Multiview confocal super-resolution microscopy.

Confocal microscopy1 remains a major workhorse in biomedical optical microscopy owing to its reliability and flexibility in imaging various samples, but suffers from substantial point spread function anisotropy, diffraction-limited resolution, depth-dependent degradation in scattering samples and volumetric bleaching2. Here we address these problems, enhancing confocal microscopy performance from the sub-micrometre to millimetre spatial scale and the millisecond to hour temporal scale, improving both lateral and axial resolution more than twofold while simultaneously reducing phototoxicity. We achieve these gains using an integrated, four-pronged approach: (1) developing compact line scanners that enable sensitive, rapid, diffraction-limited imaging over large areas; (2) combining line-scanning with multiview imaging, developing reconstruction algorithms that improve resolution isotropy and recover signal otherwise lost to scattering; (3) adapting techniques from structured illumination microscopy, achieving super-resolution imaging in densely labelled, thick samples; (4) synergizing deep learning with these advances, further improving imaging speed, resolution and duration. We demonstrate these capabilities on more than 20 distinct fixed and live samples, including protein distributions in single cells; nuclei and developing neurons in Caenorhabditis elegans embryos, larvae and adults; myoblasts in imaginal disks of Drosophila wings; and mouse renal, oesophageal, cardiac and brain tissues.

MICU3 Regulates Mitochondrial Calcium and Cardiac Hypertrophy.

BACKGROUND: Calcium (Ca2+) uptake by mitochondria occurs via the mitochondrial Ca2+ uniporter. Mitochondrial Ca2+ uniporter exists as a complex, regulated by 3 MICU (mitochondrial Ca2+ uptake) proteins localized in the intermembrane space: MICU1, MICU2, and MICU3. Although MICU3 is present in the heart, its role is largely unknown. METHODS: We used CRISPR-Cas9 to generate a mouse with global deletion of MICU3 and an adeno-associated virus (AAV9) to overexpress MICU3 in wild-type mice. We examined the role of MICU3 in regulating mitochondrial calcium ([Ca2+]m) in ex vivo hearts using an optical method following adrenergic stimulation in perfused hearts loaded with a Ca2+-sensitive fluorophore. Additionally, we studied how deletion and overexpression of MICU3, respectively, impact cardiac function in vivo by echocardiography and the molecular composition of the mitochondrial Ca2+ uniporter complex via Western blot, immunoprecipitation, and Blue native-PAGE analysis. Finally, we measured MICU3 expression in failing human hearts. RESULTS: MICU3 knock out hearts and cardiomyocytes exhibited a significantly smaller increase in [Ca2+]m than wild-type hearts following acute isoproterenol infusion. In contrast, heart with overexpression of MICU3 exhibited an enhanced increase in [Ca2+]m compared with control hearts. Echocardiography analysis showed no significant difference in cardiac function in knock out MICU3 mice relative to wild-type mice at baseline. However, mice with overexpression of MICU3 exhibited significantly reduced ejection fraction and fractional shortening compared with control mice. We observed a significant increase in the ratio of heart weight to tibia length in hearts with overexpression of MICU3 compared with controls, consistent with hypertrophy. We also found a significant decrease in MICU3 protein and expression in failing human hearts. CONCLUSIONS: Our results indicate that increased and decreased expression of MICU3 enhances and reduces, respectively, the uptake of [Ca2+]m in the heart. We conclude that MICU3 plays an important role in regulating [Ca2+]m physiologically, and overexpression of MICU3 is sufficient to induce cardiac hypertrophy, making MICU3 a possible therapeutic target.

Chromatographic Separation: A Versatile Strategy to Prepare Discrete and Well-Defined Polymer Libraries.

