Accurate de novo design of membrane-traversing macrocycles.

We use computational design coupled with experimental characterization to systematically investigate the design principles for macrocycle membrane permeability and oral bioavailability. We designed 184 6-12 residue macrocycles with a wide range of predicted structures containing noncanonical backbone modifications and experimentally determined structures of 35; 29 are very close to the computational models. With such control, we show that membrane permeability can be systematically achieved by ensuring all amide (NH) groups are engaged in internal hydrogen bonding interactions. 84 designs over the 6-12 residue size range cross membranes with an apparent permeability greater than 1 × 10-6 cm/s. Designs with exposed NH groups can be made membrane permeable through the design of an alternative isoenergetic fully hydrogen-bonded state favored in the lipid membrane. The ability to robustly design membrane-permeable and orally bioavailable peptides with high structural accuracy should contribute to the next generation of designed macrocycle therapeutics.

The population genetics of the causative agent of snake fungal disease indicate recent introductions to the USA.

Snake fungal disease (SFD; ophidiomycosis), caused by the pathogen Ophidiomyces ophiodiicola (Oo), has been documented in wild snakes in North America and Eurasia, and is considered an emerging disease in the eastern United States of America. However, a lack of historical disease data has made it challenging to determine whether Oo is a recent arrival to the USA or whether SFD emergence is due to other factors. Here, we examined the genomes of 82 Oo strains to determine the pathogen's history in the eastern USA. Oo strains from the USA formed a clade (Clade II) distinct from European strains (Clade I), and molecular dating indicated that these clades diverged too recently (approximately 2,000 years ago) for transcontinental dispersal of Oo to have occurred via natural snake movements across Beringia. A lack of nonrecombinant intermediates between clonal lineages in Clade II indicates that Oo has actually been introduced multiple times to North America from an unsampled source population, and molecular dating indicates that several of these introductions occurred within the last few hundred years. Molecular dating also indicated that the most common Clade II clonal lineages have expanded recently in the USA, with time of most recent common ancestor mean estimates ranging from 1985 to 2007 CE. The presence of Clade II in captive snakes worldwide demonstrates a potential mechanism of introduction and highlights that additional incursions are likely unless action is taken to reduce the risk of pathogen translocation and spillover into wild snake populations.

Long-Lived Charge Separation in Single Crystals of an Electron Donor Covalently Linked to Four Acceptor Molecules.

Crystalline donor-acceptor (D-A) systems serve as an excellent platform for studying CT exciton creation, migration, and dissociation into free charge carriers for solar energy conversion. Donor-acceptor cocrystals have been utilized to develop an understanding of CT exciton formation in ordered organic solids; however, the strong electronic coupling of the D and A units can sometimes limit charge separation lifetimes due to their close proximity. Covalent D-A systems that preorganize specific donor-acceptor structures can assist in engineering crystal morphologies that promote long-lived charge separation to overcome this limitation. Here we investigate photogenerated CT exciton formation in a single crystal of a 2,5,8,11-tetraphenylperylene (PerPh4) donor to which four identical naphthalene-(1,4:5,8)-bis(dicarboximide) (NDI) electron acceptors are covalently attached at the para positions of the PerPh4 phenyl groups to yield PerPh4-NDI4. X-ray crystallography shows that the four NDIs pack pairwise into two distinct motifs. Two NDI acceptors of one PerPh4-NDI4 are positioned over the PerPh4 donors of adjacent PerPh4-NDI4 molecules with the donor and acceptor π-systems having a large dihedral angle between them, while the other two NDIs of PerPh4-NDI4 form xylene-NDI van der Waals π-stacks with the corresponding NDIs in adjacent PerPh4-NDI4 molecules. Upon selective photoexcitation of PerPh4 in the single crystal, CT exciton formation occurs in <300 fs yielding electron-hole pairs that live for more than ∼16 µs. This demonstrates the effectiveness of covalently linked D-A systems for engineering single crystal structures that promote efficient and long-lived charge separation for solar energy conversion.

Oriented Triplet Excitons as Long-Lived Electron Spin Qutrits in a Molecular Donor-Acceptor Single Cocrystal.

