Strong plasmonic fluorescence enhancement of individual plant light-harvesting complexes

Plasmonic coupling of metallic nanoparticles and adjacent pigments can dramatically increase the brightness of the pigments due to the enhanced local electric field. Here, we demonstrate that the fluorescence brightness of a single plant light-harvesting complex (LHCII) can be significantly enhanced when coupled to single gold nanorods (AuNRs). The AuNRs utilized in this study were prepared via chemical reactions, and the hybrid system was constructed using a simple and economical spin-assisted layer-by-layer technique. Enhancement of fluorescence brightness of up to 240-fold was observed, accompanied by a 109-fold decrease in the average (amplitude-weighted) fluorescence lifetime from approximately 3.5 ns down to 32 ps, corresponding to an excitation enhancement of 63-fold and emission enhancement of up to 3.8-fold. This large enhancement is due to the strong spectral overlap of the longitudinal localized surface plasmon resonance of the utilized AuNRs and the absorption or emission bands of LHCII. This study provides an inexpensive strategy to explore the fluorescence dynamics of weakly emitting photosynthetic light-harvesting complexes at the single molecule level.Comment: 23 pages, 6 figures, 2 supplementary figures, and supplementary equation

The incidence, root-causes, and outcomes of adverse events in surgical units: implication for potential prevention strategies

<p>Abstract</p> <p>Background</p> <p>We need to know the scale and underlying causes of surgical adverse events (AEs) in order to improve the safety of care in surgical units. However, there is little recent data. Previous record review studies that reported on surgical AEs in detail are now more than ten years old. Since then surgical technology and quality assurance have changed rapidly. The objective of this study was to provide more recent data on the incidence, consequences, preventability, causes and potential strategies to prevent AEs among hospitalized patients in surgical units.</p> <p>Methods</p> <p>A structured record review study of 7,926 patient records was carried out by trained nurses and medical specialist reviewers in 21 Dutch hospitals. The aim was to determine the presence of AEs during hospitalizations in 2004 and to consider how far they could be prevented. Of all AEs, the consequences, responsible medical specialty, causes and potential prevention strategies were identified. Surgical AEs were defined as AEs attributable to surgical treatment and care processes and were selected for analysis in detail.</p> <p>Results</p> <p>Surgical AEs occurred in 3.6% of hospital admissions and represented 65% of all AEs. Forty-one percent of the surgical AEs was considered to be preventable. The consequences of surgical AEs were more severe than for other types of AEs, resulting in more permanent disability, extra treatment, prolonged hospital stay, unplanned readmissions and extra outpatient visits. Almost 40% of the surgical AEs were infections, 23% bleeding, and 22% injury by mechanical, physical or chemical cause. Human factors were involved in the causation of 65% of surgical AEs and were considered to be preventable through quality assurance and training.</p> <p>Conclusions</p> <p>Surgical AEs occur more often than other types of AEs, are more often preventable and their consequences are more severe. Therefore, surgical AEs have a major impact on the burden of AEs during hospitalizations. These findings concur with the results from previous studies. However, evidence-based solutions to reduce surgical AEs are increasingly available. Interventions directed at human causes are recommended to improve the safety of surgical care. Examples are team training and the surgical safety checklist. In addition, specific strategies are needed to improve appropriate use of antibiotic prophylaxis and sustainable implementation of hygiene guidelines to reduce infections.</p

A Dutch Fanconi Anemia FANCC Founder Mutation in Canadian Manitoba Mennonites

Fanconi anemia (FA) is a recessive DNA instability disorder associated with developmental abnormalities, bone marrow failure, and a predisposition to cancer. Based on their sensitivity to DNA cross-linking agents, FA cells have been assigned to 15 complementation groups, and the associated genes have been identified. Founder mutations have been found in different FA genes in several populations. The majority of Dutch FA patients belongs to complementation group FA-C. Here, we report 15 patients of Dutch ancestry and a large Canadian Manitoba Mennonite kindred carrying the FANCC c.67delG mutation. Genealogical investigation into the ancestors of the Dutch patients shows that these ancestors lived in four distinct areas in The Netherlands. We also show that the Dutch and Manitoba Mennonite FANCC c.67delG patients share the same haplotype surrounding this mutation, indicating a common founder

The PKC, HOG and Ca2+ signalling pathways co-ordinately regulate chitin synthesis in Candida albicans

Open Access via PMC2649417Peer reviewedPublisher PD

Ethical Issues in the Use of Animal Models for Tissue Engineering:Reflections on Legal Aspects, Moral Theory, Three Rs Strategies, and Harm-Benefit Analysis