ConspectusThe preparation of discrete and well-defined polymers is an emerging strategy for emulating the remarkable precision achieved by macromolecular synthesis in nature. Although modern controlled polymerization techniques have unlocked access to a cornucopia of materials spanning a broad range of monomers, molecular weights, and architectures, the word "controlled" is not to be confused with "perfect". Indeed, even the highest-fidelity polymerization techniques─yielding molar mass dispersities in the vicinity of D = 1.05─unavoidably create a considerable degree of structural and/or compositional dispersity due to the statistical nature of chain growth. Such dispersity impacts many of the properties that researchers seek to control in the design of soft materials.The development of strategies to minimize or entirely eliminate dispersity and access molecularly precise polymers therefore remains a key contemporary challenge. While significant advances have been made in the realm of iterative synthetic methods that construct oligomers with an exact molecular weight, head-to-tail connectivity, and even stereochemistry via small-molecule organic chemistry, as the word "iterative" suggests, these techniques involve manually propagating monomers one reaction at a time, often with intervening protection and deprotection steps. As a result, these strategies are time-consuming, difficult to scale, and remain limited to lower molecular weights. The focus of this Account is on an alternative strategy that is more accessible to the general scientific community because of its simplicity, versatility, and affordability: chromatography. Researchers unfamiliar with the intricacies of synthesis may recall being exposed to chromatography in an undergraduate chemistry lab. This operationally simple, yet remarkably powerful, technique is most commonly encountered in the purification of small molecules through their selective (differential) adsorption to a column packed with a low-cost stationary phase, usually silica. Because the requisite equipment is readily available and the actual separation takes little time (on the order of 1 h), chromatography is used extensively in small-molecule chemistry throughout industry and academia alike. It is, therefore, perhaps surprising that similar types of chromatography are not more widely leveraged in the field of polymer science as well.Here, we discuss recent advances in using chromatography to control the structure and properties of polymeric materials. Emphasis is placed on the utility of an adsorption-based mechanism that separates polymers based on polarity and composition at tractable (gram) scales for materials science, in contrast to size exclusion, which is extremely common but typically analyzes very small quantities of a sample (∼1 mg) and is limited to separating by molar mass. Key concepts that are highlighted include (1) the separation of low-molecular-weight homopolymers into discrete oligomers (D = 1.0) with precise chain lengths and (2) the efficient fractionation of block copolymers into high-quality and widely varied libraries for accelerating materials discovery. In summary, the authors hope to convey the exciting possibilities in polymer science afforded by chromatography as a scalable, versatile, and even automated technique that unlocks new avenues of exploration into well-defined materials for a diverse assortment of researchers with different training and expertise.

Regulation of Mitochondrial Ca2+ Uptake.

Mitochondria are responsible for ATP production but are also known as regulators of cell death, and mitochondrial matrix Ca2+ is a key modulator of both ATP production and cell death. Although mitochondrial Ca2+ uptake and efflux have been studied for over 50 years, it is only in the past decade that the proteins responsible for mitochondrial Ca2+ uptake and efflux have been identified. The identification of the mitochondrial Ca2+ uniporter (MCU) led to an explosion of studies identifying regulators of the MCU. The levels of these regulators vary in a tissue- and disease-specific manner, providing new insight into how mitochondrial Ca2+ is regulated. This review focuses on the proteins responsible for mitochondrial transport and what we have learned from mouse studies with genetic alterations in these proteins.

Loss of mitochondrial Ca2+ uptake protein 3 impairs skeletal muscle calcium handling and exercise capacity.

Mitochondrial calcium concentration ([Ca2+ ]m ) plays an essential role in bioenergetics, and loss of [Ca2+ ]m homeostasis can trigger diseases and cell death in numerous cell types. Ca2+ uptake into mitochondria occurs via the mitochondrial Ca2+ uniporter (MCU), which is regulated by three mitochondrial Ca2+ uptake (MICU) proteins localized in the intermembrane space, MICU1, 2, and 3. We generated a mouse model of systemic MICU3 ablation and examined its physiological role in skeletal muscle. We found that loss of MICU3 led to impaired exercise capacity. When the muscles were directly stimulated there was a decrease in time to fatigue. MICU3 ablation significantly increased the maximal force of the KO muscle and altered fibre type composition with an increase in the ratio of type IIb (low oxidative capacity) to type IIa (high oxidative capacity) fibres. Furthermore, MICU3-KO mitochondria have reduced uptake of Ca2+ and increased phosphorylation of pyruvate dehydrogenase, indicating that KO animals contain less Ca2+ in their mitochondria. Skeletal muscle from MICU3-KO mice exhibited lower net oxidation of NADH during electrically stimulated muscle contraction compared with wild-type. These data demonstrate that MICU3 plays a role in skeletal muscle physiology by setting the proper threshold for mitochondrial Ca2+ uptake, which is important for matching energy demand and supply in muscle. KEY POINTS: Mitochondrial calcium uptake is an important regulator of bioenergetics and cell death and is regulated by the mitochondrial calcium uniporter (MCU) and three calcium sensitive regulatory proteins (MICU1, 2 and 3). Loss of MICU3 leads to impaired exercise capacity and decreased time to skeletal muscle fatigue. Skeletal muscle from MICU3-KO mice exhibits a net oxidation of NADH during electrically stimulated muscle contractions, suggesting that MICU3 plays a role in skeletal muscle physiology by matching energy demand and supply.

