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1.
Nature ; 630(8016): 493-500, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38718835

ABSTRACT

The introduction of AlphaFold 21 has spurred a revolution in modelling the structure of proteins and their interactions, enabling a huge range of applications in protein modelling and design2-6. Here we describe our AlphaFold 3 model with a substantially updated diffusion-based architecture that is capable of predicting the joint structure of complexes including proteins, nucleic acids, small molecules, ions and modified residues. The new AlphaFold model demonstrates substantially improved accuracy over many previous specialized tools: far greater accuracy for protein-ligand interactions compared with state-of-the-art docking tools, much higher accuracy for protein-nucleic acid interactions compared with nucleic-acid-specific predictors and substantially higher antibody-antigen prediction accuracy compared with AlphaFold-Multimer v.2.37,8. Together, these results show that high-accuracy modelling across biomolecular space is possible within a single unified deep-learning framework.


Subject(s)
Deep Learning , Ligands , Models, Molecular , Proteins , Software , Humans , Antibodies/chemistry , Antibodies/metabolism , Antigens/metabolism , Antigens/chemistry , Deep Learning/standards , Ions/chemistry , Ions/metabolism , Molecular Docking Simulation , Nucleic Acids/chemistry , Nucleic Acids/metabolism , Protein Binding , Protein Conformation , Proteins/chemistry , Proteins/metabolism , Reproducibility of Results , Software/standards
2.
Nature ; 596(7873): 583-589, 2021 08.
Article in English | MEDLINE | ID: mdl-34265844

ABSTRACT

Proteins are essential to life, and understanding their structure can facilitate a mechanistic understanding of their function. Through an enormous experimental effort1-4, the structures of around 100,000 unique proteins have been determined5, but this represents a small fraction of the billions of known protein sequences6,7. Structural coverage is bottlenecked by the months to years of painstaking effort required to determine a single protein structure. Accurate computational approaches are needed to address this gap and to enable large-scale structural bioinformatics. Predicting the three-dimensional structure that a protein will adopt based solely on its amino acid sequence-the structure prediction component of the 'protein folding problem'8-has been an important open research problem for more than 50 years9. Despite recent progress10-14, existing methods fall far short of atomic accuracy, especially when no homologous structure is available. Here we provide the first computational method that can regularly predict protein structures with atomic accuracy even in cases in which no similar structure is known. We validated an entirely redesigned version of our neural network-based model, AlphaFold, in the challenging 14th Critical Assessment of protein Structure Prediction (CASP14)15, demonstrating accuracy competitive with experimental structures in a majority of cases and greatly outperforming other methods. Underpinning the latest version of AlphaFold is a novel machine learning approach that incorporates physical and biological knowledge about protein structure, leveraging multi-sequence alignments, into the design of the deep learning algorithm.


Subject(s)
Neural Networks, Computer , Protein Conformation , Protein Folding , Proteins/chemistry , Amino Acid Sequence , Computational Biology/methods , Computational Biology/standards , Databases, Protein , Deep Learning/standards , Models, Molecular , Reproducibility of Results , Sequence Alignment
3.
Nature ; 596(7873): 590-596, 2021 08.
Article in English | MEDLINE | ID: mdl-34293799

ABSTRACT

Protein structures can provide invaluable information, both for reasoning about biological processes and for enabling interventions such as structure-based drug development or targeted mutagenesis. After decades of effort, 17% of the total residues in human protein sequences are covered by an experimentally determined structure1. Here we markedly expand the structural coverage of the proteome by applying the state-of-the-art machine learning method, AlphaFold2, at a scale that covers almost the entire human proteome (98.5% of human proteins). The resulting dataset covers 58% of residues with a confident prediction, of which a subset (36% of all residues) have very high confidence. We introduce several metrics developed by building on the AlphaFold model and use them to interpret the dataset, identifying strong multi-domain predictions as well as regions that are likely to be disordered. Finally, we provide some case studies to illustrate how high-quality predictions could be used to generate biological hypotheses. We are making our predictions freely available to the community and anticipate that routine large-scale and high-accuracy structure prediction will become an important tool that will allow new questions to be addressed from a structural perspective.


