Evaluating silicosis risk: Assessing dust constitution and influence of water as a primary prevention measure in cutting and polishing of silica agglomerates, granite and marble.

An increasing number of silicosis cases have been reported related to the use of silica agglomerates. Many studies agree on the severity of this disease, which often presents with severe clinical forms in young workers and after a short latency period. Are there differences in the composition of dust generated by cutting and polishing with silica agglomerates versus granite and marble? Does the use of water injection reduce the risk associated with the use of these materials? We carried out a comparative observational-analytical study, measuring the concentration of dust generated during different machining operations on three different materials: granite, marble, and silica agglomerates. The effect of water injection on dust generation was evaluated. Personal sampling pumps were used, connected to a cyclone with polyvinyl chloride filters. The flow rate of the pumps was adjusted using a piston flowmeter. Measurements with a cascade impactor were made to assess the size distribution of respirable crystalline silica particles within the respirable fraction. In addition, environmental measurements with a spectrometer were made. 10 tests were carried out on granite and silica agglomerates for each procedure. In the case of marble, with very low silica content, only 2 tests of each type were carried out. Duration of each measurement was between 6 and 25 min. Cleaning times were set for each of the operations. The amount of dust collected in the respirable fraction was 70.85, 32.50 and 35.78 mg/m3 for dry cutting; 6.50, 3.75 and 3.95 mg/m3 for wet cutting; and 21.35, 13.68 and 17.50 mg/m3 for dry polishing, for granite, marble, and silica agglomerates respectively. Dry procedures in marble, silica agglomerates and granite showed higher dust concentration of particles smaller than 0.5 µm. Silica agglomerates showed higher concentrations of respirable crystalline silica particles than granite and marble, mainly with dry procedures. The greater production of small particles in dry and wet procedures with silica agglomerates shows that water injection is an insufficient preventive measure.

Prehospital Pediatric Emergency Training Using Augmented Reality Simulation: A Prospective, Mixed Methods Study.

OBJECTIVE: Pediatric emergencies are high-stakes yet low-volume clinical encounters for emergency medical services (EMS) clinicians, necessitating innovative approaches to training. We sought to explore the acceptability, usability, and ergonomics of a novel augmented reality (AR) software for EMS crisis management training. METHODS: This was a prospective, mixed-methods study employing qualitative and quantitative analyses. We enrolled emergency medical technicians (EMTs) and paramedics at a municipal fire service in Northern California. We ran the Chariot Augmented Reality Medical simulation software (Stanford Chariot Program, Stanford University, Stanford, CA) on the ML1 headset (Magic Leap, Inc., Plantation, FL), which enabled participants to view an AR image of a patient overlaid with real-world training objects. Participants completed a simulation of a pediatric hypoglycemia-induced seizure and cardiac arrest. Participants subsequently engaged in structured focus group interviews assessing acceptability, which we coded and thematically analyzed. We evaluated the usability of the AR system and ergonomics of the ML1 headset using previously validated scales, and we analyzed findings with descriptive statistics. RESULTS: Twenty-two EMS clinicians participated. We categorized focus group interview statements into seven domains after an iterative thematic analysis: general appraisal, realism, learning efficacy, mixed reality feasibility, technology acceptance, software optimization, and alternate use cases. Participants valued the realism and the mixed reality functionality of the training simulation. They reported that AR could be effective for practicing pediatric clinical algorithms and task prioritization, building verbal communication skills, and promoting stress indoctrination. However, participants also noted challenges with integrating AR images with real-world objects, the learning curve required to adapt to the technology, and areas for software improvement. Participants favorably evaluated the ease of use of the technology and comfortability of wearing the hardware; however, most participants reported that they would need technical support. CONCLUSION: Participants positively evaluated the acceptability, usability, and ergonomics of an AR simulator for pediatric emergency management training, and participants identified current technological limitations and areas for improvement. AR simulation may serve as an effective training adjunct for prehospital clinicians.

A Prospective Randomized Controlled Trial Using Virtual Reality in Pediatric Pre-intervention Echocardiograms to Decrease Child Anxiety and Fear.

