bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of chronic treatment with the vasopeptidase inhibitor AVE 7688 and ramipril on endothelial function in atherogenic diet rabbits
Authors: Weckler Nadine , Leitzbach Daniela , Kalinowski Leszek , Malinski Tadeusz , Busch Andreas E , Linz Wolfgang
Published: May 2007

Cardiovascular disease is the major cause of death in Western nations, although improved possibilities regarding diagnosis and therapy now exist. Endothelial dysfunction is triggered by cardiovascular risk factors such as hypercholesterolaemia, hypertension, adiposity and smoking, contributing to the common endpoint of atherosclerosis.

This study examined the pharmacological effects of angiotensin-converting enzyme (ACE) and combined ACE-neutral endopeptidase (NEP) (vasopeptidase) inhibitors on endothelial dysfunction in the model of hyperlipidaemic rabbits. The focus of the study was to assess endothelial function after treatment with the ACE-NEP inhibitor AVE 7688 (30 mg/kg/day) in comparison to the ACE inhibitor (ACE-I) ramipril (1 mg/kg/day). Different parameters, such as endothelial function, blood pressure (BP), expansion of plaques, endothelial nitric oxide (NO) and superoxide (O2 ) release and plasma levels of various lipidaemic parameters were analysed. Control groups consisted of one group fed only with normal diet, one group fed only with atherogenic diet and the direct control group fed with varied diets (six weeks atherogenic diet followed by 12 weeks normal diet). Since for the treatment of atherosclerosis, a change in feeding is absolutely necessary, in the present study, at the start of the treatments with AVE 7688 and ramipril, the rabbits food was changed to a normal diet.

At the end of the study, mean arterial blood pressure (MAP) was measured in the anaesthetised animals. The values in standard, atherogenic and varied diet-fed rabbits were around 73±2 mmHg. Angiotensin I (Ang I) given intravenous (i.v.) induced a strong increase in MAP of about 20%. In both the treated groups Ang I-induced BP increase was inhibited. In contrast, i.v. bradykinin led to a strong reduction in MAP in both the treated groups of around 50%.

Six weeks' feeding with an atherogenic diet in the rabbits induced an enduring endothelial dysfunction despite the food subsequently being changed to a normal chow. All measured parameters indicated a significant favourable effect on endothelial dysfunction as a result of the two treatment regimens. Endothelial function measured in the organ chamber showed somewhat greater improvement in the ACE-NEP treated group than in the ACE-I treated group. The treatment with ramipril, as well as with AVE 7688, restored endothelial function by increasing the ratio of NO to O2- concentration and bioavailability of NO. In this study, a similar protective effect on endothelial function was shown by ACE-NEP inhibition as already seen with ACE inhibitors in an animal model of atherosclerosis.
Aldosterone and cardiovascular remodelling: focus on myocardial failure
Authors: Shieh Frederick K , Kotlyar Eugene , Sam Flora
Published: May 2007

Heart failure is a clinical syndrome that may result from different disease states or conditions that injure the myocardium. The activation of circulating neurohormones, particularly aldosterone, may play a pivotal role in left ventricular (LV) remodelling. The Randomized Aldactone Evaluation Study and Eplerenone Post-Acute Myocardial Infarction Heart Failure Efficacy and Survival trial have emphasised the clinical importance of aldosterone. This review addresses some of the proposed mechanisms of LV remodelling in heart failure.
Effect of candesartan and lisinopril alone and in combination on blood pressure and microalbuminuria
Authors: Morgan Trefor , Anderson Adrianne , Bertram Denise , MacInnis Robert Jeffrey
Published: May 2007

Background

Angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blocking drugs (ARB) block the effect of angiotensin II by different mechanisms. It has been suggested that combined therapy may be more effective at reducing blood pressure (BP) than higher doses of either drug.

