The role of contaminations in ion beam spectroscopy with freestanding 2D materials: A study on thermal treatment.

As surface-only materials, freestanding 2D materials are known to have a high level of contamination-mostly in the form of hydrocarbons, water, and residuals from production and exfoliation. For well-designed experiments, it is of particular importance to develop effective cleaning procedures, especially since standard surface science techniques are typically not applicable. We perform ion spectroscopy with highly charged ions transmitted through freestanding atomically thin materials and present two techniques to achieve clean samples, both based on thermal treatment. Ion charge exchange and energy loss are used to analyze the degree of sample contamination. We find that even after cleaning, heavily contaminated spots remain on single layer graphene. The contamination coverage, however, clusters in strand-like structures leaving large clean areas. We present a way to discriminate clean from contaminated areas with our ion beam spectroscopy if the heterogeneity of the surface is increased sufficiently enough. We expect a similar discrimination to be necessary in most other experimental techniques.

The shortcomings of accurate rate estimations in cultivation processes and a solution for precise and robust process modeling.

The accurate estimation of cell growth or the substrate consumption rate is crucial for the understanding of the current state of a bioprocess. Rates unveil the actual cell status, making them valuable for quality-by-design concepts. However, in bioprocesses, the real rates are commonly not accessible due to analytical errors. We simulated Escherichia coli fed-batch fermentations, sampled at four different intervals and added five levels of noise to mimic analytical inaccuracy. We computed stepwise integral estimations with and without using moving average estimations, and smoothing spline interpolations to compare the accuracy and precision of each method to calculate the rates. We demonstrate that stepwise integration results in low accuracy and precision, especially at higher sampling frequencies. Contrary, a simple smoothing spline function displayed both the highest accuracy and precision regardless of the chosen sampling interval. Based on this, we tested three different options for substrate uptake rate estimations.

Second nationwide anti-tuberculosis drug resistance survey in Namibia.

SETTING: Namibia ranks among the 30 high TB burden countries worldwide. Here, we report results of the second nationwide anti-TB drug resistance survey.OBJECTIVE: To assess the prevalence and trends of multidrug-resistant TB (MDR-TB) in Namibia.METHODS: From 2014 to 2015, patients with presumptive TB in all regions of Namibia had sputum subjected to mycobacterial culture and phenotypic drug susceptibility testing (DST) for rifampicin, isoniazid, ethambutol and streptomycin if positive on smear microscopy and/or Xpert MTB/RIF.RESULTS: Of the 4124 eligible for culture, 3279 (79.5%) had Mycobacterium tuberculosis isolated. 3126 (95%) had a first-line DST completed (2392 new patients, 699 previously treated patients, 35 with unknown treatment history). MDR-TB was detected in 4.5% (95%CI 3.7-5.4) of new patients, and 7.9% (95%CI 6.0-10.1) of individuals treated previously. MDR-TB was significantly associated with previous treatment (OR 1.8, 95%CI 1.3-2.5) but not with HIV infection, sex, age or other demographic factors. Prior treatment failure demonstrated the strongest association with MDR-TB (OR 17.6, 95%CI 5.3-58.7).CONCLUSION: The prevalence of MDR-TB among new TB patients in Namibia is high and, compared with the first drug resistance survey, has decreased significantly among those treated previously. Namibia should implement routine screening of drug resistance among all TB patients.

Anxiety spectrum disorders are common in patients with orthostatic tremor.

BACKGROUND: Orthostatic Tremor (OT) is a rare movement disorder characterized by a sensation of unsteadiness while standing and associated with high frequency tremors. Patients with OT commonly report a fear of falling and significant limitations in everyday activities. The prevalence of psychiatric comorbidities in OT patients has not been well-studied. METHODS: Subjects were evaluated by trained psychiatry researchers using the Mini International Neuropsychiatric Interview (M.I.N.I.). The M.I.N.I is a validated screening tool for psychiatric disorders. A standardized history covering previous psychiatric symptoms and illnesses was also obtained. RESULTS: 29 OT subjects were evaluated. The mean age was 67.7 years with female preponderance (89.3%). The average disease symptom duration was 18.2 years. 58.6% of the subjects had seen a mental health professional during the course of their OT illness. 24.1% of the subjects had a past history of depression, and 10.3% reported a family history of any psychiatric condition. 37.9% of the subjects screened positive for agoraphobia. Two of 29 subjects (6.9%) were classified as having a current major depressive episode and one subject (3.4%) was at risk for suicide. CONCLUSIONS: Psychiatric comorbidities are highly prevalent in OT patients, especially anxiety-spectrum disorders. Further studies are needed to understand if psychiatric disorders appear as a secondary response to the patient's symptoms, or are a primary non-motor manifestation of OT.

