Herein we report the development of a turn‐on lanthanide luminescent probe for time‐gated detection of nitroreductases (NTRs) in live bacteria. The probe is activated through NTR‐induced formation of the sensitizing carbostyril antenna and resulting energy transfer to the lanthanide center. This novel NTR‐responsive trigger is virtually non‐fluorescent in its inactivated form and features a large signal increase upon activation. We show that the probe is capable of selectively sensing NTR in lysates as well as in live bacteria of the ESKAPE family which are clinically highly relevant multiresistant pathogens responsible for the majority of hospital infections. The results suggest that our probe could be used to develop diagnostic tools for bacterial infections. Illuminating pathogens: A terbium‐based luminescent turn‐on probe was developed capable of tracing nitroreductase in live bacteria using fluorescence lifetime imaging. The probe thus could be used as a new tool for the imaging of bacterial infections. Optical imaging tools are an indispensable analytical modality for the investigation and understanding of complex biological processes ranging from molecular level to whole organisms. Small‐molecule fluorophores are of particular relevance as their properties are readily tuned and modified to incorporate specific functions for monitoring and determining biological activity in situ. In this context, luminescent lanthanide complexes have attracted considerable attention since they have several inherent advantages over conventional organic fluorophores, making them highly promising tools for future medical applications, such as biosensing and bioimaging.1O2, HCO3−, and pH changes in cells.As a result of Laporte‐forbidden f–f transitions and the resulting low extinction coefficient, effective excitation of the lanthanide requires a sensitizing antenna in the form of an organic chromophore enabling energy transfer.Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species), which are responsible for the majority of hospital infections with multiresistant strains escaping the standard antibiotics treatment, makes this enzyme family a highly relevant diagnostic target for the detection of bacterial infections.As part of our program on DOTA‐based fluorescent probesHerein, we present the development of the first enzyme‐triggered lanthanide NTR probe which 1) is based on a novel responsive antenna‐forming element, 2) is highly sensitive, selective and stable, 3) gives a fluorescence readout over virtually no background signal and 4) is capable of selectively tracking NTR activity in live bacteria.para‐nitro benzylcarbamate to the corresponding aniline, initiating fragmentation to the iminoquinone methide  complexation was accomplished by reaction with TbCl3 in ethanol at slightly elevated temperatures with small amounts of water to facilitate dissolution. The application of such mild conditions ensured that the ethyl esters of both 10 and 12 remained intact during the course of the reaction.The synthesis of both the antenna 10 and the fluorescence spectrum of the caged precursor 12. As expected, the caged probe 12 does not exhibit any fluorescence at all, also showing that the caged antenna 8 is not able to sensitize the terbium(III) complex.Figure 10, constituting the probe's activated state, contains the strong antenna fluorescence signal at 435 nm, under time‐gated conditions (50 μs delay) only the terbium emission bands are visible. The absorption and excitation spectrum are similar, validating Tb sensitization by the antenna. The total luminescence quantum yield of complex 10 was determined to be 1.67 %, which is amongst the best values for turn‐on luminescent probes featuring analyte‐triggered antenna formation.While the steady‐state emission of reference probe 12 in presence of increasing amounts of NTR. While in absence of the activating enzyme no fluorescence can be detected, the emission intensities gradually increase with rising concentrations of NTR with a 126‐fold signal increase at 550 nm at 1 μg mL−1 NTR. A linear correlation was obtained over a broad range of enzyme concentration versus emission intensity at 550 nm. Furthermore, the detection limit (3σ/k)−1. The apparent kinetic parameters KM and vmax for the activation of our probe by NTR  are in good agreement with previously reported values for other NTR probes.12 by NTR suggested in Scheme 10 as well as revealing the appearance of a carbamic acid intermediate resulting from the fragmentation . Evidence for the NTR‐specificity of our probe emerged from the addition of ascending concentrations of the NTR‐inhibitor dicoumarinNext, we investigated the probe's response to NTR and its ability for sensing NTR in a biochemical setting. Figure 12 against other commonly present bioanalytes in the bacterial cellular environment, as it is crucial to exclude any interfering factors for an accurate determination of NTR activity when applied in bacteria. As shown in Figure Subsequently, we determined the specificity and stability of our probe E. coli were selected. The bacteria were lysed by sonication and the lysate was incubated with probe 12 with or without dicoumarin inhibitor for 2 h before recording the emission signal at 550 nm. As shown in Figure K. pneumoniae, A. baumannii, E. cloacae, and E. coli while the activation was less pronounced in the other three strains. Co‐incubation with the NTR‐inhibitor significantly reduced probe activation in K. pneumonia, A. baumannii, E. cloacae, and E. coli, indicating selective intracellular activation by NTR, while showing little to no effect in the other three. These differences could be attributed to different expression levels as well as species differences of NTR enzymes amongst the bacterial strains, as sequence alignments of those enzymes showed low conservation amongst the bacterial strains as proposed in preceding work.We then examined the ability of our probe to detect NTR in bacterial lysates. Six bacterial strains of the clinically relevant ESKAPE panel as well as K. pneumoniae, A. baumannii, E. cloacae, and E. coli to those obtained with the lysates. While probe 12 was highly activated in all four strains, co‐incubation with NTR‐inhibitor dicoumarin led to a drastic decrease in activation  in live E. coli. Figure 12 was readily taken up by the bacterial cells and triggered by intracellular NTRs. To our knowledge, this is the first example of FLIM applied to image enzymatic activity in live bacteria with lanthanide luminescent probes. Interestingly, we observed that in contrast to caged probe 12, which was readily taken up by bacterial cells, the activated reference 10 was not able to permeate into and label bacterial cells . Moreover, in the FLIM experiments activated probe 10 remained localized in the bacterial intracellular compartments and was not cleared to the extracellular medium, for example, by an efflux mechanism, as observed for a previous enzyme‐activatable lanthanide probe.10.We advanced to test whether we could detect NTR in live bacteria. We were pleased to get similar results in In summary, we have developed the first luminescent turn‐on probe for the highly selective and sensitive detection of nitroreductase. Installation of a new type of analyte‐responsive carbostyril forming switch was enabled through the key Buchwald–Hartwig type synthetic transformation providing a robust modular approach for the facile access to similar probes. Owing to its effective intracellular enrichment, our probe enables the simple detection and imaging of nitroreductase activity in live bacteria that belong to potentially multiresistant strains of the clinically highly relevant ESKAPE panel. This permitted the first demonstration of fluorescence lifetime imaging (FLIM) to trace enzymatic activity in live bacteria with lanthanide luminescent probes. Taken together these features illustrate that this type of probe concept is an attractive option for future analytical applications in medical diagnostics.The authors declare no conflict of interest.As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re‐organized for online delivery, but are not copy‐edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors.SupplementaryClick here for additional data file.