Animal experimentation requires a solid and rational moral foundation. Objective and emphatic decision-making and protocol evaluation by researchers and ethics committees remain a difficult and sensitive matter. This article presents three perspectives that facilitate a consideration of the minimally acceptable standard for animal experiments, in particular, in tissue engineering (TE) and regenerative medicine. First, we review the boundaries provided by law and public opinion in America and Europe. Second, we review contemporary moral theory to introduce the Neo-Rawlsian contractarian theory to objectively evaluate the ethics of animal experiments. Third, we introduce the importance of available reduction, replacement, and refinement strategies, which should be accounted for in moral decision-making and protocol evaluation of animal experiments. The three perspectives are integrated into an algorithmic and graphic harm-benefit analysis tool based on the most relevant aspects of animal models in TE. We conclude with a consideration of future avenues to improve animal experiments

Early Indicators of COVID-19 Infection Prevention Behaviors:Machine Learning Identifies Personal and Country-Level Factors

The Coronavirus is highly infectious and potentially deadly. In the absence of a cure or a vaccine, the infection prevention behaviors recommended by the World Health Organization constitute the only measure that is presently available to combat the pandemic. The unprecedented impact of this pandemic calls for swift identification of factors most important for predicting infection prevention behavior. In this paper, we used a machine learning approach to assess the relative importance of potential indicators of personal infection prevention behavior in a global psychological survey we conducted between March-May 2020 (N = 56,072 across 28 countries). The survey data were enriched with society-level variables relevant to the pandemic. Results indicated that the two most important indicators of self-reported infection prevention behavior were individual-level injunctive norms—beliefs that people in the community should engage in social distancing and self-isolation, followed by endorsement of restrictive containment measures (e.g., mandatory vaccination). Society-level factors (e.g., national healthcare infrastructure, confirmed infections) also emerged as important indicators. Social attitudes and norms were more important than personal factors considered most important by theories of health behavior. The model accounted for 52% of the variance in infection prevention behavior in a separate test sample—above the performance of psychological models of health behavior. These results suggest that individuals are intuitively aware that this pandemic constitutes a social dilemma situation, where their own infection risk is partly dependent on the behaviors of others. If everybody engaged in infection prevention behavior, the virus could be defeated even without a vaccine

The Nonsteroidal Farnesoid X Receptor Agonist Cilofexor (GS-9674) Improves Markers of Cholestasis and Liver Injury in Patients With Primary Sclerosing Cholangitis

Primary sclerosing cholangitis (PSC) represents a major unmet medical need. In a phase II double-blind, placebo-controlled study, we tested the safety and efficacy of cilofexor (formerly GS-9674), a nonsteroidal farnesoid X receptor agonist in patients without cirrhosis with large-duct PSC. Patients were randomized to receive cilofexor 100 mg (n = 22), 30 mg (n = 20), or placebo (n = 10) orally once daily for 12 weeks. All patients had serum alkaline phosphatase (ALP) > 1.67 × upper limit of normal and total bilirubin ≤ 2 mg/dL at baseline. Safety, tolerability, pharmacodynamic effects of cilofexor (serum C4 [7α-hydroxy-4-cholesten-3-one] and bile acids), and changes in liver biochemistry and serum fibrosis markers were evaluated. Overall, 52 patients were randomized (median age 43 years, 58% male, 60% with inflammatory bowel disease, 46% on ursodeoxycholic acid). Baseline median serum ALP and bilirubin were 348 U/L (interquartile range 288-439) and 0.7 mg/dL (0.5-1.0), respectively. Dose-dependent reductions in liver biochemistry were observed. At week 12, cilofexor 100 mg led to significant reductions in serum ALP (median reduction -21%; P = 0.029 versus placebo), gamma-glutamyl transferase (-30%; P < 0.001), alanine aminotransferase (ALT) (-49%; P = 0.009), and aspartate aminotransferase (-42%; P = 0.019). Cilofexor reduced serum C4 compared with placebo; reductions in bile acids were greatest with 100 mg. Relative reductions in ALP were similar between ursodeoxycholic acid-treated and untreated patients. At week 12, cilofexor-treated patients with a 25% or more relative reduction in ALP had greater reductions in serum alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transferase, tissue inhibitor of metalloproteinase 1, C-reactive protein, and bile acids than nonresponders. Adverse events were similar between cilofexor and placebo-treated patients. Rates of grade 2 or 3 pruritus were 14% with 100 mg, 20% with 30 mg, and 40% with placebo. Conclusion: In this 12-week, randomized, placebo-controlled study, cilofexor was well tolerated and led to significant improvements in liver biochemistries and markers of cholestasis in patients with PSC

Booms and busts in commodity markets: bubbles or fundamentals?

This paper considers whether there were periodically collapsing rational speculative bubbles in commodity prices over a 40-year period from the late 1960s. We apply a switching regression approach to a broad range of commodities using two different measures of fundamental values—estimated from convenience yields and from a set of macroeconomic factors believed to affect commodity demand. We find reliable evidence for bubbles only among crude oil and feeder cattle, showing the popular belief that the extreme price movements observed in commodity markets were caused by pure speculation to be unsustainabl