Whose blood is it? Application of DEPArray™ technology for the identification of individual/s who contributed blood to a mixed stain.

The interpretation and statistical evaluation of mixed DNA profiles often presents a particular challenge in forensic DNA investigations. Only in specific combinations can single cellular components of a mixture be assigned to one contributor. In this study, the DEPArray™ technology, which enables image-assisted immunofluorescent-sorting of rare single cells using dielectrophoretic (DEP) forces, was applied together with different preliminary tests to identify the individual/s who contributed blood to a given mixture. The technique was successfully applied in two routine casework samples. In order to ascertain how old a stain can be and still be processed successfully, white blood cells from two 10- and one 27-year-old stains were investigated. Depending on the stain's age, the associated DNA degradation level and the number of target cells successfully isolated, the final profile reflects a compromise between the gain of information due to isolation of pure cells of a specific cell type from a single contributor and the loss of discriminatory power due to incomplete profiles caused by DNA degradation.

Amyloid deposition in 2 feline thymomas.

Two cases of feline thymoma with amyloid deposition were encountered between 1982 and 2010. Neoplastic cells were separated by abundant, pale eosinophilic, homogeneous material that was congophilic and birefringent. Ultrastructurally, the neoplastic cells were connected by desmosomes, and the extracellular deposits were composed of nonbranching, hollow-cored fibrils, 8-10 nm in diameter. In the case with sufficient archived tissue for additional sections, the amyloid remained congophilic following potassium permanganate incubation, and the neoplastic cells were immunoreactive for pancytokeratin. The histologic, histochemical, ultrastructural, and immunohistochemical features of both neoplasms are consistent with epithelial-predominant thymoma with the unusual feature of intratumoral amyloid deposition. The affinity of the amyloid for Congo red following potassium permanganate incubation is consistent with non-AA amyloid. The ultrastructural findings were consistent with amyloid production by the neoplastic epithelial cells.

Comparison of telogen hair analyses: genRES MPX-2SP kit versus genRES MPX-SP1 and genRES MPX-SP2 kits.

STR investigations of telogen hair are invariably difficult due to the small amounts of nuclear DNA and its degradation products. However, in recent years there has been a considerable improvement. This study examined the suitability of a new STR kit with shortened amplicons for the investigation of hair in routine casework. This kit allows the simultaneous amplification of the eight STR-loci D3S1358, VWA, FGA, TH01, SE33, D8S1179, D18S51, and D21S11, and the sex-determining amelogenin system. It was tested against the genRES MPX-SP1 and genRES MPX-SP2 kits. The sensitivity of the new genRES MPX-2SP kit was demonstrated to be inferior to that of the genRES MPX-SP1, but almost equal to that of the genRES MPX-SP2 kit.

Sex-specific fluorescent labelling of cells for laser microdissection and DNA profiling.

Sex-specific isolation of cells from mixtures would greatly facilitate forensic casework. Thus, male and female cell mixtures were marked with a fluorescent X/Y-probe CEP X SpectrumOrange/Y SpectrumGreen DNA probe kit for fluorescence in situ hybridization, and single cells were isolated via laser microdissection (LMD). DNA profiling of LMD isolated, hybridized cells showed usable short tandem repeat profiles for at least 20 cells, which are comparable with results from other studies. To simulate casework samples, the method was also optimized for air-dried samples.

Comparative investigation of hair with the genRES(®) MPX-SP1, genRES MPX-SP2, and genRES MPX-2 kits.

In recent years there has been considerable improvement in short-tandem repeat (STR) investigations of hair, which were previously marred by small amounts of nuclear DNA and its degradation. This study examined the suitability of two STR kits with shortened amplicons for the investigation of hairs from routine casework. The overall sucess rate was more than 20%. Furthermore, the usefulness of quantification with real-time ploymerase chain reaction as a screening method was demonstrated.

Digoxigenin labelling and laser capture microdissection of male cells.

