Metal nanoparticles are key electrode materials in a variety of electrochemical applications including basic electron-transfer study, electrochemical sensing, and electrochemical surface enhanced ...Raman spectroscopy (SERS). Metal nanoparticles have also been extensively applied to electrocatalytic processes in recent years due to their high catalytic activity and large surface areas. Because the catalytic activity of metal nanoparticle is often highly dependent on their size, shape, surface ligands, and so forth, methods for examining and better understanding the correlation between particle structure and function are of great utility in the development of more efficient catalytic systems. Despite considerable progress in this field, the understanding of the structure–activity relationships remains challenging in nanoparticle-based electrochemistry and electrocatalysis due to limitations associated with traditional ensemble measurements. One of the major issues is the ensemble averaging of the electrocatalytic response which occurs over a very large number of nanoparticles of various sizes and shapes. Additionally, the electrochemical response can also be greatly affected by properties of the ensemble itself, such as the particle spacing. The ability to directly measure kinetics of electrochemical reactions at structurally well-characterized single nanoparticles opens up new possibilities in many important areas including nanoscale electrochemistry, electrochemical sensing, and nanoparticle electrocatalysis. When a macroscopic electrode is placed in a solution containing redox molecules and metal nanoparticles, random collision and adsorption of nanoparticles occurs at the electrode surface in addition to redox reactions when a suitable potential is present on the electrode. In a special case where particles are catalytically more active than the substrate, the faradaic signals can be greatly amplified on particle surfaces and a steady shift in the baseline current would be expected due to many particles adsorbing on the electrode. Single particle events can be temporally resolved when an ultramicroelectrode (UME) is used as the recording electrode. The use of an UME not only reduces the collision frequency, but also greatly decreases baseline noise, thereby resulting in clear resolution of single collision events. Single particle collision has quickly grown into a popular electroanalytical technique in recent years. Alternatively, one can use nanoelectrodes to immobilize single nanoparticles so that they can be individually studied in electrochemistry and electrocatalysis. Nanoparticle immobilization also allows one to obtain detailed structural information on the same particles and offers enormous potential for developing more comprehensive understanding of the structure–function relationship in nanoparticle-based electrocatalysts. This Account summarizes recent electrochemical experiments of single metal nanoparticles which have been performed by our group using both of these schemes.
The 2021 guidelines primary panel selected clinically relevant questions and produced updated recommendations, on the basis of important new findings that have emerged since the 2016 guidelines. In ...patients with clinical atherosclerosis, abdominal aortic aneurysm, most patients with diabetes or chronic kidney disease, and those with low-density lipoprotein cholesterol ≥ 5 mmol/L, statin therapy continues to be recommended. We have introduced the concept of lipid/lipoprotein treatment thresholds for intensifying lipid-lowering therapy with nonstatin agents, and have identified the secondary prevention patients who have been shown to derive the largest benefit from intensification of therapy with these agents. For all other patients, we emphasize risk assessment linked to lipid/lipoprotein evaluation to optimize clinical decision-making. Lipoprotein(a) measurement is now recommended once in a patient's lifetime, as part of initial lipid screening to assess cardiovascular risk. For any patient with triglycerides ˃ 1.5 mmol/L, either non-high-density lipoprotein cholesterol or apolipoprotein B are the preferred lipid parameter for screening, rather than low-density lipoprotein cholesterol. We provide updated recommendations regarding the role of coronary artery calcium scoring as a clinical decision tool to aid the decision to initiate statin therapy. There are new recommendations on the preventative care of women with hypertensive disorders of pregnancy. Health behaviour modification, including regular exercise and a heart-healthy diet, remain the cornerstone of cardiovascular disease prevention. These guidelines are intended to provide a platform for meaningful conversation and shared-decision making between patient and care provider, so that individual decisions can be made for risk screening, assessment, and treatment.