Subject(s)
Computational Biology/standards , Deep Learning/standards , Models, Molecular , Protein Conformation , Proteome/chemistry , Datasets as Topic/standards , Diacylglycerol O-Acyltransferase/chemistry , Glucose-6-Phosphatase/chemistry , Humans , Membrane Proteins/chemistry , Protein Folding , Reproducibility of Results
4.
Nature ; 577(7792): 706-710, 2020 01.
Article in English | MEDLINE | ID: mdl-31942072

ABSTRACT

Protein structure prediction can be used to determine the three-dimensional shape of a protein from its amino acid sequence1. This problem is of fundamental importance as the structure of a protein largely determines its function2; however, protein structures can be difficult to determine experimentally. Considerable progress has recently been made by leveraging genetic information. It is possible to infer which amino acid residues are in contact by analysing covariation in homologous sequences, which aids in the prediction of protein structures3. Here we show that we can train a neural network to make accurate predictions of the distances between pairs of residues, which convey more information about the structure than contact predictions. Using this information, we construct a potential of mean force4 that can accurately describe the shape of a protein. We find that the resulting potential can be optimized by a simple gradient descent algorithm to generate structures without complex sampling procedures. The resulting system, named AlphaFold, achieves high accuracy, even for sequences with fewer homologous sequences. In the recent Critical Assessment of Protein Structure Prediction5 (CASP13)-a blind assessment of the state of the field-AlphaFold created high-accuracy structures (with template modelling (TM) scores6 of 0.7 or higher) for 24 out of 43 free modelling domains, whereas the next best method, which used sampling and contact information, achieved such accuracy for only 14 out of 43 domains. AlphaFold represents a considerable advance in protein-structure prediction. We expect this increased accuracy to enable insights into the function and malfunction of proteins, especially in cases for which no structures for homologous proteins have been experimentally determined7.


Subject(s)
Deep Learning , Models, Molecular , Protein Conformation , Proteins/chemistry , Software , Amino Acid Sequence , Caspases/chemistry , Caspases/genetics , Datasets as Topic , Protein Folding , Proteins/genetics
5.
N Engl J Med ; 387(15): 1351-1360, 2022 10 13.
Article in English | MEDLINE | ID: mdl-36027563

ABSTRACT

BACKGROUND: Whether revascularization by percutaneous coronary intervention (PCI) can improve event-free survival and left ventricular function in patients with severe ischemic left ventricular systolic dysfunction, as compared with optimal medical therapy (i.e., individually adjusted pharmacologic and device therapy for heart failure) alone, is unknown. METHODS: We randomly assigned patients with a left ventricular ejection fraction of 35% or less, extensive coronary artery disease amenable to PCI, and demonstrable myocardial viability to a strategy of either PCI plus optimal medical therapy (PCI group) or optimal medical therapy alone (optimal-medical-therapy group). The primary composite outcome was death from any cause or hospitalization for heart failure. Major secondary outcomes were left ventricular ejection fraction at 6 and 12 months and quality-of-life scores. RESULTS: A total of 700 patients underwent randomization - 347 were assigned to the PCI group and 353 to the optimal-medical-therapy group. Over a median of 41 months, a primary-outcome event occurred in 129 patients (37.2%) in the PCI group and in 134 patients (38.0%) in the optimal-medical-therapy group (hazard ratio, 0.99; 95% confidence interval [CI], 0.78 to 1.27; P = 0.96). The left ventricular ejection fraction was similar in the two groups at 6 months (mean difference, -1.6 percentage points; 95% CI, -3.7 to 0.5) and at 12 months (mean difference, 0.9 percentage points; 95% CI, -1.7 to 3.4). Quality-of-life scores at 6 and 12 months appeared to favor the PCI group, but the difference had diminished at 24 months. CONCLUSIONS: Among patients with severe ischemic left ventricular systolic dysfunction who received optimal medical therapy, revascularization by PCI did not result in a lower incidence of death from any cause or hospitalization for heart failure. (Funded by the National Institute for Health and Care Research Health Technology Assessment Program; REVIVED-BCIS2 ClinicalTrials.gov number, NCT01920048.).


Subject(s)
Coronary Artery Disease , Heart Failure , Percutaneous Coronary Intervention , Ventricular Dysfunction, Left , Humans , Heart Failure/etiology , Heart Failure/therapy , Stroke Volume , Treatment Outcome , Ventricular Dysfunction, Left/drug therapy , Ventricular Dysfunction, Left/etiology , Ventricular Dysfunction, Left/mortality , Ventricular Dysfunction, Left/surgery , Ventricular Function, Left , Coronary Artery Disease/complications , Coronary Artery Disease/drug therapy , Coronary Artery Disease/mortality , Coronary Artery Disease/surgery , Cardiovascular Agents/therapeutic use , Myocardial Ischemia/drug therapy , Myocardial Ischemia/etiology , Myocardial Ischemia/mortality , Myocardial Ischemia/surgery
6.
Circulation ; 148(11): 862-871, 2023 09 12.
Article in English | MEDLINE | ID: mdl-37555345