Methods

Twenty-three elderly patients with systolic hypertension completed a double-blind crossover study comparing placebo, candesartan (C) 16 mg, C32 mg, lisinopril (L) 20 mg, L40 mg and C16 mg + L20 mg. Treatment periods were one month and ambulatory BP measurements were performed at the end of each period. The effects on albumin excretion in eight patients with microalbuminuria were determined.

Results

All treatments lowered BP. The falls in systolic and diastolic BP with C16, C32, L20 and L40 were similar. Plasma renin rose to a similar extent. A plateau effect was reached with C16 and L20. Systolic BP on the combination of C16 + L20 was lower than on each monotherapy (C16, 3.8 mmHg [p=0.002]; C32, 6.4 [0.0003]; L20, 2.9 [0.05]; L40, 3.3 [0.003]). The additional fall in BP with the combination appeared to be due to recruitment of non-responders, rather than to an additive effect in most patients. All treatments reduced microalbuminuria to a similar extent. The combination was well tolerated and there was no deterioration in renal function.

Conclusion

When patients are on a plateau dose of an ACE inhibitor or an ARB, addition of the other drug class has a small but significant incremental effect on BP in the overall group. However, some patients respond better to one drug class than to the other and this may explain the results. This study lends no support to the use of these two drugs in combination to treat hypertension.
Comparative study of the inhibitory effects of adrenomedullin on angiotensin II contraction in rat conductance and resistance arteries
Authors: Haulica Ion , Bild Walther , Mihaila Christian , Serban Dragomir N , Serban Lacramioara , Boisteanu Daniela , Ionita Teodor , Radasanu Oana
Published: May 2007

Adrenomedullin (ADM), a ubiquitous vasoactive peptide, has been the target of a multitude of studies concerning its effect on the vascular tone. The present work aims at clarifying a series of its interactions with the renin-angiotensin system.

The study uses the rat aorta ring as a model of conductance vessels, with or without vascular endothelium, and the second order branch of rat mesenteric arteries as a model of resistance arteries. Interactions between various concentrations of ADM and angiotensin II (Ang II) were studied, in the presence of L-NAME (a nitric oxide [NO] synthase inhibitor) and methylene blue (MB; a soluble guanylate cyclase inhibitor).

Results point out differences in the mechanism of the inhibitory action of ADM upon Ang II effects in the two vessel types studied. Inhibition of Ang II contraction by ADM involves guanylate cyclase in both cases. However, NO is involved in ADM-induced inhibition of angiotensinergic not in the resistance ones. vasoconstriction only in the conductance arteries, not in the resistance ones.
The epidemiology of heart failure
Authors: Tendera Michal
Published: May 2007

Heart failure is becoming increasingly common. More than 20 million people worldwide are estimated to have heart failure. Prevalence is rising because the population is ageing: in both men and women, the prevalence of heart failure in those aged 80–89 years is roughly 10 times the prevalence in those aged 50–59 years.

Coronary artery disease is now the most common cause of heart failure. Better treatment of myocardial infarction means that more people survive with impaired myocardial function, and some of these will develop heart failure in time. Hypertension is also an important contributing factor. Valvular disease, once a major cause of heart failure, has become less prevalent.

The median survival after diagnosis of heart failure was only 1.7 years for men and 3.2 years for women, according to Framingham data for the years 1948 to 1988. After five years, only 25% of men and 38% of women were still alive. Preventive and treatment measures have improved this picture somewhat: deaths from heart failure have decreased by about 12% per decade. However, heart failure continues to carry a grave prognosis.
Review: The revised role of ACE-inhibition after myocardial infarction in the thrombolytic/primary PCI era
Authors: de Kam Pieter J , Voors Adriaan A , Fici Francesco , van Veldhuisen Dirk J , van Gilst Wiek H
Published: May 2007

Many studies have investigated the process of left ventricular (LV) dilatation and the effects of angiotensin-converting enzyme (ACE) inhibitors after myocardial infarction (MI). It has been generally accepted that progression of LV dilatation is a major predictor of heart failure and death after MI. Also, attenuation of LV dilatation is thought to be one of the main mechanisms by which ACE inhibitors (ACE-Is) produce their beneficial effects. However, evidence for this hypothesis came from studies that were performed before thrombolytic therapy and primary percutaneous coronary intervention (PCI) were routinely used after acute MI. Nowadays, reperfusion is obtained much more frequently and LV dilatation after MI has become less prevalent. Nevertheless, ACE-Is proved effective in reducing cardiac morbidity and mortality. Therefore, mechanisms other than attenuation of LV dilatation, such as anti-atherosclerotic effects or plaque stabilisation, may explain the long-term beneficial effects of ACE-Is after MI.