Virtual reality (VR) as a distraction tool decreases anxiety and fear in children undergoing procedures, but its use has not been studied during transthoracic echocardiograms (TTEs). We hypothesized that VR in children undergoing pre-intervention TTEs decreases anxiety and fear and increases TTE study comprehensiveness and diagnostic accuracy when compared with standard distractors (television, mobile devices). Patients (6-18 years old) scheduled for pre-intervention TTEs at Lucile Packard Children's Hospital in 2021 and 2022 were prospectively enrolled and randomized to VR and non-VR groups. Patients completed pre- and post-TTE surveys using the Children's Anxiety Meter-State (CAM-S) and Children's Fear Scale (CFS). Patients, parents, and sonographers completed post-TTE experience surveys. TTEs were reviewed by pediatric cardiologists for study comprehensiveness and compared with electronic medical records for diagnostic accuracy. Among 67 enrolled patients, 6 declined VR, 31 randomized to the VR group, and 30 to the non-VR group. Anxiety (average CAM-S difference 0.78 ± 1.80, p = 0.0012) and fear (average CFS difference 0.36 ± 0.74, p = 0.0005) decreased in both groups. There was no difference between groups in the change in anxiety and fear pre- and post-TTE (p = 0.96-1.00). TTE study comprehensiveness and diagnostic accuracy were high in both groups. Procedure time (time in the echocardiography room) was less for the VR group (48.4 ± 18.1 min) than the non-VR group (58.8 ± 24.4 min), but without a statistically significant difference (p = 0.075). VR is similar to standard distractors and may decrease procedure time. Patients, parents, and sonographers rated the VR experience highly and encouraged its use with future procedures.

Near-infrared absorption of fused core-modified expanded porphyrins for dye-sensitized solar cells.

Photophysical, photovoltaic, and charge transport properties of fused core-modified expanded porphyrins containing two pyrroles, one dithienothiophene (DTT) unit, and 1-4 thiophenes (1-4) were inspected by using density functional theory (DFT) and time-dependent DFT. Compounds 1-3 have been investigated experimentally before, but 4 is a theoretical proposal whose photophysical features match those extrapolated from 1 to 3. They exhibit absorption in the range of 700-970 nm for their Q bands and 500-645 nm for their Soret bands. The rise of thiophene rings placed in front of the DTT unit in the expanded porphyrin ring causes a bathochromic shift of the longest absorption wavelength, leading to near-infrared absorptions, which represent 49% of the solar energy. All the systems show a thermodynamically favorable process for the electron injection from the dye to TiO2 and adsorption on a finite TiO2 model. The electron regeneration of the dye is only thermodynamically feasible for the smallest expanded porphyrins 1 and 2 when I-/I3- electrolyte is used. The charge transport study shows that for voltages lower than 0.4 V, junctions featuring pentaphyrin 1 and octaphyrin 4 are more conductive than those containing hexaphyrin 2 or heptaphyrin 3. The results showed that the four fused core-modified expanded porphyrins investigated are potential dyes for applications in dye-sensitized solar cells, mainly pentaphyrin 1 and hexaphyrin 2. Moreover, increasing the number of thiophene rings in the macrocycle proved fruitful in favoring absorption in the near-infrared region, which is highly desired for dye-sensitized solar cells.

Exercise effects on functional capacity and quality of life in older patients with colorectal cancer: study protocol for the ECOOL randomized controlled trial.

BACKGROUND: Surgery and treatment for colorectal cancer (CRC) in the elderly patient increase the risk of developing post-operative complications, losing functional independence, and worsening health-related quality of life (HRQoL). There is a lack of high-quality randomized controlled trials evaluating the potential benefit of exercise as a countermeasure. The primary aim of this study is to evaluate the effectiveness of a home-based multicomponent exercise program for improving HRQoL and functional capacity in older adults undergoing CRC surgery and treatment. METHODS: This randomized, controlled, observer-blinded, single-center trial aims to randomize 250 patients (>74 years) to either an intervention or a control group (i.e., usual care). The intervention group will perform an individualized home-based multicomponent exercise program with weekly telephone supervision from diagnosis until three months post-surgery. The primary outcomes will be HRQoL (EORTC QLQ-C30; CR29; and ELD14) and functional capacity (Barthel Index and Short Physical Performance Battery), which will be assessed at diagnosis, at discharge, and one, three, and six months after surgery. Secondary outcomes will be frailty, physical fitness, physical activity, inspiratory muscle function, sarcopenia and cachexia, anxiety and depression, ambulation ability, surgical complications, and hospital length of stay, readmission and mortality. DISCUSSION: This study will examine the effects of an exercise program in older patients with CRC across a range of health-related outcomes. Expected findings are improvement in HRQoL and physical functioning. If proven effective, this simple exercise program may be applied in clinical practice to improve CRC care in older patients. TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT05448846.