ABSTRACT

BACKGROUND: Ventricular arrhythmia is an important cause of mortality in patients with ischemic left ventricular dysfunction. Revascularization with coronary artery bypass graft or percutaneous coronary intervention is often recommended for these patients before implantation of a cardiac defibrillator because it is assumed that this may reduce the incidence of fatal and potentially fatal ventricular arrhythmias, although this premise has not been evaluated in a randomized trial to date. METHODS: Patients with severe left ventricular dysfunction, extensive coronary disease, and viable myocardium were randomly assigned to receive either percutaneous coronary intervention (PCI) plus optimal medical and device therapy (OMT) or OMT alone. The composite primary outcome was all-cause death or aborted sudden death (defined as an appropriate implantable cardioverter defibrillator therapy or a resuscitated cardiac arrest) at a minimum of 24 months, analyzed as time to first event on an intention-to-treat basis. Secondary outcomes included cardiovascular death or aborted sudden death, appropriate implantable cardioverter defibrillator (ICD) therapy or sustained ventricular arrhythmia, and number of appropriate ICD therapies. RESULTS: Between August 28, 2013, and March 19, 2020, 700 patients were enrolled across 40 centers in the United Kingdom. A total of 347 patients were assigned to the PCI+OMT group and 353 to the OMT alone group. The mean age of participants was 69 years; 88% were male; 56% had hypertension; 41% had diabetes; and 53% had a clinical history of myocardial infarction. The median left ventricular ejection fraction was 28%; 53.1% had an implantable defibrillator inserted before randomization or during follow-up. All-cause death or aborted sudden death occurred in 144 patients (41.6%) in the PCI group and 142 patients (40.2%) in the OMT group (hazard ratio, 1.03 [95% CI, 0.82-1.30]; P=0.80). There was no between-group difference in the occurrence of any of the secondary outcomes. CONCLUSIONS: PCI was not associated with a reduction in all-cause mortality or aborted sudden death. In patients with ischemic cardiomyopathy, PCI is not beneficial solely for the purpose of reducing potentially fatal ventricular arrhythmias. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT01920048.


Subject(s)
Defibrillators, Implantable , Ventricular Dysfunction, Left , Humans , Male , Aged , Female , Stroke Volume , Death, Sudden, Cardiac/epidemiology , Death, Sudden, Cardiac/etiology , Death, Sudden, Cardiac/prevention & control , Ventricular Function, Left , Arrhythmias, Cardiac/etiology , Ventricular Dysfunction, Left/etiology , Defibrillators, Implantable/adverse effects , Treatment Outcome
7.
Ann Surg ; 2024 Sep 02.
Article in English | MEDLINE | ID: mdl-39219545

ABSTRACT

OBJECTIVE: The aim of this study was to quantify LNM risk and outcomes following treatment of early esophago-gastric (EG) adenocarcinoma. BACKGROUND: The standard of care for early T1N0 EG cancer is endoscopic resection (ER). Radical surgical resection is recommended for patients perceived to be at risk of lymph node metastasis (LNM). Current models to select organ-preserving vs. surgical treatment are inconsistent. METHODS: CONGRESS is a UK-based multicentre retrospective cohort study. Patients diagnosed with clinical or pathological T1N0 EG adenocarcinoma from 2015-2022 were included. Outcomes and rates of LNM were assessed. Cox regression was performed to assess the impact of prognostic and treatment factors on overall survival. RESULTS: 1,601 patients from 26 centres were included, with median follow-up 32 months(IQR 14-53). 1285/1612(80.3%) underwent ER, 497/1601(31.0%) underwent surgery. Overall rate of LNM was 13.5%. On ER staging, tumour depth (T1bsm2-3 17.6% vs. T1a 7.1%), lymphovascular invasion (17.2% vs. 12.6%), or signet cells (28.6% vs. 13.0%) were associated with LNM. In multivariable regression analysis, these were not significantly associated with LNM rates or survival. Adjusting for demographic and tumour variables, surgery after ER was associated with significant survival benefit, HR 0.33(0.15-0.77),P=0.010. CONCLUSION: This large multicentre dataset suggests that early EG adenocarcinoma is associated with significant risk of LNM. This data is representative of current real clinical practice with ER-based staging, and suggests previously held beliefs regarding reliability of predictive factors for LNM may need to be reconsidered. Further research to identify patients who may benefit from organ-preserving vs. surgical treatment is urgently required.