The photogeneration of multiple unpaired electron spins within molecules is a promising route to applications in quantum information science because they can be initialized into well-defined, multilevel quantum states (S > 1/2) and reproducibly fabricated by chemical synthesis. However, coherent manipulation of these spin states is difficult to realize in typical molecular systems due to the lack of selective addressability and short coherence times of the spin transitions. Here, these challenges are addressed by using donor-acceptor single cocrystals composed of pyrene and naphthalene dianhydride to host spatially oriented triplet excitons, which exhibit promising photogenerated qutrit properties. Time-resolved electron paramagnetic resonance (TREPR) spectroscopy demonstrates that spatially orienting triplet excitons in a single crystal platform imparts narrow, well-resolved, tunable resonances in the triplet EPR spectrum, allowing selective addressability of the spin sublevel transitions. Pulse-EPR spectroscopy reveals that at temperatures above 30 K, spin decoherence of these triplet excitons is driven by exciton diffusion. However, coherence is limited by electronic spin dipolar coupling below 30 K, where T2 varies nonlinearly with the optical excitation density due to exciton annihilation. Overall, an optimized coherence time of T2 = 7.1 µs at 20 K is achieved. These results provide important insights into designing solid-state molecular excitonic materials with improved spin qutrit properties.

End of life decision making when home mechanical ventilation is used to sustain breathing in Motor Neurone Disease: patient and family perspectives.

BACKGROUND: Motor Neurone Disease (MND) leads to muscle weakening, affecting movement, speech, and breathing. Home mechanical ventilation, particularly non-invasive ventilation (NIV), is used to alleviate symptoms and support breathing in people living with MND. While home mechanical ventilation can alleviate symptoms and improve survival, it does not slow the progression of MND. This study addresses gaps in understanding end-of-life decision-making in those dependent on home mechanical ventilation, considering the perspectives of patients, family members, and bereaved families. METHODS: A UK-wide qualitative study using flexible interviews to explore the experiences of people living with MND (n = 16), their family members (n = 10), and bereaved family members (n = 36) about the use of home mechanical ventilation at the end of life. RESULTS: Some participants expressed a reluctance to discuss end-of-life decisions, often framed as a desire to "live for the day" due to the considerable uncertainty faced by those with MND. Participants who avoided end-of-life discussions often engaged in 'selective decision-making' related to personal planning, involving practical and emotional preparations. Many faced challenges in hypothesising about future decisions given the unpredictability of the disease, opting to make 'timely decisions' as and when needed. For those who became dependent on ventilation and did not want to discuss end of life, decisions were often 'defaulted' to others, especially once capacity was lost. 'Proactive decisions', including advance care planning and withdrawal of treatment, were found to empower some patients, providing a sense of control over the timing of their death. A significant proportion lacked a clear understanding of the dying process and available options. CONCLUSIONS: The study highlights the complexity and evolution of decision-making, often influenced by the dynamic and uncertain nature of MND. The study emphasises the need for a nuanced understanding of decision-making in the context of MND.

A Tag-Free Platform for Synthesis and Screening of Cyclic Peptide Libraries.

In the realm of high-throughput screening (HTS), macrocyclic peptide libraries traditionally necessitate decoding tags, essential for both library synthesis and identifying hit peptide sequences post-screening. Our innovation introduces a tag-free technology platform for synthesizing cyclic peptide libraries in solution and facilitates screening against biological targets to identify peptide binders through unconventional intramolecular CyClick and DeClick chemistries (CCDC) discovered through our research. This combination allows for the synthesis of diverse cyclic peptide libraries, the incorporation of various amino acids, and facile linearization and decoding of cyclic peptide binder sequences. Our sensitivity-enhancing derivatization method, utilized in tandem with nano LC-MS/MS, enables the sequencing of peptides even at exceedingly low picomolar concentrations. Employing our technology platform, we have successfully unearthed novel cyclic peptide binders against a monoclonal antibody and the first cyclic peptide binder of HIV capsid protein responsible for viral infections as validated by microscale thermal shift assays (TSA), biolayer interferometry (BLI) and functional assays.

A global community-sourced assessment of the state of conservation technology.