Leveraging Virtual Reality and Augmented Reality to Combat Chronic Pain in Youth: Position Paper From the Interdisciplinary Network on Virtual and Augmented Technologies for Pain Management.

BACKGROUND: Virtual reality (VR) and augmented reality (AR) interventions are emerging as promising tools in the treatment of pediatric chronic pain conditions. However, in this young field, there is little consensus to guide the process of engaging in the development and evaluation of targeted VR-based interventions. OBJECTIVE: The INOVATE-Pain (Interdisciplinary Network on Virtual and Augmented Technologies for Pain management) consortium aims to advance the field of VR for pediatric chronic pain rehabilitation by providing guidance for best practices in the design, evaluation, and dissemination of VR-based interventions targeting this population. METHODS: An interdisciplinary meeting of 16 academics, clinicians, industry partners, and philanthropy partners was held in January 2020. RESULTS: Reviewing the state of the field, the consortium identified important directions for research-driven innovation in VR and AR clinical care, highlighted key opportunities and challenges facing the field, and established a consensus on best methodological practices to adopt in future efforts to advance the research and practice of VR and AR in pediatric pain. The consortium also identified important next steps to undertake to continue to advance the work in this promising new area of digital health pain interventions. CONCLUSIONS: To realize the promise of this realm of innovation, key ingredients for success include productive partnerships among industry, academic, and clinical stakeholders; a uniform set of outcome domains and measures for standardized evaluation; and widespread access to the latest opportunities, tools, and resources. The INOVATE-Pain collaborative hopes to promote the creation, rigorous yet efficient evaluation, and dissemination of innovative VR-based interventions to reduce pain and improve quality of life for children.

Small surgeries, big smiles: using virtual reality to reduce the need for sedation or general anesthesia during minor surgical procedures.

PURPOSE: Children often require anesthesia for simple diagnostic and therapeutic procedures. The aim of this study was to evaluate the feasibility of using virtual reality (VR) to reduce sedation in children undergoing minor surgical procedures. METHOD: In this prospective, non-randomized clinical trial, pediatric patients at a free-standing children's hospital undergoing hormone implant placement, removal, or exchange were recruited to use VR and local anesthesia instead of procedural sedation or general anesthesia (GA). Patients were enrolled between November 2017 and March 2020, and were compared to historic controls who underwent similar procedures without VR between April 2016 and February 2020. Primary outcome measure was successful procedure completion without sedation or GA. Secondary measures included assessments of pain, fear and anxiety, patient compliance, procedural and recovery times. RESULTS: Twenty-eight patients underwent 29 procedures with VR. Hormone implants (72%), removals (7%), or exchanges (21%) were completed without GA, sedation or IV placement. Procedure lengths and pain scores were similar between VR patients and historic controls, but recovery times were significantly shorter in VR patients (18 vs 65 min, p < 0.001). Participant satisfaction scores were high, with 95% recommending VR to others. CONCLUSIONS: VR is a feasible alternative to sedation or GA for select pediatric patients undergoing minor surgical procedures.

Assessing threats, regulations, and strategies to abate plastic pollution in LAC beaches during COVID-19 pandemic.

