In KB cells productively infected with adenovirus type 2, alkali-stable >100S and 40-100S viral DNAs are synthesized starting 2-4 hr postinfection, i.e., before unit length (34 S) viral DNA is made. ...The amount of >100S and 40-100S viral DNA increases when 34S viral DNA synthesis begins, and at 16-18 hr postinfection, the 40-100S viral DNA represents 5-20% of the total intracellular viral DNA. The 40-100S viral DNA is synthesized throughout infection. Part of the 40-100S DNA synthesized 5-8 hr postinfection has a density in alkaline CsCl gradients intermediate between those of viral and cellular DNAs. This finding indicates that newly synthesized viral DNA is covalently linked to cellular DNA. Viral sequences can be excised from the cellular DNA of infected cells with the EcoRI restriction endonuclease. Fragments of viral DNA are detected in polyacrylamide-agarose gels by DNA· DNA hybridization, and these fragments correspond in size to most of the known EcoRI fragments of adenovirus 2 DNA. Viral DNA sequences in size-classes between the EcoRI-A and -C fragments are also found and probably represent viral DNA linked to cellular sequences.
Transformation of Imine Cages into Hydrocarbon Cages Schick, Tobias H. G.; Lauer, Jochen C.; Rominger, Frank ...
Angewandte Chemie (International ed.),
February 4, 2019, Letnik:
58, Številka:
6
Journal Article
Recenzirano
Odprti dostop
In contrast to organic cages which are formed by exploiting dynamic covalent chemistry, such as boronic ester cages, imine cages, or disulfide cages, those with a fully carbonaceous backbone are ...rarer. With the exception of alkyne metathesis based approaches, the vast majority of hydrocarbon cages need to be synthesized by kinetically controlled bond formation. This strategy implies a multiple step synthesis and no correction mechanism in the final macrocyclization step, both of which are responsible for low overall yields. Whereas for smaller cages the intrinsic drawbacks are not always obvious, larger cages are seldom synthesized in yields beyond a few tenths of a percent. Presented herein is a three‐step method to convert imine cages into hydrocarbon cages. The method has been successfully applied to even larger structures such as derivatives of C72H72 , an unknown cage suggested by Fritz Vögtle more than 20 years ago.
All‐carbon cages: In just three steps imine cages are converted into hydrocarbon cages by reduction, nitrosylation, and formation of the C−C bonds by an Overberger reaction. The method has been successfully applied to even larger structures, such as derivatives of C72H72.
Broadband dielectric spectroscopy (BDS), spectroscopic vis-ellipsometry (SE), X-ray reflectometry (XRR), and alternating current (ACC) as well as differential scanning calorimetry (DSC) are combined ...to study glassy dynamics and the glass transition in nanometric thin (≥5 nm) layers of polystyrene (PS) having widely varying molecular weights (27 500−8 090 000 g/mol). For the dielectric measurements two sample geometries are employed, the common technique using evaporated electrodes and a recently developed approach taking advantage of nanostructures as spacers. All applied methods deliver the concurring result that deviations from glassy dynamics and from the glass transition of the bulk do not exceed margins of ±3 K independent of the layer thickness and the molecular weight of the polymer under study. Our findings are discussed in the context of the highly controversial literature and prove that an appropriate sample preparation is of paramount importance.
Syngas fermentation is a potential player for future emission reduction. The first demonstration and commercial plants have been successfully established. However, due to its novelty, development of ...syngas fermentation processes is still in its infancy, and the need to systematically unravel and understand further phenomena, such as substrate toxicity as well as gas transfer and uptake rates, still persists. This study describes a new online monitoring device based on the respiration activity monitoring system for cultivation of syngas fermenting microorganisms with gaseous substrates. The new device is designed to online monitor the carbon dioxide transfer rate (CO2TR) and the gross gas transfer rate during cultivation. Online measured data are used for the calculation of the carbon monoxide transfer rate (COTR) and hydrogen transfer rate (H2TR). In cultivation on pure CO and CO + H2, CO was continuously limiting, whereas hydrogen, when present, was sufficiently available. The maximum COTR measured was approximately 5 mmol/L/h for pure CO cultivation, and approximately 6 mmol/L/h for cultivation with additional H2 in the gas supply. Additionally, calculation of the ratio of evolved carbon dioxide to consumed monoxide, similar to the respiratory quotient for aerobic fermentation, allows the prediction of whether acetate or ethanol is predominantly produced. Clostridium ljungdahlii, a model acetogen for syngas fermentation, was cultivated using only CO, and CO in combination with H2. Online monitoring of the mentioned parameters revealed a metabolic shift in fermentation with sole CO, depending on COTR. The device presented herein allows fast process development, because crucial parameters for scale‐up can be measured online in small‐scale gas fermentation.
