Probing the composition dependence of residual stress distribution in tungsten-titanium nanocrystalline thin films

Nanocrystalline alloy thin films offer a variety of attractive properties, such as high hardness, strength and wear resistance. A disadvantage is the large residual stresses that result from their fabrication by deposition, and subsequent susceptibility to defects. Here, we use experimental and modelling methods to understand the impact of minority element concentration on residual stresses that emerge after deposition in a tungsten-titanium film with different titanium concentrations. We perform local residual stress measurements using micro-cantilever samples and employ machine learning for data extraction and stress prediction. The results are correlated with accompanying microstructure and elemental analysis as well as atomistic modelling. We discuss how titanium enrichment significantly affects the stress stored in the nanocrystalline thin film. These findings may be useful for designing stable nanocrystalline thin films.

Delirium-associated medication in people at risk: A systematic update review, meta-analyses, and GRADE-profiles

BACKGROUND

Drug-associated delirium is a common but potentially preventable neuropsychiatric syndrome associated with detrimental outcomes. Empirical evidence for delirium-associated medication is uncertain due to a lack of high-quality studies. We aimed to further investigate the body of evidence for drugs suspected to trigger delirium.

METHODS

A systematic update review and meta-analyses of prospective studies presenting drug associations with incident delirium in adult study populations was conducted. Two authors independently searched MEDLINE, PsycINFO, Embase, and Google Scholar dated from October 1, 2009 to June 23, 2020, after screening a previous review published in 2011. The most reliable results on drug-delirium associations were pooled in meta-analyses using the random-effects model. Quality of evidence was assessed using the GRADE-approach. This study is preregistered with OSF (DOI https://doi.org.10.17605/OSF.IO/4PUHY).

RESULTS

The 31 eligible studies, presenting results for 24 medication classes were identified. Meta-analyses and GRADE level of evidence ratings show no increased delirium risk for Haloperidol (OR: 0.96, 95% CI 0.72-1.28; high-quality evidence), Olanzapine (OR: 0.25, 95% CI 0.15-0.40), Ketamine (OR: 0.72, 95% CI 0.35-1.46) or corticosteroids (OR: 0.69, 95% CI 0.32-1.50; moderate quality evidence, respectively). Low-level evidence suggests a three-fold increased risk for anticholinergics (OR: 3.11, 95% CI 1.04-9.26). Opioids, benzodiazepines, H₁ -antihistamines, and antidepressants did not reach reliable evidence levels in our analyses.

CONCLUSION

We investigated the retrievable body of evidence for delirium-associated medication. The results of this systematic review were then interpreted in conjunction with other evidence-based works and guidelines providing conclusions for clinical decision-making.

Disintegration of the agricultural by-product wheat bran under subcritical conditions

BACKGROUND

The disintegration of destarched wheat bran in water and sulfuric acid (pH 3) under subcritical conditions (275-300 °C) and at short reaction times (1-4 min) was investigated. A cascade process comprising a stepwise separation of the liquid was applied to reduce the formation of undesired degradation products.

RESULTS

The highest degree of biomass disintegration (67% dry mass solubilization) was achieved by application of a cascade process at 275 °C (pH 3). Regarding the dissolution of carbohydrates (monomeric and oligomeric form), the total glucose yields remained below 60%, while the total xylose and arabinose yields were about 76% and 67%. Approximately 74% of the protein and 95% of the mineral fraction could be extracted. The application of the cascade process enabled a substantially reduced formation of degradation products.

CONCLUSION

When operating hydrothermally and subcritically in order to avoid some problematic aspects of a biorefinery, an extensive disintegration and monomerization of wheat bran and its constituents remains difficult even under the tested conditions (300 °C, pH 3). However, the applied cascade process proved to be useful to increase the yields and to substantially reduce the formation of undesired degradation products. Despite this fact, increased water consumption has to be conceded. © 2018 Society of Chemical Industry.