Plastic use and production have dramatically increased globally over the past 65 years with the improvement of life quality by the daily use of plastic products. Still, around 50% of the plastic produced is disposable products that generate substantial waste. Several reports pointed out the adverse effects of plastic litter in coastal environments in recent years, emphasizing single-use plastics (SUP). In this manner, Latin America and the Caribbean (LAC) coastal environments are highly vulnerable due to wastewater treatment facilities scarcity and poor plastic waste management strategies. Since COVID-19 pandemic, the single-use plastic waste/person rate is expected to rise due to the use of personal protective equipment and SUP as health care measures. Based on literature research and the review of plastic waste regulations, this paper will assess the main COVID-19 plastic pollution threats and LAC beaches' regulations to suggest possible measures to abate this problem. The main findings suggest that unifying the ongoing fragmented and overlapped policies is key to abate plastic pollution, including plastic industry regulations and circular economies. In addition, increasing public risk perception about plastic pollution is critical to reducing plastic waste generation. Research advances in the adverse effects of plastic debris could improve the public's perception of plastic pollution risk, pushing forward global marine plastic governance.

Virtual reality during pediatric vascular access: A pragmatic, prospective randomized, controlled trial.

BACKGROUND: Vascular access is a minor procedure that is associated with reported pain and fear in pediatric patients, often resulting in procedural incompliance. Virtual reality has been shown to be effective in adult populations for reducing pain and anxiety in various medical settings, although large studies are lacking in pediatrics. AIMS: The primary aim was to determine whether pain would be reduced in pediatric patients using virtual reality undergoing vascular access. The four secondary aims measured patient fear, procedural compliance, satisfaction, and adverse events. METHODS: A prospective, randomized, controlled trial was completed at a pediatric hospital, enrolling children 7-18 years old undergoing vascular access in a variety of clinical settings, randomized to virtual reality or standard of care. Pain scores were measured using a numeric pain faces scale. The secondary outcomes of patient fear, procedural compliance, satisfaction, and adverse events were measured with the Child Fear Scale, modified Induction Compliance Checklist, and satisfaction surveys, respectively. Chi-squared, t tests, and regression models were used to analyze the results. RESULTS: The analysis included 106 patients in the virtual reality group and 114 in the control. There were no significant differences in postprocedure pain (VR group estimated 0.11 points lower, 95% confidence interval: 0.50 points lower to 0.28 points greater, P = .59), postprocedure fear (VR group estimated 0.05 points lower, 95% confidence interval: 0.23 points lower to 0.13 points greater), or compliance (adjusted odds ratio 2.31, 95% confidence interval: 0.96-5.56). Children in the virtual reality group were satisfied with the intervention. There were no adverse events. CONCLUSION: This study demonstrates no reduction in pain while using Virtual reality (VR) across a heterogeneous pediatric inpatient population undergoing vascular access.

All-oral direct-acting antiviral therapy against hepatitis C virus (HCV) in human immunodeficiency virus/HCV-coinfected subjects in real-world practice: Madrid coinfection registry findings.

We evaluated treatment outcomes in a prospective registry of human immunodeficiency virus/hepatitis C virus (HCV)-coinfected patients treated with interferon-free direct-acting antiviral agent-based therapy in hospitals from the region of Madrid between November 2014 and August 2016. We assessed sustained viral response at 12 weeks after completion of treatment and used multivariable logistic regression to identify predictors of treatment failure. We evaluated 2,369 patients, of whom 59.5% did not have cirrhosis, 33.9% had compensated cirrhosis, and 6.6% had decompensated cirrhosis. The predominant HCV genotypes were 1a (40.9%), 4 (22.4%), 1b (15.1%), and 3 (15.0%). Treatment regimens included sofosbuvir (SOF)/ledipasvir (61.9%), SOF plus daclatasvir (14.6%), dasabuvir plus ombitasvir/paritaprevir/ritonavir (13.2%), and other regimens (10.3%). Ribavirin was used in 30.6% of patients. Less than 1% of patients discontinued therapy owing to adverse events. The frequency of sustained viral response by intention-to-treat analysis was 92.0% (95% confidence interval, 90.9%-93.1%) overall, 93.8% (92.4%-95.0%) for no cirrhosis, 91.0% (88.8%-92.9%) for compensated cirrhosis, and 80.8% (73.7%-86.6%) for decompensated cirrhosis. The factors associated with treatment failure were male sex (adjusted odds ratio, 1.75; 95% confidence interval, 1.14-2.69), Centers for Diseases Control and Prevention category C (adjusted odds ratio, 1.65; 95% confidence interval, 1.12-2.41), a baseline cluster of differentiation 4-positive (CD4+) T-cell count <200/mm3 (adjusted odds ratio, 2.30; 95% confidence interval, 1.35-3.92), an HCV RNA load ≥800,000 IU/mL (adjusted odds ratio, 1.63; 95% confidence interval, 1.14-2.36), compensated cirrhosis (adjusted odds ratio, 1.35; 95% confidence interval, 0.96-1.89), decompensated cirrhosis (adjusted odds ratio, 2.92; 95% confidence interval, 1.76-4.87), and the use of SOF plus simeprevir, SOF plus ribavirin, and simeprevir plus daclatasvir. CONCLUSION: In this large real-world study, direct-acting antiviral agent-based therapy was safe and highly effective in coinfected patients; predictors of failure included gender, human immunodeficiency virus-related immunosuppression, HCV RNA load, severity of liver disease, and the use of suboptimal direct-acting antiviral agent-based regimens. (Hepatology 2018;68:32-47).