In the present overview, we evaluate the role of LV dilatation and the effects of ACE-Is after MI in the thrombolytic/primary PCI era and provide recommendations on ACE-I use in clinical practice.
Elevated dietary sodium intake exacerbates myocardial hypertrophy associated with cardiac-specific overproduction of angiotensin II
Authors: Porrello Enzo R , Huggins Catherine E , Curl Claire L , Domenighetti Andrea A , Pedrazzini Thierry , Delbridge Leanne MD , Morgan Trefor O
Published: May 2007

Introduction/hypothesis

Cardiac hypertrophy is an independent risk factor predictive of cardiovascular disease and is significantly associated with morbidity and mortality. The mechanism by which angiotensin II (Ang II) and dietary sodium exert additive effects on the development of cardiac hypertrophy is unclear. The goal of this study was to evaluate the hypothesis that, where there is a genetic predisposition to Ang II-dependent hypertrophy, there is also an increased susceptibility to sodium-induced hypertrophy mediated by AT1-receptor expression.

Methods

Diets of low sodium (LS, 0.3% w:w) and high sodium (HS, 4.0% w:w) content were fed to adult (age 25 weeks) control wild-type mice (WT) and to weeks) control wild-type mice (WT) and to transgenic mice exhibiting cardiac specific overexpression of angiotensinogen (TG). At the conclusion of a 40-day dietary treatment period, cardiac tissue weights were compared and the relative expression levels of Ang II receptor subtypes (AT1A and AT2) were evaluated using RT-PCR.

Results

WT and TG mice fed HS and LS diets maintained comparable weight gains during the treatment period. The normalised heart weights of TG mice were elevated compared to WT, and the extent of the increase was greater for mice maintained on the HS diet treatments (WT 12% vs. TG 41% increase in cardiac weight index). While a similar pattern of growth was observed for ventricular tissues, the atrial weight parameters demonstrated an additional significant effect of dietary sodium intake on tissue weight, independent of animal genetic type. No differences in the relative (GAPDH normalised) expression levels of AT1A- and AT2-receptor mRNA were observed between diet or animal genetic groups.

Conclusion

This study demonstrates that, where there is a pre-existing genetic condition of Ang II-dependent cardiac hypertrophy, the pro-growth effect of elevated dietary sodium intake is selectively augmented. In TG and WT mice, this effect was evident with a relatively short dietary treatment intervention (40 days). Evaluation of the levels of Ang II receptor mRNA further demonstrated that this differential growth response was not associated with an altered relative expression of either AT1A- or AT2-receptor subtypes. The cellular mechanistic bases for this specific Ang II-dietary sodium interaction remain to be elucidated.
Angiotensin (1-7) re-establishes impulse conduction in cardiac muscle during ischaemia-reperfusion. The role of the sodium pump
Authors: De Mello Walmor C
Published: May 2007

Introduction

The effect of angiotensin (1-7) (Ang 1-7) on membrane potential and excitability of rat heart muscle under ischaemia/reperfusion was investigated.