Laser capture microdissection (LMD) is a relatively new technique for the isolation of single cells. The application in forensic investigations has become more and more widespread, especially to select spermatozoa out of mixtures with vaginal cells. In particular in cases with low numbers of sperm it could be profitable to isolate all male cells (e.g. sperm and male epithelial cells) instead of focussing on the sperm only. Therefore, the specific labelling and detection of the male cells in a male/female cell mixture is necessary. In order to label all cells carrying a Y-chromosome we used a digoxigenin labelled chromosome Y hybridisation probe (Q Biogen). The stained cells were isolated with the SL microCut LMD system from Molecular Machines & Industries AG (MMI). At least ten diploid male cells were required to obtain a partial STR profile, with 20 cells, a full profile could be obtained.

Ninhydrin treatment as a screening method for the suitability of swabs taken from contact stains for DNA analysis.

More and more swabs containing unknown traces of biological material are submitted for forensic DNA analysis. Most of the samples are swabs taken from handled items such as tools, weapons and handles etc. Therefore, we tried to develop a screening method in order to focus the investigation on samples containing biomolecules, such as amino acids which might be associated with nucleic acids. A total of 285 swabs taken from various items collected during crime scene investigations were treated with ninhydrin which leads to a purple colour for samples containing amino acids. Of the swabs 158 were classified as ninhydrin positive and 76% of these samples yielded DNA profiles that fulfil the criteria for inclusion in the German national DNA database (profile frequency greater than 1 in 100,000) or in DNA mixtures which could at least be compared with suspects. In comparison only 9% of the 127 samples shown to be ninhydrin negative, revealed a usable DNA profile. Consequently, ninhydrin treatment was found to be an effective screening method which resulted in an increase in the rate of successfully typed samples and subsequently in a reduction of the costs due to the lower number of samples that needed to be typed.

Speciation of nitrogen - [N(3-)] and [N(2)(2-)] - in binary compounds.

The nitrogen content of the binary compounds SrN = Sr(4)[N](2)[N(2)], Sr[N(2)], and Ba[N(2)] (prepared by high-pressure syntheses) was determined analytically by using the carrier gas hot extraction method. For handling of the air- and moisture-sensitive samples, a transfer chamber was constructed to protect the compounds against decomposition before being analyzed. Additionally, it was necessary to develop a method allowing controlled and variable heating of the electrode furnace to get analytical results with high precision and accuracy. By means of a suitable temperature program it was possible not only to verify the existence but also to quantify the two different nitrogen species ([N(3-)] and [N(2)(2-)]), and thus confirm the results of recent neutron diffraction studies.

Ligand density determines the efficiency of negative selection in the thymus.

To study the influence of antigen density on the efficiency of negative selection in the thymus, MHC class I (H-2K(b), K(b)) transgenic mice were generated, which expressed a K(b) transgene under the control of its natural promoter at 33% (K(b-lo)) or 150% (K(b-hi)) the surface density of Kb in C57BL/6 (B6, H-2(b)) mice. These mice were crossed to anti-K(b) T-cell receptor (Des-TCR) transgenic mice. In Des-TCRxK(b-hi) double transgenic mice, Des-TCR bearing T cells were completely eliminated during thymocyte maturation. In contrast, in Des-TCRxK(b-lo) double transgenic mice, two populations of Des-TCR T cells were evident, which either expressed the Des-TCR at intermediate density in the absence of CD8 (Des-TCR(int)CD8(-)) or expressed both the Des-TCR and CD8 at low density (Des-TCRloCD8lo). In the thymus of both types of double transgenic mice, no Des-TCR(+)CD4(+)CD8(+) thymocytes were detected, suggesting that deletion of Des-TCR cells occurred before the CD4(+)CD8(+) stage. Because only very few Des-TCR(+) thymocytes were found in Des-TCRxK(b-hi) transgenic mice, deletion of these T cells apparently occurred upon expression of the Des-TCR. By contrast, Des-TCRxK(b-lo) transgenic mice showed distinct populations of Des-TCR(int)CD4-8- and Des-TCR(lo)CD8(lo) thymocytes, suggesting that expression of the CD8 coreceptor was required to allow negative selection to proceed. Functional analyses showed that sublethally irradiated Des-TCRxK(b-lo) double transgenic mice were protected from lethal graft-versus-host disease by injected Des-TCR lymph node cells.

Mechanisms of cocaine-induced decreases in immune cell function.