Cylinders-in-Undulating-Lamellae Morphology from ABC Bottlebrush Block Terpolymers.

Block polymer self-assembly affords a versatile bottom-up strategy to develop materials with the desired properties dictated by specific symmetries and dimensions. Owing to distinct properties compared with linear counterparts, bottlebrush block polymers with side chains densely grafted on a backbone have attracted extensive attention. However, the morphologies found in bottlebrush block polymers so far are limited, and only lamellar and cylindrical ordered phases have been reported in diblock bottlebrushes. The absence of complex morphologies, such as networks, might originate from the intrinsically stiff backbone architecture. We experimentally investigated the morphologies of nonfrustrated ABC bottlebrush block terpolymers, based on two chemistries, poly(ethylene-alt-propylene)-b-polystyrene-b-poly(dl-lactic acid) (PEP-PS-PLA) and PEP-b-PS-b-poly(ethylene oxide) (PEP-PS-PEO), synthesized by ring-opening metathesis polymerization of norbornene-terminated macromonomers. Structural characterization based on small-angle X-ray scattering and transmission electron microscopy measurements revealed an unprecedented cylinders-in-undulating-lamellae (CUL) morphology with p2 symmetry for both systems. Additionally, automated liquid chromatography was employed to fractionate the PEP-PS-PLA bottlebrush polymer, leading to fractions with a spectrum of morphologies, including the CUL. These findings underscore the significance of macromolecular dispersity in nominally narrow dispersity bottlebrush polymers while demonstrating the power of this fractionation technique.

Prevalence of trauma history and symptoms in patients who have received vaginal brachytherapy as part of their endometrial cancer treatment.

OBJECTIVE: Vaginal brachytherapy (VBT) is an essential component of curative intent treatment for many patients with endometrial cancer. The prevalence of trauma history in this population is unknown and important to understand considering VBT requires patients to have an instrument vaginally inserted while in the vulnerable lithotomy position. We aim to identify patients treated with intracavitary VBT and collect survey data to assess trauma endpoints. METHODS: We retrospectively identified patients with endometrial cancer who underwent intracavitary VBT at our institution between 01/2017 and 08/2022. Patients were mailed and/or electronically mailed a survey that included demographics, psychosocial background, and validated trauma surveys to be filled out as they relate to their trauma experiences prior to VBT and again considering any trauma symptomatology related to VBT. Electronic medical record review was performed. Descriptive statistics as well as multivariate analysis were performed. RESULTS: 206 patients met inclusion criteria, 66 (32.1%) of whom returned the survey and were included for analysis. Thirty-two percent of patients self-reported a personal history of any prior mental health diagnosis. Eighty-eight percent of patients screened positive for a history of trauma exposure, 23% endorsed symptoms of PTSD related to their VBT experience, and 5% screened positive for a likely PTSD diagnosis from VBT. CONCLUSION: A majority of included patients had a history of trauma exposure prior to VBT. In a subset of patients, VBT re-induced trauma and was considered to be an independent traumatic event. This study highlights the importance of practicing trauma informed care, particularly in this patient population.

The carbon footprint of different modes of birth in the UK and the Netherlands: An exploratory study using life cycle assessment.

OBJECTIVE: To compare the carbon footprint of caesarean and vaginal birth. DESIGN: Life cycle assessment (LCA). SETTING: Tertiary maternity units and home births in the UK and the Netherlands. POPULATION: Birthing women. METHODS: A cradle-to-grave LCA using openLCA software to model the carbon footprint of different modes of delivery in the UK and the Netherlands. MAIN OUTCOME MEASURES: 'Carbon footprint' (in kgCO2 equivalents [kgCO2 e]). RESULTS: Excluding analgesia, the carbon footprint of a caesarean birth in the UK was 31.21 kgCO2 e, compared with 12.47 kgCO2 e for vaginal birth in hospital and 7.63 kgCO2 e at home. In the Netherlands the carbon footprint of a caesarean was higher (32.96 kgCO2 e), but lower for vaginal birth in hospital and home (10.74 and 6.27 kgCO2 e, respectively). Emissions associated with analgesia for vaginal birth ranged from 0.08 kgCO2 e (with opioid analgesia) to 237.33 kgCO2 e (nitrous oxide with oxygen). Differences in analgesia use resulted in a lower average carbon footprint for vaginal birth in the Netherlands than the UK (11.64 versus 193.26 kgCO2 e). CONCLUSION: The carbon footprint of a caesarean is higher than for a vaginal birth if analgesia is excluded, but this is very sensitive to the analgesia used; use of nitrous oxide with oxygen multiplies the carbon footprint of vaginal birth 25-fold. Alternative methods of pain relief or nitrous oxide destruction systems would lead to a substantial improvement in carbon footprint. Although clinical need and maternal choice are paramount, protocols should consider the environmental impact of different choices.