Development of an orthotopic canine prostate cancer model expressing human GRPr.

BACKGROUND: Ace-1 canine prostate cancer cells grow orthotopically in cyclosporine immunosuppressed laboratory beagles. We previously transfected (human Gastrin-Releasing Peptide Receptor, huGRPr) into Ace-1 cells and demonstrated receptor-targeted NIRF imaging with IR800-G-Abz4-t-BBN, an agonist to huGRPr. Herein, we used the new cell line to develop the first canine prostate cancer model expressing a human growth factor receptor. METHODS: Dogs were immunosuppressed with cyclosporine, azathioprine, prednisolone, and methylprednisolone. Their prostate glands were implanted with Ace-1huGRPr cells. The implantation wounds were sealed with a cyanoacrylic adhesive to prevent extraprostatic tumor growth. Intraprostatic tumors grew in 4-5 week. A lobar prostatic artery was then catheterized via the carotid artery and 25-100 nmol IR800-Abz4-t-BBN was infused in 2 mL followed by euthanasia in dogs 1-2, and recovery for 24 h before euthanasia in dogs 3-6. Excised tissues were imaged optically imaged, and histopathology performed. RESULTS: Dog1 grew no tumors with cyclosporine alone. Using the four drug protocol, Dogs 2-6 grew abundant 1-2 mm intracapsular and 1-2 cm intraglandular tumors. Tumors grew >5 cm when the prostate cancer cells became extracapsular. Dogs 4-6 with sealed prostatic capsule implantation sites had growth of intracapsular and intraglandular tumors and LN metastases at 5 weeks. High tumor to background BPH signal in the NIRF images of sectioned prostate glands resulted from the 100 nmol dose (∼8 nmol/kg) in dogs 2-4 and 50 nmol dose in dog 5, but not from the 25 nmol dose in Dog 6. Imaging of mouse Ace-1huGRPr tumors required an intravenous dose of 500 nmol/kg body wt. A lymph node that drained the prostate gland was detectable in Dog 4. Histologic findings confirmed the imaging data. CONCLUSION: Ace-1huGRPr cells created viable, huGRPr-expressing tumors when implanted orthotopically into immune-suppressed dogs. Local delivery of an imaging agent through the prostatic artery allowed a very low imaging dose, suggesting that therapeutic agents could be used safely for treatment of early localized intraglandular prostate cancer as adjuvant therapy for active surveillance or focal ablation therapies, or for treating multifocal intraglandular disease where focal ablation therapies are not indicated or ineffective.

Human respiratory syncytial virus load normalized by cell quantification as predictor of acute respiratory tract infection.