Current questionnaires designed to evaluate the burden of haemorrhoidal disease ignore symptoms such as bleeding, pain and itching. A specific questionnaire is needed to evaluate the global impact of anal disorders on patients’ daily lives.HEMO‐FISS‐QoL) to assess the symptom burden of anal disorders and administered it to 256 patients  with haemorrhoidal disease (67.2%), anal fissure (29.3%) or both (3.5%). Psychometric properties were evaluated by testing the acceptability, construct validity and reliability of the questionnaire. Principal components and multi‐trait analyses were used to identify dimensions and to assess construct validity. Backward Cronbach alpha curves and a graded response model were used to reduce the number of items and modalities. External validity was evaluated against SF‐12 and the Psychological Global Well‐Being Index (PGWBI) using Spearman's correlation coefficient.We developed a questionnaire (HEMO‐FISS‐QoL scores correlated well with those of the SF‐12 and PGWBI (P < 0.001). Cronbach's coefficients  reflected good internal reliability of the different dimensions. The total score increased with the severity of the anal disorders and with their consequences .Principal component analysis defined four dimensions: physical disorders, psychology, defaecation and sexuality. The number of questions was reduced from 38 to 23. The HEMO‐FISS‐QoL questionnaire reliably evaluates the global impact of haemorrhoids and anal fissures on patients’ daily lives. This simple tool may prove useful for treatment evaluation in clinical trials and daily practice.The  This study validates the first tool developed to evaluate the overall impact of haemorrhoidal disease and anal fissures on patients’ quality of life. The HEMO‐FISS‐QoL questionnaire should prove useful for research and routine clinical purposes.An anal fissure is an ulcer arising in the squamous epithelium just distal to the mucocutaneous junction Haemorrhoidal disease is a common chronic disorder As haemorrhoidal disease and anal fissures share similar symptoms, we have developed and validated a specific questionnaire (HEMO‐FISS‐QoL) designed to evaluate their impact on patients’ daily lives.The study was performed according to French law: an ethical committee was not required in the case of a non‐interventional study where nominative information was not collected. Patients were orally informed of the purpose of the interviews.Our objective was to develop and validate a patient self‐completed questionnaire covering both haemorrhoids and anal fissures that would be sufficiently short and simple for use in research and daily practice. The questionnaire, named HEMO‐FISS‐QoL (HF‐QoL), was developed in collaboration with clinicians specializing in the treatment of haemorrhoidal disease and anal fissures .The present paper focuses on the psychometric properties of a patient self‐completed questionnaire covering both haemorrhoids and anal fissures and designed to evaluate their impact on patients’ daily lives. The development of this questionnaire followed the steps reported below.A preliminary conceptual framework (CF) was developed using a systematic literature review along with an initial list of questions derived from already existing patient reported outcome aimed at identifying concepts and domains of interest for patients suffering from haemorrhoids and anal fissures.Semi‐structured patient interviews were conducted on patients suffering from haemorrhoids and anal fissures: after the first 5–10 interviews the remainder were conducted by several researchers at a different site. Participants’ responses were reported verbatim then analysed using qualitative content analyses to understand how patients suffering from haemorrhoids and anal fissures perceived the disease burden and its impact on their daily lives; these responses allowed us to generate items for the questionnaire.The CF was updated following a meeting with clinical experts from the GREP. This meeting was set up to review and discuss the preliminary conceptual framework and to capture the insights of clinical experts. The clinical experts comprised a proctologist, a gastroenterologist and a surgeon, and they provided their feedback by describing their experiences and revising the preliminary conceptual model.n = 5) were organized to review and discuss the preliminary version of the questionnaire in terms of acceptability, comprehensiveness and consistent interpretation.Cognitive debriefing interviews with patients  to 6 . Patients unconcerned by the question recorded a score of 7 (‘not applicable’).The questionnaire was developed in French, then translated into English using forward translation, reconciliation, back translation and review and cognitive debriefing in the English population of the interest.The questionnaire was proposed to consecutive patients consulting senior investigating proctologists for haemorrhoids or anal fissures. The psychometric properties of the questionnaire were evaluated by testing its acceptability, construct validity and reliability (see below).All statistical analyses used SAS software version 9.4 .The acceptability of the questionnaire was evaluated by considering the proportion of missing values, ‘not applicable’ answers (score 7), and the floor and ceiling effects for each question. The ‘not applicable’ modality was evaluated by using multiple correspondence factor analysis, comparing profiles of ‘concerned’ and ‘unconcerned’ answers.Assessment of the construct validity of the questionnaire involved five main steps and a series of complementary analyses.First, an exploratory principal component analysis (PCA) was conducted, using Varimax rotation to identify the different dimensions of the questionnaire. Second, the unidimensionality of each previously defined dimension was evaluated using backward Cronbach alpha curves (BCAC). Third, a graded response model (GRM) These methods were used to identify redundant questions in a given dimension and to minimize the number of answers to a given question, in order to obtain the shortest possible questionnaire without losing information.Fourth, the convergent and divergent validity of the retained items was evaluated by multi‐trait analysis (MTA) in order to confirm the internal validity of the questionnaire. This method measures the relationship between each item and its corresponding dimension, as well as the other dimensions, in order to verify that each item correlates strongly with its own dimension (Pearson coefficient ≥ 0.4) and weakly with the other dimensions.External validity was assessed using SF‐12 Haemorrhoidal diseases and anal fissures become chronic in the most severely affected patients with little or no time between crises. As such, the impact of these diseases is on both physical functioning and the emotional aspect  All these dimensions are properly captured by PGWBI and SF‐12. We expected correlations between some HEMO‐FISS dimensions and the above generic scales. Then, as HEMO‐FISS is more specific, with dedicated questions, we expected it to have more sensitivity.Published algorithms were used to calculate the dimensions of SF‐12 and PGWBI. Spearman correlation coefficients between SF‐12 Reliability was evaluated by calculating the Cronbach alpha coefficients (CACs) for each dimension. Values above 0.7 were considered to show good internal consistency and reliability The final version of the questionnaire is composed of 23 items and six modalities, distributed in four dimensions: physical disorders (eleven items), psychology (seven items), defaecation (three items) and sexuality (two items). The six modalities are never (score 1), rarely (2), regularly (3), very often (4), always (5) and not applicable (6). An end user algorithm support is available as Appendix S1.A score is calculated for each dimension, provided that fewer than 50% of the items are missing (‘not applicable’ items are not considered to be missing data); if 50% or more of the items in a given dimension are missing, a score cannot be calculated and is considered to be missing.First rule: if items scored from 1 to 5  are present in a dimension, the ‘not applicable’ items as well as the missing data are replaced with the mean score of the items completed by the patient .Second rule: if zero items are scored from 1 to 5 (meaning that only ‘not applicable’ items or both ‘not applicable’ and missing items are present in the dimension), then the score of the dimension is replaced with the mean score of the study population for this dimension.When the score is calculable (fewer than 50% of the items are missing), the score of each dimension is the mean of the items. If missing data are present, specific rules apply for the calculation of the score, as follows:The score of each dimension for each patient ranges from 0 to 100 after transformation, according to the following formula:transformed scorepatient raw score ‐ lowest possible scorehighest possible score ‐ lowest possible score×100.The ‘highest possible score’ of each dimension in the formula is 5  and the ‘lowest possible score’ is 1 . A high score corresponds to a high symptom burden.A total score is calculated if the scores of the four dimensions are themselves calculable . The total score is the mean of the scores of all items .The scoring can be simplified in daily clinical practice for a given patient. A score is calculated for each dimension provided that fewer than 50% of the items are missing (‘not applicable’ answers are counted as not missing). The score of each dimension is the mean of the items scored from 1 to 5 (not taking into account the ‘not applicable’ answers). The same rules are applied for the computation of the total score which is calculated if the four dimensions are themselves calculable.A total of 256 patients were included in the study Table . Their mGlobal pain and current pain were estimated with a mean of 2.8 for both, on a VAS scale from 0 (no pain) to 10 (unbearable pain): global pain and current pain scores were significantly higher in patients with anal fissure, either alone or associated with other anal symptoms  P‐values were not significant in the graded response model. As a consequence, these modalities were clustered to create a new ‘regularly’ modality. Therefore, the questionnaire was reduced in terms of both the number of questions and the answer modalities.Based on the results of BCAC and GRM, respectively, two and four items were removed Table , yieldinThe results of multi‐trait analysis (MTA) are shown in Table P < 0.001). These correlations were clinically consistent. Thus, the physical disorders dimension of the HF‐QoL questionnaire correlated strongly with the physical health dimension of SF‐12 and the general health dimension of the PGWBI. Similarly, the psychology dimension of the HF‐QoL questionnaire correlated strongly with the mental health score of SF‐12 and the global score of PGWBI. The dimensions defaecation and sexuality were more specific to the HF‐QoL questionnaire and consequently had weaker correlations with the SF‐12 and PGWBI.Finally, as shown in Table While no difference was found between haemorrhoids and anal fissures for the physical, psychology and sexuality scores, patients with anal fissures had much higher defaecation and total scores Table .P < 0.001), and the CAC ranged from 0.86 to 0.95 for all items, reflecting the good internal consistency (>0.7) of the different dimensions.Correlations between scores for all dimensions of the HF‐QoL questionnaire were significant .In the entire study population there was a significant correlation between the HF‐QoL total score and the VAS pain score  and patients with anal fissure only .A significant correlation between the pain score and the HF‐QoL total score was also observed in specific populations, namely patients with thrombosis  .Patients who were forced to take time off sick or to stop work because of their anal problems within the last 6 months had a significantly higher HF‐QoL total score  in patients with haemorrhoidal disease and anal fissures, and also with the impact on daily life .The very good and clinically consistent correlations of the physical disorders and psychology dimensions of the HF‐QoL questionnaire with the relevant dimensions of widely used and validated quality‐of‐life scales (SF‐12 and PGWBI) endorse the quality of the selected items to measure the impact on QoL. This is further reinforced by the weaker correlations between the disease‐specific dimensions of the HF‐QoL questionnaire  and the different dimensions of SF‐12 and PGWBI. Thus, this new tool quantifies both the general impact of these painful disorders and their specific impact on the affected body region (anus).Significant correlations were obtained between the VAS pain scores and the HF‐QoL total score, both in the entire study population and also in subgroups of patients with haemorrhoidal thrombosis or anal fissure alone. Patients with anal fissures had higher mean subscores for the defaecation dimension, indicating a greater impact on quality of life than in patients with haemorrhoids. This is consistent with the significantly higher VAS pain scores in patients with fissures than in patients with haemorrhoidal disease. This is the first study to clearly show what is routinely observed by proctologists in clinical practice, namely the greater pain intensity and symptom burden of anal fissures relative to haemorrhoidal disease.Only two questions were retained for the sexuality dimension, but removing this dimension would have prevented the assessment of this aspect of daily life, which also appears to be affected by these disorders.et al. proposed a VAS‐based proctological symptom scale for pain, itching/irritation, discharge/moisture and bleeding, but excluded prolapse et al. Other tools have recently been developed to evaluate common proctological disorders, but they focus more on symptom severity than on quality of life. Thus, Kraemer a priori, based on the similarity of the answers given by the two groups of patients while developing the questionnaire. This decision is post hoc supported by our statistical analysis. The use of a single questionnaire is logical given the similar symptoms of these two conditions, namely pain, swelling , bleeding and pruritus. Another limitation is the lack of sensitivity of the analysis to clinical changes, based on score changes after treatment. This will be looked at in further studies. A test–retest measure of reliability has not been performed and temporal stability will require another study.Our study has some limitations. The decision to use a single questionnaire for both haemorrhoidal disease and anal fissures was taken In conclusion, we have developed and validated a questionnaire designed to evaluate the burden of haemorrhoidal disease and anal fissures with respect to patients’ daily lives. The HF‐QoL questionnaire scores correlate with all features of these two disorders. This simple tool should prove useful for evaluation of the burden of illness in both clinical trials and in daily practice, in longitudinal and cross‐sectional designs, when the patient point of view needs to be disease‐specific, i.e. when a generic QoL instrument is not enough. This questionnaire is available in French and English.C. M. Eleouet‐Kaplan, Hôpital Bagatelle, Talence, France; D. Soudan, Groupe Hospitalier Saint Joseph, Paris, France; Alexandra Popescu, AP‐HP, Proctologie Médico‐Chirurgicale, Service de Gastroentérologie, CHU Bichat, Paris, France.AZ and GB were employees of Pierre Fabre SA at the time of the writing of the manuscript; LA is a consultant for Abbvie, Allergan, Bayer, Coloplast, F Care, Meda and Sanofi. The other authors did not declare any conflict of interest.Appendix S1. HEMO‐FISS questionnaire.Click here for additional data file.