Mitochondrial permeability transition pore-dependent necrosis.

Mitochondrial permeability transition pore (mPTP)-dependent cell death is a form of necrotic cell death that is driven by mitochondrial dysfunction by the opening of the mPTP and is triggered by increases in matrix levels of Ca2+ and reactive oxygen species. This form of cell death has been implicated in ischemic injuries of the heart and brain as well as numerous degenerative diseases in the brain and skeletal muscle. This review focuses on the molecular triggers and regulators of mPTP-dependent necrosis in the context of myocardial ischemia reperfusion injury. Research over the past 50 years has led to the identity of regulators and putative pore-forming components of the mPTP. Finally, downstream consequences of activation of the mPTP as well as ongoing questions and areas of research are discussed. These questions pose a particular interest as targeting the mPTP could potentially represent an efficacious therapeutic strategy to reduce infarct size following an ischemic event.

OGFOD1 modulates the transcriptional and proteomic landscapes to alter isoproterenol-induced hypertrophy susceptibility.

Cardiac hypertrophy is associated with increased translation. However, little is known of the mechanisms that regulate translation in hypertrophy. Members of the 2-oxoglutarate-dependent dioxygenase family regulate several aspects of gene expression, including translation. An important member of this family is OGFOD1. Here, we show OGFOD1 accumulates in failing human hearts. Upon OGFOD1 deletion, murine hearts showed transcriptomic and proteomic changes, with only 21 proteins and mRNAs (0.6%) changing in the same direction. Additionally, OGFOD1-KO mice were protected from induced hypertrophy, supporting a role for OGFOD1 in the cardiac response to chronic stress.

Tailoring Writability and Performance of Star Block Copolypeptides Hydrogels through Side-Chain Design.

Shear-recoverable hydrogels based on block copolypeptides with rapid self-recovery hold potential in extrudable and injectable 3D-printing applications. In this work, a series of 3-arm star-shaped block copolypeptides composed of an inner hydrophilic poly(l-glutamate) domain and an outer ß-sheet forming domain is synthesized with varying side chains and block lengths. By changing the ß-sheet forming domains, hydrogels with diverse microstructures and mechanical properties are prepared and structure-function relationships are determined using scattering and rheological techniques. Differences in the properties of these materials are amplified during direct-ink writing with a strong correlation observed between printability and material chemistry. Significantly, it is observed that non-canonical ß-sheet blocks based on phenyl glycine form more stable networks with superior mechanical properties and writability compared to widely used natural amino acid counterparts. The versatile design available through block copolypeptide materials provides a robust platform to access tunable material properties based solely on molecular design. These systems can be exploited in extrusion-based applications such as 3D-printing without the need for additives.

Virtual reality (VR) therapy for patients with psychosis: satisfaction and side effects.

BACKGROUND: Automated virtual reality therapies are being developed to increase access to psychological interventions. We assessed the experience with one such therapy of patients diagnosed with psychosis, including satisfaction, side effects, and positive experiences of access to the technology. We tested whether side effects affected therapy. METHODS: In a clinical trial 122 patients diagnosed with psychosis completed baseline measures of psychiatric symptoms, received gameChange VR therapy, and then completed a satisfaction questionnaire, the Oxford-VR Side Effects Checklist, and outcome measures. RESULTS: 79 (65.8%) patients were very satisfied with VR therapy, 37 (30.8%) were mostly satisfied, 3 (2.5%) were indifferent/mildly dissatisfied, and 1 (0.8%) person was quite dissatisfied. The most common side effects were: difficulties concentrating because of thinking about what might be happening in the room (n = 17, 14.2%); lasting headache (n = 10, 8.3%); and the headset causing feelings of panic (n = 9, 7.4%). Side effects formed three factors: difficulties concentrating when wearing a headset, feelings of panic using VR, and worries following VR. The occurrence of side effects was not associated with number of VR sessions, therapy outcomes, or psychiatric symptoms. Difficulties concentrating in VR were associated with slightly lower satisfaction. VR therapy provision and engagement made patients feel: proud (n = 99, 81.8%); valued (n = 97, 80.2%); and optimistic (n = 96, 79.3%). CONCLUSIONS: Patients with psychosis were generally very positive towards the VR therapy, valued having the opportunity to try the technology, and experienced few adverse effects. Side effects did not significantly impact VR therapy. Patient experience of VR is likely to facilitate widespread adoption.