8.
Ann Surg ; 280(4): 650-658, 2024 Oct 01.
Article in English | MEDLINE | ID: mdl-38904105

ABSTRACT

OBJECTIVE: To evaluate prognostic differences between minimally invasive esophagectomy (MIE) and open esophagectomy (OE) in patients with surgery after a prolonged interval (>12 wk) following chemoradiotherapy (CRT). BACKGROUND: Previously, we established that a prolonged interval after CRT before esophagectomy was associated with poorer long-term survival. METHODS: This was an international multicenter cohort study involving 17 tertiary centers, including patients who received CRT followed by surgery between 2010 and 2020. Patients undergoing MIE were defined as thoracoscopic and laparoscopic approaches. RESULTS: A total of 428 patients (145 MIE and 283 OE) had surgery between 12 weeks and 2 years after CRT. Significant differences were observed in American Society of Anesthesiologists grade, radiation dose, clinical T stage, and histologic subtype. There were no significant differences between the groups in age, sex, body mass index, pathologic T or N stage, resection margin status, tumor location, surgical technique, or 90-day mortality. Survival analysis showed MIE was associated with improved survival in univariate ( P =0.014), multivariate analysis after adjustment for smoking, T and N stage, and histology (HR=1.69; 95% CI: 1.14-2.5) and propensity-matched analysis ( P =0.02). Further subgroup analyses by radiation dose and interval after CRT showed survival advantage for MIE in 40 to 50 Gy dose groups (HR=1.9; 95% CI: 1.2-3.0) and in patients having surgery within 6 months of CRT (HR=1.6; 95% CI: 1.1-2.2). CONCLUSIONS: MIE was associated with improved overall survival compared with OE in patients with a prolonged interval from CRT to surgery. The mechanism for this observed improvement in survival remains unknown, with potential hypotheses including a reduction in complications and improved functional recovery after MIE.


Subject(s)
Chemoradiotherapy , Esophageal Neoplasms , Esophagectomy , Humans , Esophagectomy/methods , Male , Female , Esophageal Neoplasms/therapy , Esophageal Neoplasms/mortality , Esophageal Neoplasms/pathology , Middle Aged , Prognosis , Chemoradiotherapy/methods , Aged , Survival Rate , Time Factors , Minimally Invasive Surgical Procedures , Retrospective Studies , Thoracoscopy/methods
9.
Lancet ; 402(10410): 1329-1337, 2023 Oct 14.
Article in English | MEDLINE | ID: mdl-37647928

ABSTRACT

BACKGROUND: The International Liaison Committee on Resuscitation has called for a randomised trial of delivery to a cardiac arrest centre. We aimed to assess whether expedited delivery to a cardiac arrest centre compared with current standard of care following resuscitated cardiac arrest reduces deaths. METHODS: ARREST is a prospective, parallel, multicentre, open-label, randomised superiority trial. Patients (aged ≥18 years) with return of spontaneous circulation following out-of-hospital cardiac arrest without ST elevation were randomly assigned (1:1) at the scene of their cardiac arrest by London Ambulance Service staff using a secure online randomisation system to expedited delivery to the cardiac catheter laboratory at one of seven cardiac arrest centres or standard of care with delivery to the geographically closest emergency department at one of 32 hospitals in London, UK. Masking of the ambulance staff who delivered the interventions and those reporting treatment outcomes in hospital was not possible. The primary outcome was all-cause mortality at 30 days, analysed in the intention-to-treat (ITT) population excluding those with unknown mortality status. Safety outcomes were analysed in the ITT population. The trial was prospectively registered with the International Standard Randomised Controlled Trials Registry, 96585404. FINDINGS: Between Jan 15, 2018, and Dec 1, 2022, 862 patients were enrolled, of whom 431 (50%) were randomly assigned to a cardiac arrest centre and 431 (50%) to standard care. 20 participants withdrew from the cardiac arrest centre group and 19 from the standard care group, due to lack of consent or unknown mortality status, leaving 411 participants in the cardiac arrest centre group and 412 in the standard care group for the primary analysis. Of 822 participants for whom data were available, 560 (68%) were male and 262 (32%) were female. The primary endpoint of 30-day mortality occurred in 258 (63%) of 411 participants in the cardiac arrest centre group and in 258 (63%) of 412 in the standard care group (unadjusted risk ratio for survival 1·00, 95% CI 0·90-1·11; p=0·96). Eight (2%) of 414 patients in the cardiac arrest centre group and three (1%) of 413 in the standard care group had serious adverse events, none of which were deemed related to the trial intervention. INTERPRETATION: In adult patients without ST elevation, transfer to a cardiac arrest centre following resuscitated cardiac arrest in the community did not reduce deaths. FUNDING: British Heart Foundation.


Subject(s)
Out-of-Hospital Cardiac Arrest , ST Elevation Myocardial Infarction , Adult , Humans , Male , Female , Adolescent , Out-of-Hospital Cardiac Arrest/therapy , Prospective Studies , Treatment Outcome , London/epidemiology , Randomized Controlled Trials as Topic
10.
Gastroenterology ; 165(6): 1420-1429.e10, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37597631