Materials and methods

The hearts of adult rats were removed under deep anaesthesia and perfused using the Langendorff method. After 40 minutes of global no-flow ischaemia, the heart was reperfused for five minutes and the right ventricle was dissected out and transferred to a transparent chamber, through which normal oxygenated Krebs solution flowed continuously (37°C). Measurements of membrane potential were performed using an intracellular microelectrode connected to a high impedance preamplifier. The muscle was stimulated with rectangular current pulses (3 ms duration; 0.6 Hz) generated by an electronic stimulator and isolation unit. To study the influence of Ang (1-7) on sodium pump current, isolated myocytes were voltageclamped at -40 mV and the current generated by the pump was recorded before and after the administration of Ang (1-7) (10 M)to the bath.

Results

Results

Ang (1-7) (10-8 M) hyperpolarised the ischaemic heart fibre and re-established impulse propagation. The increment of resting potential was related to the activation of the sodium pump. Indeed, Ang (1-7) (10-8 M) enhanced the transient outward current generated by an electrogenic sodium pump. Both effects of Ang (1-7) on membrane potential and pump current were abolished by ouabain (10-7 M). The cardiac refractoriness was also increased by Ang (1-7) (10-8 M).

Conclusions

Ang (1-7) activates the sodium pump, hyperpolarises the heart cell and re-establishes the impulse conduction during ischaemia/reperfusion. These effects of Ang (1-7), and the increment of cardiac refractoriness, provide an explanation for the reduced incidence of arrhythmias during ischaemia/reperfusion in the presence of Ang (1-7).
Review: Molecular-specific effects of angiotensin II antagonists: clinical relevance to treating hypertension?
Authors: Reid John L
Published: May 2007

Angiotensin II receptor blockers (ARBs) may produce a number of molecule-specific effects that appear to be independent of interaction with the angiotensin II type 1 (AT1)-receptor. These include antagonism of the thromboxane A2receptor, inhibition of platelet aggregation, induction of peroxisome proliferator-activated receptor gamma (PPARγ) activity, and reduction of serum uric acid levels. However, definitive evidence is lacking that these molecule-specific effects give rise to a therapeutic advantage of one ARB over another. Currently, the possibility of a link between a molecule-specific effect of an ARB and an improvement in clinical outcomes is best illustrated by a reduction in serum uric acid levels with losartan. Data from Losartan Intervention For Endpoint reduction in hypertension (LIFE) study suggest treatment-induced decrease in serum uric acid may contribute to the treatment benefit of a losaran-based versus atenolol-based therapy on the composite endpoint (death, myocardial infarction, or stroke). This finding should prompt further studies to investigate the long-term cardioprotective benefits issue of reducing hyperuricaemia in hypertensive patients.
Effects of Intravenous PD 123319 on Haemodynamic and Arterial Stiffness Indices in Healthy Volunteers
Authors: Brillante Divina G , Johnstone Martina T , Howes Laurence G
Published: May 2007

Relatively little is known about the functional expression of cardiovascular angiotensin type 2 (AT2)-receptors in healthy young adult humans. We performed a randomised, placebo-controlled crossover study of the effects of intravenous administration of the selective AT2-receptor antagonist PD 123319 on haemodynamics and arterial stiffness in normal volunteers.

Sixteen normal subjects aged 29.9 ± 13.8 years (range 18—30 years) received an intravenous infusion of PD 123319 (10 mcg/minute for 5 minutes) and placebo, separated by one week. Haemodynamics (cardiac index, stroke index and systemic vascular resistance) were measured non-invasively using a BioZ.com thoracic impedance detection system. Blood pressure was measured from an arm cuff using oscillometry. Stiffness index, a measure of arterial stiffness, was measured using a PulseTrace recorder.

No significant changes in blood pressure (p=0.92), cardiac index (p=0.52), stroke index (p=0.61), systemic vascular resistance index (p=0.32) or stiffness index (p=0.57) was demonstrated following PD 123319 infusion, compared with placebo.