Conservation technology holds the potential to vastly increase conservationists' ability to understand and address critical environmental challenges, but systemic constraints appear to hamper its development and adoption. Understanding of these constraints and opportunities for advancement remains limited. We conducted a global online survey of 248 conservation technology users and developers to identify perceptions of existing tools' current performance and potential impact, user and developer constraints, and key opportunities for growth. We also conducted focus groups with 45 leading experts to triangulate findings. The technologies with the highest perceived potential were machine learning and computer vision, eDNA and genomics, and networked sensors. A total of 95%, 94%, and 92% respondents, respectively, rated them as very helpful or game changers. The most pressing challenges affecting the field as a whole were competition for limited funding, duplication of efforts, and inadequate capacity building. A total of 76%, 67%, and 55% respondents, respectively, identified these as primary concerns. The key opportunities for growth identified in focus groups were increasing collaboration and information sharing, improving the interoperability of tools, and enhancing capacity for data analyses at scale. Some constraints appeared to disproportionately affect marginalized groups. Respondents in countries with developing economies were more likely to report being constrained by upfront costs, maintenance costs, and development funding (p = 0.048, odds ratio [OR] = 2.78; p = 0.005, OR = 4.23; p = 0.024, OR = 4.26), and female respondents were more likely to report being constrained by development funding and perceived technical skills (p = 0.027, OR = 3.98; p = 0.048, OR = 2.33). To our knowledge, this is the first attempt to formally capture the perspectives and needs of the global conservation technology community, providing foundational data that can serve as a benchmark to measure progress. We see tremendous potential for this community to further the vision they define, in which collaboration trumps competition; solutions are open, accessible, and interoperable; and user-friendly processing tools empower the rapid translation of data into conservation action. Article impact statement: Addressing financing, coordination, and capacity-building constraints is critical to the development and adoption of conservation technology.

La tecnología de conservación tiene el potencial para incrementar considerablemente la habilidad de los conservacionistas para entender y lidiar con los retos ambientales más importantes, pero las restricciones sistémicas parecen dificultar su desarrollo y adopción. La comprensión de estas restricciones y las oportunidades para el avance todavía son limitadas. Encuestamos en línea a 248 usuarios y programadores mundiales de tecnología de conservación para identificar las percepciones existentes del desempeño e impacto potencial de las herramientas actuales, restricciones para los usuarios y programadores y oportunidades clave para el crecimiento. También realizamos grupos de discusión con 45 expertos destacados para triangular los hallazgos. Las tecnologías con el potencial percibido más alto fueron el aprendizaje mecánico y la visión por computadora, la genómica y el eADN y los sensores en red. El 95%, 94% y 92% de los respondientes, respectivamente, clasificó estas tecnologías como muy útiles o como puntos de inflexión. Los retos más apremiantes que afectaron al área como conjunto fueron la competencia por el financiamiento limitado, la duplicación de esfuerzos y el desarrollo inadecuado de capacidades. El 76%, 67% y 55% de los respondientes, respectivamente, identificaron estos retos como de interés primario. Las oportunidades clave para el crecimiento que se identificaron en los grupos de diálogo fueron el incremento de la colaboración y la distribución de información, la mejoría de la operatividad entre herramientas y la potenciación de la capacidad de análisis de datos a escala. Algunas restricciones parecieron afectar desproporcionadamente a grupos marginalizados. Los respondientes de países con economías en desarrollo tuvieron mayor probabilidad de reportar la restricción por los costos iniciales, costos de mantenimiento y la financiación del desarrollo (p = 0.048, tasa de probabilidad [OR] = 2.78; p = 0.005, OR = 4.23; p = 0.024, OR = 4.26), y las mujeres respondientes tuvieron una mayor probabilidad de reportar restricciones por la financiación del desarrollo y habilidades técnicas percibidas (p = 0.027, OR = 3.98; p = 0.048, OR = 2.33). A nuestro entendimiento, este es el primero intento por capturar formalmente las perspectivas y necesidades de la comunidad mundial de la tecnología de conservación, proporcionando datos fundamentales que pueden servir como referencia para medir el progreso. Vemos un potencial tremendo para que esta comunidad amplíe la visión que definen, en la cual la colaboración se sobrepone a la competencia; las soluciones son abierta, accesibles e interoperativas; y las herramientas intuitivas de procesamiento capacitan la traducción veloz de datos a acciones de conservación.