Biodegradable Mg‐based metals may be promising orthopedic implants for treating challenging bone diseases, attributed to their desirable mechanical and osteopromotive properties. This Review summarizes the current status and future research trends for Mg‐based orthopedic implants. First, the properties between Mg‐based implants and traditional orthopedic implants are compared on the following aspects: in vitro and in vivo degradation mechanisms of Mg‐based implants, peri‐implant bone responses, the fate of the degradation products, and the cellular and molecular mechanisms underlying the beneficial effects of Mg ions on osteogenesis. Then, the preclinical studies conducted at the low weight bearing sites of animals are introduced. The innovative strategies  are discussed to address the limitations of Mg‐based metals prior to their clinical applications at weight‐bearing sites. Finally, the available clinical studies are summarized and the challenges and perspectives of Mg‐based orthopedic implants are discussed. Taken together, the progress made on the development of Mg‐based implants in basic, translational, and clinical research has laid down a foundation for developing a new era in the treatment of challenging and prevalent bone diseases. This Review summarizes the current status and future research trends for Mg‐based or containing orthopedic implants. The progress made on the development of Mg‐based or containing implants in basic, translational, and clinical research can lay down a foundation for opening a new era to improve clinical healing outcomes in the treatment of challenging bone diseases. Thes2.2FigureThe definition of an absorbable metallic material by American Society for Testing and Materials (ASTM)‐F3160 in 2016, states: “an initially distinct foreign material or substance that either directly or through intended degradation can pass through or be metabolized or assimilated by cells and/or tissue.”Figure2, MgCO3, Mg3(PO4)2, CaCO3, and Ca3(PO4)2.2) gas, which is accompanied with the production of Mg ions, could attenuate oxidative stress‐induced senescence process during mesenchymal stem cell (MSC) expansion,2 gas can be exchanged quickly in the local tissue via measuring H2 concentration,2 accumulation.−) is also accompanied, but the alkaline condition  adjacent to the Mg‐based implants in vivo could be quickly neutralized according to the in situ measurement using a micro‐pH sensor.The presence of inorganic salts in the aqueous solutions of the human body complicates the degradation of Mg‐based metals Figure3A. The 2.3FiguresZheng et al.−3m) and high pH, which reduces the fusion of pre‐osteoclast cells and the activity of osteoclasts  reconstruction, the surrounding trabecular bone quality was greatly improved,s Figure , therebyWhen Mg‐based nails are implanted into the marrow cavity of long bones, e.g., femur, Mg ions can be released with implantation over time. There are two pathways for the diffuse of the released Mg ions. The first one is along the natural (Harversian and Volkmann's) or artificial (the bone‐fracture gaps/lines) canals. The other one is from the marrow to the periosteal region that is densely occupied by periosteum stem cells PSCs) and sensory neuron fibers Figure –C.18 Thrs and sen2.3.1Inspired by previous literatures reporting that Mg ions promoted the CGRP secretion in women with preeclampsia,2.3.2−3m Mg ions to cell cultures of human bone marrow mesenchymal stem cells (hBMSCs) and differentiating osteoblasts  could successfully fix the long bone fractures without inducing pathological reactions in the internal organs, the degradation of Mg–Ag pins caused long‐term serious abnormal morphology in the long bone, which displayed over 70% increase in the bone marrow cavity diameter and relative low bone mineral density even after 133‐day implantation when compared to the stainless steel implanted bone.Although SMAT is a surface treatment technology, a gradient distribution from several nanometers to a few micrometers is formed on the surface layer of the treated samples, contributing to dramatic improvement in the mechanical properties in both inert metalsFigureIn order to improve the corrosion resistance of Mg‐based metals treated with either SMAT or SNDP, the development of a complex surface coating strategy may be necessary to develop clinically available Mg‐based orthopedic implants that possess both excellent mechanical strength and a suitable degradation rate Figure9A,B. Po4.2xZn may impair the corrosion resistance, so the development of the ternary alloy series may be feasible to guarantee the performance in both mechanical and degradation properties. For example, 0.2% Ca addition could reduce approximately one third of the degradation rate of as‐cast Mg‐4Zn alloy.Generally, Mg alloys corrode faster than high purity Mg because of microgalvanic acceleration of the corrosion of the alpha Mg matrix by precipitated second phases,5In addition to aforementioned methods to enhance corrosion resistance and mechanical strength in Mg‐based metals, the development of a Mg‐based hybrid system may be another promising strategy to develop Mg‐containing implants suitable in high weight‐bearing skeletal sites.5.1FigureOsteoporotic fractures are increased with global population aging and have become a major public health burden.5.2−1) for 3 months was used to test the feasibility of using Mg‐IMN for fracture fixation. The results suggest that Mg‐IMN can achieve biological healing of AFF  treatment are at a high risk of suffering a new kind of bone fracture, known as atypical femoral fracture (AFF).F Figure  through 5.3Ilizarov's principle suggests that new bone tissue can be generated to fill a bone defect and help restore the bone length, with the aid of external fixators to pull the shorted bony ends apart.6FigureThe history of Mg‐based orthopedic implants dates back a century, but the relatively high degradation rate, impurities, and undeveloped processing techniques of Mg‐based implants inhibited their further clinical application, until recently.7Although the biodegradable Mg‐based metals have been accepted as the potential orthopedic implants by clinicians, there are still some challenges for the commercialization of the Mg‐based implants especially for weight‐bearing skeletal sites.First, the degradation mode of the Mg‐based orthopedic implants should be optimized. Most recently, some researchers have found that there are cavities surrounded by the fibrous tissue in the peri‐implant space after the degradation of the Mg‐based screws.Second, innovative design should be explored to address the concerns in the insufficient mechanical strength of the Mg‐based implants. The breakage of the screw head may sometimes happen during the operation, indicating the requirement of new structural design for the Mg‐based orthopedic implants to meet the needs of a higher torque for future clinical use.Third, more biosafety tests should be performed to identify the subjects suitable for the use of the Mg‐based implants. The stages of chronic renal failure should be classified in animal models to mimic patients with different glomerular filtration rate (GFR) levels for clear identification of indication or contraindication. In addition, the long‐term biosafety assessment of Mg implantation in animals with renal failure is lack, which should be supplemented in future studies to address clinical concerns.77.Fourthly, in addition to the metallic implants, the Mg‐containing polymer‐ or ceramic‐based scaffold can be developed to promote healing in segmental bone defects through inducing and accelerating new bone formation in the presence of bioactive Mg ionsFinally, the Mg‐containing hybrid systems should be explored to extend the clinical indications. The combined use of Mg‐based implants and the inert metals can largely expand the application scope, including low and high weight‐bearing skeletal sites, which can greatly push the Mg‐involved implants forward into clinical use in orthopedic field.8Mg‐based implants have been successfully developed and applied in a series of clinical trials attributed to their superior biocompatibility with natural cortical bone, appropriate Young's modulus, and biodegradation into products with osteopromotive properties. Numerous animal studies have been conducted to validate the beneficial effects of Mg‐based implants on bone tissue healing, with encouraging results demonstrating that these implants may revolutionize the treatment of challenging bone diseases including osteoporotic fracture, osteonecrosis, atypical femoral fracture, and long bone distraction in patients. Surface modification strategies and Mg‐based hybrid systems may broaden the potential applications of Mg‐based implants to treat challenging bone diseases, particularly in heavy weight‐bearing skeletal sites. By understanding the physical, chemical, and biological constraints of Mg and its alloys, to identify methods for overcoming these constraints, suitable Mg‐based implants shall be developed for various clinical indications. These studies have established translational potentials by bridging the gap between basic research and clinical applications on Mg‐based orthopedic implants, with the goal to improve the well‐being of patients suffering from challenging bone diseases.The authors declare no conflict of interest.Supporting InformationClick here for additional data file.