The results of this study do not support the functional presence of cardiovascular AT2receptors that mediate acute haemodynamic effects in healthy young adults. It remains possible that higher doses of PD 123319 may be required to demonstrate functional cardiovascular AT2-receptors in this population, if they are present.
Angiotensin Receptor Blockers: Cardiovascular Protection in the Metabolic Syndrome
Authors: Deedwania Prakash C , Schmieder Roland
Published: May 2007

It is well recognised that the metabolic syndrome, a constellation of risk factors including obesity, hypertension, insulin resistance and dyslipidaemia, is associated with an increased risk of cardiovascular complications and the development of Type 2 diabetes. Consequently, timely identification and management of all components of the metabolic syndrome is warranted. In particular, guidelines have emphasised the importance of targeting elevated blood pressure (BP) and dyslipidaemia as a method of reducing global cardiovascular risk.

Findings from the Valsartan Antihypertensive Long-term Use Evaluation (VALUE) trial show that the angiotensin receptor blocker, valsartan, reduces cardiovascular events and the development of Type 2 diabetes in high-risk individuals. This profile is being further explored in the ongoing Nateglinide And Valsartan in Impaired Glucose Tolerance Outcomes Research (NAVIGATOR) trial.

Given the potential advantages to patients and physicians of tackling more than one of the components of the metabolic syndrome, antihypertensive agents such as valsartan would appear to be an important addition to the management of vulnerable patients at high risk of cardiovascular events.
Vasopeptidase Inhibition Prevents Target Organ Damage and Improves Survival in Spontaneously Hypertensive Rats
Authors: Linz Wolfgang , Schäfer Stefan , Afkham Freni , Gerl Martin , Schmidts Hans-Ludwig , Rütten Hartmut
Published: May 2007

Background. Vasopeptidase inhibition has been shown to be an effective antihypertensive principle but its long-term effects on hypertensive target organ damage are not known. We investigated the myocardial, vascular and renal effects of chronic vasopeptidase inhibition in arterial hypertension.

Methods and Results. One hundred and thirty-nine male spontaneously hypertensive rats aged 15 months were treated chronically with either the pure angiotensin-converting enzyme (ACE) inhibitor, ramipril (1 mg/kg/d in drinking water, n=46), or the vasopeptidase inhibitor AVE7688 (30 mg/kg/d in chow, n=46), or placebo (n=47) and followed up until they died. After six months, both ramipril and AVE7688 had markedly reduced plasma ACE activity, normalised blood pressure (BP), reduced left ventricular mass and improved systolic function to similar extents. Acetylcholine mediated relaxation of aortic rings was improved by both ramipril and AVE7688. There was substantial albuminuria in the placebo group (albumin-to-creatinine ratio 107±54 µg/mg), which was significantly reduced by ramipril to 57±34 µg/mg, and practically abolished in the AVE7688 group (22±12 µg/mg, p<0.05 vs. placebo and ramipril).Tubulointerstitial damage (semi-quantitative score) was significantly reduced by AVE7688 and ramipril. significantly reduced byAVE7688 and ramipril. Overall mortality was markedly reduced in the ramipril and AVE7688 groups (13% and 16% at six months, respectively), both p<0.05 vs. placebo (71%).

Conclusions. Vasopeptidase inhibition effectively controls BP and reduces myocardial, vascular and renal target organ damage, resulting in a markedly prolonged survival.At similar degrees of plasma ACE inhibition, AVE7688 compared to ramipril offers superior protection against hypertensive kidney damage.
Cognitive Effects Attributed to Angiotensin II may Result from its Conversion to Angiotensin IV
Authors: Braszko Jan Jozef , Walesiuk Anna , Wielgat Przemyslaw
Published: May 2007