Predator preferences shape the diets of arthropodivorous bats more than quantitative local prey abundance.

Although most predators are generalists, the majority of studies on the association between prey availability and prey consumption have focused on specialist predators. To investigate the role of highly generalist predators in a complex food web, we measured the relationships between prey consumption and prey availability in two common arthropodivorous bats. Specifically, we used high-throughput amplicon sequencing coupled with a known mock community to characterize seasonal changes in little brown and big brown bat diets. We then linked spatiotemporal variation in prey consumption with quantitative prey availability estimated from intensive prey community sampling. We found that although quantitative prey availability fluctuated substantially over space and time, the most commonly consumed prey items were consistently detected in bat diets independently of their respective abundance. Positive relationships between prey abundance and probability of consumption were found only among prey groups that were less frequently detected in bat diets. While the probability of prey consumption was largely unrelated to abundance, the community structure of prey detected in bat diets was influenced by the local or regional abundance of prey. Observed patterns suggest that while little brown and big brown bats maintain preferences for particular prey independently of quantitative prey availability, total dietary composition may reflect some degree of opportunistic foraging. Overall, our findings suggest that generalist predators can display strong prey preferences that persist despite quantitative changes in prey availability.

Understanding the influence of geometric and electronic structure on the excited state dynamical and photoredox properties of perinone chromophores.

In this work, a series of eight similarly structured perinone chromophores were synthesized and photophysically characterized to elucidate the electronic and structural tunability of their excited state properties, including excited state redox potentials and fluorescence lifetimes/quantum yields. Despite their similar structure, these chromophores exhibited a broad range of visible absorption properties, quantum yields, and excited state lifetimes. In conjunction with static and time-resolved spectroscopies from the ultrafast to nanosecond time regimes, time-dependent computational modeling was used to correlate this behavior to the relationship between non-radiative decay and the energy-gap law. Additionally, the ground and excited state redox potentials were calculated and found to be tunable over a range of 1 V depending on the diamine or anhydride used in their synthesis (Ered* = 0.45-1.55 V; Eox* = -0.88 to -1.67 V), which is difficult to achieve with typical photoredox-active transition metal complexes. These diverse chromophores can be easily prepared, and with their range of photophysical tunability, will be valuable for future use in photofunctional applications.

The sexual spore pigment asperthecin is required for normal ascospore production and protection from UV light in Aspergillus nidulans.

Many fungi develop both asexual and sexual spores that serve as propagules for dissemination and/or recombination of genetic traits. Asexual spores are often heavily pigmented and this pigmentation provides protection from UV light. However, little is known about any purpose pigmentation that may serve for sexual spores. The model Ascomycete Aspergillus nidulans produces both green pigmented asexual spores (conidia) and red pigmented sexual spores (ascospores). Here we find that the previously characterized red pigment, asperthecin, is the A. nidulans ascospore pigment. The asperthecin biosynthetic gene cluster is composed of three genes: aptA, aptB, and aptC, where deletion of either aptA (encoding a polyketide synthase) or aptB (encoding a thioesterase) yields small, mishappen hyaline ascospores; while deletion of aptC (encoding a monooxygenase) yields morphologically normal but purple ascospores. ∆aptA and ∆aptB but not ∆aptC or wild type ascospores are extremely sensitive to UV light. We find that two historical ascospore color mutants, clA6 and clB1, possess mutations in aptA and aptB sequences, respectively.

Noise Evaluation of Arthroplasty Theaters: Results From the NEAT Study.

