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1.
Biodivers Data J ; 12: e119539, 2024.
Article in English | MEDLINE | ID: mdl-38841134

ABSTRACT

Background: Biological invasions pose an increasing risk to nature, social security and the economy, being ranked amongst the top five threats to biodiversity. Managing alien and invasive species is a priority for the European Union, as outlined in the EU Biodiversity Strategy for 2030 and the Kunming-Montreal Global Biodiversity Framework. Alien plant species are acknowledged to impact the economy and biodiversity; thus, analysing the distribution of such species provides valuable inputs for the management and decision-making processes. The database presented in the current study is the first consolidated checklist of alien plant species that are present in Romania, both of European Union concern and of national interest. This database complements a prior published distribution, based only on records from literature, bringing new information regarding the occurrence of alien plants in Romania, as revealed by a nationwide field survey. We consider this database a valuable instrument for managing biological invasions at both national and regional levels, as it can be utilised in further research studies and in drafting management and action plans, assisting stakeholders in making informed decisions and implementing management actions. New information: We present the results of the first nationwide survey of alien plant species in Romania, conducted between 2019 and 2022, in the framework of a national project coordinated by the Ministry of Environment, Waters and Forests and the University of Bucharest. The present database complements and updates the database published by Sirbu et. al (2022), which included occurrence records published until 2019. The new database includes 98323 occurrence records for 396 alien plant species in 77 families, with most species belonging to the Asteraceae family. One alien plant species in our database, the black locust Robiniapseudoacacia L., had more than 10,000 occurrence records. The distribution database also includes information on newly-reported invasive alien plant species of European Union concern in Romania (i.e. the floating primrose-willow Ludwigiapeploides (Kunth) P.H.Raven) and documents the presence of plants in 44 additional families compared to Sirbu et al. (2022). Each entry includes information on species taxonomy, location, year, person who recorded and identified the alien plant, geographical coordinates and taxon rank.

2.
Phys Chem Chem Phys ; 26(18): 13740-13750, 2024 May 08.
Article in English | MEDLINE | ID: mdl-38683102

ABSTRACT

The selective hydrogenation of acetylene catalyzed by Pd nanoparticles is industrially used to increase the purity of ethylene. Despite the implementation of Pd based catalysts on an industrial scale, little is known about metal-support interactions on a fundamental level due to the complexity of these systems. In this study, the influence of metal-support interactions between Pd nanoparticles and two electronically modified a-SiO2 thin films on acetylene hydrogenation is investigated under ultra-high vacuum (UHV) conditions. The hydrogenation is performed under isothermal reaction conditions using a pulsed molecular beam reactive scattering (pMBRS) technique. Besides the activity and selectivity of clean Pd particles also the impact of dehydrogenated species intentionally introduced a priori is elucidated, whereas the active phase of the catalyst is additionally characterized by CO infrared reflection-absorption spectroscopy (IRRAS) and post-mortem temperature-programmed reaction (TPR). Metal-support interactions are found to influence the catalytic properties of Pd particles by charge-transfer, where positive charging leads to increased activity for acetylene hydrogenation. However, the increased activity is accompanied by formation of undesired byproducts. The active sites for acetylene and ethylene hydrogenation are shown to be different as previously proposed by the A and E model. The availability of the two different active sites on the Pd nanoparticles is determined by dehydrogenated species, whose nature and stability can be tuned by metal-support interactions. Based on these findings an electronic model is proposed how selectivity for acetylene hydrogenation can be steered solely by metal-support interactions leading to blocking of unselective sites in situ.

3.
Balkan J Med Genet ; 26(1): 75-82, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37576793

ABSTRACT

Wolf-Hirschhorn syndrome is a rare condition caused by terminal deletions, of variable size, in the short arm of chromosome 4. The syndrome displays the combination of typical morphological facial variations, intellectual disability, language delay, and various malformations. This report describes the clinical aspect and developmental evolution of a male patient with Wolf-Hirschhorn syndrome, from infancy to adolescence. The patient was first examined and diagnosed at 11 months, with follow-up at the ages of 4 and 16.