ABSTRACT

BACKGROUND & AIMS: Tools that can automatically predict incident esophageal adenocarcinoma (EAC) and gastric cardia adenocarcinoma (GCA) using electronic health records to guide screening decisions are needed. METHODS: The Veterans Health Administration (VHA) Corporate Data Warehouse was accessed to identify Veterans with 1 or more encounters between 2005 and 2018. Patients diagnosed with EAC (n = 8430) or GCA (n = 2965) were identified in the VHA Central Cancer Registry and compared with 10,256,887 controls. Predictors included demographic characteristics, prescriptions, laboratory results, and diagnoses between 1 and 5 years before the index date. The Kettles Esophageal and Cardia Adenocarcinoma predictioN (K-ECAN) tool was developed and internally validated using simple random sampling imputation and extreme gradient boosting, a machine learning method. Training was performed in 50% of the data, preliminary validation in 25% of the data, and final testing in 25% of the data. RESULTS: K-ECAN was well-calibrated and had better discrimination (area under the receiver operating characteristic curve [AuROC], 0.77) than previously validated models, such as the Nord-Trøndelag Health Study (AuROC, 0.68) and Kunzmann model (AuROC, 0.64), or published guidelines. Using only data from between 3 and 5 years before index diminished its accuracy slightly (AuROC, 0.75). Undersampling men to simulate a non-VHA population, AUCs of the Nord-Trøndelag Health Study and Kunzmann model improved, but K-ECAN was still the most accurate (AuROC, 0.85). Although gastroesophageal reflux disease was strongly associated with EAC, it contributed only a small proportion of gain in information for prediction. CONCLUSIONS: K-ECAN is a novel, internally validated tool predicting incident EAC and GCA using electronic health records data. Further work is needed to validate K-ECAN outside VHA and to assess how best to implement it within electronic health records.


Subject(s)
Adenocarcinoma , Esophageal Neoplasms , Stomach Neoplasms , Male , Humans , Cardia/pathology , Electronic Health Records , Esophageal Neoplasms/diagnosis , Esophageal Neoplasms/epidemiology , Esophageal Neoplasms/pathology , Adenocarcinoma/diagnosis , Adenocarcinoma/epidemiology , Adenocarcinoma/pathology , Esophagus , Stomach Neoplasms/diagnosis , Stomach Neoplasms/epidemiology , Stomach Neoplasms/pathology , Machine Learning
11.
Clin Proteomics ; 21(1): 1, 2024 Jan 03.
Article in English | MEDLINE | ID: mdl-38172678

ABSTRACT

BACKGROUND: Ovarian cancer is the most lethal gynecologic malignancy in women, and high-grade serous ovarian cancer (HGSOC) is the most common subtype. Currently, no clinical test has been approved by the FDA to screen the general population for ovarian cancer. This underscores the critical need for the development of a robust methodology combined with novel technology to detect diagnostic biomarkers for HGSOC in the sera of women. Targeted mass spectrometry (MS) can be used to identify and quantify specific peptides/proteins in complex biological samples with high accuracy, sensitivity, and reproducibility. In this study, we sought to develop and conduct analytical validation of a multiplexed Tier 2 targeted MS parallel reaction monitoring (PRM) assay for the relative quantification of 23 putative ovarian cancer protein biomarkers in sera. METHODS: To develop a PRM method for our target peptides in sera, we followed nationally recognized consensus guidelines for validating fit-for-purpose Tier 2 targeted MS assays. The endogenous target peptide concentrations were calculated using the calibration curves in serum for each target peptide. Receiver operating characteristic (ROC) curves were analyzed to evaluate the diagnostic performance of the biomarker candidates. RESULTS: We describe an effort to develop and analytically validate a multiplexed Tier 2 targeted PRM MS assay to quantify candidate ovarian cancer protein biomarkers in sera. Among the 64 peptides corresponding to 23 proteins in our PRM assay, 24 peptides corresponding to 16 proteins passed the assay validation acceptability criteria. A total of 6 of these peptides from insulin-like growth factor-binding protein 2 (IBP2), sex hormone-binding globulin (SHBG), and TIMP metalloproteinase inhibitor 1 (TIMP1) were quantified in sera from a cohort of 69 patients with early-stage HGSOC, late-stage HGSOC, benign ovarian conditions, and healthy (non-cancer) controls. Confirming the results from previously published studies using orthogonal analytical approaches, IBP2 was identified as a diagnostic biomarker candidate based on its significantly increased abundance in the late-stage HGSOC patient sera compared to the healthy controls and patients with benign ovarian conditions. CONCLUSIONS: A multiplexed targeted PRM MS assay was applied to detect candidate diagnostic biomarkers in HGSOC sera. To evaluate the clinical utility of the IBP2 PRM assay for HGSOC detection, further studies need to be performed using a larger patient cohort.

12.
Chemistry ; 30(49): e202401728, 2024 Sep 02.
Article in English | MEDLINE | ID: mdl-38888459

ABSTRACT

Transitioning towards a circular economy, extensive research has focused on dynamic covalent bonds (DCBs) to pave the way for more sustainable materials. These bonds enable debonding and rebonding on demand, as well as facilitating end-of-life recycling. Acylhydrazone/hydrazone chemistry offers a material with high stability under neutral and basic conditions making it a promising candidate for materials research, though the material is susceptible to acid degradation. However, this degradation under acidic conditions can be exploited, making it widely applicable in self-healing and biomedical fields, with potential for reprocessing and recycling. This review highlights studies exploring the reversibility of acylhydrazone/hydrazone bonds in various polymers, altering their properties, and utilizing them in applications such as self-healing, reprocessing, and recycling. The review also focuses on how the mechanical properties are affected by the presence of dynamic linkages, and methods to improve the mechanical performance.

