Metabolic precision labeling enables selective probing of O-linked N-acetylgalactosamine glycosylation.

Protein glycosylation events that happen early in the secretory pathway are often dysregulated during tumorigenesis. These events can be probed, in principle, by monosaccharides with bioorthogonal tags that would ideally be specific for distinct glycan subtypes. However, metabolic interconversion into other monosaccharides drastically reduces such specificity in the living cell. Here, we use a structure-based design process to develop the monosaccharide probe N-(S)-azidopropionylgalactosamine (GalNAzMe) that is specific for cancer-relevant Ser/Thr(O)-linked N-acetylgalactosamine (GalNAc) glycosylation. By virtue of a branched N-acylamide side chain, GalNAzMe is not interconverted by epimerization to the corresponding N-acetylglucosamine analog by the epimerase N-acetylgalactosamine-4-epimerase (GALE) like conventional GalNAc-based probes. GalNAzMe enters O-GalNAc glycosylation but does not enter other major cell surface glycan types including Asn(N)-linked glycans. We transfect cells with the engineered pyrophosphorylase mut-AGX1 to biosynthesize the nucleotide-sugar donor uridine diphosphate (UDP)-GalNAzMe from a sugar-1-phosphate precursor. Tagged with a bioorthogonal azide group, GalNAzMe serves as an O-glycan-specific reporter in superresolution microscopy, chemical glycoproteomics, a genome-wide CRISPR-knockout (CRISPR-KO) screen, and imaging of intestinal organoids. Additional ectopic expression of an engineered glycosyltransferase, "bump-and-hole" (BH)-GalNAc-T2, boosts labeling in a programmable fashion by increasing incorporation of GalNAzMe into the cell surface glycoproteome. Alleviating the need for GALE-KO cells in metabolic labeling experiments, GalNAzMe is a precision tool that allows a detailed view into the biology of a major type of cancer-relevant protein glycosylation.

Why is active travel more satisfying than motorized travel? Evidence from Dublin.

Some trips are better than others, and more and more studies find that active travel (walking and cycling) is more satisfying than motorized forms of travel (using the car or public transport). Why is this the case? Using data on travel satisfaction from 4134 commutes to a large University campus in Dublin, Ireland, this paper replicates the differences in travel satisfaction between active and motorized travel. We attribute these differences in large part to the duration of the trip. Subjective trip characteristics, such as safety and convenience, also play important roles. The trip duration explains rush-hour effects as well as why people starting from less affluent and more difficult-to-reach places are less satisfied with their trips. Longer-term policy options suggested by these results include infrastructure developments and spatial development strategies. A shorter-term initiative would be to delay university schedules in the morning to avoid low travel satisfaction during the slow rush-hour period and simultaneously ease pressure on the transport network at peak times.

What is wrong with quantitative structure-property relations models based on three-dimensional descriptors?

Quantitative structure-property relations (QSPR) employing descriptors derived from the three-dimensional (3D) molecular structure are frequently applied for property prediction in various fields of research. However, there is no common understanding of the necessary degree of detail to which molecular structure has to be known for reliable descriptor evaluation, but computational methods used vary from simplified molecular mechanics up to rigorous ab initio programs. In order to quantify the yet unknown error due to this heterogeneity, widely used 3D molecular descriptors from diverse fields of application are evaluated for molecular structures computed by different computational methods. The results clearly indicate that the widespread, exclusive use of the most stable molecular conformation as well as too simplistic computational methods yield systematically erroneous descriptor values with misleading information for the inferred structure-property relations. Thus, generating an awareness and understanding of this fundamental problem is considered an important first step to make 3D QSPR a generally accepted property prediction method.

Reaction of the i-C4H5 (CH2CCHCH2) radical with O2.

