A toolbox to engineer the highly productive cyanobacterium Synechococcus sp. PCC 11901.

Synechococcus sp. PCC 11901 (PCC 11901) is a fast-growing marine cyanobacterial strain that has a capacity for sustained biomass accumulation to very high cell densities, comparable to that achieved by commercially relevant heterotrophic organisms. However, genetic tools to engineer PCC 11901 for biotechnology applications are limited. Here we describe a suite of tools based on the CyanoGate MoClo system to unlock the engineering potential of PCC 11901. First, we characterised neutral sites suitable for stable genomic integration that do not affect growth even at high cell densities. Second, we tested a suite of constitutive promoters, terminators, and inducible promoters including a 2,4-diacetylphloroglucinol (DAPG)-inducible PhlF repressor system, which has not previously been demonstrated in cyanobacteria, and showed tight regulation and a 228-fold dynamic range of induction. Lastly, we developed a DAPG-inducible dCas9-based CRISPR interference (CRISPRi) system and a modular method to generate markerless mutants using CRISPR-Cas12a. Based on our findings, PCC 11901 is highly responsive to CRISPRi-based repression and showed high efficiencies for single insertion (31-81%) and multiplex double insertion (25%) genome editing with Cas12a. We envision that these tools will lay the foundations for the adoption of PCC 11901 as a robust model strain for engineering biology and green biotechnology.

Vascular adhesion protein-1 blockade in primary sclerosing cholangitis: Open-label, multicenter, single-arm, phase II trial.

BACKGROUND: Primary sclerosing cholangitis is a progressive inflammatory liver disease characterized by biliary and liver fibrosis. Vascular adhesion protein-1 (VAP-1) is important in the inflammatory process driving liver fibrosis. We evaluated the safety and efficacy of VAP-1 blockade with a monoclonal antibody (timolumab, BTT1023) in patients with primary sclerosing cholangitis. METHODS: BUTEO was a prospective, single-arm, open-label, multicenter, phase II trial, conducted in 6 centers in the United Kingdom. Patients with primary sclerosing cholangitis aged 18-75 years had an alkaline phosphatase value of >1.5 times the upper limit of normal. The dose-confirmatory stage aimed to confirm the safety of timolumab through the incidence of dose-limiting toxicity and sufficient trough levels of circulating antibody to block VAP-1 function. The primary outcome of the dose-expansion portion of the trial was patient's response to timolumab at day 99, as measured by a reduction in serum alkaline phosphatase by 25% or more from baseline to day 99. RESULTS: Twenty-three patients were recruited: 7 into the initial dose-confirmatory stage and a further 16 into an expansion stage. Timolumab (8 mg/kg) was confirmed to be safe for the duration of administration with sufficient circulating levels. Only 2 of the 18 evaluable patients (11.1%) achieved a reduction in alkaline phosphatase levels of 25% or more, and both the proportion of circulating inflammatory cell populations and biomarkers of fibrosis remained unchanged from baseline. CONCLUSIONS: The BUTEO trial confirmed 8 mg/kg timolumab had no short-term safety signals and resulted in sufficient circulating levels of VAP-1 blocking timolumab. However, the trial was stopped after an interim assessment due to a lack of efficacy as determined by no significant change in serum liver tests.

Free hemi-hamate arthroplasty: A review of donor site outcomes.

Introduction: The use of the dorsal hamate as a free osteochondral bone graft or vascularized bone flap has become the mainstay for large, comminuted middle phalanx volar lip fractures. To date, few studies have been conducted in the assessment of donor site morbidity for the hemi-hamate graft or flap, and none have discussed modes of repair or reconstruction of this donor site. Methods: A retrospective analysis of 14 hemi-hamate arthroplasty (HHA) procedures, including 6 vascularized and 8 non-vascularized grafts, from two surgeons was performed. Four hamate defect reconstruction techniques were utilized: no formal reconstruction, autologous bone grafting, gel foam, or synthetic bone substitute. The dorsal capsule was repaired with either extensor retinaculum grafting or by direct closure. Wrist range of motion, pain scores, and radiographic alignment were assessed. Results: At 6 months follow-up, all patients achieved full, pain-free wrist motion compared to the uninjured side, with visual analog scale pain scores of 0. Serial radiographs showed maintained carpal alignment without instability or subluxation. No differences based on the hamate defect reconstruction method or capsular repair technique was demonstrated. Conclusion: Safe return to pain free, unrestricted wrist function is achievable after HHA, regardless of hamate donor site management. Adequate dorsal capsular repair appears critical to prevent instability. Further study is needed to compare techniques, but choice may be guided by surgeon preference in the absence of clear evidence.