E. coli, OmpF and OmpC, were overexpressed from the host and the corresponding OMVs were collected. Each OMV fusion surprisingly revealed only single or few channel activities. The asymmetry of the OMVs translates after fusion into the lipid membrane with the lipopolysaccharides (LPS) dominantly present at the side of OMV addition. Compared to the conventional reconstitution method, the channels fused from OMVs containing LPS have similar conductance but a much broader distribution and significantly lower permeation. We suggest using outer membrane vesicles for functional and structural studies of membrane channels in the native membrane.Multi‐drug resistance in Gram‐negative bacteria is often associated with low permeability of the outer membrane. To investigate the role of membrane channels in the uptake of antibiotics, we present an approach using fusion of native outer membrane vesicles (OMVs) into a planar lipid bilayer, allowing characterization of membrane protein channels in their native environment. Two major membrane channels from  Uptake of antibiotics: To investigate the role of membrane channels in the uptake of antibiotics, outer membrane vesicles from E. coli were fused to a horizontal planar lipid bilayer. This method allows single channel recording in their native environment. One identified bottleneck in the development of new antibiotics against Gram‐negative bacteria is the low permeability across the cell wall and within the ND4BB platform; the “Translocation” project was devoted to investigating the low permeability issue.Multi‐drug resistant (MDR) bacterial pathogens, especially the “ESKAPE” family or the so‐called superbugs, are responsible for ca. two‐thirds of serious infection issues in clinic worldwide.The envelope of Gram‐negative bacteria allows selective permeation of nutrients while protecting from toxic substances. Gram‐negative species contain a cellular inner membrane and an outer membrane with a peptidoglycan layer sandwiched in the middle. The outer membrane layer is structurally rigid due to the lipopolysaccharide (LPS) layer towards the environment. The LPS layer mainly protects the bacteria from certain chemical attack. Crystal structures showed that the LPS has a docking position at some of the outer membrane proteins  are spherical vesicles naturally secreted by Gram‐negative bacteria, involved in their survival under stress conditions and regulating microbial interactions within communities.Within the current urgent need for novel antibiotics, the key questions concerning the contribution of the so‐called porins to drug uptake are: why do some molecules permeate rapidly whereas others do not; which channels are involved; and what are the flux‐limiting interactions between antibiotics and channels? Recently established methods such as whole cell uptake assays and mass spectrometry provide an answer to the total penetration, which is the relevant parameter for the survival of a cell.Here, we developed a direct approach to study porins in their native membrane using OMVs, with the goal to investigate to what extent the presence of LPS influences the flux of small molecules across porins. A further advantage is that such an OMV fusion approach is easy with respect to handling and may allow automatization.E. coli BL21(DE3)omp8 bacteria. The purification process yielded samples containing the overexpressed porins as their major protein component  or OmpC (8.5 μm). Dynamic light scattering (DLS) analysis of the OMV samples showed average sizes of 95 nm for OmpF‐containing OMV and 102 nm for OmpC‐containing OMV .The critical voltage necessary to observe channel gating was below −125 mV at a negative voltage or above +150 mV at a positive voltage, comparable to previous observations with purified porin reconstituted into an artificial bilayer. At a transmembrane voltage of −150 mV, the change of the average current baseline due to OmpF monomeric gating is 39±5 pA corresponding to 1.1±0.1 nS for a trimeric OmpF . This observed conductance value is similar to purified OmpF reconstitution .To investigate whether this is a general feature of OMV reconstitution and not specific to OmpF, we then overexpressed OmpC, an OmpF homolog, in the same strain and fused the secreted OMVs to a planar lipid bilayer. The induced channel activity confirmed the trend for OmpF. The typical ion current versus applied voltage is plotted in Figure m EDTA and incubated the vesicles at 4 °C overnight. Within the experimental error, we did not see a significant change .To elucidate possible stabilization effects of LPS in presence of divalent ions, we added 5 mm) to the same side as OMV addition. In agreement with previous single channel recording, interaction spikes were observed at a negative transmembrane voltage   of Enrofloxacin interaction with the channel at −50 mV . We further studied other antibiotics like Norfloxacin, Ciprofloxacin and Kanamycin sulfate through OMV‐OmpF and compared it with the OmpF‐WT. The chemical structures of the analytes are illustrated in Figure S6. In Figure In a second series of measurements, we tested four otherwise well studied antibiotics to elucidate the effect of the LPS barrier.e Figure  A,B. A s) Figure  A and diIn a further set of experiments, we followed another approach by fusing OMVs with giant unilamellar vesicles (GUVs) leading to giant vesicles with a typical final diameter in the range of 10 to 20 μm, large enough to be used in a patch‐clamp setup. Under the microscope, the vesicles appeared spherical and were subsequently patched in the Port‐a‐Patch . Both OmpF and OmpC channel activities could be obtained from their gating behaviour at high voltages  and were comparable with the OMV fusion .cis side, which is the OMV addition side. This orientation will help further understanding of the electrostatic interaction between LPS and the antibiotic molecules when treated under different buffer conditions.According to previous studies using the conventional purified protein reconstitution approach,[25] Single‐channel current traces resulted in somewhat lower conductance and with a broad standard deviation compared to purified and reconstituted single membrane protein. We compared single channel translocation data of OmpF‐OMV with purified OmpF‐WT and identified a barrier effect: lower event rates and slower translocation times. We expect that this approach is also valid for many other porins to study not only the permeation of small drug molecules but the single entity electrochemical behavior.Based on our results described above, we suggest a direct approach to study membrane proteins in their native environment. Fusion of OMV with planar lipid bilayer allows single or few porin insertion. The reason for such an unexpected low porin number might be an intrinsic selection for single channel reconstitution. Other conditions resulted in 2D crystals, which in all likeliness are not readily able to fuse with a lipid bilayer.The authors declare no conflict of interest.As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re‐organized for online delivery, but are not copy‐edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors.SupplementaryClick here for additional data file.