The resonantly stabilized radical i-C(4)H(5) (CH(2)CCHCH(2)) is an important intermediate in the combustion of unsaturated hydrocarbons and is thought to be involved in the formation of polycyclic aromatic hydrocarbons through its reaction with acetylene (C(2)H(2)) to form benzene + H. This study uses quantum chemistry and statistical reaction rate theory to investigate the mechanism and kinetics of the i-C(4)H(5) + O(2) reaction as a function of temperature and pressure, and unlike most resonantly stabilized radicals we show that i-C(4)H(5) is consumed relatively rapidly by its reaction with molecular oxygen. O(2) addition occurs at the vinylic and allenic radical sites in i-C(4)H(5), with respective barriers of 0.9 and 4.9 kcal mol(-1). Addition to the allenic radical form produces an allenemethylperoxy radical adduct with only around 20 kcal mol(-1) excess vibrational energy. This adduct can isomerize to the ca. 14 kcal mol(-1) more stable 1,3-divinyl-2-peroxy radical via concerted and stepwise processes, both steps with barriers around 10 kcal mol(-1) below the entrance channel energy. Addition of O(2) to the vinylic radical site in i-C(4)H(5) directly forms the 1,3-divinyl-2-peroxy radical with a small barrier and around 36.8 kcal mol(-1) of excess energy. The 1,3-divinyl-2-peroxy radical isomerizes via ipso addition of the O(2) moiety followed by O atom insertion into the adjacent C-C bond. This process forms an unstable intermediate that ultimately dissociates to give the vinyl radical, formaldehyde, and CO. At higher temperatures formation of vinylacetylene + HO(2), the vinoxyl radical + ketene, and the 1,3-divinyl-2-oxyl radical + O paths have some importance. Because of the adiabatic transition states for O(2) addition, and significant reverse dissociation channels in the peroxy radical adducts, the i-C(4)H(5) + O(2) reaction proceeds to new products with rate constant of around 10(11) cm(3) mol(-1) s(-1) at typical combustion temperatures (1000-2000 K). For fuel-rich flames we show that the reaction of i-C(4)H(5) with O(2) is likely to be faster than that with C(2)H(2), bringing into question the importance of the i-C(4)H(5) + C(2)H(2) reaction in initiating ring formation in sooting flames.

Daily emotional well-being during the COVID-19 pandemic.

The COVID-19 outbreak has become one of the largest public health crises of our time. Governments have responded by implementing self-isolation and physical distancing measures that have profoundly impacted daily life throughout the world. In this study, we aimed to investigate how people experience the activities, interactions, and settings of their lives during the pandemic. The sample (N = 604) was assessed in Ireland on the 25 March 2020, following the closure of schools and non-essential businesses. We examined within-person variance in emotional well-being and how people spend their time. We found that while most time was spent in the home (74%), time spent outdoors (8%) was associated with markedly raised positive affect and reduced negative emotions. Exercising, going for walks, gardening, pursuing hobbies, and taking care of children were the activities associated with the greatest affective benefits. Home-schooling children and obtaining information about COVID-19 were ranked lowest of all activities in terms of emotional experience. These findings highlight activities that may play a protective role in relation to well-being during the pandemic, the importance of setting limits for exposure to COVID-19-related media coverage, and the need for greater educational supports to facilitate home-schooling during this challenging period.

Mba1, a novel component of the mitochondrial protein export machinery of the yeast Saccharomyces cerevisiae.

The biogenesis of mitochondria requires the integration of many proteins into the inner membrane from the matrix side. The inner membrane protein Oxa1 plays an important role in this process. We identified Mba1 as a second mitochondrial component that is required for efficient protein insertion. Like Oxa1, Mba1 specifically interacts both with mitochondrial translation products and with conservatively sorted, nuclear-encoded proteins during their integration into the inner membrane. Oxa1 and Mba1 overlap in function and substrate specificity, but both can act independently of each other. We conclude that Mba1 is part of the mitochondrial protein export machinery and represents the first component of a novel Oxa1-independent insertion pathway into the mitochondrial inner membrane.

Role of the ABC transporter Mdl1 in peptide export from mitochondria.

ATP-binding cassette (ABC) adenosine triphosphatases actively transport a wide variety of compounds across biological membranes. Here, the ABC protein Mdl1 was identified as an intracellular peptide transporter localized in the inner membrane of yeast mitochondria. Mdl1 was required for mitochondrial export of peptides with molecular masses of approximately 2100 to 600 daltons generated by proteolysis of inner-membrane proteins by the m-AAA protease in the mitochondrial matrix. Proteolysis by the i-AAA protease in the intermembrane space led to the release of similar-sized peptides independent of Mdl1. Thus, two pathways of peptide efflux from mitochondria exist that may allow communication between mitochondria and their cellular environment.

Preparation and pre-vivo evaluation of no-carrier-added, carrier-added and cross-complexed [(68)Ga]-EDTMP formulations.