AIMS: The aim of this study was to define the levels of noise exposure for the surgeon, assistant, scrub nurse, and anesthetist during total hip and knee arthroplasty surgery. In addition, we sought to determine whether the noise exposure during these procedures reaches or exceeds the action values set out by the U.K. Noise at Work Regulations (2005). MATERIALS AND METHODS: Individual noise exposure during arthroplasty hip and knee surgery was recorded using a personal noise Dosemeter System model 22 (DM22) (Pulsar instruments, Filey, U.K.). Recordings were taken in real-time during five separate theater sessions. Each theater session included two arthroplasty procedures and lasted approximately 4 hrs. Personal noise exposure was expressed in terms of peak sound pressure and an average noise exposure over an 8-hour time-period to reflect the noise experienced by the ear over a working day. RESULTS: In all three sessions involving total hip replacement surgery, the peak sound pressure, for the operating surgeon exceeded the exposure action values set out by the U.K. Noise at Work Regulations. Theater sessions involving total knee replacement surgery did not exceed any exposure action values for LCPeak or LEPd. CONCLUSION: Arthroplasty surgery is a working environment with significant noise exposure. We recommend any surgeon or theater member who is concerned about the noise generated in their theater to have noise levels formally assessed using appropriately positioned recording devices.

Drivers of genetic diversity in secondary metabolic gene clusters within a fungal species.

Filamentous fungi produce a diverse array of secondary metabolites (SMs) critical for defense, virulence, and communication. The metabolic pathways that produce SMs are found in contiguous gene clusters in fungal genomes, an atypical arrangement for metabolic pathways in other eukaryotes. Comparative studies of filamentous fungal species have shown that SM gene clusters are often either highly divergent or uniquely present in one or a handful of species, hampering efforts to determine the genetic basis and evolutionary drivers of SM gene cluster divergence. Here, we examined SM variation in 66 cosmopolitan strains of a single species, the opportunistic human pathogen Aspergillus fumigatus. Investigation of genome-wide within-species variation revealed 5 general types of variation in SM gene clusters: nonfunctional gene polymorphisms; gene gain and loss polymorphisms; whole cluster gain and loss polymorphisms; allelic polymorphisms, in which different alleles corresponded to distinct, nonhomologous clusters; and location polymorphisms, in which a cluster was found to differ in its genomic location across strains. These polymorphisms affect the function of representative A. fumigatus SM gene clusters, such as those involved in the production of gliotoxin, fumigaclavine, and helvolic acid as well as the function of clusters with undefined products. In addition to enabling the identification of polymorphisms, the detection of which requires extensive genome-wide synteny conservation (e.g., mobile gene clusters and nonhomologous cluster alleles), our approach also implicated multiple underlying genetic drivers, including point mutations, recombination, and genomic deletion and insertion events as well as horizontal gene transfer from distant fungi. Finally, most of the variants that we uncover within A. fumigatus have been previously hypothesized to contribute to SM gene cluster diversity across entire fungal classes and phyla. We suggest that the drivers of genetic diversity operating within a fungal species shown here are sufficient to explain SM cluster macroevolutionary patterns.

Energy Migration Processes in Re(I) MLCT Complexes Featuring a Chromophoric Ancillary Ligand.

We present the synthesis, structural characterization, electronic structure calculations, and ultrafast and supra-nanosecond photophysical properties of a series of five Re(I) bichromophores exhibiting metal to ligand charge transfer (MLCT) excited states based on the general formula fac-[Re(N∧N)(CO)3(PNI-py)]PF6, where PNI-py is 4-piperidinyl-1,8-naphthalimidepyridine and N∧N is a diimine ligand (Re1-5), along with their corresponding model chromophores where 4-ethylpyridine was substituted for PNI-py (Mod1-5). The diimine ligands used include 1,10-phenanthroline (phen, 1), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (bcp, 2), 4,4'-di-tert-butyl-2,2'-bipyridine (dtbb, 3), 4,4'-diethyl ester-2,2'-bipyridine (deeb, 4), and 2,2'-biquinoline (biq, 5). In these metal-organic bichromophores, structural modification of the diimine ligand resulted in substantial changes to the observed energy transfer efficiencies between the two chromophores as a result of the variation in 3MLCT excited-state energies. The photophysical properties and energetic pathways of the model chromophores were investigated in parallel to accurately track the changes that arose from introduction of the organic chromophore pendant on the ancillary ligand. All relevant photophysical and energy transfer processes were probed and characterized using time-resolved photoluminescence spectroscopy, ultrafast and nanosecond transient absorption spectroscopy, and time-dependent density functional theory calculations. Of the five bichromophores in this study, four (Re1-4) exhibited a thermal equilibrium between the 3PNI-py and the 3MLCT excited state, drastically extending the lifetimes of the parent model chromophores.