Chemical Conversions within the Mo-Ga-C System: Layered Solids with Variable Ga Content.

Layered carbides are fascinating compounds due to their enormous structural and chemical diversity, as well as their potential to possess useful and tunable functional properties. Their preparation, however, is challenging and forces synthesis scientists to develop creative and innovative strategies to access high-quality materials. One unique compound among carbides is Mo2Ga2C. Its structure is related to the large and steadily growing family of 211 MAX phases that crystallize in a hexagonal structure (space group P63/mmc) with alternating layers of edge-sharing M6X octahedra and layers of the A-element. Mo2Ga2C also crystallizes in the same space group, with the difference that the A-element layer is occupied by two A-elements, here Ga, that sit right on top of each other (hence named "221" compound). Here, we propose that the Ga content in this compound is variable between 2:2, 2:1, and 2: ≤1 (and 2:0) Mo/Ga ratios. We demonstrate that one Ga layer can be selectively removed from Mo2Ga2C without jeopardizing the hexagonal P63/mmc structure. This is realized by chemical treatment of the 221 phase Mo2Ga2C with a Lewis acid, leading to the "conventional" 211 MAX phase Mo2GaC. Upon further reaction with CuCl2, more Ga is removed and replaced with Cu (instead of fully exfoliating into the Ga-free Mo2CTx MXene), leading to Mo2Ga1-xCuxC still crystallizing with space group P63/mmc, however, with a significantly larger c-lattice parameter. Furthermore, 211 Mo2GaC can be reacted with Ga to recover the initial 221 Mo2Ga2C. All three reaction pathways have not been reported previously and are supported by powder X-ray diffraction (PXRD), electron microscopy, X-ray spectroscopy, and density functional theory (DFT) calculations.

Exploring Age-Related Variations in Carpal Bone Volume: Implications for Clinical Practice and Anatomical Understanding.

BACKGROUND: Clinically recognizing the changes in carpal bone volumes and understanding their implications in predicting osteoarthritis (OA) is crucial in clinical practice This study aimed to explore age-related differences in carpal bone volumes across genders, leveraging computed tomography (CT) wrist scans to create 3D surface models of these bones. METHODS: Carpal bone volumes were calculated using the 3D Slicer software from CT scans obtained from Frankston Hospital and additional datasets from Brown and Auckland Universities. The data were statistically processed using Stata V13. Double-sided P-values < .05 were considered statistically significant. The study was conducted in accordance with the ethical standards laid out in the Declaration of Helsinki. RESULTS: A total of 181 patients were analyzed, and 48% of whom were female. A statistically significant positive Spearman correlation (rho = 0.37-0.611, P <.05) was observed between increasing age and the volume of all surveyed carpal bones (scaphoid, lunate, triquetrum, pisiform, hamate, capitate, and trapezium) across genders. Intrauser and interuser reliabilities for 3D Slicer-generated volumes of trapezium and pisiform bones were statistically significant, with Interclass Correlation Coefficient (ICC) values of 0.86 and 0.95, respectively. CONCLUSION: Trapezial volumes increase with age, potentially due to the presence of OA and consequent osteophyte formation. This pattern is more prevalent among older individuals and women. However, the positive correlation between carpal bone volume and age was consistent across all carpal bones and both genders, regardless of OA presence. These findings suggest that carpal bone volume may naturally increase with age, independent of OA-related changes. LEVEL OF EVIDENCE: III, cohort study.

A unique subseafloor microbiosphere in the Mariana Trench driven by episodic sedimentation.