4.
Viruses ; 15(7)2023 07 21.
Article in English | MEDLINE | ID: mdl-37515278

ABSTRACT

Yam (Dioscorea spp.) productivity is constrained significantly by the lack of a formal seed system. Vegetative propagation, through tuber setts as 'seed' yams, encourages the recycling of virus-infected planting materials, contributing to high virus incidence and yield losses. Efforts are ongoing to increase the production of high-quality seed yams in a formal seed system to reduce virus-induced yield losses and enhance the crop's productivity and food security. Specific and sensitive diagnostic tests are imperative to prevent the multiplication of virus-infected materials contributing to a sustainable seed yam certification system. During routine indexing of yam accessions, discrepancies were observed between the results obtained from the reverse transcription loop-mediated isothermal amplification (RT-LAMP) test and those from reverse transcription polymerase chain reaction (RT-PCR); RT-LAMP failed to detect Yam mosaic virus (YMV) in some samples that tested positive by RT-PCR. This prompted the design of a new set of LAMP primers, YMV1-OPT primers. These primers detected as little as 0.1 fg/µL of purified RNA obtained from a YMV-infected plant, a sensitivity equivalent to that obtained with RT-PCR. RT-LAMP using YMV1-OPT primers is recommended for all future virus-indexing of seed yams for YMV, offering a rapid, sensitive, and cost-effective approach.


Subject(s)
Dioscorea , Reverse Transcription , Nucleic Acid Amplification Techniques/methods , RNA, Viral/genetics , DNA Primers/genetics , Sensitivity and Specificity
5.
Sensors (Basel) ; 23(4)2023 Feb 09.
Article in English | MEDLINE | ID: mdl-36850557

ABSTRACT

Mixed criticality systems are one of the relatively new directions of development for the classical real-time systems. As the real-time embedded systems become more and more complex, incorporating different tasks with different criticality levels, the continuous development of mixed criticality systems is only natural. These systems have practically entered every field where embedded systems are present: avionics, automotive, medical systems, wearable devices, home automation, industry and even the Internet of Things. While scheduling techniques have already been proposed in the literature for different types of mixed criticality systems, the number of papers addressing multiprocessor platforms running in a time-triggered mixed criticality environment is relatively low. These algorithms are easier to certify due to their complete determinism and isolation between components of different criticalities. Our research has centered on the problem of real-time scheduling on multiprocessor platforms for periodic tasks in a time-triggered mixed criticality environment. A partitioned, non-preemptive, table-driven scheduling algorithm was proposed, called Partitioned Time-Triggered Own Criticality Based Priority, based on a uniprocessor mixed criticality method. Furthermore, an analysis of the scheduling algorithm is provided in terms of success ratio by comparing it against an event-driven and a time-triggered method.

6.
J Comput Chem ; 44(6): 788-800, 2023 03 05.
Article in English | MEDLINE | ID: mdl-36471909

ABSTRACT

An integrated design environment (IDE) has been developed that allows the capture of design ideas, virtual compounds, and design hypotheses for medicinal chemistry projects. Specific consideration for rational molecular design, including design strategy and tactics, as well as comparator reference compounds have been incorporated to more easily convey the proposed design idea. A hierarchical tree architecture and customizable layouts allow for facile browsing across multiple programs and rapid examination of both ongoing and newly designed virtual compounds enabling centralized team discussions to ensure the most efficient prosecution of a queue of these target compounds. Additionally, a "whiteboard" module was incorporated for the rapid evaluation of virtual compounds against a suite of computational models enabling real-time design and triage. Finally, aggregation of cross-project design data enables broader analyses that can indicate portfolio-wide design challenges.