Lifestyle intervention (LI) can prevent type 2 diabetes, but response to LI varies depending on risk subphenotypes. We tested whether individuals with prediabetes with low risk (LR) benefit from ...conventional LI and individuals with high risk (HR) benefit from an intensification of LI in a multicenter randomized controlled intervention over 12 months with 2 years' follow-up. A total of 1,105 individuals with prediabetes based on American Diabetes Association glucose criteria were stratified into an HR or LR phenotype based on previously described thresholds of insulin secretion, insulin sensitivity, and liver fat content. LR individuals were randomly assigned to conventional LI according to the Diabetes Prevention Program (DPP) protocol or control (1:1) and HR individuals to conventional or intensified LI with doubling of required exercise (1:1). A total of 908 (82%) participants completed the study. In HR individuals, the difference between conventional and intensified LI in postchallenge glucose change was -0.29 mmol/L 95% CI -0.54; -0.04,
= 0.025. Liver fat (-1.34 percentage points 95% CI -2.17; -0.50,
= 0.002) and cardiovascular risk (-1.82 percentage points 95% CI -3.13; -0.50,
= 0.007) underwent larger reductions with intensified than with conventional LI. During a follow-up of 3 years, intensified compared with conventional LI had a higher probability of normalizing glucose tolerance (
= 0.008). In conclusion, it is possible in HR individuals with prediabetes to improve glycemic and cardiometabolic outcomes by intensification of LI. Individualized, risk phenotype-based LI may be beneficial for the prevention of diabetes.
Although an unintended aircraft landing on water (referred to as ditching) is a rare event, the potential for occupant injury/fatality increases immediately following the event due to adverse ...conditions. However, to date, few studies have addressed the subject. Herein, ditching events and post-ditching survival were investigated.
Ditchings (1982-2022) in the United States were identified from the National Transportation Safety Board database. Occupant injury severity, aircraft type, pilot experience, flight conditions, and number of occupants were extracted. Poisson distribution, the Chi-squared test (2-tailed), Mann-Whitney U test, and Kruskal-Wallis one-way analysis of variance were employed.
A total of 96 ditchings were identified. A systematic survey was hampered by the lack of a standardized reporting matrix in the reports. In total, 77 reports were included in the analysis. Across all ditchings, 128 of 169 (76%) occupants survived ditching and were rescued. Importantly, the initial ditching event was survived by 95% of all occupants. However, 32 (19%) occupants died post-ditching by drowning (21/32 cases) or for undetermined reasons. Considering probability per ditching event, in 26 (34%) of all ditchings, one or more occupants was/were fatally injured.
Initial survival of the emergency ditching is high. Drowning was the leading cause of death after ditching and reduced the overall survival to 76%. Further investigation is needed to identify risk factors for fatal outcomes and/or improve probability of survival after ditching.
Background
Shared decision‐making (SDM) has been advocated as an ethical framework for decision‐making in cancer care. According to SDM, patients make decisions in light of their values and based on ...the available evidence. However, SDM is difficult to implement in cancer care. A lack of applicability in practice is often reported. This empirical‐ethical study explores factors potentially relevant to current difficulties in translating the concept of SDM into clinical practice.
Methods
This study was conducted with nonparticipant observation of the decision‐making process in patients with gastrointestinal cancers for whom the benefit of adjuvant chemotherapy was uncertain according to clinical guidelines. Triangulation of qualitative data analysis was conducted by means of semistructured interviews subsequent to the observation. Observation notes and interview transcripts were analyzed according to the principles of grounded theory.
Results
Deviating from the concept of SDM, oncologists initiated a process of eliciting values and medical information prior to conveying information. The purpose of this approach was to select and individualize information relevant to the treatment decision. In doing so, the oncologists observed used two strategies: “biographical communication” and a “metacommunicative approach.” Both strategies could be shown to be effective or to fail depending on patients’ characteristics such as their view of the physicians’ role and the relevance of value‐related information for medical decision‐making.
Conclusion
In contrast to the conceptual account of SDM, oncologists are in need of patient‐related information prior to conveying information. Both strategies observed to elicit such information are in principle justifiable but need to be adapted in accordance with patient preferences and decision‐making styles.
Implications for Practice
This study showed that knowledge of patients’ values and preferences is very important to properly adapt the giving of medical information and to further the process of shared decision‐making. Shared decision‐making (SDM) trainings should consider different strategies of talking about values. The right strategy depends largely on the patient's preferences in communication. To be aware of the role of values in SDM and to be able to switch communicative strategies might prove to be of particular value. A more systematic evaluation of the patient's decision‐making preferences as part of routine procedures in hospitals might help to reduce value‐related barriers in communication.
Although shared decision making is advocated in most fields of medicine, implementation in oncology is challenging. Considering the importance of patient involvement in the era of individualized oncology, this article analyzes barriers to shared decision making.
Background
Physicians' clinical expertise forms an exclusive body of competences, which helps them to find the appropriate diagnostics and treatment for each individual patient. Empirical evidence, ...however, suggests that there is an inverse relationship between the number of years in practice and the quality of care provided by a physician. Knowledge and adherence to professional standards (such as clinical guidelines) are often used as indicators in previous research.
Methods
Semistructured interviews and the Q method were used for an explorative study on oncologists' views on the interplay between their own clinical expertise, intuition, and the external evidence incorporated in clinical guidelines. The interviews were audio recorded, transcribed ad verbatim, and analysed using qualitative content analysis.
Results
Data analysis shows the complex character of clinical expertise with respect to experience, professional development, and intuition. An irreplaceable role is attributed to personal and bodily experience during the providing of care for a patient. Professional experience becomes important, particularly in those situations that lie out of the focus of “guideline medicine.” Intuition is regarded as having a strong emotional component and helps for deciding which therapeutic option the patient can deal with.
Conclusions
Using measurable knowledge and adherence to standards as indicators does not account for the complexity of clinical expertise. Other factors, such as the importance of bodily experience and physicians' intuitive knowledge, must be considered, also with respect to the occurrence of treatment biases.
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