The combination of DNA origami nanostructures and polymers provides a new possibility to access defined structures in the 100 nm range. In general, DNA origami serves as a versatile template for the highly specific arrangement of polymer chains. Polymer‐DNA hybrid nanostructures can either be created by growing the polymer from the DNA template or by attaching preformed polymers to the DNA scaffold. These conjugations can be of a covalent nature or be based on base‐pair hybridization between respectively modified polymers and DNA origami. Furthermore, the negatively charged DNA backbone permits interaction with positively charged polyelectrolytes to form stable complexes. The combination of polymers with tuneable characteristics and DNA origami allows the creation of a new class of hybrid materials, which could offer exciting applications for controlled energy transfer, nanoscale organic circuits, or the templated synthesis of nanopatterned polymeric structures. The combination of DNA origami with synthetic polymers results in a new class of materials with interesting properties and characteristics. This approach is more precise than conventional nanofabrication methods, such as the positioning of single polymer strands. This Minireview shows the potential preparation of nanostructures from polymers and two‐ or three‐dimensional DNA origami. Besides the synthesis of such materials, the improvement in the fabrication of smaller and more precise geometries as well as the development of precisely addressable surfaces is also of interest. Significant improvements in such fabrication techniques could be of further usage for, for example, reducing the size of data storage, optical devices, or the development of new drug‐delivery systems.2, 3Such nanostructures can be fabricated in many ways, but two of the most important methods are lithography and self‐assembly. Lithography, as a top‐down technique, enables manipulation of larger objects to result in smaller‐size geometries with the desired shape.One prominent example for a versatile self‐assembling process in nature is the formation of the DNA double helix, which is based on hydrogen bonding between complementary base pairs. In 1982, Seeman took inspiration from such processes and realized the folding of DNA into designed superstructures.12, 13In this Minireview, we focus on the functionalization of DNA origami nanostructures with synthetic polymers or polymer‐oligonucleotide conjugates to afford unique hybrid nanostructures that are very challenging to achieve with other techniques. However, in contrast to previous contributions, the pure self‐assembly behavior of polymer‐DNA conjugates will not be discussed.17, 182The combination of polymers and DNA origami has the power to merge the fields of synthetic and natural macromolecules, while getting the best of both worlds.19, 20On the molecular level, the underlying principles for polymer attachment are manifold. The polymer can be electrostatically trapped to the negatively charged DNA backbone by the incorporation of respective positive counter charges or be bound to the DNA origami surface through base‐pair hybridization. The oligonucleotides required for this can be introduced by click reactions, by established bioconjugation techniques, or grown from nucleotides. Furthermore, hydrophobic interactions between the implemented polymers can be exploited to arrange polymer‐DNA constructs into higher ordered structures (see Section 2.3). However, the rather small number of publications in the field of DNA origami and polymer hybrids gives a first hint of how challenging this topic seems to be. Not only does synthesis suffer from various issues, such as solubility issues or steric hindrance of both the DNA and polymer reactive sites, but the characterization techniques are also very limited. One of the key drawbacks is the typically extremely low amount of DNA origami structures available, which impedes or even prohibits, for example, freeze‐pump‐thaw cycles for controlled radical polymerizations, sufficient amounts of attached initiator sites, or conventional polymer analysis by size‐exclusion chromatography (SEC), nuclear magnetic resonance (NMR), or dynamic light scattering (DLS).2.1The grafting from strategy is a convenient approach towards the synthesis of biomolecule‐polymer constructs with tailored properties, which are characterized by facile purification of the conjugate and commonly a high graft density.para‐coupling reaction, wherein the generated aniline radicals diffuse to the charged DNA surface. The regioselective formation of PANI was then transferred to 2D origami triangles  (PEG12kDa‐PLys18) by ring‐opening polymerization of Nϵ‐trifluoroacetyl‐l‐lysine N‐carboxyanhydride initiated by an amine‐terminated 12 kDa PEG macroinitiator. In contrast to bare origami structures, polymer‐coated objects resisted the treatment of DNase I, fetal bovine serum (FBS), and low salt levels, and maintained structural integrity. However, the attachment of sterically demanding gold nanoparticles (AuNP) did not survive the process of polyplex formation; detachment could by visualized by transmission scanning electron microscopy (tSEM). The problem could be circumvented by employing shorter PEG chains, which still offer the same protection efficiency. These findings are in agreement with a similar study by Shih and co‐workers, who examined the beneficial contribution of the PEG5kDaPLys10 polymer coating to the origami stability. They could further prove that surface addressability of the DNA nanostructures was not constrained by the polymer film and immobilized ligands were capable of targeting receptors, thereby leading to cellular uptake of the hybrid objects. Very recently, Gang and co‐workers endeavored to also push the limits of the stability of DNA assembly in complex biological fluids By this approach, the symmetric oligomers with azide groups at each end were “double‐clicked” by CuAAc to oligonucleotide strands containing a propargyl residue. Consequently, the obtained structure consisted of a polymer with oligonucleotide sequences at both ends. By hybridizing the polymer‐DNA constructs to a DNA origami frame with four complementary anchor strands, the semiconductors were brought into proximity, thereby forming a cross‐like structure. By tuning the oxidation state of polyaniline, the energy transfer from HPV to OANI could be tuned, as visualized by an altered fluorescence signal. However, the hybridization efficiency of only 20 % correctly formed polymer‐DNA origami structures (determined by AFM) illustrates how challenging the formation of these hybrid objects is, although base‐pair hybridization is often assumed to be straightforward. Mertig and co‐workers also employed click reactions to conjugate conducting polymers in distinct patterns to an origami surface Figure .[38] F2.3In addition to the attachment methods discussed above, one can also make use of the hydrophobic effect to form higher ordered structures built from DNA origami and polymers. By applying hydrophobic polymers to DNA scaffolds, surface properties can be altered significantly and, thus, self‐assembly of amphiphilic structures can be induced.In 2015, Liu and co‐workers showed that attaching hydrophobic dendrons to DNA origami rectangles could lead to the formation of surface areas with a high local concentration of hydrophobic molecules, which, as a result of the hydrophobic effect, guided origami folding into various thermodynamically stable products. Poly(aryl ether) dendrons were conjugated to oligonucleotides through solid‐phase synthesis, whereas modification with oligo(ethylene glycol) tails should increase the water solubility of the dendrons. Upon traditional origami annealing in the presence of both elongated capture strands (handles on the origami) and oligonucleotide‐bearing dendrons (complementary to handles on the origami), sandwich‐like structures were created. In a follow‐up study, the same group created polymer vesicles on the shell of a DNA origami cube Figure .[40]The attachment of the above‐mentioned hydrophobic dendrons to origami cubes led to aggregation and precipitation events, most likely because of π‐π stacking between several cuboid frames (frame–frame interactions). The addition of a second hydrophobic dendron, the so‐called principal amphiphile (PA), to the amphiphilic construct breaks the frame–frame interactions and promotes stronger PA–frame interactions, thereby resulting in the formation of heterovesicles. To demonstrate the applicability of this process to different molecules, the dendrons were substituted by polymers: DNA cuboids were covered with thermoresponsive poly(propylene oxide) (PPO) and upon heating, the polymer became hydrophobic and, thus, guided a second PPO polymer to form heterovesicles.6HEG6 block copolymer was exceptional, as it formed rings of three to five polymer‐decorated DNA cubes in a doughnut‐like fashion instead of the expected micellar structures. By increasing the length of the hydrophilic HEG block, the diameter of the ringlike assemblies could be increased, in contrast to the HE6HEG6 block copolymer, which indicates that the HEG block acts as a spacer.This is an impressive example of higher order assemblies based on polymer‐decorated DNA origami structures; however, the intricate technique requires a strong background in the field of frame‐guided assembly to be successful. The use of hydrophobic interactions between polymers attached to 3D DNA nanostructures was also shown to yield larger DNA micelles.41, 423In the previous section, we highlighted different techniques for linking polymers and DNA origami as well as the influence on each other. Although there are fewer examples than one might expect regarding the potential provided by these materials, and although there are still some challenges to overcome, several studies report the first steps towards future applications and prospects.Gothelf and co‐workers exploited their system of attaching a conjugated brush‐like polymer with oligonucleotide side chains onto DNA origami tiles to contribute to the area of nanophotonic and nanoelectronic devices. They not only attached the polymer to the origami platform, they also precisely forced the polymer to switch its position and conformation Figure .[43] FDNA origami is an emerging platform to direct the motion of various objects on the nanoscale; however, the movement of the attached objects is often “fuel‐based”, that is, employing strand displacement reactions of respectively designed oligonucleotides to break and create old and new bonds. Thus, purification after each step is often necessary. Baumberg and co‐workers developed a DNA origami flexor whose actuation is mediated by a thermoresponsive polymer which can be stimulated externally Figure .[39]N‐isopropylacrylamide) (PNIPAM) was attached on either side of the hinge. In this way, a PNIPAM‐DNA conjugate was formed by catalyst‐free strain‐promoted cycloaddition and attached to the complementary capture strands within the hinge region. By fixing a gold nanoparticle and a fluorescent dye at opposite ends, the switch between the opened and closed state of the hinge could be optically monitored. Upon heating above the lower critical solution temperature (LCST) of 32 °C, PNIMPM becomes hydrophobic and forces the hinge to close. This could be conclusively tracked by an increase in fluorescence as well as changes in the size distribution (DLS). However, the AFM images obtained are a vivid example of how difficult direct visualization of conformation‐altering DNA origami structures can be.They designed a flexible DNA origami hinge structure, whereby poly, and received her master's degree in 2018. During her studies she focused on the synthesis of hyperbranched star polymers as well as amphiphilic biomacromolecule conjugates. She joined the group of Prof. Dr. Tanja Weil at the Max Planck Institute for Polymer Research, Mainz, in 2018 as a PhD student, and is now working on the development of DNA origami hybrid nanostructures.Tanja Weil studied chemistry at the TU Braunschweig (Germany) and the University of Bordeaux (France) and completed her PhD at the Max Planck Institute for Polymer Research (MPIP) in Mainz, for which was awarded the Otto‐Hahn Medal in 2003. After several years in industry, she returned to academia by accepting an Associate Professor position at the National University of Singapore in 2008. In 2010, she joined the University of Ulm as Director of the Institute of Organic Chemistry III. Since 2017, she has been Director at the MPIP, heading the department “Synthesis of Macromolecules”.Ulrich S. Schubert studied chemistry in Frankfurt and Bayreuth (both Germany) and at Virginia Commonwealth University, Richmond (USA). After PhD studies at the Universities of Bayreuth and South Florida, and postdoctoral training with J.‐M. Lehn, he moved to the TU Munich (Germany), where he obtained his Habilitation in 1999. 1999–2000 he was Professor at the University of Munich and 2000–2007 Full Professor at the TU Eindhoven (The Netherlands). Since 2007, he has been a Full Professor at the Friedrich Schiller University Jena (Germany). He is an elected member of the German National Academy of Science and Engineering (acatech) and external scientific member of the Max‐Planck‐Gesellschaft .