Subject(s)
Chemistry, Pharmaceutical , Software
7.
Bio Protoc ; 12(18)2022 Sep 20.
Article in English | MEDLINE | ID: mdl-36248609

ABSTRACT

Cancer cells often overexpress glutaminase enzymes, in particular glutaminase C (GAC). GAC resides in the mitochondria and catalyzes the hydrolysis of glutamine to glutamate. High levels of GAC have been observed in aggressive cancers and the inhibition of its enzymatic activity has been shown to reduce their growth and survival. Numerous GAC inhibitors have been reported, the most heavily investigated being a class of compounds derived from the small molecule BPTES (bis-2-(5-phenylacetamido-1,3,4-thiadiazol-2-yl)ethyl sulfide). X-ray structure determination under cryo-cooled conditions showed that the binding contacts for the different inhibitors were largely conserved despite their varying potencies. However, using the emerging technique serial room temperature crystallography, we were able to observe clear differences between the binding conformations of inhibitors. Here, we describe a step-by-step protocol for crystal handling, data collection, and data processing of GAC in complex with allosteric inhibitors using serial room temperature crystallography. Graphical abstract: Figure 1. Workflow for serial room temperature crystallography. Diagram showing the processing and scaling routine for crystals analyzed using serial room temperature crystallography.

8.
J Pediatr Gastroenterol Nutr ; 73(3): 325-328, 2021 09 01.
Article in English | MEDLINE | ID: mdl-34415261

ABSTRACT

OBJECTIVES: Inadequate bowel preparation (IBP) for colonoscopy leads to missed diagnosis, longer anesthesia time, higher chance of complications and increased costs. Adult studies have demonstrated that patient characteristics such as male gender and obesity are associated with IBP. Little is known about factors affecting bowel preparation in children. Our aim was to determine factors associated with IBP in children. METHODS: We prospectively enrolled children undergoing outpatient colonoscopy. Quality of bowel preparation was assessed using Boston Bowel Preparation Scale (BBPS) score (range 0-9). Data collected included patient demographics, indication, and type of insurance. Patients were divided into two groups based on BBPS score-adequate (BBPS score > 5) and inadequate (BBPS score < 5) and groups were compared using Student t-test and chi-square test. Possible predictors were analyzed using multivariate logistic regression models. RESULTS: A total of 334 children were prospectively enrolled of whom 321 were studied further (age range 2-18 years; mean age 12.4 years; 60.4% female; 85.9% Caucasian). The mean BBPS score was 6.8 (standard deviation of ±2). IBP was reported in 12.8% (41/321). Multivariable logistic regression analysis did not show statistical differences between the groups in studied patient factors including age, gender, obesity, race, insurance type, and indication for colonoscopy. CONCLUSION: Contrary to several adult studies, the results of our prospective study did not show any relationship between examined patient factors and IBP in children. Interestingly, IBP was less prevalent in our pediatric study compared to published adult data (12.8% vs 20-40%).


Subject(s)
Cathartics , Colonoscopy , Adolescent , Adult , Chi-Square Distribution , Child , Child, Preschool , Female , Humans , Logistic Models , Male , Prospective Studies
9.
Proc Natl Acad Sci U S A ; 118(34)2021 08 24.
Article in English | MEDLINE | ID: mdl-34400495

ABSTRACT

Although most patients recover from acute COVID-19, some experience postacute sequelae of severe acute respiratory syndrome coronavirus 2 infection (PASC). One subgroup of PASC is a syndrome called "long COVID-19," reminiscent of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). ME/CFS is a debilitating condition, often triggered by viral and bacterial infections, leading to years-long debilitating symptoms including profound fatigue, postexertional malaise, unrefreshing sleep, cognitive deficits, and orthostatic intolerance. Some are skeptical that either ME/CFS or long COVID-19 involves underlying biological abnormalities. However, in this review, we summarize the evidence that people with acute COVID-19 and with ME/CFS have biological abnormalities including redox imbalance, systemic inflammation and neuroinflammation, an impaired ability to generate adenosine triphosphate, and a general hypometabolic state. These phenomena have not yet been well studied in people with long COVID-19, and each of them has been reported in other diseases as well, particularly neurological diseases. We also examine the bidirectional relationship between redox imbalance, inflammation, energy metabolic deficits, and a hypometabolic state. We speculate as to what may be causing these abnormalities. Thus, understanding the molecular underpinnings of both PASC and ME/CFS may lead to the development of novel therapeutics.