Wheat bran biorefinery--an insight into the process chain for the production of lactic acid

The present study investigates a wheat bran biorefinery including major processing steps pre-extraction, pre-treatment and lactic acid fermentation. Concerning the dry mass distribution, during the pre-extraction 32% of the feedstock was recovered, offering some perspectives for applications in food area. The pre-treatment (hydrothermal/enzymatic hydrolysis) of the remaining cake solubilized 34% of dry mass and led to a fermentable sugar concentration of 21g/L. The fermentation resulted in a lactic acid yield of 0.73g/g substrate. Concentrating the fermentation feed via nanofiltration did not improve the lactic acid productivity. Taking into account that Lactobacillus pentosus, a heterofermentative microorganism was used, the dry mass balance revealed a product yield of 47% (32% extract, 15% lactic acid). Based on a theoretical consideration involving a cellulolytic enzyme production (10% feedstock allocation) and lignin utilization, under optimized conditions a maximum product yield of around 80% (35% extract, 39% lactic acid, 6% lignin) could be expected.

Investigations on a wheat bran biorefinery involving organosolv fractionation and enzymatic treatment

The present study elucidates the organosolv treatment of wheat bran, the major by-product of the milling industry. The influence of temperature (160-200°C) and ethanol concentration (30-60% (w/w)) at a given process time of 30min was investigated. Enzymatic treatments of the organosolv extracts including solid residues led to an overall glucose yield of 75%. The conversion of hemicelluloses into xylose and arabinose was approximately 60% and 45%, respectively. Proteins could be almost completely dissolved, however, practically no free amino acids were obtained. Surprisingly, only around 30% of lignin and 65% of minerals were dissolved. Severe treatment conditions induced the disintegration of fat into glycerol and fatty acids as well as the formation of sugar degradation products. During the lignin precipitation step, proteins partially coprecipitated.

Wheat bran biorefinery: an investigation on the starch derived glucose extraction accompanied by pre- and post-treatment steps

Wheat bran, a side product of the milling industry, can be considered as a feedstock for biorefineries. Unlike other lignocellulosic feedstock, wheat bran contains a reasonable amount of starch, which is not of recalcitrant nature. Therefore, it can be extracted without a costly pretreatment process. The present work evaluates the extraction of starch derived glucose in relation to a wheat bran biorefinery. The purity of free glucose extracted quantitatively was 44%. The extract was concentrated by threefold via nanofiltration, thereby reaching a glucose concentration of 49 g/L. Hydrothermal treatment (180°C - 20 min) of the starch-free bran did not induce the formation of hydroxymethylfurfural and levulinic acid. Interestingly, the furfural level increased compared to the process, in which bran was treated hydrothermally without a preceding starch extraction. By separation of water-extractables prior to enzymatic hydrolysis, the free glucose purity was increased to 58%, however the yield of glucose decreased to 61%.

High-throughput quantification of stabilizers in polymeric materials by flow injection tandem mass spectrometry

RATIONALE

High-throughput methods for identification and quantification of stabilizers in plastic materials are of significant importance in order to evaluate the suitability of materials of unknown origin for specific application areas, to clarify reasons for failure of materials, or for comparison of materials from different sources.

METHODS

In the present study, a highly sensitive and rapid flow injection method coupled to selected reaction monitoring mass spectrometry (MS) for comprehensive analysis of 21 polymer stabilizers in polyolefins is demonstrated. A critical factor for this approach is the choice of ionization mode, as no separation was performed prior to MS detection. Differences between several ionization techniques regarding matrix effects are reported.

RESULTS

Atmospheric pressure chemical ionization was found to be the most suitable ionization technique, with no significant matrix effects observed. The developed method has a linear dynamic range over two to three orders of magnitude with correlation coefficients better than 0.99 for all studied analytes. Following a multistep sample preparation protocol, the method allowed quantification down to minimum values of between 0.0001 and 0.04 wt% depending on the type of stabilizer. Results were compared to an established chromatographic approach and showed very good correlation (bias below 7.5%).

CONCLUSIONS

The applicability of the optimized method could be demonstrated for both the qualitative and quantitative determination of polymer stabilizers in polyolefins. Furthermore, the described approach yields a complete analysis in a much shorter time than can be achieved with commonly applied chromatographic methods.