In 2018, ARPANSA published updated national DRLs for adult CT, which were first published in 2012, and augmented the national DRL categories. This paper presents the updated national DRLs and describes the process by which they were produced.Examine patient survey data submitted to the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) National Diagnostic Reference Level Service (NDRLS). Determine the quartiles of the distributions of median survey dose metrics with categorisation by procedure type. Engage a liaison panel representing the radiology professions to review procedure categories and recommend revised national DRLs. The revised NDRL procedure categories are: head (non‐contrast brain (trauma/headache)), cervical spine (Non‐contrast (trauma)), soft‐tissue neck (post‐contrast (oncology)), chest (post‐contrast (oncology)), abdomen–pelvis (post‐contrast (oncology)), kidney–ureter–bladder ), chest–abdomen–pelvis (post‐contrast (oncology)) and lumbar spine (non‐contrast (degenerative pain)).The existing six procedure categories were revised and refined. Updated Australian national diagnostic reference levels for adult CT were recommended and endorsed for eight procedure categories: head (52 mGy/880 mGycm), cervical spine (23 mGy/470 mGycm),soft‐tissue neck (17 mGy/450 mGycm), chest (10 mGy/390 mGycm), abdomen–pelvis (13 mGy/600 mGycm), kidney–ureter–bladder (13 mGy/600 mGycm), chest–abdomen–pelvis (11 mGy/940 mGycm) and lumbar spine (26 mGy/670 mGycm). The updated national DRLs are between 12 and 26% lower than the previous DRLs for dose‐length product and between 13 and 63% lower for volume computed tomography dose index.Australian national DRLs for adult CT have been reviewed and revised. The revised national DRLs are lower, better reflecting current practice among imaging facilities in Australia. The revised Australian national DRLs are similar to those in other developed countries. Australian national DRLs for adult CT have been reviewed and revised. Revised DRLs are set at the 75th percentile of the distribution of facility medians in 2017 data. The revised DRLs better reflect current practice and are similar to those in other developed countries. The use of Multi‐Detector Computed Tomography (MDCT) in diagnosis and therapy is indisputably of great benefit, however its application is presumed to carry some risk of cancer and other effects due to radiation exposure.To identify facilities that could benefit from optimisation of acquisition protocols, it is considered international best practice for regulatory and health authorities, in partnership with relevant professional associations, to promulgate Diagnostic Reference Levels (DRLs).DRLs are a type of investigation level used in medical imaging to indicate whether, in routine conditions, the amount of radiation used for a type of procedure is unusually high or low. DRLs are based on dosimetry surveys that measure the spread of doses used for similar radiological investigations across various institutions.The establishment of DRLs has proved to be a useful tool in the standardisation and optimisation of radiation doses received from common medical imaging protocols.In Australia, the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) is responsible for setting National DRLs (NDRLs) and conducts an ongoing national dosimetry survey of common MDCT protocols for this purpose.Since the first publication of the Australian NDRLs for adult MDCT in 2012,vol), dose length product (DLP), patient weight and gender, scanner information and protocol information . The details of the service have been described in a previous publication.ARPANSA’s National Diagnostic Reference Level Service (NDRLS) provides an online survey for registered facilities to submit patient dosimetry information. The online service collects volume computed tomography dose index  to refer to these site‐scanner‐protocol‐specific survey medians. In Australia, the NDRLs have been set at rounded third quartiles (75th percentiles) of the distributions of FRLs, the implication being that sites with an FRL above the DRL deliver a dose greater than that of 75% of their peers. This is consistent with ICRP recommendationsSurveys can be initiated at any time and remain open to accumulate patient data progressively before manual submission at a later date. At the end of a given calendar year all remaining open surveys are automatically closed and a facility must create new surveys for the following calendar year. In return for submitting data to the NDRLS, participants receive a report comparing their FRL with the relevant DRL, which can in turn be used to demonstrate compliance with state regulations or Diagnostic Imaging Accreditation Scheme (DIAS) requirements.ARPANSA began a review of the data collected by the NDRLS at the end of 2017. In analysing the FRL distributions to derive DRLs, each survey median (FRL) was treated as an independent sample. Analysis was restricted to surveys where the median patient age was >20 years and to single‐series studies, except in the case of chest–abdomen–pelvis studies where both single‐series and dual‐series scans were included. Surveys with a median age of less than 20 were excluded to remove a small number of submissions from paediatric facilities in which all patients were aged between 15 and 18 years because these represent a potentially distinct patient population in comparison with the general adult population.The results of the review were provided to a liaison panel who were tasked with advising on the new Australian DRLs. In addition to setting new NDRL values, the panel was given the scope to alter the NDRL categories and definitions. The panel comprised representatives from ARPANSA, the Australian Government Department of Health (DoH), the Royal Australian and New Zealand College of Radiologists (RANZCR), the Australasian College of Physical Scientists and Engineers in Medicine (ACPSEM), the Australian Diagnostic Imaging Association (ADIA) and the Australian Society of Medical Imaging and Radiation Therapy (ASMIRT). The liaison panel reached their recommendations by consensus with subsequent formal endorsement by all participating bodies.The use of a liaison panel of industry experts to guide the DRL program ensured that the development of DRLs was a collaborative process. A similar panel was used to develop the initial MDCT NDRLs.vol and to the nearest factor of 10 for DLP. In addition, the liaison panel requested that the existing neck protocol be split into separate cervical spine and soft tissue neck protocols and that a new category be introduced for kidney–ureter–bladder (KUB) scans for the assessment of renal colic. These alterations were made to better reflect clinical practice and to reduce ambiguity in scan definition.The liaison panel considered setting separate NDRLs with and without the use of iterative reconstruction but favoured the simplicity of keeping a single NDRL for each protocol, deciding to continue with categorisation at the protocol level. The revised NDRLs were chosen by rounding the third quartiles of the 2017 FRL distributions up to the nearest integer for CTDIvol. Figure Since the NDRLS only collected data for a unified ‘neck’ protocol, it was necessary to re‐categorise the existing neck surveys into the new cervical spine and soft‐tissue neck categories. Classification was based on: supplementary information about the procedure supplied by the facility in the NDRLS survey comment field, the use of contrast and the apparent scan length. The apparent scan length was obtained by dividing the DLP by the CTDIFor KUB scans, ARPANSA did not have access to any relevant dose data. Instead, a provisional DRL was set using the same values as were used for abdomen–pelvis scans.vol across all series as requested in the NDRLS user instructions, many participants submitted the sum of the CTDIvol. Data following this pattern resulted in the 2012 CAP CTDIvol DRL being double the abdomen–pelvis and chest CTDIvol values. To correct for this error, the reported CTDIvol was halved for any surveys with a median apparent scan length <55 cm.For the chest–abdomen–pelvis (CAP) category, it was thought that a number of survey participants had submitted incorrect information. The issue arose from facilities submitting data from scans that required multiple series to cover the entire CAP scan length. In these instances, rather than submit the sum of the DLP and the average CTDINonparametric quantile regression models were used to test the differences between the third quartiles of FRLs for data submitted to the ARPANSA NDRLS in 2011 and 2017. Quantile regression is a method that makes no assumptions about the underlying data distribution. A two‐tailed p‐value of 0.05 was used to indicate statistical significance. Statistical analyses were performed using Stata/SE V.16.0 .The number of surveys completed for each protocol for adult patients in each year and the proportion of such surveys that indicated the use of iterative reconstruction (IR) is outlined in Table th and 95th percentiles.The distributions of FRLs in 2017 for each dose metric, categorised by protocol, are shown in Figure The historical variation of the FRL distribution for all protocols is shown in Figure Figure Figure The updated Australian NDRLs are displayed in Table The number of surveys submitted to the NDRLS in each protocol category has increased from around 40–50 in 2011 to around 400 in 2017  Dose Index Registry (DIR), as well as data from Germany and Korea (see Table vol across the component series. The NDRLs released in 2012 (Table vol (30 mGy) implied a rather short scan length (40 cm) and the CTDIvol was twice that for the individual chest and abdomen–pelvis scans (15 mGy). Figure vol NDRL for CAP is markedly lower (11 mGy) in comparison to the previous value (30 mGy) but similar to the new CTDIvol NDRLs for chest (10 mGy) and abdomen–pelvis (13 mGy).Chest–abdomen–pelvis scans are frequently performed as two separate scan series, an arterial chest phase followed by a portal venous abdomen phase. The NDRLs for this protocol assume the reporting of the total DLP and the average CTDI12 Table  containes scans 1 mGy. FigProvisional NDRLs have been established for kidney–ureter–bladder scans  using the data collected for abdomen–pelvis scans. ARPANSA believes that the dose delivered during KUB scans is generally lower than abdominal‐pelvis scans and that, as a result, the provisional KUB values are conservative. A review of the KUB data will be undertaken in 2020 to establish updated NDRLs for this procedure that reflect actual observed practice.vol are seen in the case of CAP and soft‐tissue neck, as discussed above. Increasing use of iterative reconstruction technology has