The Oxford Agoraphobic Avoidance Scale.

BACKGROUND: Agoraphobic avoidance of everyday situations is a common feature in many mental health disorders. Avoidance can be due to a variety of fears, including concerns about negative social evaluation, panicking, and harm from others. The result is inactivity and isolation. Behavioural avoidance tasks (BATs) provide an objective assessment of avoidance and in situ anxiety but are challenging to administer and lack standardisation. Our aim was to draw on the principles of BATs to develop a self-report measure of agoraphobia symptoms. METHOD: The scale was developed with 194 patients with agoraphobia in the context of psychosis, 427 individuals in the general population with high levels of agoraphobia, and 1094 individuals with low levels of agoraphobia. Factor analysis, item response theory, and receiver operating characteristic analyses were used. Validity was assessed against a BAT, actigraphy data, and an existing agoraphobia measure. Test-retest reliability was assessed with 264 participants. RESULTS: An eight-item questionnaire with avoidance and distress response scales was developed. The avoidance and distress scales each had an excellent model fit and reliably assessed agoraphobic symptoms across the severity spectrum. All items were highly discriminative (avoidance: a = 1.24-5.43; distress: a = 1.60-5.48), indicating that small increases in agoraphobic symptoms led to a high probability of item endorsement. The scale demonstrated good internal reliability, test-retest reliability, and validity. CONCLUSIONS: The Oxford Agoraphobic Avoidance Scale has excellent psychometric properties. Clinical cut-offs and score ranges are provided. This precise assessment tool may help focus attention on the clinically important problem of agoraphobic avoidance.

Development and Validation of a Tool to Identify Anal Incontinence in Pregnant and Postnatal Women.

BACKGROUND: Neuromuscular and mechanical damage to the pelvic floor because of pregnancy and birth can result in anal incontinence. Pregnant and postnatal women are rarely screened for anal incontinence by clinicians who specialize in the care of these women, and no screening tool has been developed for routine use in these women. OBJECTIVE: To develop and validate a tool for use in everyday clinical practice in the care of pregnant and postnatal women. DATA SOURCES: The study includes 2 test phases with separate data sources. Phase I included test and retest phases of the Bowel-Screening Questionnaire in health professionals and women who were pregnant or had recently birthed (n = 45). Phase II included a pilot of the tool compared to 2 current scoring systems (n = 358). SETTING: Large tertiary hospital in South Australia. PATIENTS: Phase II: prospective recruitment of 358 prenatal parous women attending a first antenatal appointment. MAIN OUTCOMES MEASURES: To evaluate the reliability and validity of the developed tool. RESULTS: Test-retest agreement in phase I was excellent for each of the 6 items, with each κ statistic being between 0.83 and 1.0. In phase II, agreement between new and existing tools was fair to good for the detection of anal incontinence symptoms addressed as a composite question (κ between 0.41 and 0.71). Anal incontinence was detected in 191 women (53%) using the new tool, and there was a lower prevalence reported using the Vaizey score (n = 118) and Wexner score (n = 129). Completion rates of the new tool were 99%, higher than both the Vaizey score (33%) and Wexner score (36%). LIMITATIONS: Sample size limits the generalization of findings. CONCLUSION: The questionnaire is reliable and valid, reporting a high incidence of bowel incontinence, with predominant symptoms of rectal urgency and flatus as precursors for worsening function. DESARROLLO Y VALIDACIN DE UNA HERRAMIENTA PARA IDENTIFICAR LA INCONTINENCIA ANAL EN MUJERES EMBARAZADAS Y PURPERAS: ANTECEDENTES:El daño neuromuscular y mecánico del piso pélvico debido al embarazo y al parto puede resultar en incontinencia anal. Las mujeres embarazadas y puérperas rara vez son examinadas para la incontinencia anal por médicos que se especializan en el cuidado de estas mujeres, y no se ha desarrollado ninguna herramienta de detección para uso rutinario en estas mujeres.OBJETIVO:Desarrollar y validar una herramienta para uso en la práctica clínica diaria en el cuidado de las mujeres embarazadas y puérperas.FUENTES DE DATOS:El estudio incluye 2 fases de prueba con fuentes de datos separadas. Fase 1, fase test y retest del Bowel Screening Questionnaire en profesionales sanitarios y mujeres embarazadas o recién paridas (n = 45). La Fase 2 incluyó una prueba piloto de la herramienta en comparación con dos sistemas de puntuación actuales (n = 358).ENTORNO CLINICO:Gran hospital terciario en el sur de Australia.PACIENTES:Fase 2: reclutamiento prospectivo de 358 mujeres con parto prenatal que asisten a una primera cita prenatal.PRINCIPALES MEDIDAS DE VALORACIÓN:Evaluar la confiabilidad y validez de la herramienta desarrollada.RESULTADOS:La concordancia test-retest en la fase 1 fue excelente para cada uno de los 6 ítems con cada estadística kappa entre 0,83 y 1,0. En la fase 2, el acuerdo entre las herramientas nuevas y las existentes fue regular a bueno para la detección de síntomas de incontinencia anal abordados como una pregunta compuesta (kappa entre 0,41 y 0,71). Se detectó incontinencia anal en 191 (53%) de las mujeres que utilizaban la nueva herramienta, y se notificó una prevalencia más baja utilizando la puntuación de Vaizey (n = 118) y la puntuación de Wexner (n = 129). Las tasas de finalización de la nueva herramienta fueron del 99%, más altas que la puntuación de Vaizey (33%) y las puntuaciones de Wexner (36%).LIMITACIONES:El tamaño de la muestra limita la generalización de los hallazgos.CONCLUSIONES:El cuestionario es confiable y válido reportando una alta incidencia de incontinencia intestinal, con síntomas predominantes de urgencia rectal y flatos como precursores del empeoramiento de la función. (Traducción-Dr. Ingrid Melo ).