Wheat bran biorefinery--a detailed investigation on hydrothermal and enzymatic treatment

Due to the enormous quantities arising in the milling industry and its specific properties, wheat bran can be considered as a feedstock for future biorefineries. In the present work, a detailed investigation was carried out on the hydrothermal (140-200°C) and enzymatic treatment of wheat bran. After hydrothermal pretreatment and a subsequent enzymatic hydrolysis a glucose yield of 65% and 90% was achieved, respectively. Interestingly, the hemicelluloses could be disintegrated to monomers only to approx. 50%. About 70% of the proteins were dissolved, however, practically no free amino acids were obtained under given conditions. Severe treatment conditions induce elevated losses of some amino acids. Minerals could be extracted almost completely. To disintegrate fat into glycerol and fatty acids severe process conditions were necessary. The formation of undesired by-products such as furfural or hydroxymethylfurfural starts at approx. 180°C.

Blood transfusion and the risk of recurrence in squamous carcinoma of the vulva

OBJECTIVE

Our purpose was to determine if postoperative transfusion increases the risk of recurrence in patients who have undergone operation for squamous carcinoma of the vulva.

STUDY DESIGN

Data from 154 patients with squamous carcinoma of the vulva treated at Indiana University Medical Center from 1974 through 1988 were retrospectively analyzed to determine the influence of postoperative transfusion on recurrence risk. Patients were evaluated for International Federation of Gynecology and Obstetrics stage, lesion size, lesion depth, grade, patient age, number of transfusions, and recurrence with chi 2 analysis, Fisher's exact test, and the Student t test where appropriate.

RESULTS

Transfusions were given to 57 patients (37%) with a mean of 2.2 units delivered (range 1 to 5 units). Transfused patients differed significantly from those not transfused in that they had more advanced stage (p = 0.002), more positive nodes (p = 0.03), and higher grade lesions (p = 0.03), and they were older (p = 0.005). Recurrences developed in 25 patients (16.2%). Recurrences were more common in those with positive nodes (10-39, 25.6%) than in those with negative nodes (8/99, 8%), (p = 0.01). Only nodal status was predictive of recurrence in this series. Transfused patients had a 14% (8/57) rate of recurrence, whereas the recurrence risk was 17.5% (17/97) in those not transfused (p = 0.65).

CONCLUSIONS

We have been unable to confirm that postoperative transfusions increase the risk of recurrence in patients with squamous carcinoma of the vulva.

On the structure of albumin-bound bilirubin. Selective binding of intramolecularly hydrogen-bonded conformational enantiomers

The intramolecularly hydrogen-bonded bichromophoric tetrapyrrole pigments, bilirubin-IX alpha and mesobilirubin-XIII alpha, adopt either of two folded, intramolecularly hydrogen-bonded, enantiomeric conformations which are in dynamic equilibrium in solution. Added human serum albumin binds preferentially, although not necessarily exclusively, to one conformational enantiomer, and the solutions exhibit bisignate circular dichroism Cotton effects in the region of the pigment's long wavelength electronic transition. In contrast, the bichromophoric tetrapyrrole pigment mesobilirubin-IV alpha, which is incapable of adopting intramolecularly hydrogen-bonded folded conformations, and the monochromophoric pyrromethenone, xanthobilirubic acid, show only monosignate induced circular dichroism Cotton effects under the same conditions. Application of exciton coupling theory indicates a preference for complexation of the right-handed (or positive) chirality conformational enantiomer of bilirubin-IX alpha or mesobilirubin-XIII alpha to human serum albumin at physiologic pH.

Buprenorphine as new treatment for heroin dependence

Dr. Jasinski suggested years ago that on the basis of some preliminary findings buprenorphine could hold promise for the treatment of heroin dependence (D. Jasinski, J.S. Pevnick and J.D. Griffith, Arch. Gen. Psychiatry, 35 (1978) 501)). No significant report has been published to confirm that assumption, and no treatment program seems to have started on that ground. Buprenorphine is now available in several countries including Belgium. We tried to devise a treatment program for heroin addicts combining chemotherapy with sublingual buprenorphine and psychotherapy. The interim results of this treatment program--initiated in 65 heroin addicts and undertaken by 34 of them for periods varying from 2 to 17 months--seem sufficiently promising to pursue our research.