contributed to this reduction.As can be seen from Table th percentile as an optimisation target, an ‘achievable dose’.vol and DLP along with the NDRLs (75th percentiles). The 25th and 50th percentiles have no official status in Australia; but are published on the ARPANSA websiteThe ICRP and some national bodies have discussed using the 50Table The revised NDRLs provide updated benchmarks for facilities that are more consistent with current practice. National DRLs need to be updated routinely to ensure that they keep pace with changes in technology and practice as facilities apply the optimisation principle to maximise the benefit‐to‐risk ratio of their scans. ARPANSA expects to conduct another review of the data in 2021 to assess whether there have been further changes that would warrant an update of the NDRLs.It is important to recognise that attention to dose for an imaging procedure is only one component of the optimisation process. It is vitally important that image quality is also assessed to ensure that it is sufficient for the diagnostic task. The NDRLs do not address this aspect. Facilities are encouraged to utilise the image quality self‐audit offered by the RANZCR to ensure that dose reduction is not achieved at the expense of diagnostic efficacy.ARPANSA, in partnership with professional associations, has reviewed and revised the Australian NDRLs for multi‐detector CT for adult patients. The new NDRLs are lower than the previous NDRLs, and better reflect current practice among imaging facilities in Australia. The new Australian NDRLs are similar to those in other developed countries. It should be noted that due to the voluntary nature in submitting the surveys, the NDRLs could be biased. In addition, the KUB NDRLs are preliminary reference levels based on the abdomen–pelvis reference levels. ARPANSA will conduct a review of the KUB NDRLs in 2021. Use of the ARPANSA National Diagnostic Reference Level Service continues to increase, providing valuable feedback to imaging facilities on how dose levels for their scans compare to those of their peers.This work was supported by the Australian Government.The authors declare that they have no conflict of interest.


Health knowledge, as an important resource of online health communities (OHCs), attracts users to engage in OHCs and improve the traffics within OHCs, thereby promoting the development of OHCs. Seeking and contributing health knowledge are basic activities in OHCs and are helpful for users to solve their health‐related problems, improve their health conditions and thus influence their evaluation of OHCs . However, how do patients’ health knowledge seeking and health knowledge contributing behaviours together with other factors influence their perceived value of OHCs? We still have little knowledge.In order to address the above gap, we root the current study in social cognitive theory and prior related literature on health knowledge sharing in OHCs and patients’ perceived value. We treat health knowledge seeking and health knowledge contributing behaviours as behavioural factors and structural social capital as an environmental factor and explore their impacts on patients’ perceived value of OHCs.We have built a theoretical model composed of five hypotheses. We have designed a questionnaire composed of four key constructs and then collected data via an online survey.We have distributed the questionnaire in two Chinese OHCs. We obtained a sample of 352 valid responses that were completed by patients having a variety of conditions.The empirical results indicate that health knowledge seeking and health knowledge contributing have positive impacts on patients’ perceived value of OHCs. The impact of health knowledge seeking on patients’ perceived value of OHCs is greater than the impact of health knowledge contributing. In addition, structural social capital moderates the effects of health knowledge seeking and health knowledge contributing on patients’ perceived value of OHCs. It weakens the effect of health knowledge seeking but enhances the effect of health knowledge contributing on patients’ perceived value of OHCs.These findings contribute to the literature on patients’ perceived value of OHCs and on the role of structural social capital in OHCs. For OHC managers, they should provide their users more opportunities to seek or contribute health knowledge in their communities. OHCs are a type of health‐related virtual community (VC) designed particularly for different health‐related stakeholders, for example health insurance, pharmaceutical companies, hospitals, health professionals, patients, and patients’ relatives or friends.Exchanging health knowledge and information is a kind of basic activity in OHCs.In addition to exploring its antecedent factors, scholars recently began to explore the health outcomes of exchanging health knowledge in OHCs. For example, knowledge seekers can obtain health knowledge for their health issues and then use it to improve their health conditions.In order to address the above gap, we adopted social cognitive theory (SCT) as theoretical foundation. We treated health knowledge seeking and health knowledge contributing as behavioural factors and structural social capital as a social environmental factor, and, finally, built a model composed of five hypotheses. We tested our hypotheses with a sample of 352 valid responses.22.1Social cognitive theory (SCT) is a classical theory on individual behaviours. According to SCT, personal behaviours are shaped by the factors from three domains ; the factors from any two domains can interact with each other and then influence the factors in the third domain.In addition to being used to explain personal knowledge sharing behaviours in VCs,2.2Following prior studies,As shown in Table 2.3Social capital is defined as the sum of the actual and potential resources that an individual obtains from the network of relationships.Prior studies have explored the impacts of social capital on users’ health expectations by OHCs use. For example, structural social capital can alleviate patients’ perceived stress, depression and coping,As discussed above, prior studies primarily focus on the direct effects on users’ health expectations2.4Perceived value of OHCs is defined as patients’ perception of the overall utility based on a trade‐off between perceived benefits and costs of using OHCs.As shown in Table Users’ behaviours positively influence their perceived value.3This study aimed to examine how patients’ knowledge sharing behaviours and their structural social capital influenced their perceived value of OHCs. Specifically, we conceptualized health knowledge seeking and health knowledge contributing as behavioural factors and structural social capital as a social environmental factor. We proposed that both environmental factors and behavioural factors directly influence patients’ perceived value; in addition, structural social capital as a social environmental factor moderates the effects of behavioural factors on patients’ perceived value of OHCs. The proposed research model is shown in Figure 3.1Health knowledge seeking is defined as users’ search, acquisition or consumption of health knowledge in OHCs.H1a: Health knowledge seeking behaviour has a positive impact on patients’ perceived value of OHCsHealth knowledge contributing refers to patients’ generation or provision of health knowledge in OHCs.H1b: Health knowledge contributing behaviour has a positive impact on patients’ perceived value of OHCsStructural social capital describes the strength of relationships, the level of time spent and/or the frequency of the interactions among patients in the same OHC.H2: Structural social capital has a positive impact on patients’ perceived value of OHCs3.2According to SCT, individuals’ behaviours together with environmental factors can reshape their cognitions.H3a: Structural social capital weakens the impact of patients’ knowledge seeking behaviours on their perceived value of OHCs: when structural social capital is high, the effect of knowledge seeking behaviours will be weaker, else will be stronger.As a social environmental factor, structural social capital provides patients new channels to interact with each other.H3b: Structural social capital enhances the impact of health knowledge contributing on patients’ perceived value of OHCs: when structural social capital is high, the effect of knowledge contributing behaviours will be stronger.In addition to the above variables, prior studies have found that women are more likely to continue participating in sharing,4We designed a questionnaire and an online survey for data collection and hypothesis test. This research was approved by the Shantou University Academic and Ethics Board.4.1All scales for our four key constructs were adopted from prior research and adapted to the OHC context. We took the following precautions to translate the English scales into Chinese with an iteration to ensure the meanings of the scale in English and in Chinese were consistent. First, the second author together with two graduate students translated all construct scales into Chinese and did necessary iterations to make a draft Chinese version. Second, the first author and third author who are bilinguals further checked the draft version and made necessary changes to make sure the meaning of all constructs in English and in Chinese converged. Third, in order to make sure all measurement items were clear and understandable, we also did a pilot study by inviting 12 undergraduate students who have OHC use experience to complete the questionnaire. During the process, we asked them to tell us any confusing issues and then modified them accordingly. The questionnaire was frozen when the back‐and‐forth translation and pilot test were completed. We used a 5‐point Likert‐type scale (note: 1 for completely disagree and 5 for completely agree). Table 4.2Seeking Health, www.mijian360.com) and Yuaigongwu . We clearly informed all participants that the survey was voluntary, and all data would be used only for academic research. We added two questions ('Have you ever used OHCs?' and 'Please write down the name of the OHC you use most frequently') to determine whether the participant had ever used OHCs. If they had never used an OHC, the survey ended. Each participant could respond to the questionnaire only once. The survey began on 28 January 2019 and lasted for 41 days. After deleting 24 invalid items , we obtained a sample of 352 valid responses. Based on the sample of 352 valid responses, we conducted descriptive statistics, assessed the measurement model and tested the structural model.Data were collected via an online survey in two Chinese OHCs, that is Mijian  than male ones. We