This study tests the hypothesis that the facilitation of learning and improvement of memory observed after an intracerebroventricular (i.c.v.) injection of angiotensin II (Ang II) is, in fact, caused by its derivative angiotensin IV (Ang IV). We ran two memory tests as well as an auxiliary test assessing motor performance in rats injected (i.c.v., 1 nmol in 2 μl saline) with Ang II or Ang IV. There were separate groups receiving peptide or saline five, 10 and 15 minutes before testing. Ang IV significantly increased step-through latencies in a passive avoidance paradigm as well as improved discrimination between familiar and unfamiliar objects in an object recognition test in all groups showing better retrieval of memory of aversive as well as appetitive stimuli in the peptide-treated groups regardless of the time of its injection. In contrast, rats treated with Ang II demonstrated significant improvement of memory of aversive and appetitive stimuli in the same tests only 15 minutes after its i.c.v. injection, with no effect in the groups injected five minutes before testing and slight efficacy in those injected 10 minutes before the test. Numbers of crossings, rearings and bar approaches in an `open' field were similar both in the peptide-treated and control groups making it unlikely that changes in motor performance affected the memory tests. In line with the present views on the intracellular metabolism of Ang II, these results suggest degradation to Ang IV by aminopeptidases A and N is necessary before the cognitive effects can occur.
Direct renin inhibition — a new way of targeting the renin system
Authors: Brown Morris J
Published: May 2007

The renin system plays a key role in the pathology of hypertension and is influenced, both directly and indirectly, by most antihypertensive agents. The system is the target of several established classes of antihypertensive agents including angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and beta-blockers. Of currently available drugs, only the beta-blockers suppress renin secretion, but these also reduce heart rate and cardiac output. Calcium channel blockers and diuretics cause a modest activation of the renin system secondary to the fall in renal afferent arteriolar pressure and reduction in filtered sodium load. Aliskiren is the first orally available direct inhibitor that blocks the renin system at its rate limiting step and is shown to reduce angiotensin I and II and plasma renin activity.
Early, but not late therapy with a vasopressin V1a-antagonist ameliorates the development of renal damage after 5/6 nephrectomy
Authors: Windt Willemijn AKM , Tahara Atsua , Kluppel Alex CA , de Zeeuw Dick , Henning Robert H , van Dokkum Richard PE
Published: May 2007

Introduction. Vasopressin, mainly through the V1a-receptor, is thought to be a major player in the maintenance of hyperfiltration. Its inhibition could therefore lead to a decrease in progression of chronic renal failure.To this end, the effect of the vasopressin V1a-receptor-selective antagonist, YM218, was studied on proteinuria and focal glomerulosclerosis in early and late intervention after 5/6 nephrectomy in rats, and compared with an angiotensin-converting enzyme inhibitor (ACE-I).

Materials and methods. After 5/6 nephrectomy, early intervention was performed between week 2 and 10 thereafter with the V1a-receptor-selective antagonist (VRA, 10 mg/kg/day, n=10), enalapril (ACE-I, 10 mg/kg/day, n=9), or vehicle (n=8). Late intervention was performed in another group between week 6 and 12 with VRA (10 mg/kg/day, n=7), lisinopril (ACE-I, 5 mg/kg/day, n=7), or vehicle (n=7).

Results. In early intervention, proteinuria and focal glomerulosclerosis were significantly decreased by VRA compared to vehicle (44 7% and 59+8% respectively). ACE-I significantly decreased proteinuria (67 7%) and a trend towards a decrease in focal glomerulosclerosis was observed (30 18%). In late intervention, VRA did not decrease proteinuria and focal glomerulosclerosis compared to vehicle (21 20% and 0%, respectively),ACE-I significantly lowered proteinuria (92 2%) and a focal glomerulosclerosis (69+1%) lowering trend was observed.

Conclusion. These results indicate that VRA may protect against early progression of renal injury after 5/6 nephrectomy, whereas its effectiveness seems limited in established renal damage.
What Is Priapism?
Authors: Asanad Kian , Halpern Joshua A. , Brannigan Robert E.
Published: March 2024

This JAMA Patient Page describes the diagnosis, prevention, and treatment of priapism.
The State of Health Insurance Coverage and the 2024 Election
Authors: Glied Sherry
Published: March 2024

This JAMA Forum discusses record health insurance enrollments and the risks to continuing gains in coverage.
Citations of microRNA Biomarker Articles That Were Retracted
Authors: Zhu Hongmei , Jia Yongliang , Leung Siu-wai
Published: March 2024

Importance

Retraction is a tool that journals can use to deter research misconduct and alert their audience to erroneous content published in the journals. However, retracted articles may continue to damage science if they are still cited as legitimate articles.