Varus alignment of the proximal tibia is associated with structural progression in early to moderate varus osteoarthritis of the knee.

PURPOSE: Lower limb malalignment is a strong predictor of progression in knee osteoarthritis. The purpose of this study is to identify the individual alignment variables that predict progression in early to moderate osteoarthritis of the knee. METHOD: A longitudinal cohort study using data from the Osteoarthritis Initiative. In total, 955 individuals (1329 knees) with early to moderate osteoarthritis (Kellgren-Lawrence grade 1, 2 or 3) were identified. All subjects had full-limb radiographs analysed using the Osteotomy module within Medicad® Classic (Hectec GMBH) to give a series of individual alignment variables relevant to the coronal alignment of the lower limb. Logistic regression models, with generalised estimating equations were used to identify which of these individual alignment variables predict symptom worsening (WOMAC score > 9 points) and or structural progression (joint space narrowing progression in the medial compartment > 0.7mm) over 24 months. RESULTS: Individual alignment variable were associated with both valgus and varus alignment (mechanical Lateral Distal Femoral Angle, Medial Proximal Tibial Angle and mechanical Lateral Distal Tibial Angle). Only the Medial Proximal Tibial Angle was significantly associated with structural progression and none of the variables was associated with symptom progression. The odds of joint space narrowing progression in the medial compartment occurring at 24 months increased by 21% for every one degree decrease (more varus) in Medial Proximal Tibial Angle (p < 0.001) CONCLUSIONS: Our results suggest that the risk of structural progression in the medial compartment is associated with greater varus alignment of the proximal tibia. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Relationships among wood-boring beetles, fungi, and the decomposition of forest biomass.

A prevailing paradigm in forest ecology is that wood-boring beetles facilitate wood decay and carbon cycling, but empirical tests have yielded mixed results. We experimentally determined the effects of wood borers on fungal community assembly and wood decay within pine trunks in the southeastern United States. Pine trunks were made either beetle-accessible or inaccessible. Fungal communities were compared using culturing and high-throughput amplicon sequencing (HTAS) of DNA and RNA. Prior to beetle infestation, living pines had diverse fungal endophyte communities. Endophytes were displaced by beetle-associated fungi in beetle-accessible trees, whereas some endophytes persisted as saprotrophs in beetle-excluded trees. Beetles increased fungal diversity several fold. Over forty taxa of Ascomycota were significantly associated with beetles, but beetles were not consistently associated with any known wood-decaying fungi. Instead, increasing ambrosia beetle infestations caused reduced decay, consistent with previous in vitro experiments that showed beetle-associated fungi reduce decay rates by competing with decay fungi. No effect of bark-inhabiting beetles on decay was detected. Platypodines carried significantly more fungal taxa than scolytines. Molecular results were validated by synthetic and biological mock communities and were consistent across methodologies. RNA sequencing confirmed that beetle-associated fungi were biologically active in the wood. Metabarcode sequencing of the LSU/28S marker recovered important fungal symbionts that were missed by ITS2, though community-level effects were similar between markers. In contrast to the current paradigm, our results indicate ambrosia beetles introduce diverse fungal communities that do not extensively decay wood, but instead reduce decay rates by competing with wood decay fungi.

A scalable platform to identify fungal secondary metabolites and their gene clusters.

The genomes of filamentous fungi contain up to 90 biosynthetic gene clusters (BGCs) encoding diverse secondary metabolites-an enormous reservoir of untapped chemical potential. However, the recalcitrant genetics, cryptic expression, and unculturability of these fungi prevent scientists from systematically exploiting these gene clusters and harvesting their products. As heterologous expression of fungal BGCs is largely limited to the expression of single or partial clusters, we established a scalable process for the expression of large numbers of full-length gene clusters, called FAC-MS. Using fungal artificial chromosomes (FACs) and metabolomic scoring (MS), we screened 56 secondary metabolite BGCs from diverse fungal species for expression in Aspergillus nidulans. We discovered 15 new metabolites and assigned them with confidence to their BGCs. Using the FAC-MS platform, we extensively characterized a new macrolactone, valactamide A, and its hybrid nonribosomal peptide synthetase-polyketide synthase (NRPS-PKS). The ability to regularize access to fungal secondary metabolites at an unprecedented scale stands to revitalize drug discovery platforms with renewable sources of natural products.