Human respiratory syncytial virus (HRSV) is a common cause of respiratory infections. The main objective is to analyze the prediction ability of viral load of HRSV normalized by cell number in respiratory symptoms. A prospective, descriptive, and analytical study was performed. From 7307 respiratory samples processed between December 2014 to April 2016, 1019 HRSV-positive samples, were included in this study. Low respiratory tract infection was present in 729 patients (71.54%). Normalized HRSV load was calculated by quantification of HRSV genome and human ß-globin gene and expressed as log10 copies/1000 cells. HRSV mean loads were 4.09 ± 2.08 and 4.82 ± 2.09 log10 copies/1000 cells in the 549 pharyngeal and 470 nasopharyngeal samples, respectively (P < 0.001). The viral mean load was 4.81 ± 1.98 log10 copies/1000 cells for patients under the age of 4-year-old (P < 0.001). The viral mean loads were 4.51 ± 2.04 cells in patients with low respiratory tract infection and 4.22 ± 2.28 log10 copies/1000 cells with upper respiratory tract infection or febrile syndrome (P < 0.05). A possible cut off value to predict LRTI evolution was tentatively established. Normalization of viral load by cell number in the samples is essential to ensure an optimal virological molecular diagnosis avoiding that the quality of samples affects the results. A high viral load can be a useful marker to predict disease progression.

Whole-genome sequence analysis of the Mycobacterium avium complex and proposal of the transfer of Mycobacterium yongonense to Mycobacterium intracellulare subsp. yongonense subsp. nov.

Bacterial whole-genome sequences contain informative features of their evolutionary pathways. Comparison of whole-genome sequences have become the method of choice for classification of prokaryotes, thus allowing the identification of bacteria from an evolutionary perspective, and providing data to resolve some current controversies. Currently, controversy exists about the assignment of members of the Mycobacterium avium complex, as is for the cases of Mycobacterium yongonense and 'Mycobacterium indicus pranii'. These two mycobacteria, closely related to Mycobacterium intracellulare on the basis of standard phenotypic and single gene-sequences comparisons, were not considered a member of such species on the basis on some particular differences displayed by a single strain. Whole-genome sequence comparison procedures, namely the average nucleotide identity and the genome distance, showed that those two mycobacteria should be considered members of the species M. intracellulare. The results were confirmed with other whole-genome comparison supplementary methods. According to the data provided, Mycobacterium yongonense and 'Mycobacterium indicus pranii' should be considered and renamed and included as members of M. intracellulare. This study highlights the problems caused when a novel species is accepted on the basis of a single strain, as was the case for M. yongonense. Based mainly on whole-genome sequence analysis, we conclude that M. yongonense should be reclassified as a subspecies of Mycobacterium intracellulareas Mycobacterium intracellularesubsp. yongonense and 'Mycobacterium indicus pranii' classified in the same subspecies as the type strain of Mycobacterium intracellulare and classified as Mycobacterium intracellularesubsp. intracellulare.

Torquoselective Mechanochemical Activation of the Staudinger Reaction To Form ß-Lactams.

The Staudinger reaction yielding ß-lactam rings via [2 + 2] cycloaddition is a torquoselective reaction where the stereochemistry of the product can be steered by suitable substituents. Although the mechanochemical ring-opening of ß-lactams has been investigated recently, the force-assisted synthesis of this important functional four-ring motif remains unexplored. As it will be computationally demonstrated, mechanochemical activation greatly reduces the barrier of the rate-limiting ring-closure step while, at the same time, preserves its torquoselectivity. This finding strongly suggests that strained four-membered rings can be readily incorporated in chain molecules using sonication techniques that greatly enhance reactivity while conserving selectivity.

Feasibility of Na18F PET/CT and MRI for Noninvasive In Vivo Quantification of Knee Pathophysiological Bone Metabolism in a Canine Model of Post-traumatic Osteoarthritis.