Hadal trenches are characterized by enhanced and infrequent high-rate episodic sedimentation events that likely introduce not only labile organic carbon and key nutrients but also new microbes that significantly alter the subseafloor microbiosphere. Currently, the role of high-rate episodic sedimentation in controlling the composition of the hadal subseafloor microbiosphere is unknown. Here, analyses of carbon isotope composition in a ~ 750 cm long sediment core from the Challenger Deep revealed noncontinuous deposition, with anomalous 14C ages likely caused by seismically driven mass transport and the funneling effect of trench geomorphology. Microbial community composition and diverse enzyme activities in the upper ~ 27 cm differed from those at lower depths, probably due to sudden sediment deposition and differences in redox condition and organic matter availability. At lower depths, microbial population numbers, and composition remained relatively constant, except at some discrete depths with altered enzyme activity and microbial phyla abundance, possibly due to additional sudden sedimentation events of different magnitude. Evidence is provided of a unique role for high-rate episodic sedimentation events in controlling the subsurface microbiosphere in Earth's deepest ocean floor and highlight the need to perform thorough analysis over a large depth range to characterize hadal benthic populations. Such depositional processes are likely crucial in shaping deep-water geochemical environments and thereby the deep subseafloor biosphere. Supplementary Information: The online version contains supplementary material available at 10.1007/s42995-023-00212-y.

Laser-assisted dacryocystorhinostomy of acquired dacryops in a dog.

OBJECTIVE: To describe a novel minimally invasive surgical approach to treatment of a nasolacrimal duct cyst in a dog and outcome. ANIMAL STUDIED: A 10-year-old, male entire, Springer Spaniel with a chronic right-sided maxillary swelling and associated right eye epiphora and sneezing. PROCEDURE: Computed tomography with dacryocystography confirmed a cystic structure and destruction of the right maxilla and zygomatic bone with invasion of the nasal cavity. Obstruction of the nasolacrimal duct was confirmed. Rhinoscopy was performed allowing visualization of the ventromedial wall of the cyst. Under direct visualization, dacryocystorhinostomy was performed and the wall of the cyst was ablated with the aid of a thulium laser fiber. RESULTS: No intraoperative complications occurred during the procedure. Full resolution of clinical signs was noted within 2 weeks of treatment. No recurrence had occurred on long-term follow-up at 32 months. CONCLUSIONS: Laser-assisted dacrocystorhinostomy under direct visualization was successful in the treatment and resolution of a nasolacrimal duct cyst (dacryops) in this case.

The provision of general surgery in rural Australia: a narrative review.

Rural surgery is most commonly provided by general surgeons to the 29% of people (7 million) living in rural Australia. The provision of rural general surgery to enable equitable and safe surgical care for rural Australians is a multifaceted issue concerning recruitment, training, retention, surgical procedures and surgical outcomes. Sustaining the rural general surgical workforce will be dependent upon growing an increased number of resident rural general surgeons, as well as changed models of care, with a need for ongoing review to track the outcomes of these changes. To increase recruitment, rural general surgical training must improve to be less stressful for trainees and to be incorporated alongside a rural-facing generalist curriculum. Rural general surgical outcomes (excluding some oncology conditions) achieve comparable results to metropolitan centres. Access to, and outcomes of, surgical oncology services continues to be inequitable for rural Australians and should be a major focus for improved service delivery.

Artificial Intelligence Language Model Performance for Rapid Intraoperative Queries in Plastic Surgery: ChatGPT and the Deep Inferior Epigastric Perforator Flap.

Background: The integration of artificial intelligence in healthcare has led to the development of large language models that can address various medical queries, including intraoperatively. This study investigates the potential of ChatGPT in addressing intraoperative questions during the deep inferior epigastric perforator flap procedure. Methods: A series of six intraoperative questions specific to the DIEP flap procedure, derived from real-world clinical scenarios, were proposed to ChatGPT. A panel of four experienced board-certified plastic surgeons evaluated ChatGPT's performance in providing accurate, relevant, and comprehensible responses. Results: The Likert scale demonstrated to be medically accurate, systematic in presentation, and logical when providing alternative solutions. The mean readability score of the Flesch Reading Ease Score was 28.7 (±0.8), the Flesch-Kincaid Grade Level was 12.4 (±0.5), and the Coleman-Liau Index was 14.5 (±0.5). Suitability-wise, the DISCERN score of ChatGPT was 48 (±2.5) indicating suitable and comprehensible language for experts. Conclusions: Generative AI tools such as ChatGPT can serve as a supplementary tool for surgeons to offer valuable insights and foster intraoperative problem-solving abilities. However, it lacks consideration of individual patient factors and surgical nuances. Nevertheless, further refinement of its training data and rigorous scrutiny under experts to ensure the accuracy and up-to-date nature of the information holds the potential for it to be utilized in the surgical field.