Cocaine has previously been shown to decrease mitogen-induced T lymphocyte proliferation in rats following intravenous administration. However, in this report, it is demonstrated that central administration of cocaine (1-50 microg) had no effect on lymphocyte proliferation responses. Similarly, the quaternary derivative, cocaine methiodide, also suppressed lymphocyte proliferation only when administered peripherally (6.5 mg/kg), and not centrally (1-20 microg). These results suggest that the effects of cocaine were mediated through a peripheral mechanism. Since significant elevations in plasma corticosterone were observed with all routes of administration of cocaine, the effects of cocaine did not appear to be due entirely to activation of the HPA axis. Instead, the peripheral administration of the local anesthetic, lidocaine (5 mg/kg) or the monoamine reuptake inhibitor, RTI-55 (2-5 mg/kg), produced significant suppressive effects on proliferation. suggesting that both of these peripheral activities of cocaine may be involved in the alteration of lymphocyte responses.

Morphine-induced conditioned taste aversions in the LEW/N and F344/N rat strains.

Previous reports have shown that the LEW/N and F344/N inbred rat strains display a differential sensitivity to cocaine in a number of preparations, with the LEW/N rats displaying an increased sensitivity to both the reinforcing and aversive effects of cocaine (relative to the F344/N rats). Given that the LEW/N rats are also more sensitive to the reinforcing effects of morphine than the F344/N strain, the present experiment examined the ability of morphine to condition taste aversions in the LEW/N and F344/N strains to determine if the general sensitivity to cocaine generalizes to another drug of abuse. Specifically, on four conditioning trials, 35 LEW/N and 33 F344/N female rats were allowed access to a novel saccharin solution and then injected with varying doses of morphine (0, 10, 32 and 56 mg/kg). On intervening recovery days, subjects were allowed 20-min access to water. Following the fourth trial, a final aversion test was administered. The F344/N rats, but not the LEW/N rats, rapidly acquired morphine-induced taste aversions at all doses of morphine. Pharmacokinetic differences between the strains were also assessed. Specifically, 10 mg/kg morphine (or vehicle) was administered to subjects of both strains and plasma morphine levels were analyzed at 0.5, 2 and 4 h postinjection. No differences in plasma levels between the strains were observed. Unlike with cocaine, the LEW/N rats do not seem generally sensitive to morphine (relative to the F344/N rats). Rather, the differential sensitivity of the two strains to these compounds seems to be preparation dependent. Possible mechanisms underlying the differential sensitivity evident in the strains were discussed.

Identification of the skeletal remains of Martin Bormann by mtDNA analysis.

Contrary to statements of an eye-witness who reported that Martin Bormann, the second most powerful man in the Third Reich, died on 2 May 1945 in Berlin, rumours persisted over the years that he had escaped from Germany after World War II. In 1972, skeletal remains were found during construction work, and by investigating the teeth and the bones experts concluded that they were from Bormann. Nevertheless, new rumours arose and in order to end this speculation we were commissioned to identify the skeletal remains by mitochondrial DNA analysis. The comparison of the sequence of HV1 and HV2 from the skeletal remains and a living maternal relative of Martin Bormann revealed no differences and this sequence was not found in 1,500 Caucasoid reference sequences. Based on this investigation, we support the hypothesis that the skeletal remains are those of Martin Bormann.

Reversal of acute effects of high dose morphine on lymphocyte activity by chlorisondamine.

To explore the mechanisms mediating the effects of acute morphine on the immune system, effects of ganglionic blockade with chlorisondamine on acute high dose morphine-induced alterations in blood lymphocyte proliferation, white blood cell counts, spleen lymphocyte proliferation and splenic natural killer (NK) cell cytolytic activity were examined in male Sprague--Dawley rats. Two hours after morphine (30 mg/kg, s.c.) administration, blood lymphocyte proliferation (ConA) was decreased 85%; this effect was antagonized by chlorisondamine (5 mg/kg, i.p.). Notably, however, such morphine exposure did not significantly decrease splenic lymphocyte proliferation, although depression of NK cell activity was also evident and appeared to be chlorisondamine-sensitive. Immune effects of morphine 1 h after treatment were somewhat different. In this case, blood lymphocyte proliferation decreased and plasma levels of corticosterone increased, with ED(50) values of 2.2 and 7.8 mg/kg, respectively. Splenic lymphocyte proliferation and NK activity were also significantly depressed in the 1-h exposure paradigm, but only after administration of 30 mg/kg morphine. These results indicate that chlorisondamine blocks the effects of relatively high doses of morphine on blood lymphocyte activity and indicate that blood lymphocyte proliferation is more sensitive to effects of acute morphine exposure than splenic lymphocyte proliferation, NK cell cytolytic activity and activation of the HPA axis.