Le panel principal responsable des lignes directrices 2021 a sélectionné des éléments cliniquement pertinents et a soumis des recommandations actualisées, basées sur de nouvelles découvertes d'importance apparues depuis les lignes directrices de 2016. Ainsi, le traitement par statine reste recommandé pour les patients atteints d'athérosclérose clinique, d'anévrisme de l'aorte abdominale, pour la plupart des patients diabétiques ou atteints d'insuffisance rénale chronique, et chez ceux dont le cholestérol à lipoprotéines de basse densité est ≥ 5 mmol/l. Nous avons introduit la notion de seuils pour le traitement des lipides/lipoprotéines afin d'intensifier le traitement hypolipidémiant avec des agents non-statiniques, et nous avons identifié les patients en prévention secondaire distingués comme ayant tirer le plus grand bénéfice de l'intensification du traitement avec ces agents. Pour tous les autres patients, nous mettons l'accent sur l'appréciation du risque par le biais de l'évaluation des lipides/lipoprotéines afin d'optimiser la prise de décision clinique. Le dosage de la lipoprotéine (a) est maintenant recommandé une fois dans la vie d'un patient, dans le cadre du dépistage initial des lipides pour évaluer le risque cardiovasculaire. Pour tout patient présentant des taux de triglycérides ˃ 1,5 mmol/l, l'apolipoprotéine B ou le cholestérol lié aux lipoprotéines autres que celles de haute densité sont les indices lipidiques à privilégier pour le dépistage, plutôt que le cholestérol à lipoprotéines de basse densité. Nous proposons des recommandations actualisées concernant le rôle du score calcique des artères coronaires en tant qu'outil de décision clinique pour aider à la décision d'administrer un traitement par statine. Il existe de nouvelles recommandations concernant les soins préventifs des femmes souffrant de troubles hypertensifs de la grossesse. Le changement de comportement en matière de santé, incluant l'exercice physique régulier et une alimentation saine pour le coeur, reste la pierre angulaire de la prévention des maladies cardiovasculaires. Ces lignes directrices visent à fournir une plateforme pour une discussion constructive et une prise de décision partagée entre le patient et le prestataire de soins, afin que des décisions individuelles puissent être prises pour le dépistage, l'évaluation et le traitement des risques.
In this report, we describe the fabrication, characterization, and use of a massive array of closed bipolar ultramicroelectrodes (UMEs) in electrochemical imaging applications. The bipolar UME array ...is 1 cm2 in size and contains >146 000 carbon electrodes embedded in a 15 μm thick insulating and freestanding membrane of Parylene C. Structural characterization with optical and electron microscopies shows that the carbon UMEs are highly uniform in size, shape, and interelectrode spacing. The bipolar UME array was used in electrochemical imaging to probe highly dynamic redox processes in which the reduction of redox molecules on one side the array is electrically coupled to an oxidative electrochemilumescence (ECL) process on the opposite side. This allows one to simultaneously monitor electrochemical reactions on hundreds of thousands of individual electrodes with millisecond temporal resolution. Our results suggest that microfabricated closed bipolar UME arrays can be useful for imaging fast and transient electrochemical processes in which scanning probe methods are inapplicable due to their limited temporal resolution.
In this work, we describe the preparation and use of a thin metal film modified Indium Tin Oxide (ITO) electrode as a highly conductive, transparent, and electrocatalytically active electrode ...material for studying nanobubbles generated at the electrode/solution interface. Hydrogen and oxygen nanobubbles were generated from water electrolysis on the surface of a Au/Pd alloy modified ITO electrode. The formation of single H
and O
nanobubbles was imaged in real time during a potential scan using single-molecule fluorescence microscopy. Our results show that while O
nanobubbles can be detected at an early stage in the oxygen evolution reaction (OER), the formation of H
nanobubbles requires a significant overpotential. Our study shows that thin-film-coated ITO electrodes are simple to make and can be useful electrode substrates for (single molecule) spectroelectrochemistry research.
Metformin has been used as an oral anti-hyperglycaemic drug since the late 1950s; however, following the release in 1998 of the findings of the 20-year United Kingdom Prospective Diabetes Study ...(UKPDS), metformin use rapidly increased and today is the first-choice anti-hyperglycaemic drug for patients with type 2 diabetes (T2D). Metformin is in daily use by an estimated 150 million people worldwide. Historically, the benefits of metformin as an anti-diabetic and cardiovascular-protective drug have been linked to effects in the liver, where it acts to inhibit gluconeogenesis and lipogenesis, as well as reduce insulin resistance and enhance peripheral glucose utilization. However, direct protective effects on the endothelium and effects in the gut prior to metformin absorption are now recognized as important. In the gut, metformin modulates the glucagon-like peptide- 1 (GLP-1) - gut-brain axis and impacts the intestinal microbiota. As the apparent number of putative tissue and cellular targets for metformin has increased, so has the interest in re-purposing metformin to treat other diseases that include polycystic ovary syndrome (PCOS), cancer, neurodegenerative diseases, and COVID-19. Metformin is also being investigated as an anti-ageing drug. Of particular interest is whether metformin provides the same level of vascular protection in individuals other than those with T2D, including obese individuals with metabolic syndrome, or in the setting of vascular thromboinflammation caused by SARS-CoV-2. In this review, we critically evaluate the literature to highlight clinical settings in which metformin might be therapeutically repurposed for the prevention and treatment of vascular disease.