Comparison of large language models in management advice for melanoma: Google's AI BARD, BingAI and ChatGPT.

Large language models (LLMs) are emerging artificial intelligence (AI) technology refining research and healthcare. Their use in medicine has seen numerous recent applications. One area where LLMs have shown particular promise is in the provision of medical information and guidance to practitioners. This study aims to assess three prominent LLMs-Google's AI BARD, BingAI and ChatGPT-4 in providing management advice for melanoma by comparing their responses to current clinical guidelines and existing literature. Five questions on melanoma pathology were prompted to three LLMs. A panel of three experienced Board-certified plastic surgeons evaluated the responses for reliability using reliability matrix (Flesch Reading Ease Score, the Flesch-Kincaid Grade Level and the Coleman-Liau Index), suitability (modified DISCERN score) and comparing them to existing guidelines. t-Test was performed to calculate differences in mean readability and reliability scores between LLMs and p value <0.05 was considered statistically significant. The mean readability scores across three LLMs were same. ChatGPT exhibited superiority with a Flesch Reading Ease Score of 35.42 (±21.02), Flesch-Kincaid Grade Level of 11.98 (±4.49) and Coleman-Liau Index of 12.00 (±5.10), however all of these were insignificant (p > 0.05). Suitability-wise using DISCERN score, ChatGPT 58 (±6.44) significantly (p = 0.04) outperformed BARD 36.2 (±34.06) and was insignificant to BingAI's 49.8 (±22.28). This study demonstrates that ChatGPT marginally outperforms BARD and BingAI in providing reliable, evidence-based clinical advice, but they still face limitations in depth and specificity. Future research should improve LLM performance by integrating specialized databases and expert knowledge to support patient-centred care.

CyanoCyc cyanobacterial web portal.

CyanoCyc is a web portal that integrates an exceptionally rich database collection of information about cyanobacterial genomes with an extensive suite of bioinformatics tools. It was developed to address the needs of the cyanobacterial research and biotechnology communities. The 277 annotated cyanobacterial genomes currently in CyanoCyc are supplemented with computational inferences including predicted metabolic pathways, operons, protein complexes, and orthologs; and with data imported from external databases, such as protein features and Gene Ontology (GO) terms imported from UniProt. Five of the genome databases have undergone manual curation with input from more than a dozen cyanobacteria experts to correct errors and integrate information from more than 1,765 published articles. CyanoCyc has bioinformatics tools that encompass genome, metabolic pathway and regulatory informatics; omics data analysis; and comparative analyses, including visualizations of multiple genomes aligned at orthologous genes, and comparisons of metabolic networks for multiple organisms. CyanoCyc is a high-quality, reliable knowledgebase that accelerates scientists' work by enabling users to quickly find accurate information using its powerful set of search tools, to understand gene function through expert mini-reviews with citations, to acquire information quickly using its interactive visualization tools, and to inform better decision-making for fundamental and applied research.

Comparison of immunoassay and LC-tandem mass spectrometry analyses of ractopamine in hog oral fluid.

The accurate detection of ractopamine in food animals is crucial for marketing since some entities require animals or animal carcasses to be free of ractopamine residues. Field-based ractopamine screening tests that are rapid, sensitive, and capable of high-throughput are highly desirable to ensure that inadvertent exposure to ractopamine did not occur in animals marketed as animals that have not been fed ractopamine. An immunochemically based lateral flow assay was used to analyze oral fluids from hogs never exposed to ractopamine and from hogs that were presumed positives and results were confirmed using an enhanced sensitivity LC-MSMS method. We found that an immunochemically based lateral flow system having a working range of 2.5 to 15 ng mL-1 worked well as a screening assay with 1.7% false positive results in freshly collected hog oral fluids. Using ractopamine glucuronide standards and LC-MSMS, we determined that the false positive results were not due to the presence of ractopamine glucuronide metabolites in oral fluids.

Autologous Fat Grafting in Breast Augmentation: A Systematic Review Highlighting the Need for Clinical Caution.