PURPOSE: The present study aimed to develop convenient preparation and quality control protocols for [(68)Ga]-EDTMP, a potential radiotracer for skeletal PET imaging. Furthermore, bone binding characteristics with special focus on the influence of carrier addition were evaluated. METHODS: No-carrier-added (nca), carrier-added and novel cross-complexed [(68)Ga]-EDTMP formulations were prepared using [(68)Ga]-gallium chloride and a commercial EDTMP kit. Respective bone binding characteristics were determined on the basis of an established in-vitro method using hydroxyapatite and human bone powders as binding matrices. RESULTS: Pre-vivo evaluation of nca [(68)Ga]-EDTMP yielded irreversible binding on the mineral bone phase characterised by fast binding kinetics. Generally, nca [(68)Ga]-EDTMP showed low uptake values comparable to nca [(99m)Tc]-EDTMP. Interestingly, the bone binding affinity of [(68)Ga]-EDTMP could be increased by the addition of carriers, presumably by changing the complex structure. CONCLUSIONS: This fast and reliable preparation protocol could enable small PET facilities without onsite cyclotron to perform PET bone scans. A comparison of all cross-complexed [(68)Ga]-EDTMP preparations further strengthens the recently presented "foreign carrier theory", which highlights carrier addition as a factor strongly affecting bone uptake of radiolabelled polyphosphonates. The clinical applicability of [(68)Ga]-EDTMP - particularly with respect to lesion specificity and sensitivity - should be clarified in forthcoming in-vivo studies.

3D-Lattice Monte Carlo simulations of model proteins. Size effects on folding thermodynamics and kinetics.

Recently, we devised an energy scale to vary systematically amino-acid residue-solvent interactions for Monte Carlo simulations of lattice-model proteins in water. For 27-mer proteins, the folding behavior varies appreciably with the choice of interaction parameters. We now perform similar simulations with 64-mers to study the size dependence of the optimal energy parameter set for representing realistic behavior typical of many real proteins (i.e. fast folding and high cooperativity for single chains). We find that 64-mers are considerably more stable and more cooperative compared to 27-mers. The optimal interfacial-interaction-energy parameter set, however, is relatively size independent.

Efficacy of hepatitis B screening in a private obstetrical population.

We sought to determine whether the recent Centers for Disease Control recommendation of universal prenatal screening for hepatitis B surface antigen (HBsAg) is necessary or cost-effective in a population of private patients. During the 21 months of our study there were 17,973 deliveries at Magee-Womens Hospital, the largest-volume private obstetrics service in the United States. We screened 12,377 of these patients for HBsAg. Only 11 patients, 0.09% of those screened (5 private and 6 clinic) tested positive. We administered questionnaires regarding historical risk factors for hepatitis B to all 11 patients testing positive for HBsAg and to 100 controls who tested negative for HBsAg. All private patients and 5 of 6 clinic patients testing positive for HBsAg had identifiable risk factors for hepatitis B. In addition, historical risk factors for hepatitis B were identified in 29% of the women testing negative for HBsAg. We found historical risk factors to be excellent predictors of the presence of HBsAg in our private patients. Our data indicate that universal screening for HBsAg is not necessary in private patients.

Can schizophrenic be prevented? Empirical results obtained by the examination of schizophrenic twins and schizophrenic children.

Concrete findings indicate the possibility of preventing schizophrenia, but it cannot be too strongly emphasized that the findings only relate to certain forms of theillness. Schizophrenias running an insidiously progressive course could very seldom be obsserved in monozygotic twins. So these pairs provide evidence that forms with this course can be prevented. It is to be supposed that the close communication usually found in identical twins, prevents withdrawal from environment and in consequence prevents schizophrenia. This assumption seems to be confirmed by our observation in insidiously progressive childhood schizophrenias which accumulate in only children and sometimes break out already in early childhood while the infants, staying in a hospital or a home, are suffering lack of communication. So it seems possible to prevent these forms of schizophrenia when we succeed in providing a close contact of the child and the adolescent with an intimate friend who directs his thinking outwards and protects him from withdrawal. But, unfortunately, in cases with phasic course the provoking factors correlate with the factors preventing the insidiously progressive forms. However, in detail, not quite the same factors prevent the one forms as precipitate the others, so that we can avoid doing harm simultaneously when we succeed in doing good. Besides, we must take account of the fact that some schizophrenias running a remitting course, especially periodic catatonia, are of hereditary origin and cannot be prevent psychosocially.

Treatment of landfill leachate--high tech or low tech? A case study.