PURPOSE: To assess and quantify by molecular imaging knee osseous metabolic changes serially in an in vivo canine model of posttraumatic osteoarthritis (PTOA) of the knee utilizing sodium fluoride (Na18F) positron emission tomography (PET)/computed tomography (CT) coregistered with magnetic resonance imaging (MRI). MATERIALS AND METHODS: Sodium fluoride PET imaging of 5 canines was performed prior to anterior cruciate ligament transection (ACLT) and 2 times post-ACLT (3 and 12 weeks). The PET/CT was coregistered with MRI, enabling serial anatomically guided visual and quantitative three-dimensional (3D) region of interest (ROI) assessment by maximum standardized uptake value. RESULTS: Prior to ACLT, every 3D ROI assessed in both knees showed no Na18F uptake above background. The uptake of Na18F in the bone of the ACLT knees increased exponentially, presenting significantly higher uptake at 12 weeks in every region compared to the ACLT knees at baseline. Furthermore, the uninjured contralateral limb and the ipsilateral distal bones and joints presented Na18F uptake at 3 and 12 weeks post-ACLT. CONCLUSION: This study demonstrated that Na18F PET/CT coregistered with MRI is a feasible molecular imaging biomarker to assess knee osseous metabolic changes serially in an in vivo canine model of knee PTOA. Moreover, it brings a novel musculoskeletal preclinical imaging methodology that can provide unique insights into PTOA pathophysiology.

Preclinical Multimodal Molecular Imaging Using 18F-FDG PET/CT and MRI in a Phase I Study of a Knee Osteoarthritis in In Vivo Canine Model.

The aim of this study was to use a multimodal molecular imaging approach to serially assess regional metabolic changes in the knee in an in vivo anterior cruciate ligament transection (ACLT) canine model of osteoarthritis (OA). Five canine underwent ACLT in one knee and the contralateral knee served as uninjured control. Prior, 3, 6, and 12 weeks post-ACLT, the dogs underwent 18F-fluoro-d-glucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) and magnetic resonance imaging (MRI). The MRI was coregistered with the PET/CT, and 3-dimensional regions of interest (ROIs) were traced manually and maximum standardized uptake values (SUVmax) were evaluated. 18F-fluoro-d-glucose SUVmax in the ACLT knee ROIs was significantly higher compared to the uninjured contralateral knees at 3, 6, and 12 weeks. Higher 18F-FDG uptake observed in ACLT knees compared to the uninjured knees reflects greater metabolic changes in the injured knees over time. Knee 18F-FDG uptake in an in vivo ACLT canine model using combined PET/CT and MRI demonstrated to be highly sensitive in the detection of metabolic alterations in osseous and nonosteochondral structures comprising the knee joint. 18F-fluoro-d-glucose appeared to be a capable potential imaging biomarker for early human knee OA diagnosis, prognosis, and management.

Unmasking the Action of Phosphinous Acid Ligands in Nitrile Hydration Reactions Catalyzed by Arene-Ruthenium(II) Complexes.

The catalytic hydration of benzonitrile and acetonitrile has been studied by employing different arene-ruthenium(II) complexes with phosphinous (PR2OH) and phosphorous acid (P(OR)2OH) ligands as catalysts. Marked differences in activity were found, depending on the nature of both the P-donor and η(6)-coordinated arene ligand. Faster transformations were always observed with the phosphinous acids. DFT computations unveiled the intriguing mechanism of acetonitrile hydration catalyzed by these arene-ruthenium(II) complexes. The process starts with attack on the nitrile carbon atom of the hydroxyl group of the P-donor ligand instead of on a solvent water molecule, as previously suggested. The experimental results presented herein for acetonitrile and benzonitrile hydration catalyzed by different arene-ruthenium(II) complexes could be rationalized in terms of such a mechanism.

Understanding the hydrolysis mechanism of ethyl acetate catalyzed by an aqueous molybdocene: a computational chemistry investigation.