Surgical interventions for symptomatic mild to moderate knee osteoarthritis.

BACKGROUND: Osteoarthritis affecting the knee is common and represents a continuum of disease from early cartilage thinning to full-thickness cartilage loss, bony erosion, and deformity. Many studies do not stratify their results based on the severity of the disease at baseline or recruitment. OBJECTIVES: To assess the benefits and harms of surgical intervention for the management of symptomatic mild to moderate knee osteoarthritis defined as knee pain and radiographic evidence of non-end stage osteoarthritis (Kellgren-Lawrence grade 1, 2, 3 or equivalent on MRI/arthroscopy). Outcomes of interest included pain, function, radiographic progression, quality of life, short-term serious adverse events, re-operation rates and withdrawals due to adverse events. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase up to May 2018. We also conducted searches of ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform for ongoing trials. Authors of trials were contacted if some but not all their participants appeared to fit our inclusion criteria. SELECTION CRITERIA: We included randomised controlled trials that compared surgery to non-surgical interventions (including sham and placebo control groups, exercise or physiotherapy, and analgesic or other medication), injectable therapies, and trials that compared one type of surgical intervention to another surgical intervention in people with symptomatic mild to moderate knee osteoarthritis. DATA COLLECTION AND ANALYSIS: Two review authors independently selected trials and extracted data using standardised forms. We analysed the quality of evidence using the GRADE (Grades of Recommendation, Assessment, Development and Evaluation) approach. MAIN RESULTS: A total of five studies involving 566 participants were identified as eligible for this review. Single studies compared arthroscopic partial meniscectomy to physical therapy (320 participants), arthroscopic surgery (debridement ± synovectomy ± chondroplasty) to closed needle joint lavage with saline (32 participants) and high tibial osteotomy surgery to knee joint distraction surgery (62 participants). Two studies (152 participants) compared arthroscopic surgery (washout ± debridement; debridement) to a hyaluronic acid injection. Only one study was at low risk of selection bias, and due to the difficulty of blinding participants to their treatment, all studies were at risk of performance and detection bias.Reporting of results in this summary has been restricted to the primary comparison: surgical intervention versus non-surgical intervention.A single study, included 320 participants with symptoms consistent with meniscal tear. All subjects had the meniscal tear confirmed on knee MRI and radiographic evidence of mild to moderate osteoarthritis (osteophytes, cartilage defect or joint space narrowing). Patients with severe osteoarthritis (KL grade 4) were excluded. The study compared arthroscopic partial meniscectomy and physical therapy to physical therapy alone (a six-week individualised progressive home exercise program). This study was at low risk of selection bias and outcome reporting biases, but was susceptible to performance and detection biases. A high rate of cross-over (30.2%) occurred from the physical therapy group to the arthroscopic group.Low-quality evidence suggests there may be little difference in pain and function at 12 months follow-up in people who have arthroscopic partial meniscectomy and those who have physical therapy. Evidence was downgraded to low quality due to risk of bias and imprecision.Mean pain was 19.3 points on a 0 to 100 point KOOS pain scale with physical therapy at 12 months follow-up and was 0.2 points better with surgery (95% confidence interval (CI) 4.05 better to 3.65 points worse with surgery, an absolute improvement of 0.2% (95% CI 4% better to 4% worse) and relative improvement 0.4% (95% CI 9% better to 8% worse) (low quality evidence). Mean function was 14.5 on a 0 to 100 point KOOS function scale with physical therapy at 12 months follow-up and 0.8 points better with surgery (95% CI 4.3 better to 2.7 worse); 0.8% absolute improvement (95% CI 4% better to 3% worse) and 2.1% relative improvement (95% CI 11% better to 7% worse) (low quality evidence).Radiographic structural osteoarthritis progression and quality of life outcomes were not reported.Due to very low quality evidence, we are uncertain if surgery is associated with an increased risk of serious adverse events, incidence of total knee replacement or withdrawal rates. Evidence was downgraded twice due to very low event rates, and once for risk of bias.At 12 months, the surgery group had a total of three serious adverse events including fatal pulmonary embolism, myocardial infarction and hypoxaemia. The physical therapy alone group had two serious adverse events including sudden death and stroke (Peto OR 1.58, 95% CI 0.27 to 9.21); 1% more events with surgery (95% CI 2% less to 3% more) and 58% relative change (95% CI 73% less to 821% more). One participant in each group withdrew due to adverse events.Two of 164 participants (1.2%) in the physical therapy group and three of 156 in the surgery group underwent conversion to total knee replacement within 12 months (Peto OR 1.76, 95% CI 0.43 to 7.13); 1% more events with surgery (95% CI 2% less to 5% more); 76% relative change (95% CI 57% less to 613% more). AUTHORS' CONCLUSIONS: The review found no placebo-or sham-controlled trials of surgery in participants with symptomatic mild to moderate knee osteoarthritis. There was low quality evidence that there may be no evidence of a difference between arthroscopic partial meniscectomy surgery and a home exercise program for the treatment of this condition. Similarly, low-quality evidence from a few small trials indicates there may not be any benefit of arthroscopic surgery over other non-surgical treatments including saline irrigation and hyaluronic acid injection, or one type of surgery over another. We are uncertain of the risk of adverse events or of progressing to total knee replacement due to very small event rates. Thus, there is uncertainty around the current evidence to support or oppose the use of surgery in mild to moderate knee osteoarthritis. As no benefit has been demonstrated from the low quality trials included in this review, it is possible that future higher quality trials for these surgical interventions may not contradict these results.