Objective

To characterize patterns of postretraction citations, particularly in microRNA biomarker research, a field with one of the highest rates of retraction.

Evidence Review

Retracted scientific articles on microRNAs were retrieved from PubMed, Web of Science, and Retraction Watch between database inception and July 17, 2021, according to preestablished search strategies. Control articles with characteristics in common with retracted articles (ie, published in the same journals in the same years and months and with the same number of authors) were matched and retrieved from PubMed. Citation metrics of retractions and control articles were collected from Web of Science. PubPeer was referenced to examine the public response or comments on included retractions. Data were analyzed from September 2021 through March 2023.

Findings

A total of 10 461 articles were analyzed, with 887 retractions and 9574 articles as controls. Among retracted articles, which were published from 1999 to 2021, there were 756 articles (85.23%) written by researchers affiliated with Chinese institutions. Retracted articles were cited 6327 times after retraction. Of 792 retracted articles that were cited, 621 articles (78.41%) were cited at least once after retraction and 238 articles (30.05%) were cited more often after retraction than before retraction. Overall citations (comprising citations before and after retraction) and postretraction citations accumulated over time (eg, the median [IQR] number of postretraction citations was 1 [1-2] and 23 [9-44] citations at the first 6 and 66 months, respectively, between retraction and citation retrieval). A random sample of 87 retracted articles (9.81%) recorded 478 citations after retraction, with 208 citations (43.51%) in articles published 12 months or longer after retraction. Of these citing articles, 19 articles (3.97%) mentioned the retractions. Compared with the control group of 1620 nonretracted articles, no significant differences were found in overall number of citations or citations after retraction. Among 478 articles citing retracted articles, 414 articles were found on PubMed and had matched control articles; these articles had higher odds of being subsequently retracted than 7954 matched control articles (odds ratio, 6.57; 95% CI, 3.39-12.72).

Conclusions and Relevance

In this study, retraction was not associated with a reduction in citations of retracted articles, but articles that cited retracted publications had higher odds of later retraction. These findings suggest that journals may need to implement mechanisms for detection of postretraction citations.
Prevalence of Lung Cancer Screening in the US, 2022
Authors: Henderson Louise M. , Su I-Hsuan , Rivera M. Patricia , Pak Joyce , Chen Xiaomeng , Reuland Daniel S. , Lund Jennifer L.
Published: March 2024

This cross-sectional study compares lung cancer screening prevalence in 2022 among individuals eligible by 2021 vs 2013 criteria by sociodemographics and state.
Molecular analysis of the extracellular microenvironment: from form to function
Authors: Macdonald Jade K. , Mehta Anand S. , Drake Richard R. , Angel Peggi M.
Published: March 2024

The extracellular matrix (ECM) proteome represents an important component of the tissue microenvironment that controls chemical flux and induces cell signaling through encoded structure. The analysis of the ECM represents an analytical challenge through high levels of post‐translational modifications, protease‐resistant structures, and crosslinked, insoluble proteins. This review provides a comprehensive overview of the analytical challenges involved in addressing the complexities of spatially profiling the extracellular matrix proteome. A synopsis of the process of synthesizing the ECM structure, detailing inherent chemical complexity, is included to present the scope of the analytical challenge. Current chromatographic and spatial techniques addressing these challenges are detailed. Capabilities for multimodal multiplexing with cellular populations are discussed with a perspective on developing a holistic view of disease processes that includes both the cellular and extracellular microenvironment.
Understanding the Room Temperature Recovery Behavior in a Ti–24Nb–4Zr–8Sn Superelastic Alloy
Authors: Reed Oliver G. , Church Nicole L. , Jones Nicholas G.
Published: March 2024