At the sanitary landfill of the city of Penzberg (Germany), two diverse approaches to leachate treatment were studied as parts of a three-stage treatment concept. The performance of a simple aerobic pond was compared to that of an advanced multistage treatment unit, the latter comprising a membrane biological reactor and a two-stage activated carbon filter. For 274 days of the year (75%) the pond was able to provide sufficient treatment even under cold weather conditions. For temperatures lower than 5 degrees C, a higher biomass content and temporal storage of the raw leachate (e.g. increasing hydraulic retention time) could close the gap of insufficient treatment. In contrast, the advanced treatment system could only accomplish limited treatment capabilities due to insufficient maintenance, low loading conditions and deficient coordination between the individual treatment steps. As a result, degradation rates were low and operational problems frequent. Limits for Ntot were exceeded regularly (Ntot,e = 60-70 mg/L), throughput broke down and excessive nitrite production occurred (NO2-Ne = 10 mg/L) as a result of microbial activity inside the activated carbon filters. This case study clearly suggests aerobic ponds as an appropriate solution for the treatment of landfill leachate in areas where operational independence is essential.

Three-dimensional lattice Monte Carlo simulations of model proteins. IV. Proteins at an oil-water interface.

Lattice Monte Carlo simulations describe the adsorption of protein-like heteropolymer chains at an oil/water interface. The heteropolymers are designed sequences of 27 and 64 amino acid-type lattice sites taken from a 20-letter alphabet. We use our recently suggested energy scale to model oil and water. We investigate the effect of the oil parameters on adsorption properties of a single chain and on the aggregation of adsorbed chains while keeping the water parameters fixed to their optimum values found previously. By varying the oil parameters, we can cause a large range of adsorption behavior: from no adsorption to reversible adsorption to irreversible adsorption. We compare adsorption at a liquid/solid interface to that at a liquid/liquid interface. A liquid interface leads to stronger adsorption and denaturation than a solid interface with the same water and oil interaction parameters. We propose "optimal" oil parameters and use them to study multichain adsorption at a liquid interface.

[What increases the probability of manifestation in hereditary schizophrenia?]. / Wodurch wird die Manifestationswahrscheinlichkeit bei den erblichen Formen von Schizophrenie erhöht?

Hereditary causes are decisive for the development of unsystematic forms of schizophrenia. In periodic catatonia a dominant, and in affective paraphrenia a recessive hereditary succession must be assumed. In cataphasia, the findings do not give any clear information about the hereditary succession. In all three forms, considerable variations of the manifestations are found. Imperative indications have been observed suggesting that the brother-and-sister constellations, which have scientifically been too much neglected, have an essential share in these phenomena. In periodic catatonia, the lack of brothers and sisters and in particular a lack of elder sisters proved to be an essential factor. Affective paraphrenics frequently are the youngest of the brothers and sisters in a family. An attempt has been made to give an explanation of these findings. Further external influences proved to be essential. In persons suffering from cataphasia, for example, the origin from rural districts and, on the other hand, the origin from a large town seem to play a role.

[The origin of cycloid psychoses]. / Genese der zykloiden Psychosen.

Hereditary affliction with psychosis is not a marked phenomenon in cycloid psychoses, it is, however, found that parents may promote the outbreak of the disease by their abnormal behaviour. Of greater importance are causes which--unlike other forms of endogenic psychosis--develop their effect in infancy. Inharmonious constellations among brothers and sisters have been found to be essential. It has been proved that in the physiological and psychic development of man the mutual influence of children plays an important role. Paying more attention to the influence exerted by the parents, especially the mother, this law has been overlooked until now. The constellations of brothers and sisters, which are of course an everyday phenomenon, are not effective in themselves, but will only become effective when they coincide in a specific manner with temperaments that in their nature show a certain relationship with psychoses. On the other hand, physical influences do exist in a form that is found in no other type of the so-called endogenous psychoses. As regards their quite peculiar genesis, the demarkation of the cycloid psychoses from the unsystematic forms of schizophrenia, which are mainly hereditary, is indispensable. In the term "schizo-affective psychoses" of the WHO the two forms are unfortunately mixed up.

[Configuration of the dream in REM sleep]. / Die Gestalt des Traumes im REM-Schlaf.

Dreams during REM sleep have a characteristic form. They are, so to speak, "chain dreams, in which the scenes follow consecutively and, although distinctly separate from each other, are welded into a coherent dream by the primary integrating thoughts underlying the dream. The contents of the different scenes are difficult to reconcile with the integrating thought behind the dream because they are not stimulated by the thought alone but, in a certain way, also by past experiences. The author describes a dream which apparently filled the REM phase from beginning to end. It has been possible to explain the background of the integrating thought and the origins of the different scenes. The peculiar character of such dreams should find more attention in scientific research.