Role of Mitochondrial Calcium and the Permeability Transition Pore in Regulating Cell Death.

Adult cardiomyocytes are postmitotic cells that undergo very limited cell division. Thus, cardiomyocyte death as occurs during myocardial infarction has very detrimental consequences for the heart. Mitochondria have emerged as an important regulator of cardiovascular health and disease. Mitochondria are well established as bioenergetic hubs for generating ATP but have also been shown to regulate cell death pathways. Indeed many of the same signals used to regulate metabolism and ATP production, such as calcium and reactive oxygen species, are also key regulators of mitochondrial cell death pathways. It is widely hypothesized that an increase in calcium and reactive oxygen species activate a large conductance channel in the inner mitochondrial membrane known as the PTP (permeability transition pore) and that opening of this pore leads to necroptosis, a regulated form of necrotic cell death. Strategies to reduce PTP opening either by inhibition of PTP or inhibiting the rise in mitochondrial calcium or reactive oxygen species that activate PTP have been proposed. A major limitation of inhibiting the PTP is the lack of knowledge about the identity of the protein(s) that form the PTP and how they are activated by calcium and reactive oxygen species. This review will critically evaluate the candidates for the pore-forming unit of the PTP and discuss recent data suggesting that assumption that the PTP is formed by a single molecular identity may need to be reconsidered.

Negative pressure wound therapy for surgical wounds healing by primary closure.