Background:
Treatment options for pediatric and adolescent anterior cruciate ligament (ACL) injuries include early operative, delayed operative, and nonoperative management. Currently, there is a ...lack of consensus regarding the optimal treatment for these injuries.
Purpose/Hypothesis:
The purpose was to determine the optimal treatment strategy for ACL injuries in pediatric and adolescent patients. We hypothesized that (1) early ACL reconstruction results in fewer meniscal tears than delayed reconstruction but yields no difference in knee stability and (2) when compared with nonoperative management, any operative management results in fewer meniscal tears and cartilage injuries, greater knee stability, and higher return-to-sport rates.
Study Design:
Systematic review and meta-analysis; Level of evidence, 4.
Methods:
A systematic search of databases was performed including PubMed, Embase, and Cochrane Library using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Inclusion criteria were a pediatric and adolescent patient population (≤19 years old at surgery), the reporting of clinical outcomes after treatment of primary ACL injury, and original scientific research article. Exclusion criteria were revision ACL reconstruction, tibial spine avulsion fracture, case report or small case series (<5 patients), non–English language manuscripts, multiligamentous injuries, and nonclinical studies.
Results:
A total of 30 studies containing 50 cohorts and representing 1176 patients met our criteria. With respect to nonoperative treatment, knee instability was observed in 20% to 100%, and return to preinjury level of sports ranged from 6% to 50% at final follow-up. Regarding operative treatment, meta-analysis results favored early ACL reconstruction over delayed reconstruction (>12 weeks) for the presence of any meniscal tear (odds ratio, 0.23; P = .006) and irreparable meniscal tear (odds ratio, 0.31; P = .001). Comparison of any side-to-side differences in KT-1000 arthrometer testing did not favor early or delayed ACL reconstruction in either continuous mean differences (P = .413) or proportion with difference ≥3 mm (P = .181). Return to preinjury level of competition rates for early and delayed ACL reconstruction ranged from 57% to 100%.
Conclusion:
Delaying ACL reconstruction in pediatric or adolescent patients for >12 weeks significantly increased the risk of meniscal injuries and irreparable meniscal tears; however, early and delayed operative treatment achieved satisfactory knee stability. Nonoperative management resulted in high rates of residual knee instability, increased risk of meniscal tears, and comparatively low rates of return to sports.
Retrospective review.
(1) To describe change in treatment patterns for degenerative spondylolisthesis (DS). (2) To report regional variation in treatment of DS. (3) To describe variation in ...surgeon-reported outcomes for DS based on treatment.
Spinal stenosis associated with DS is commonly treated with decompression and fusion but little is known about the optimal fusion technique. During a 6-month period, American Board of Orthopaedic Surgery step II candidates submit procedure lists; these lists have been stored in an electronic database since 1999.
The American Board of Orthopaedic Surgery database was retrospectively queried to identify patients who underwent surgery for DS from 1999 to 2011. Included patients underwent uninstrumented fusion, fusion with posterior instrumentation, fusion using interbody device, or decompression without fusion. Utilization of these procedures was analyzed by year and geographic region.
The study period included 5639 cases; the annual number of cases doubled during the study period. The percentage of cases treated with interbody fusion (IF) increased significantly throughout the study period, from 13.6% (1999-2001) to 32% (2009-2011) (P<0.001). The percentage of DS cases treated with posterolateral fusion peaked in 2003 then decreased as the rate of IF increased. In 2011, the rates of posterolateral fusion (40%) and posterolateral fusion with IF (37%) were nearly identical. The Northwest had the highest rate of IF (41%), >10% higher than any other region (P<0.001) and more than 23% higher than the Southeast (P<0.001).
Despite little evidence guiding treatment strategy for DS, national treatment patterns have changed dramatically during the past 13 years. The rapid adoption of IF and substantial regional variation in treatment utilization patterns raises questions about drivers of change including perceptions about associated fusion rates, the importance of sagittal balance and differential reimbursement.
4.
Retrospective subgroup analysis of prospectively collected data according to treatment received.
The purpose of this study was to determine whether obesity affects treatment outcomes for lumbar ...stenosis (SpS) and degenerative spondylolisthesis (DS).
Obesity is thought to be associated with increased complications and potentially less favorable outcomes after the treatment of degenerative conditions of the lumbar spine. This, however, remains a matter of debate in the existing literature.