13.
Soft Matter ; 20(26): 5153-5163, 2024 Jul 03.
Article in English | MEDLINE | ID: mdl-38895763

ABSTRACT

Polymers of intrinsic microporosity exhibit a combination of high gas permeability and reasonable permselectivity, which makes them attractive candidates for gas separation membrane materials. The diffusional selective gas transport properties are connected to the molecular mobility of these polymers in the condensed state. Incoherent quasielastic neutron scattering was carried out on two polymers of intrinsic microporosity, PIM-EA-TB(CH3) and its demethylated counterpart PIM-EA-TB(H2), which have high Brunauer-Emmett-Teller surface area values of 1030 m2 g-1 and 836 m2 g-1, respectively. As these two polymers only differ in the presence of two methyl groups at the ethanoanthracene unit, the effect of methyl group rotation can be investigated solely. To cover a broad dynamic range, neutron time-of-flight was combined with neutron backscattering. The demethylated PIM-EA-TB(H2) exhibits a relaxation process with a weak intensity at short times. As the backbone is rigid and stiff this process was assigned to bend-and-flex fluctuations. This process was also observed for the PIM-EA-TB(CH3). A further relaxation process is found for PIM-EA-TB(CH3), which is the methyl group rotation. It was analyzed by a jump-diffusion in a three-fold potential considering also the fact that only a fraction of the present hydrogens in PIM-EA-TB(CH3) participate in the methyl group rotation. This analysis can quantitatively describe the q dependence of the elastic incoherent structure factor. Furthermore, a relaxation time for the methyl group rotation can be extracted. A high activation energy of 35 kJ mol-1 was deduced. This high activation energy evidences a strong hindrance of the methyl group rotation in the bridged PIM-EA-TB(CH3) structure.

14.
Health Commun ; 39(2): 258-269, 2024 Apr.
Article in English | MEDLINE | ID: mdl-36593182

ABSTRACT

This study, inspired by the Risk Information Seeking and Processing (RISP) model, examines the mechanisms by which perceived hazard characteristics and the informational subjective norms of Chinese youth, aged from 14 to 44 years old, become associated with their intentions to seek cancer risk information online. A sample of 684 Chinese youths was collected from four cities in Mainland China with results revealing that perceived hazard characteristics and informational subjective norms motivate their online cancer risk information seeking intentions. Specifically, perceived probability, perceived severity, and institutional trust are positively related to negative affect, however the relationship between personal control and negative affect is not significant. Institutional trust and personal control are positively related to positive affect while perceived probability and perceived severity have no significant effect on positive affect. Negative affect and informational subjective norms are positively related to perceived information insufficiency, while the relationship between positive affect and perceived information insufficiency is not significant. Negative affect, positive affect, informational subjective norms, and perceived information insufficiency are all positively related to the online cancer risk information seeking intentions of Chinese youth.


Subject(s)
Neoplasms , Humans , Adolescent , Young Adult , Adult , Cities , Risk , Intention , China
15.
JAMA ; 2024 Aug 31.
Article in English | MEDLINE | ID: mdl-39215972

ABSTRACT

IMPORTANCE: Supplementing potassium in an effort to maintain high-normal serum concentrations is a widespread strategy used to prevent atrial fibrillation after cardiac surgery (AFACS), but is not evidence-based, carries risks, and is costly. OBJECTIVE: To determine whether a lower serum potassium concentration trigger for supplementation is noninferior to a high-normal trigger. DESIGN, SETTING, AND PARTICIPANTS: This open-label, noninferiority, randomized clinical trial was conducted at 23 cardiac surgical centers in the United Kingdom and Germany. Between October 20, 2020, and November 16, 2023, patients with no history of atrial dysrhythmias scheduled for isolated coronary artery bypass grafting (CABG) surgery were enrolled. The last study patient was discharged from the hospital on December 11, 2023. INTERVENTIONS: Patients were randomly assigned to a strategy of tight or relaxed potassium control (only supplementing if serum potassium concentration fell below 4.5 mEq/L or 3.6 mEq/L, respectively). Patients wore an ambulatory heart rhythm monitor, which was analyzed by a core laboratory masked to treatment assignment. MAIN OUTCOMES AND MEASURES: The prespecified primary end point was clinically detected and electrocardiographically confirmed new-onset AFACS in the first 120 hours after CABG surgery or until hospital discharge, whichever occurred first. All primary outcome events were validated by an event validation committee, which was masked to treatment assignment. Noninferiority of relaxed potassium control was defined as a risk difference for new-onset AFACS with associated upper bound of a 1-sided 97.5% CI of less than 10%. Secondary outcomes included other heart rhythm-related events, clinical outcomes, and cost related to the intervention. RESULTS: A total of 1690 patients (mean age, 65 years; 256 [15%] females) were randomized. The primary end point occurred in 26.2% of patients (n = 219) in the tight group and 27.8% of patients (n = 231) in the relaxed group, which is a risk difference of 1.7% (95% CI, -2.6% to 5.9%). There was no difference between the groups in the incidence of at least 1 AFACS episode detected by any means or by ambulatory heart rhythm monitor alone, non-AFACS dysrhythmias, in-patient mortality, or length of stay. Per-patient cost for purchasing and administering potassium was significantly lower in the relaxed group (mean difference, $111.89 [95% CI, $103.60-$120.19]; P <.001). CONCLUSIONS AND RELEVANCE: For AFACS prophylaxis, supplementation only when serum potassium concentration fell below 3.6 mEq/L was noninferior to the current widespread practice of supplementing potassium to maintain a serum potassium concentration greater than or equal to 4.5 mEq/L. The lower threshold of supplementation was not associated with any increase in dysrhythmias or adverse clinical outcomes. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04053816.