Subject(s)
COVID-19/metabolism , Encephalomyelitis/metabolism , Fatigue Syndrome, Chronic/metabolism , Animals , COVID-19/complications , COVID-19/etiology , COVID-19/immunology , Encephalomyelitis/immunology , Fatigue Syndrome, Chronic/immunology , Humans , Oxidation-Reduction , Post-Acute COVID-19 Syndrome
10.
Am J Hum Genet ; 108(9): 1765-1779, 2021 09 02.
Article in English | MEDLINE | ID: mdl-34450030

ABSTRACT

An important goal of clinical genomics is to be able to estimate the risk of adverse disease outcomes. Between 5% and 10% of individuals with ulcerative colitis (UC) require colectomy within 5 years of diagnosis, but polygenic risk scores (PRSs) utilizing findings from genome-wide association studies (GWASs) are unable to provide meaningful prediction of this adverse status. By contrast, in Crohn disease, gene expression profiling of GWAS-significant genes does provide some stratification of risk of progression to complicated disease in the form of a transcriptional risk score (TRS). Here, we demonstrate that a measured TRS based on bulk rectal gene expression in the PROTECT inception cohort study has a positive predictive value approaching 50% for colectomy. Single-cell profiling demonstrates that the genes are active in multiple diverse cell types from both the epithelial and immune compartments. Expression quantitative trait locus (QTL) analysis identifies genes with differential effects at baseline and week 52 follow-up, but for the most part, differential expression associated with colectomy risk is independent of local genetic regulation. Nevertheless, a predicted polygenic transcriptional risk score (PPTRS) derived by summation of transcriptome-wide association study (TWAS) effects identifies UC-affected individuals at 5-fold elevated risk of colectomy with data from the UK Biobank population cohort studies, independently replicated in an NIDDK-IBDGC dataset. Prediction of gene expression from relatively small transcriptome datasets can thus be used in conjunction with TWASs for stratification of risk of disease complications.


Subject(s)
Colectomy/statistics & numerical data , Colitis, Ulcerative/surgery , Crohn Disease/surgery , Quantitative Trait Loci , Transcriptome , Biological Specimen Banks , Cohort Studies , Colitis, Ulcerative/complications , Colitis, Ulcerative/diagnosis , Colitis, Ulcerative/genetics , Colon/metabolism , Colon/pathology , Colon/surgery , Crohn Disease/complications , Crohn Disease/diagnosis , Crohn Disease/genetics , Datasets as Topic , Disease Progression , Gene Expression Profiling , Genome-Wide Association Study , Humans , Multifactorial Inheritance , Prognosis , Risk Assessment , United Kingdom
12.
Phys Rev Lett ; 123(14): 146803, 2019 Oct 04.
Article in English | MEDLINE | ID: mdl-31702203

ABSTRACT

Identifying the two-dimensional (2D) topological insulating (TI) state in new materials and its control are crucial aspects towards the development of voltage-controlled spintronic devices with low-power dissipation. Members of the 2D transition metal dichalcogenides have been recently predicted and experimentally reported as a new class of 2D TI materials, but in most cases edge conduction seems fragile and limited to the monolayer phase fabricated on specified substrates. Here, we realize the controlled patterning of the 1T^{'} phase embedded into the 2H phase of thin semiconducting molybdenum-disulfide by laser beam irradiation. Integer fractions of the quantum of resistance, the dependence on laser-irradiation conditions, magnetic field, and temperature, as well as the bulk gap observation by scanning tunneling spectroscopy and theoretical calculations indicate the presence of the quantum spin Hall phase in our patterned 1T^{'} phases.

