adipose tissue can be performed by ultrasound, while postnatally skinfold measurements are performed using a Holtain caliper. The aim of this study was to compare these methods in the same patients.

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Alzheimer's disease (AD) and Parkinson's disease (PD) are the two most common neurodegenerative disorders. Why some individuals develop one disease rather than the other is not clear. Association studies with a case-control design are the time-honored approach to identifying risk factors.

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Yersinia pestis, the causative agent of plague, has caused several pandemics throughout history and remains endemic in the rodent populations of the western United States. More recently, Y. pestis is one of several bacterial pathogens considered to be a potential agent of bioterrorism.

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Parkinson's disease (PD) is a common, heterogeneous syndrome diagnosed clinically by the presence of classical neurological symptoms and the absence of 'red flags' that suggest alternative secondary parkinsonian disorders. Neuropathologically, nigrostriatal loss and the presence of proteinaceous inclusions (Lewy bodies) confirm the diagnosis. For PD, molecular profiling promises much but is yet to deliver in terms of breakthroughs for identifying at-risk individuals, detecting disease at early stages, improving diagnostic certainty, prognosticating future outcomes or providing surrogate markers of therapeutic efficacy.

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It has been reported that the adjuvant-induced inflammation could affect drug metabolism in liver. Here we further investigated the effect of inflammation on drug transport in liver using taurocholate as a model drug. The hepatic disposition kinetics of [(3)H]taurocholate in perfused normal and adjuvant-treated rat livers were investigated by the multiple indicator dilution technique and data were analyzed by a previously reported hepatobiliary taurocholate transport model.

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Purpose: This prospective study was carried out in order to investigate changes in nutritional intake during pregnancy with regard to caloric intake and macronutrient composition in normal-weight pregnant women.

Methods: Using food scales, 32 healthy pregnant women estimated their food intake over a period of 2 days at gestational week 16, 22, 30, 36 and, in addition, 6 weeks after delivery. The recorded food logs were analyzed with respect to caloric intake and macronutrient composition.

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Background: Several studies show an association of adiponectin deficiency with obesity, insulin resistance and dysfunctional fat metabolism. This study investigates to what extent the correlations described occurs in pregnant women.

Method: Metabolism parameters and adiponectin serum levels were measured in 32 pregnant women at various times during their pregnancies and during the first six postpartum weeks.

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Familial Parkinsonism (PARK) genes are strong candidates for conferring susceptibility to common forms of PD. However, most studies to date have provided little evidence that their common variants substantially influence disease risk. Recently, mutations were described in the gene, GIGYF2 (TNRC15), located at the PARK11 locus (2q37.

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A family history of Parkinson's disease (PD) is the most commonly reported risk factor after age, suggesting a genetic component to the disease in a sub-group of patients. Mutations in at least six genes have been identified that can lead to monogenic forms of PD. We screened a sample of 74 early-onset PD cases out of a cohort of 950 patients (onset <50 years) for genetic abnormalities in known familial Parkinsonism genes.

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Objective: This longitudinal study performed continuous evaluation of daily blood glucose level profiles in healthy normal-weight pregnant patients during various gestational age and determined normal levels.

Study Design: Thirty-two healthy normal-weight pregnant women received a continuous glucose monitoring system (CGMS) device for periods of 72h in the 16th, 22nd, 30th and 36th weeks of gestational age and at 6 weeks after delivery. All observations took place in the outpatient clinic of the Charité hospital.

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Background: Most patients (pts) with metastatic non-small cell lung cancer (NSCLC) receive either single agents or chemotherapy doublets. Recent studies have demonstrated that triple-agent therapies may improve the response rate, but are associated with significant toxicity, and frequently do not prolong survival. A sequential triple-agent schedule may combine acceptable tolerability and good efficacy.

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The etiologic role of oral treponemes in human periodontitis is still under debate. Although seen by dark-field microscopy in large numbers, their possible role is still unclear since they comprise some 60 different phylotypes, most of which are still uncultured. To determine their status as mere commensals or opportunistic pathogens, molecular epidemiological studies are required that include both cultured and as-yet-uncultured organisms.

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Systemic inflammation is known to affect drug disposition in the liver. This study sought to relate and quantitate changes in hepatic pharmacokinetics of propranolol with changes in hepatic architecture and physiology in adjuvant-treated rats. Transmission electron microscopy was used to assess morphological changes in mitochondria and lysosomes of adjuvant-treated rat livers.

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Objectives: The purpose of this study was to evaluate the influence of mode of delivery on sexual function.

Design: One thousand six hundred and thirteen questionnaires containing 16 questions about sexual behavior and dyspareunia before, during and after pregnancy were sent out to primiparous, ethnically homogeneous (fluent in German) patients who delivered in a large tertiary referral center between 6 months and 2(1/2) year before. The returned questionnaires were merged to clinical data from our obstetric database in an anonymous fashion.

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The effects of a Chinese snake venom preparation from Agkistrodon halys pallas, used for treatment of hepatic fibrosis/cirrhosis in China, was investigated in an in vivo rat model and using in situ hepatic perfusion. Four groups were used in the experiments: (i) healthy, (ii) healthy/venom-treated, (iii) carbon tetrachloride (CCl4)-treated, and (iv) CCl4/venom-treated. Treatment effects were assessed by determining hepatic histopathology, biochemistry and fibrosis index parameters, bile production, biliary taurocholate recovery, hepatic mRNA expression of four bile salt transporters (Ntcp, Bsep, Oatp-1, and Oatp-3), comparison of hepatic microcirculation, fibrinolytic activity, and antithrombotic effects.

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The disposition kinetics of [3H]taurocholate ([3H]TC) in perfused normal and cholestatic rat livers were studied using the multiple indicator dilution technique and several physiologically based pharmacokinetic models. The serum biochemistry levels, the outflow profiles and biliary recovery of [3H]TC were measured in three experimental groups: (i) control; (ii) 17 alpha-ethynylestradiol (EE)-treated (low dose); and (iii) EE-treated (high dose) rats. EE treatment caused cholestasis in a dose-dependent manner.

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Introduction: Maternal hyperglycemia during gestational diabetes leads to fetal hyperinsulinemia, which is associated with increased perinatal morbidity and mortality. Amniotic fluid insulin levels are therefore considered by some researchers to be ideal parameters to use in diagnosing gestational diabetes and making decisions about correct therapy. There are various recommendations about determining gestational diabetes early in pregnancy (< 24 weeks) by measuring amniotic fluid insulin.

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