16.
Ann Surg ; 278(5): 701-708, 2023 11 01.
Article in English | MEDLINE | ID: mdl-37477039

ABSTRACT

OBJECTIVE: To determine the impact of delayed surgical intervention following chemoradiotherapy (CRT) on survival from esophageal cancer. BACKGROUND: CRT is a core component of multimodality treatment for locally advanced esophageal cancer. The timing of surgery following CRT may influence the probability of performing an oncological resection and the associated operative morbidity. METHODS: This was an international, multicenter, cohort study, including patients from 17 centers who received CRT followed by surgery between 2010 and 2020. In the main analysis, patients were divided into 4 groups based upon the interval between CRT and surgery (0-50, 51-100, 101-200, and >200 days) to assess the impact upon 90-day mortality and 5-year overall survival. Multivariable logistic and Cox regression provided hazard ratios (HRs) with 95% CIs adjusted for relevant patient, oncological, and pathologic confounding factors. RESULTS: A total of 2867 patients who underwent esophagectomy after CRT were included. After adjustment for relevant confounders, prolonged interval following CRT was associated with an increased 90-day mortality compared with 0 to 50 days (reference): 51 to 100 days (HR=1.54, 95% CI: 1.04-2.29), 101 to 200 days (HR=2.14, 95% CI: 1.37-3.35), and >200 days (HR=3.06, 95% CI: 1.64-5.69). Similarly, a poorer 5-year overall survival was also observed with prolonged interval following CRT compared with 0 to 50 days (reference): 101 to 200 days (HR=1.41, 95% CI: 1.17-1.70), and >200 days (HR=1.64, 95% CI: 1.24-2.17). CONCLUSIONS: Prolonged interval following CRT before esophagectomy is associated with increased 90-day mortality and poorer long-term survival. Further investigation is needed to understand the mechanism that underpins these adverse outcomes observed with a prolonged interval to surgery.


Subject(s)
Esophageal Neoplasms , Neoadjuvant Therapy , Humans , Cohort Studies , Retrospective Studies , Chemoradiotherapy , Esophagectomy
17.
Am J Gastroenterol ; 118(7): 1168-1174, 2023 07 01.
Article in English | MEDLINE | ID: mdl-36716445

ABSTRACT

INTRODUCTION: Guidelines suggest 1-time screening with esophagogastroduodenoscopy (EGD) for Barrett's esophagus (BE) in individuals at an increased risk of esophageal adenocarcinoma (EAC). We aimed to estimate the yield of repeat EGD performed at prolonged intervals after a normal index EGD. METHODS: We conducted a national retrospective analysis within the U S Veterans Health Administration, identifying patients with a normal index EGD between 2003 and 2009 who subsequently had a repeat EGD. We tabulated the proportion with a new diagnosis of BE, EAC, or esophagogastric junction adenocarcinoma (EGJAC) and conducted manual chart review of a sample. We fitted logistic regression models for the odds of a new diagnosis of BE/EAC/EGJAC. RESULTS: We identified 71,216 individuals who had a repeat EGD between 1 and 16 years after an index EGD without billing or cancer registry codes for BE/EAC/EGJAC. Of them, 4,088 had a new billing or cancer registry code for BE/EAC/EGJAC after the repeat EGD. On manual review of a stratified sample, most did not truly have new BE/EAC/EGJAC. A longer duration between EGD was associated with greater odds of a new diagnosis (adjusted odds ratio [aOR] for each 5 years 1.31; 95% confidence interval [CI] 1.19-1.44), particularly among those who were younger during the index EGD (ages 19-29 years: aOR 3.92; 95% CI 1.24-12.4; ages 60-69 years: aOR 1.19; 95% CI 1.01-1.40). DISCUSSION: The yield of repeat EGD for BE/EAC/EGJAC seems to increase with time after a normal index EGD, particularly for younger individuals. Prospective studies are warranted to confirm these findings.