14.
Am J Transplant ; 19(10): 2926-2933, 2019 10.
Article in English | MEDLINE | ID: mdl-31155833

ABSTRACT

Whereas regular allocation avoids unacceptable mismatches on the donor organ, allocation to highly sensitized patients within the Eurotransplant Acceptable Mismatch (AM) program is based on the patient's HLA phenotype plus acceptable antigens. These are HLA antigens to which the patient never made antibodies, as determined by extensive laboratory testing. AM patients have superior long-term graft survival compared with highly sensitized patients in regular allocation. Here, we questioned whether the AM program also results in lower rejection rates. From the PROCARE cohort, consisting of all Dutch kidney transplants in 1995-2005, we selected deceased donor single transplants with a minimum of 1 HLA mismatch and determined the cumulative 6-month rejection incidence for patients in AM or regular allocation. Additionally, we determined the effect of minimal matching criteria of 1 HLA-B plus 1 HLA-DR, or 2 HLA-DR antigens on rejection incidence. AM patients showed significantly lower rejection rates than highly immunized patients in regular allocation, comparable to nonsensitized patients, independent of other risk factors for rejection. In contrast to highly sensitized patients in regular allocation, minimal matching criteria did not affect rejection rates in AM patients. Allocation based on acceptable antigens leads to relatively low-risk transplants for highly sensitized patients with rejection rates similar to those of nonimmunized individuals.


Subject(s)
Graft Rejection/diagnosis , HLA Antigens/immunology , Histocompatibility/immunology , Immunization/methods , Kidney Failure, Chronic/immunology , Kidney Transplantation/adverse effects , Patient Selection , Tissue Donors/supply & distribution , Female , Follow-Up Studies , Graft Rejection/etiology , Graft Rejection/pathology , Graft Survival/immunology , HLA Antigens/chemistry , Histocompatibility Testing , Humans , Isoantibodies/adverse effects , Kidney Failure, Chronic/surgery , Kidney Transplantation/statistics & numerical data , Male , Middle Aged , Prognosis , Risk Factors , Tissue and Organ Procurement/methods , Transplantation Immunology
15.
Plants (Basel) ; 8(6)2019 Jun 11.
Article in English | MEDLINE | ID: mdl-31212654

ABSTRACT

To date, several viruses of different genera have been reported to infect yam (Dioscorea spp.). The full diversity of viruses infecting yam, however, remains to be explored. High-throughput sequencing (HTS) methods are increasingly being used in the discovery of new plant viral genomes. In this study, we employed HTS on yam to determine whether any undiscovered viruses were present that would restrict the international distribution of yam germplasm. We discovered a new virus sequence present in 31 yam samples tested and have tentatively named this virus "yam virus Y" (YVY). Twenty-three of the samples in which YVY was detected showed mosaic and chlorotic leaf symptoms, but Yam mosaic virus was also detected in these samples. Complete genome sequences of two YVY viral isolates were assembled and found to contain five open reading frames (ORFs). ORF1 encodes a large replication-associated protein, ORF2, ORF3 and ORF4 constitute the putative triple gene block proteins, and ORF5 encodes a putative coat protein. Considering the species demarcation criteria of the family Betaflexiviridae, YVY should be considered as a novel virus species in the family Betaflexiviridae. Further work is needed to understand the association of this new virus with any symptoms and yield loss and its implication on virus-free seed yam production.