An as-treated analysis was performed on patients enrolled in the Spine Patient Outcomes Research Trial for the treatment of SpS or DS. A comparison was made between patients with a body mass index (BMI) of less than 30 ("nonobese," n = 373 SpS and 376 DS) and those with a BMI of 30 or more ("obese," n = 261 SpS and 225 DS). Baseline patient characteristics, intraoperative data, and complications were documented. Primary and secondary outcomes were measured at baseline and regular follow-up time intervals up to 4 years. The difference in improvement over baseline between surgical and nonsurgical treatment (i.e., treatment effect) was determined at each follow-up interval for the obese and nonobese groups.
At 4-year follow-up, operative and nonoperative treatment provided improvement in all primary outcome measures over baseline in patients with BMI of less than 30 and 30 or more. For patients with SpS, there were no differences in the surgical complication or reoperation rates between groups. Patients with DS with BMI of 30 or more had a higher postoperative infection rate (5% vs. 1%, P = 0.05) and twice the reoperation rate at 4-year follow-up (20% vs. 11%, P = 0.01) than those with BMI of less than 30. At 4 years, surgical treatment of SpS and DS was equally effective in both BMI groups in terms of the primary outcome measures, with the exception that obese patients with DS had less improvement from baseline in the 36-Item Short Form Health Survey (SF-36) physical function score than nonobese patients (22.6 vs. 27.9, P = 0.022). With nonoperative treatment, patients with SpS with BMI of 30 or more did worse in regard to all 3 primary outcome measures, and patients with DS with BMI of 30 or more had similar SF-36 bodily pain scores but less improvement over baseline in the SF-36 physical function and Oswestry Disability Index scores. Treatment effects for SpS and DS were significant within each BMI group for all primary outcome measures in favor of surgery. Obese patients had a significantly greater treatment effect than nonobese patients with SpS (Oswestry Disability Index, P = 0.037) and DS (SF-36 PF, P = 0.004) largely due to the relatively poor outcome of nonoperative treatment in obese patients.
Obesity does not affect the clinical outcome of operative treatment of SpS. There are higher rates of infection and reoperation and less improvement from baseline in the SF-36 physical function score in obese patients after surgery for DS. Nonoperative treatment may not be as effective in obese patients with SpS or DS.
Depression increases during menopause, and subclinical depressive symptoms increase risk for major depression. Insomnia is common among postmenopausal women and increases depression-risk in this ...already-vulnerable population. Recent evidence supports the efficacy of cognitive-behavioral therapy for insomnia (CBTI) to treat menopausal insomnia, but it remains unclear whether treating insomnia also alleviates co-occurring depressive symptoms and depressogenic features. This trial tested whether CBTI improves depressive symptoms, maladaptive thinking, and somatic hyperarousal in postmenopausal women with insomnia; as well as whether sleep restriction therapy (SRT)—a single component of CBTI—is equally efficacious.
Single-site, randomized controlled trial. 117 postmenopausal women (56.34 ± 5.41 years) with peri-or-postmenopausal onset of chronic insomnia were randomized to three treatment conditions: sleep hygiene education control (SHE), SRT, and CBTI. Blinded assessments were performed at baseline, posttreatment, and six-month follow-up.
CBTI produced moderate-to-large reductions in depressive symptoms, whereas SRT produced moderate reductions but not until six months posttreatment. Treatment effects on maladaptive thinking were mixed. CBTI and SRT both produced large improvements in dysfunctional beliefs about sleep, but weaker influences on presleep cognitive arousal, rumination, and worry. Presleep somatic arousal greatly improved in the CBTI group and moderately improved in the SRT group. Improvements in depression, maladaptive thinking, and hyperarousal were linked to improved sleep. SHE produced no durable treatment effects.
CBTI and SRT reduce depressive symptoms, dysfunctional beliefs about sleep, and presleep somatic hyperarousal in postmenopausal women, with CBTI producing superior results. Despite its cognitive emphasis, cognitive arousal did not respond strongly or durably to CBTI.
Behavioral Treatment of Menopausal Insomnia: Sleep and Daytime Outcomes.
clinicaltrials.gov.
NCT01933295.
•CBTI and SRT reduce depressive symptoms in postmenopausal women with insomnia.•CBTI and SRT reduce dysfunctional sleep beliefs and presleep somatic arousal.•Treatment effects on presleep cognitive arousal, rumination, and worry are mixed.•Sleep hygiene does not reduce depression, maladaptive thinking, or somatic arousal.•Treatment outcomes may be enhanced by better targeting cognitive arousal.
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