Subject(s)
Adenocarcinoma , Barrett Esophagus , Esophageal Neoplasms , Humans , Barrett Esophagus/diagnosis , Barrett Esophagus/pathology , Retrospective Studies , Esophageal Neoplasms/diagnosis , Esophageal Neoplasms/epidemiology , Esophageal Neoplasms/etiology , Adenocarcinoma/diagnosis , Adenocarcinoma/epidemiology , Adenocarcinoma/complications , Endoscopy, Gastrointestinal/adverse effects
18.
Small ; 19(36): e2300333, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37150875

ABSTRACT

2D magnets can potentially revolutionize information technology, but their potential application to cooling technology and magnetocaloric effect (MCE) in a material down to the monolayer limit remain unexplored. Herein, it is revealed through multiscale calculations the existence of giant MCE and its strain tunability in monolayer magnets such as CrX3 (X = F, Cl, Br, I), CrAX (A = O, S, Se; X = F, Cl, Br, I), and Fe3 GeTe2 . The maximum adiabatic temperature change ( Δ T ad max $\Delta T_{{\rm{ad}}}^{\max }$ ), maximum isothermal magnetic entropy change, and specific cooling power in monolayer CrF3 are found as high as 11 K, 35 µJ m-2  K-1 , and 3.5 nW cm-2 under a magnetic field of 5 T, respectively. A 2% biaxial and 5% a-axis uniaxial compressive strain can remarkably increase Δ T ad max $\Delta T_{{\rm{ad}}}^{\max }$ of CrCl3 and CrOF by 230% and 37% (up to 15.3 and 6.0 K), respectively. It is found that large net magnetic moment per unit area favors improved MCE. These findings advocate the giant-MCE monolayer magnets, opening new opportunities for magnetic cooling at nanoscale.

19.
Med Care ; 61(1): 36-44, 2023 01 01.
Article in English | MEDLINE | ID: mdl-36477618

ABSTRACT

BACKGROUND: Few performance measures assess presurgical value (quality and utilization). OBJECTIVES: Using carpal tunnel syndrome (CTS) as a case study: (1) develop a model to evaluate presurgical quality and utilization and (2) identify opportunities for value improvement. RESEARCH DESIGN: A retrospective cohort study utilizing Veterans Affairs (VA) national administrative data. SUBJECTS: Patients who were evaluated in a VA primary care clinic on at least 1 occasion for CTS and received carpal tunnel release over a 7-year period. MEASURES: We modeled facility-level performance on 2 outcomes: surgical delay (marker of quality) and number of presurgical encounters (utilization) for CTS, and examined association between patient, facility, and care process variables and performance. RESULTS: Among 41,912 Veterans undergoing carpal tunnel release at 127 VA medical centers, the median facility-level predicted probability of surgical delay was 48%, with 16 (13%) facilities having significantly less delay than the median and 13 (10%) facilities having greater delay. The median facility-level predicted number of presurgical encounters was 8.8 visits, with 22 (17%) facilities having significantly fewer encounters and 22 (17%) facilities having more. Care processes had a stronger association with both outcomes than structural variables included in the models. Processes associated with the greatest deviations in predicted delay and utilization included receipt of repeat electrodiagnostic testing, use of 2 or more nonoperative treatments, and community referral outside of VA. CONCLUSIONS: Using CTS as a test case, this study demonstrates the potential to assess presurgical value and identify modifiable care processes associated with presurgical delay and utilization performance.


Subject(s)
Carpal Tunnel Syndrome , Humans , Carpal Tunnel Syndrome/diagnosis , Carpal Tunnel Syndrome/surgery , Retrospective Studies
20.
Bioscience ; 73(3): 220-228, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36936383

ABSTRACT

The concept of dominance is frequently used to describe changes in rapidly reconfiguring ecosystems, but the definition of dominance can vary widely among studies. Using coral reefs as a model, we use extensive benthic composition data to explore how variability in applying dominance concepts can shape perceptions. We reveal that coral dominance is sensitive to the exclusion of key algal groups and the categorization of other benthic groups, with ramifications for detecting an ecosystem phase shift. For example, ignoring algal turf inflates the dominance of hard and soft corals in the benthic habitats underpinning reef ecosystems. We need a consensus on how dominance concepts are applied so that we can build a more comprehensive understanding of ecosystem shifts across a broad range of aquatic and terrestrial settings. For reefs, we highlight the benefits of comprehensive and inclusive surveys for evaluating and managing the altered ecosystem states that are emerging in the Anthropocene.

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