BACKGROUND: Autologous fat grafting (AFG) is a breast augmentation method for treating volume and contour abnormalities. This systematic review aims to summarize complications, radiologic safety, volume retention, and patient satisfaction associated with AFG. METHODS: The PubMed, Embase, Google Scholar, Cochrane Central Register of Controlled Trials, Wiley library, clinical key/Elsevier, and EBSCO databases were searched for relevant studies from January of 2009 to March of 2022. Articles describing AFG for breast augmentation were selected based on predetermined inclusion and exclusion criteria. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were adhered to, and the study was registered on the International Prospective Register of Systematic Reviews. The Risk of Bias in Nonrandomized Studies of Interventions assessment was used to assess the quality of studies and the risk of bias was measured using the Cochrane Risk of Bias Assessment Tool for Nonrandomized Studies of Interventions. RESULTS: A total of 35 studies comprising 3757 women were included. The average follow-up duration was 24.5 months (range, 1 to 372 months). The overall complication rate was 27.8%, with fat necrosis making up 43.7% of all complications. Average fat volume injected was 300 mL (range, 134 to 610 mL), and average volume retention was 58% (range, 44% to 83%). Volume retention was greater with supplementation of fat with platelet-rich plasma and stromal vascular fraction. The most common radiologic changes were fat necrosis (9.4%) and calcification (1.2%). After 1 year of follow-up, patient satisfaction was, on average, 92% (range, 83.2% to 97.5%). The included studies were of good quality and consisted of a moderate risk of bias. CONCLUSIONS: AFG was associated with an overall complication rate of 27.8%. Additional supplementation of fat with platelet-rich plasma and stromal vascular fraction may improve graft survival. Despite poor volume retention being a persistent drawback, patient satisfaction remains high.

Investigating the impact of innovative AI chatbot on post-pandemic medical education and clinical assistance: a comprehensive analysis.

BACKGROUND: The COVID-19 pandemic has significantly disrupted clinical experience and exposure of medical students and junior doctors. Artificial Intelligence (AI) integration in medical education has the potential to enhance learning and improve patient care. This study aimed to evaluate the effectiveness of three popular large language models (LLMs) in serving as clinical decision-making support tools for junior doctors. METHODS: A series of increasingly complex clinical scenarios were presented to ChatGPT, Google's Bard and Bing's AI. Their responses were evaluated against standard guidelines, and for reliability by the Flesch Reading Ease Score, Flesch-Kincaid Grade Level, the Coleman-Liau Index, and the modified DISCERN score for assessing suitability. Lastly, the LLMs outputs were assessed by using the Likert scale for accuracy, informativeness, and accessibility by three experienced specialists. RESULTS: In terms of readability and reliability, ChatGPT stood out among the three LLMs, recording the highest scores in Flesch Reading Ease (31.2 ± 3.5), Flesch-Kincaid Grade Level (13.5 ± 0.7), Coleman-Lau Index (13) and DISCERN (62 ± 4.4). These results suggest statistically significant superior comprehensibility and alignment with clinical guidelines in the medical advice given by ChatGPT. Bard followed closely behind, with BingAI trailing in all categories. The only non-significant statistical differences (P > 0.05) were found between ChatGPT and Bard's readability indices, and between the Flesch Reading Ease scores of ChatGPT/Bard and BingAI. CONCLUSION: This study demonstrates the potential utility of LLMs in fostering self-directed and personalized learning, as well as bolstering clinical decision-making support for junior doctors. However further development is needed for its integration into education.

Thermal Challenges in Dynamic Infrared Thermography Used for Perforator Mapping.