16.
PLoS One ; 14(4): e0208214, 2019.
Article in English | MEDLINE | ID: mdl-31026262

ABSTRACT

Micronutrient deficiency is the cause of multiple diseases in developing countries. Staple crop biofortification is an efficient means to combat such deficiencies in the diets of local consumers. Biofortified lines of sweet potato (Ipomoea batata L. Lam) with enhanced beta-carotene content have been developed in Ghana to alleviate Vitamin A Deficiency. These genotypes are propagated using meristem micropropagation to ensure the generation of virus-free propagules. In vitro culture exposes micropropagated plants to conditions that can lead to the accumulation of somaclonal variation with the potential to generate unwanted aberrant phenotypes. However, the effect of micropropagation induced somaclonal variation on the production of key nutrients by field-grown plants has not been previously studied. Here we assessed the extent of in vitro culture induced somaclonal variation, at a phenotypic, compositional and genetic/epigenetic level, by comparing field-maintained and micropropagated lines of three elite Ghanaian sweet potato genotypes grown in a common garden. Although micropropagated plants presented no observable morphological abnormalities compared to field maintained lines, they presented significantly lower levels of iron, total protein, zinc, and glucose. Methylation Sensitive Amplification Polymorphism analysis showed a high level of in vitro culture induced molecular variation in micropropagated plants. Epigenetic, rather than genetic variation, accounts for most of the observed molecular variability. Taken collectively, our results highlight the importance of ensuring the clonal fidelity of the micropropagated biofortified lines in order to reduce potential losses in the nutritional value prior to their commercial release.


Subject(s)
Biofortification , DNA Methylation , Ipomoea batatas/genetics , Biofortification/methods , DNA, Plant/genetics , Ghana , Humans , Ipomoea batatas/metabolism , Nutritive Value , Vitamin A Deficiency/prevention & control , beta Carotene/metabolism
17.
Nat Commun ; 10(1): 38, 2019 01 03.
Article in English | MEDLINE | ID: mdl-30604764

ABSTRACT

Molecular mechanisms driving disease course and response to therapy in ulcerative colitis (UC) are not well understood. Here, we use RNAseq to define pre-treatment rectal gene expression, and fecal microbiota profiles, in 206 pediatric UC patients receiving standardised therapy. We validate our key findings in adult and paediatric UC cohorts of 408 participants. We observe a marked suppression of mitochondrial genes and function across cohorts in active UC, and that increasing disease severity is notable for enrichment of adenoma/adenocarcinoma and innate immune genes. A subset of severity genes improves prediction of corticosteroid-induced remission in the discovery cohort; this gene signature is also associated with response to anti-TNFα and anti-α4ß7 integrin in adults. The severity and therapeutic response gene signatures were in turn associated with shifts in microbes previously implicated in mucosal homeostasis. Our data provide insights into UC pathogenesis, and may prioritise future therapies for nonresponders to current approaches.


Subject(s)
Colitis, Ulcerative/genetics , Genes, Mitochondrial/genetics , Intestinal Mucosa/metabolism , Mitochondrial Diseases/genetics , Transcriptome/genetics , Adolescent , Adult , Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Child , Colitis, Ulcerative/drug therapy , Colitis, Ulcerative/microbiology , Colitis, Ulcerative/pathology , Feces/microbiology , Female , Gene Expression Profiling , Glucocorticoids/therapeutic use , Humans , Integrins/antagonists & inhibitors , Intestinal Mucosa/microbiology , Intestinal Mucosa/pathology , Male , Mesalamine/therapeutic use , Microbiota , Mitochondria/genetics , Mitochondria/pathology , Mitochondrial Diseases/drug therapy , Mitochondrial Diseases/microbiology , Mitochondrial Diseases/pathology , Precision Medicine/methods , Prospective Studies , Rectum/metabolism , Rectum/microbiology , Rectum/pathology , Remission Induction/methods , Sequence Analysis, RNA , Severity of Illness Index , Treatment Outcome , Tumor Necrosis Factor-alpha/antagonists & inhibitors
18.
J Chem Phys ; 151(24): 244304, 2019 Dec 28.
Article in English | MEDLINE | ID: mdl-31893869

ABSTRACT

The hydrogenation of ethylene and acetylene was studied on a Pdn/MgO/Mo(100) model system containing palladium particles with a narrow size distribution around Pd26 (Pd20 to Pd35). Reactivity measurements were carried out in an ultrahigh vacuum chamber under isothermal conditions in the presence of deuterium. The catalyst system can readily hydrogenate both of these small molecules, and for acetylene, an alternative reaction network exists, in which it is trimerized to benzene. Distinct deactivation behavior was found for the two molecules and ascribed to different adsorption sites formed and influenced by the carbonaceous overlayer formed during the course of the reaction. These findings extend the A-E-model by Borodzinski and Golȩbiowski to extremely small particles and low partial pressures and show that it is possible to study realistic catalytic sites under highly defined conditions.