A thoroughly mechanistic investigation on the [Cp2Mo(OH)(OH2)](+)-catalyzed hydrolysis of ethyl acetate has been performed using density functional theory methodology together with continuum and discrete-continuum solvation models. The use of explicit water molecules in the PCM-B3LYP/aug-cc-pVTZ (aug-cc-pVTZ-PP for Mo)//PCM-B3LYP/aug-cc-pVDZ (aug-cc-pVDZ-PP for Mo) computations is crucial to show that the intramolecular hydroxo ligand attack is the preferred mechanism in agreement with experimental suggestions. Besides, the most stable intermediate located along this mechanism is analogous to that experimentally reported for the norbornenyl acetate hydrolysis catalyzed by molybdocenes. The three most relevant steps are the formation and cleavage of the tetrahedral intermediate immediately formed after the hydroxo ligand attack and the acetic acid formation, with the second one being the rate-determining step with a Gibbs energy barrier of 36.7 kcal/mol. Among several functionals checked, B3LYP-D3 and M06 give the best agreement with experiment as the rate-determining Gibbs energy barrier obtained only differs 0.2 and 0.7 kcal/mol, respectively, from that derived from the experimental kinetic constant measured at 296.15 K. In both cases, the acetic acid elimination becomes now the rate-determining step of the overall process as it is 0.4 kcal/mol less stable than the tetrahedral intermediate cleavage. Apart from clarifying the identity of the cyclic intermediate and discarding the tetrahedral intermediate formation as the rate-determining step for the mechanism of the acetyl acetate hydrolysis catalyzed by molybdocenes, the small difference in the Gibbs energy barrier found between the acetic acid formation and the tetrahedral intermediate cleavage also uncovers that the rate-determining step could change when studying the reactivity of carboxylic esters other than ethyl acetate substrate specific toward molybdocenes or other transition metal complexes. Therefore, in general, the information reported here could be of interest in designing new catalysts and understanding the reaction mechanism of these and other metal-catalyzed hydrolysis reactions.

Rapid synthesis of ultra-long silver nanowires for tailor-made transparent conductive electrodes: proof of concept in organic solar cells.

Rapid synthesis of ultralong silver nanowires (AgNWs) has been obtained using a one-pot polyol-mediated synthetic procedure. The AgNWs have been prepared from the base materials in less than one hour with nanowire lengths reaching 195 µm, which represents the quickest synthesis and one of the highest reported aspect ratios to date. These results have been achieved through a joint analysis of all reaction parameters, which represents a clear progress beyond the state of the art. Dispersions of the AgNWs have been used to prepare thin, flexible, transparent and conducting films using spray coating. Due to the higher aspect ratio, an improved electrical percolation network is observed. This allows a low sheet resistance (RS = 20.2 Ω/sq), whilst maintaining high optical film transparency (T = 94.7%), driving to the highest reported figure-of-merit (FoM = 338). Owing to the light-scattering influence of the AgNWs, the density of the AgNW network can also be varied to enable controllability of the optical haze through the sample. Based on the identification of the optimal haze value, organic photovoltaics (OPVs) have been fabricated using the AgNWs as the transparent electrode and have been benchmarked against indium tin oxide (ITO) electrodes. Overall, the performance of OPVs made using AgNWs sees a small decrease in power conversion efficiency (PCE), primarily due to a fall in open-circuit voltage (50 mV). This work indicates that AgNWs can provide a low cost, rapid and roll-to-roll compatible alternative to ITO in OPVs, with only a small compromise in PCE needed.

Reversible covalent immobilization of Trametes villosa laccase onto thiolsulfinate-agarose: An insoluble biocatalyst with potential for decoloring recalcitrant dyes.

The development of a solid-phase biocatalyst based on the reversible covalent immobilization of laccase onto thiol-reactive supports (thiolsulfinate-agarose [TSI-agarose]) was performed. To achieve this goal, laccase-producing strains isolated from Eucalyptus globulus were screened and white rot fungus Trametes villosa was selected as the best strain for enzyme production. Reduction of disulfide bonds and introduction of "de novo" thiol groups in partially purified laccase were assessed to perform its reversible covalent immobilization onto thiol-reactive supports (TSI-agarose). Only the thiolation process dramatically improved the immobilization yield, from 0% for the native and reduced enzyme to 60% for the thiolated enzyme. Mild conditions for the immobilization process (pH 7.5 and 4°C) allowed the achievement of nearly 100% of coupling efficiency when low loads were applied. The kinetic parameters, pH, and thermal stabilities for the immobilized biocatalyst were similar to those for the native enzyme. After the first use and three consecutives reuses, the insoluble derivative kept more than 80% of its initial capacity for decolorizing Remazol Brilliant Blue R, showing its suitability for color removal from textile industrial effluents. The possibility of reusing the support was demonstrated by the reversibility of enzyme-support binding.