Tracheostomy in motor neurone disease.

Tracheostomy-associated ventilation for the respiratory insufficiency caused by amyotrophic lateral sclerosis (motor neurone disease (MND)) is a complex issue with practical, ethical and economic dimensions. This article considers the current prevalence of tracheostomy in MND, the evidence for its benefit both for survival and quality of life, and the practicalities of its implementation. The decision to request invasive ventilatory support is among the most challenging for those living with MND. Neurologists should be prepared to discuss this option openly and objectively: we suggest a framework for discussion, including withdrawal of therapy.

An innovative warming strategy to increase patient satisfaction.

Thermal comfort helps patients maintain normothermia, decreases preoperative anxiety, and increases their sense of well-being. This article details an initiative to improve surgical patient satisfaction with thermal comfort using reflective blankets at a 115-bed major medical center and Level III trauma center in the Southwest US.

Selenate sensitivity of a laeA mutant is restored by overexpression of the bZIP protein MetR in Aspergillus fumigatus.

LaeA is a conserved global regulator of secondary metabolism and development in filamentous fungi. Examination of Aspergillus fumigatus transcriptome data of laeA deletion mutants have been fruitful in identifying genes and molecules contributing to the laeA mutant phenotype. One of the genes significantly down regulated in A. fumigatus ΔlaeA is metR, encoding a bZIP DNA binding protein required for sulfur and methionine metabolism in fungi. LaeA and MetR deletion mutants exhibit several similarities including down regulation of sulfur assimilation and methionine metabolism genes and ability to grow on the toxic sulfur analog, sodium selenate. However, unlike ΔmetR, ΔlaeA strains are able to grow on sulfur, sulfite, and cysteine. To examine if any parameter of the ΔlaeA phenotype is due to decreased metR expression, an over-expression allele (OE::metR) was placed in a ΔlaeA background. The OE::metR allele could not significantly restore expression of MetR regulated genes in ΔlaeA but did restore sensitivity to sodium selenate. In A. nidulans a second bZIP protein, MetZ, also regulates sulfur and methionine metabolism genes. However, addition of an OE::metZ construct to the A. fumigatus ΔlaeA OE::metR strain still was unable to rescue the ΔlaeA phenotype to wildtype with regards gliotoxin synthesis and virulence in a zebrafish aspergillosis model.