19.
Am J Gastroenterol ; 113(10): 1524-1529, 2018 10.
Article in English | MEDLINE | ID: mdl-30267029

ABSTRACT

OBJECTIVES: Environmental factors play an important role in the pathogenesis of Crohn's Disease (CD). In particular, by virtue of the instability of the microbiome and development of immunologic tolerance, early life factors may exert the strongest influence on disease risk and phenotype. METHODS: We used data from 1119 CD subjects recruited from RISK inception cohort to examine the impact of early life environment on disease progression. Our primary exposures of interest were breastfeeding in infancy and exposure to maternal, active, or passive smoke. Our primary outcomes were development of complicated (stricturing or penetrating) disease, and need for CD-related hospitalization, and surgery. Multivariable logistic regression models were used to define independent associations, adjusting for relevant covariates. RESULTS: Our study cohort included 1119 patients with CD among whom 15% had stricturing (B2) or penetrating disease (B3) by 3 years. 331 patients (35%) and 95 patients (10.6%) required CD-related hospitalizations and surgery respectively. 74.5% were breastfed in infancy and 31% were exposed to smoking among whom 7% were exposed to maternal smoke. On multivariable analysis, a history of breastfeeding was inversely associated with complicated (B2/B3 disease) 0.65, CI 95% 0.44-96; P = 0.03) in pediatric CD. Maternal smoking during pregnancy was associated with increased risk of hospitalization during the 3-year follow-up period (OR 1.75, CI 95% 1.05-2.89; P = 0.03). CONCLUSIONS: Early life environmental factors influence the eventual phenotypes and disease course in CD.


Subject(s)
Breast Feeding/statistics & numerical data , Crohn Disease/diagnosis , Environmental Exposure/adverse effects , Prenatal Exposure Delayed Effects/epidemiology , Smoking/adverse effects , Tobacco Smoke Pollution/adverse effects , Adolescent , Child , Colon/pathology , Constriction, Pathologic/epidemiology , Constriction, Pathologic/etiology , Crohn Disease/complications , Crohn Disease/etiology , Crohn Disease/therapy , Disease Progression , Environmental Exposure/statistics & numerical data , Female , Follow-Up Studies , Hospitalization/statistics & numerical data , Humans , Infant, Newborn , Longitudinal Studies , Male , North America/epidemiology , Phenotype , Pregnancy , Prospective Studies , Risk Factors , Severity of Illness Index , Smoking/epidemiology , Time Factors , Tobacco Smoke Pollution/statistics & numerical data
20.
J Phys Chem Lett ; 9(18): 5246-5253, 2018 Sep 20.
Article in English | MEDLINE | ID: mdl-30152701

ABSTRACT

Environmental transmission electron microscopy (ETEM) and variable-energy positron annihilation spectroscopy (VEPAS) are used to observe hydrogen-induced microstructural changes in stress-free palladium (Pd) foils and stressed Pd thin films grown on rutile TiO2 substrates. The microstructural changes in Pd strongly depend on the hydrogen pressure and on the stress state. At room temperature, enhanced Pd surface atom mobility and surface reconstruction is seen by ETEM already at low hydrogen pressures ( pH < 10 Pa). The observations are consistent with molecular dynamics simulations. A strong increase of the vacancy density was found, and so-called superabundant vacancies were identified by VEPAS. At higher pressures, migration and vanishing of intrinsic defects is observed in Pd free-standing foils. The Pd thin films demonstrate an increased density of dislocations with increase of the H2 pressure. The comparison of the two studied systems demonstrates the influence of the mechanical stress on structural evolution of Pd catalysts.

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