BACKGROUND: Indications for the use of negative pressure wound therapy (NPWT) are broad and include prophylaxis for surgical site infections (SSIs). Existing evidence for the effectiveness of NPWT on postoperative wounds healing by primary closure remains uncertain. OBJECTIVES: To assess the effects of NPWT for preventing SSI in wounds healing through primary closure, and to assess the cost-effectiveness of NPWT in wounds healing through primary closure. SEARCH METHODS: In January 2021, we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE (including In-Process & Other Non-Indexed Citations); Ovid Embase and EBSCO CINAHL Plus. We also searched clinical trials registries and references of included studies, systematic reviews and health technology reports. There were no restrictions on language, publication date or study setting. SELECTION CRITERIA: We included trials if they allocated participants to treatment randomly and compared NPWT with any other type of wound dressing, or compared one type of NPWT with another. DATA COLLECTION AND ANALYSIS: At least two review authors independently assessed trials using predetermined inclusion criteria. We carried out data extraction, assessment using the Cochrane risk of bias tool, and quality assessment according to Grading of Recommendations, Assessment, Development and Evaluations methodology. Our primary outcomes were SSI, mortality, and wound dehiscence. MAIN RESULTS: In this fourth update, we added 18 new randomised controlled trials (RCTs) and one new economic study, resulting in a total of 62 RCTs (13,340 included participants) and six economic studies. Studies evaluated NPWT in a wide range of surgeries, including orthopaedic, obstetric, vascular and general procedures. All studies compared NPWT with standard dressings. Most studies had unclear or high risk of bias for at least one key domain. Primary outcomes Eleven studies (6384 participants) which reported mortality were pooled. There is low-certainty evidence showing there may be a reduced risk of death after surgery for people treated with NPWT (0.84%) compared with standard dressings (1.17%) but there is uncertainty around this as confidence intervals include risk of benefits and harm; risk ratio (RR) 0.78 (95% CI 0.47 to 1.30; I2 = 0%). Fifty-four studies reported SSI; 44 studies (11,403 participants) were pooled. There is moderate-certainty evidence that NPWT probably results in fewer SSIs (8.7% of participants) than treatment with standard dressings (11.75%) after surgery; RR 0.73 (95% CI 0.63 to 0.85; I2 = 29%). Thirty studies reported wound dehiscence; 23 studies (8724 participants) were pooled. There is moderate-certainty evidence that there is probably little or no difference in dehiscence between people treated with NPWT (6.62%) and those treated with standard dressing (6.97%), although there is imprecision around the estimate that includes risk of benefit and harms; RR 0.97 (95% CI 0.82 to 1.16; I2 = 4%). Evidence was downgraded for imprecision, risk of bias, or a combination of these. Secondary outcomes There is low-certainty evidence for the outcomes of reoperation and seroma; in each case, confidence intervals included both benefit and harm. There may be a reduced risk of reoperation favouring the standard dressing arm, but this was imprecise: RR 1.13 (95% CI 0.91 to 1.41; I2 = 2%; 18 trials; 6272 participants). There may be a reduced risk of seroma for people treated with NPWT but this is imprecise: the RR was 0.82 (95% CI 0.65 to 1.05; I2 = 0%; 15 trials; 5436 participants). For skin blisters, there is low-certainty evidence that people treated with NPWT may be more likely to develop skin blisters compared with those treated with standard dressing (RR 3.55; 95% CI 1.43 to 8.77; I2 = 74%; 11 trials; 5015 participants). The effect of NPWT on haematoma is uncertain (RR 0.79; 95 % CI 0.48 to 1.30; I2 = 0%; 17 trials; 5909 participants; very low-certainty evidence). There is low-certainty evidence of little to no difference in reported pain between groups. Pain was measured in different ways and most studies could not be pooled; this GRADE assessment is based on all fourteen trials reporting pain; the pooled RR for the proportion of participants who experienced pain was 1.52 (95% CI 0.20, 11.31; I2 = 34%; two studies; 632 participants). Cost-effectiveness Six economic studies, based wholly or partially on trials in our review, assessed the cost-effectiveness of NPWT compared with standard care. They considered NPWT in five indications: caesarean sections in obese women; surgery for lower limb fracture; knee/hip arthroplasty; coronary artery bypass grafts; and vascular surgery with inguinal incisions. They calculated quality-adjusted life-years or an equivalent, and produced estimates of the treatments' relative cost-effectiveness. The reporting quality was good but the evidence certainty varied from moderate to very low. There is moderate-certainty evidence that NPWT in surgery for lower limb fracture was not cost-effective at any threshold of willingness-to-pay and that NPWT is probably cost-effective in obese women undergoing caesarean section. Other studies found low or very low-certainty evidence indicating that NPWT may be cost-effective for the indications assessed. AUTHORS' CONCLUSIONS: People with primary closure of their surgical wound and treated prophylactically with NPWT following surgery probably experience fewer SSIs  than people treated with standard dressings but there is probably no difference in wound dehiscence (moderate-certainty evidence). There may be a reduced risk of death after surgery for people treated with NPWT compared with standard dressings but there is uncertainty around this as confidence intervals include risk of benefit and harm (low-certainty evidence). People treated with NPWT may experience more instances of skin blistering compared with standard dressing treatment (low-certainty evidence). There are no clear differences in other secondary outcomes where most evidence is low or very low-certainty. Assessments of cost-effectiveness of NPWT produced differing results in different indications. There is a large number of ongoing studies, the results of which may change the findings of this review. Decisions about use of NPWT should take into account surgical indication and setting and consider evidence for all outcomes.