checked this over‐representation of females with the website Mijian. This ratio is appropriate, because many respondents use OHCs due to gender‐related illnesses, such as breast cancer. Over 89% of participants ranged in age from 16 to 55 years. Participants aged from 26 to 35 years account for the highest proportion (25.3%). In addition, over 55% of participants have OHC use experience of more than one year. Of all users in this study, about 67% have a college‐level or higher education. This suggests that users with higher education levels have a higher tendency to use OHCs for health knowledge.5.2We assessed the measurement model with explorative factor analysis using SPSS 20 . Namely, the coefficient of health knowledge seeking is significantly greater than the coefficient of health knowledge contributing; seeking knowledge directly meets patients’ health needs and brings patients a higher sense of value.As shown in Figure The moderating effects of structural social capital on health knowledge seeking  and health knowledge contributing  are significant. H3a and H3b are supported. Namely, patients’ structural social capital weakens the effect of health knowledge seeking but strengthens the effect of health knowledge contributing on patients’ perceived value.The direct effect of structural social capital on patients’ perceived value is not significant . H2 is unsupported. Therefore, the social environment does not directly improve patients’ perceived value of OHCs. However, structural social capital acts as a moderator that changes the effects of patients’ knowledge sharing and knowledge contributing behaviours.Finally, no control variables had a significant effect. No gender, age, education and tenure differences were shown. Patients’ perceived value is therefore related to factors other than personal demographic variables.6We have examined how health knowledge seeking and health knowledge contributing behaviours and structural social capital influence patient perceived value of OHCs with a sample of 352 valid responses. Four out of the five hypotheses were supported. As the empirical results show, health knowledge seeking and health knowledge contributing have positive impacts on patients’ perceived value of OHCs; the impact of health knowledge seeking on patients’ perceived value of OHCs is greater than the impact of health knowledge contributing. In addition, structural social capital weakens the effect of health knowledge seeking but enhances the effect of health knowledge contributing on patients’ perceived value of OHCs. In contrast to our predictions, hypothesis H2 was unsupported. This finding is controversial with a prior conclusion that individuals who have more structural social capital are more possibly perceiving a high level value.6.1Our findings make two significant theoretical contributions. First, we contribute to the literature on user‐perceived value of OHCs by verifying the impacts of patients’ health knowledge sharing behaviours. Our empirical results indicate that health knowledge seeking and knowledge contributing behaviours positively influence patients’ perceived value of OHCs. This finding is similar to prior conclusions that knowledge seeking and knowledge contributing behaviours enabled individuals to obtain a higher level of perceived valueSecond, we contribute to the literature on the roles of environmental factors by having verified a new moderator . Our empirical results indicate that patients’ structural social capital enhances the impact of health knowledge contributing but weakens the impact of health knowledge seeking on patients’ perceived value of OHCs. We provide two explanations on the negative moderating role of structural social capital. First, patients with high structure social capital have diversified channels to obtain needed health knowledge in OHCs.6.2This study makes several contributions to OHC practice. First, OHC could be used as channels for medical education. As our empirical results show, patients’ perceived value partially sources from their health knowledge exchange behaviours in OHCs. Health knowledge sharing is beneficial to meet patients’ health needs and improve their perception of value. OHC administrators could make policies to encourage more users to engage in OHCs. For example, OHC administrators can optimize OHC design or categorize health knowledge into different domains to make OHCs easy to use.Second, OHC administrators should be cautious about the use of structural social capital. As our empirical results show, the moderating effects of structural social capital are complex. It weakens the effect of health knowledge seeking but enhances the effect of health knowledge contributing. OHC administrators could lead and encourage users to participate in frequent, diverse and intensive meaningful interactions  with knowledgeable health professionals or users.6.3There are several limitations that may affect the findings in this study. First, our sample size is relatively small. Empirical findings might be more robust with a larger sample. Second, we built a concise model that includes three antecedents . We did not include the factors such as types of health knowledge,7We posit that patients’ perceived value of OHCs is influenced by both health knowledge sharing behaviours and environmental factors. We build a model composed of five hypotheses according to SCT and verified it with a sample of 352 valid responses. We have verified that health knowledge seeking and health knowledge contributing behaviours positively influence patients’ perceived value of OHCs; in addition, the impact of health knowledge seeking is greater than the impact of health knowledge contributing. Structural social capital works as a moderator that changes the impacts of patients’ health knowledge seeking and contributing behaviours on their perceived value of OHCs. It provides knowledge seekers more personal channels to seek knowledge directly from OHCs and weakens patients’ perception of value derived from knowledge seeking behaviours in OHCs; meanwhile, it provides knowledge contributors more opportunities to demonstrate their knowledge in OHCs and enhances their perception of value derived from knowledge contributing in OHCs. These findings contribute to the literature on users’ perceived value of OHCs by advancing the understanding of how behavioural factors and environmental factors influence patients’ perceived value of OHCs.The author declares that there is no conflict of interest.


Castor canadensis) modulate deadwood dynamics in many forest ecosystems. Relying on such episodes of fresh woody debris, primary wood‐boring beetles, organisms that dig tunnels into those debris for reproduction, act as important deadwood decomposers in the ecosystem. Here, we investigate how the age and size of beaver disturbances act as predictors for primary wood‐boring beetle abundance and species richness around beaver‐altered habitat patches. To do so, we sampled beetles around 16 beaver‐disturbed and unaltered watercourses within the Kouchibouguac National Park (Canada) and modeled beetle demographic responses to site conditions and their physical characteristics, distance from the watercourse, deadwood biomass, and the geographical location of the sites. Our results indicate that the size of the disturbance is positively associated with beetle abundance, which highlights unique deadwood dynamics inherent to large beaver ponds. The role of beavers in forest ecosystems by reaching multiple taxa at multiple spatiotemporal scales further exemplifies the need to study nontrophic interactions and their complex consequences in ecosystem management.Episodic natural disturbances play a key role in ecosystem renewal, and ecological engineering could do so by transforming resource accessibility. While such coupling creates nontrophic and lasting interactions between resource consumers and ecosystem engineers, it is unclear how large the disturbance must be to sustain such coupling. Natural disturbances that occur from the ecological engineering by the Canadian beaver ( The size of the disturbance created by beavers was positively associated with primary wood‐boring beetle abundance around beaver‐altered habitat patches. This shows that ecological engineering transforms resource accessibility, creating nontrophic and lasting interactions between resource consumers and ecosystem engineers. We determined the age  and the perimeter  of the disturbed area through aerial photography. We paired BEA sites with control sites (CON), which each included a watercourse without any sign of beaver activity within 100‐m radius from the CON periphery. Hereafter, we will use the term “site condition” as a general concept encompassing both BEA and CON.The study was conducted in the Acadian forest biome at Kouchibouguac National Park , a 238‐kmAt each site, we ran a 50‐m transect oriented perpendicularly to the watercourse. For BEA, each transect began at the limit of the flooded area. The transects for meadows began at the end of habitat patches linked to ancient flooding   next to each trap, on the right‐hand side of the transect from the watercourse perspective. We measured the diameter and volume, and determined the type (deciduous or coniferous) of all horizontal  or vertical  woody debris over 2 cm in diameter following the method described in Thibault and Moreau  (Table r < 0.70) and for all analyses, we used the complete models. Anisandrus sayi abundance was analyzed separately from other deciduous borers because of its sheer abundance compared with other species in this study (see Results) and other work carried out in New Brunswick, Canada  to examine the effect of ordinal numeric variables  and a categorical variable , on five dependent variables  was affected to different extents by the studied variables. For A. sayi, most of our study variables had a positive impact on abundance as revealed by a GAMM explaining 45% of the variability  to effectively assess the early successional phase of feeding guilds. Accordingly, the rejection of P3 and P4 could be explained by three reasons. First, the effect of beaver disturbances on primary wood‐boring beetle species richness could mostly be noticeable at the first flood, when the initial heterogenic resource pulse is created ; formal analysis (supporting); investigation (lead); writing – original draft (lead). Nicolas Lecomte: Conceptualization (supporting); investigation (supporting); writing – review and editing (supporting). Gaétan Moreau: Conceptualization ; data curation (supporting); formal analysis (lead); funding acquisition (lead); investigation (supporting); methodology (lead); project administration (lead); writing – review and editing (supporting).