BACKGROUND: The aim of this study is to investigate the different approaches to thermal challenges, both cold and warm, used in dynamic infrared thermography for reconstructive surgery, and explore whether it affects the success of preoperative perforator mapping. METHODS: Literature was collected from Ovid Medline, Embase, PubMed, and Cochrane. The references of the full-text articles located from the original search were also appraised. Thirteen articles were extracted for the final qualitative analysis. A systematic review was then conducted following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. RESULTS: Thirteen articles looked at a cold challenge, which included airflow cooling, direct contact cooling, and evaporation-based cooling. Two articles investigated warm challenges. One paper used no challenge, suggesting it unnecessary with a highly sensitive camera. All cold challenges were positively supported by a high level of flap perfusion success and/or a high level of correlation with other forms of investigation. CONCLUSION: Cold challenges were overall superior to no challenge and warm challenges; however, this conclusion is limited by the small participant size, the possibility of detection bias, and poor methodology detailing. Airflow cooling-specifically, using a desktop fan to blow air for 2 minutes-was noted to likely cause the least discomfort due to a low cooling capacity yet simultaneously maintain effectiveness and allow for a uniform cooling application. Warm challenges showed less conclusive results and were restricted by lack of studies. This topic would benefit from larger scale studies that compare multiple approaches while using standardized equipment to eliminate confounding factors.

C-TYPE LECTIN-2D RECEPTOR CONTRIBUTES TO HISTONE-INDUCED VASCULAR BARRIER DYSFUNCTION DURING BURN INJURY.

ABSTRACT: Severe burns are associated with massive tissue destruction and cell death where nucleus histones and other damage-associated molecular patterns are released into the circulation and contribute to the pathogenesis of multiple-organ dysfunction. Currently, there is limited information regarding the pathophysiology of extracellular histones after burns, and the mechanisms underlying histone-induced vascular injury are not fully understood. In this study, by comparing the blood samples from healthy donors and burn patients, we confirmed that burn injury promoted the release of extracellular histones into the circulation, evidenced by increased plasma levels of histones correlating with injury severity. The direct effects of extracellular histones on human endothelial monolayers were examined, and the results showed that histones caused cell-cell adherens junction discontinuity and barrier dysfunction in a dose-related manner. Like burn patients, mice subjected to a scald burn covering 25% total body surface area also displayed significantly increased plasma histones. Intravital microscopic analysis of mouse mesenteric microcirculation indicated that treatment with a histone antibody greatly attenuated burn-induced plasma leakage in postcapillary venules, supporting the pathogenic role of extracellular histones in the development of microvascular barrier dysfunction during burns. At the molecular level, intrigued by the recent discovery of C-type lectin domain family 2 member D (Clec2d) as a novel receptor of histones, we tested its potential involvement in the histone interaction with endothelial cells. Indeed, we identified abundant expression of Clec2d in vascular endothelial cells. Further proximity ligation assay demonstrated a close association between extracellular histones and endothelial expressing Clec2d. Functionally, in vivo administration of an anti-Clec2d antibody attenuated burn-induced plasma leakage across mesenteric microvessels. Consistently, Clec2d knockdown in endothelial cells partially inhibited histone-induced endothelial barrier dysfunction. Together, our data suggest that burn injury-induced increases in circulating histones contribute to microvascular leakage and endothelial barrier dysfunction via a mechanism involving the endothelial Clec2d receptor.

Synthesis and spectroscopic characterization of 13 C4 -labeled 4-cyano-2-oxobutyraldehyde semicarbazone: A metabolite of nitrofurazone.

Nitrofurazone usage in food-producing animals is prohibited in most countries, including the United States. Regulatory agencies regularly monitor its use in domestic, export/import animals' food products by measuring the semicarbazide (SEM) metabolite as a biomarker of nitrofurazone exposure. However, the use of SEM is controversial because it is also produced in food naturally and thus gives false positive results. A cyano-metabolite, 4-cyano-2-oxobutyraldehyde semicarbazone (COBS), is proposed as an alternate specific marker of nitrofurazone to distinguish nitrofurazone from treated or untreated animals. A synthetic method was developed to produce COBS via metallic hydrogenation of nitrofurazone. The product was isolated and characterized by one- and two-dimensional nuclear magnetic spectroscopy (NMR) experiments, Fourier-transform infrared spectroscopy (FT-IR), and mass spectrometry. The developed synthetic procedure was further extended to synthesize isotopically labeled 4-[13 C]-cyano-2-oxo- [2, 3, 4-13 C3 ]-butyraldehyde semicarbazone. Labeled COBS is useful as an internal standard for its quantification in food-producing animals. Thus, the developed method provides a possibility for its commercial synthesis to procure COBS. This is the first synthesis of the alternate specific marker metabolite of nitrofurazone for possible usage in regulatory analysis to solve a real-world problem.