Boundary layer hydrodynamics of patchy biofilms.

Algal biofilms, ubiquitous in aquatic systems, reduce the performance of engineered systems and alter ecosystem processes. Biofilm morphology is dynamic throughout community development, with patchiness occurring due to periodic sloughing, but little is known about how community level physical structure affects hydrodynamics. This study uses high resolution particle image velocimetry (PIV) to examine spatially explicit turbulence over sparse, uniform and patchy biofilm at turbulent Reynolds numbers. All biofilms increase the near-bed turbulence production, Reynolds shear stress, and rotational flow compared to a smooth wall, and non-uniform biofilms have the greatest increase in these parameters, compared with a uniform or sparse biofilm. However, a higher drag coefficient over uniform biofilm compared with non-uniform biofilm indicates that percent coverage (the amount of area covered by the biofilm) is a useful predictor of a biofilm's relative effect on the total drag along surfaces, and in particular the effect on ship performance.

Mercury source changes and food web shifts alter contamination signatures of predatory fish from Lake Michigan.

To understand the impact reduced mercury (Hg) loading and invasive species have had on methylmercury bioaccumulation in predator fish of Lake Michigan, we reconstructed bioaccumulation trends from a fish archive (1978 to 2012). By measuring fish Hg stable isotope ratios, we related temporal changes in Hg concentrations to varying Hg sources. Additionally, dietary tracers were necessary to identify food web influences. Through combined Hg, C, and N stable isotopic analyses, we were able to differentiate between a shift in Hg sources to fish and periods when energetic transitions (from dreissenid mussels) led to the assimilation of contrasting Hg pools (2000 to present). In the late 1980s, lake trout δ202Hg increased (0.4‰) from regulatory reductions in regional Hg emissions. After 2000, C and N isotopes ratios revealed altered food web pathways, resulting in a benthic energetic shift and changes to Hg bioaccumulation. Continued increases in δ202Hg indicate fish are responding to several United States mercury emission mitigation strategies that were initiated circa 1990 and continued through the 2011 promulgation of the Mercury and Air Toxics Standards rule. Unlike archives of sediments, this fish archive tracks Hg sources susceptible to bioaccumulation in Great Lakes fisheries. Analysis reveals that trends in fish Hg concentrations can be substantially affected by shifts in trophic structure and dietary preferences initiated by invasive species in the Great Lakes. This does not diminish the benefits of declining emissions over this period, as fish Hg concentrations would have been higher without these actions.

Video-based communication assessment for weight management counseling training in medical residents: a mixed methods study.

BACKGROUND: Physician delivered weight management counseling (WMC) occurs infrequently and physicians report lack of training and poor self-efficacy. The purpose of this study was to develop and test the Video-based Communication Assessment (VCA) for weight management counseling (WMC) training in medical residents. METHODS: This study was a mixed methods pilot conducted in 3 phases. First, we created five vignettes based on our prior data and expert feedback, then administered the vignettes via the VCA to Internal Medicine categorical residents (n = 16) from a University Medical School. Analog patients rated responses and also provided comments. We created individualized feedback reports which residents were able to view on the VCA. Lastly, we conducted debriefing interviews with the residents (n = 11) to obtain their feedback on the vignettes and personalized feedback. Interviews were transcribed, and we used thematic analysis to generate and apply codes, followed by identifying themes. RESULTS: Descriptive statistics were calculated and learning points were created for the individualized feedback reports. In VCA debriefing interviews with residents, five themes emerged: 1) Overall the VCA was easy to use, helpful and more engaging than traditional learning and assessment modes, 2) Patient scenarios were similar to those encountered in the clinic, including diversity, health literacy and different stages of change, 3) The knowledge, skills, and reminders from the VCA can be transferred to practice, 4) Feedback reports were helpful, to the point and informative, including the exemplar response of how to best respond to the scenario, and 5) The VCA provide alternatives and practice scenarios to real-life patient situations when they aren't always accessible. CONCLUSIONS: We demonstrated the feasibility and acceptability of the VCA, a technology delivered platform, for delivering WMC to residents. The VCA exposed residents to diverse patient experiences and provided potential opportunities to tailor providers responses to sociological and cultural factors in WMC scenarios. Future work will examine the effect of the VCA on WMC in actual clinical practice.