Metastable β Ti–Nb‐based superelastic alloys have potential uses in the biomedical and aerospace industries due to an attractive combination of properties. However, their mechanical response can be seen to vary with cycling, limiting their uptake. Furthermore, recent studies have also highlighted changes in properties under no applied stress at room temperature, with the reasons for these changes poorly understood. To investigate potential mechanisms for these changes, the superelastic behavior of Ti–2448 is studied during mechanical cycling both pre‐ and post‐room temperature (RT) aging treatments. On cycling, there is a reduction in both σSIM and hysteresis area, consistent with behavior commonly seen in the literature. However, during RT aging, there is a rapid, time‐dependent process leading to a partial recovery. In situ diffraction data indicated that this recovery is coincident with a reduction in internal stresses, the potential mechanisms for which are discussed.
Folded Well‐Defined 3D Architecture from Synthetic Helical and Sheet‐Like Polymers
Authors: Wang Chengyuan , Mann Arielle , Hannigan Matthew D. , Garvey Regina H. , Dumlao Bianca L. , Weck Marcus
Published: March 2024

The fabrication of truly hierarchically folded single‐chain polymeric nanoparticles with primary, secondary, and defined 3D architecture is still an unfulfilled goal. In this contribution, a polymer is reported that folds into a well‐defined 3D structure from a synthetic sheet‐helix block copolymer. The sheet‐like poly(p‐phenylene vinylene) (PPV) block is synthesized via the ring‐opening metathesis polymerization of a thymine‐bearing dialkoxy‐substituted [2.2]paracyclophane‐1,9‐diene. The PPV block is terminated with a Pd complex using a Pd‐containing chain‐terminating agent. The terminal Pd complex catalyzes the polymerization of isocyanide monomers with side‐chains containing either a chiral menthol or an achiral diaminopyridine resulting in the formation of a helical poly(isocyanide) (PIC) random copolymer. The PIC side‐chains are capable of engaging in complementary hydrogen‐bonding with thymine units along the PPV block resulting in the folding of the two secondary structural domains into a well‐defined 3D structure. The folding and unfolding of the polymer in both chloroform and THF are monitored using dynamic light scattering and NMR spectroscopy. This work is the first example of a hierarchically folded synthetic polymer featuring a defined 3D structure achieved by using two different polymer backbones with two distinct secondary structures.
Injectable pH‐Responsive CI1040 Delayed‐Release Hydrogel for the Treatment of Tendon Adhesion
Authors: Wu Rongpu , Pang Sa , Lv Wenxin , Zou Jian , Li Yuange , Li Yanhao , He Jibing , Gu Hengyu , Wang Yiting , Guan Yuanyuan , Peng Xiaochun , Wang Yi , Liu Shen
Published: March 2024

Tendon injuries, often leading to debilitating adhesions, pose significant challenges in clinical practice. Conventional treatments have limitations, necessitating novel strategies. Injectable hydrogels, known for their biocompatibility, have shown promise. To enhance their antiadhesive properties, researchers have started incorporating drugs. Existing drug delivery systems often peak in the initial days, falling short during the fibroblast proliferation phase which occurs ≈1 week after injury. In this research, CI1040 is selected as an antiadhesion drug, encapsulated within zeolitic imidazolate framework‐8(ZIF‐8), and incorporated into oxidized hyaluronic acid/N‐carboxyethyl chitosan(OHA/CEC) hydrogel(Gel), resulting in the synthesis of CI1040@ZIF@Gel. This unique pH‐responsive drug release system involves encapsulating CI1040 within ZIF‐8, a substance that degrades under acidic conditions while remaining stable in physiological environments. This system selectively releases the drug during the fibroblast proliferation phase, responding to the localized pH reduction post‐tendon injury. CI1040@ZIF@Gel exerted a 65% inhibition on extracellular signal‐regulated kinase (ERK) phosphorylation, reducing the production of collagen types III (Col III) in the adhesion area by 56%. These results indicate that CI1040@ZIF@Gel can effectively inhibit fibroblast proliferation and adhesion through the interleukin 9 receptor/mitogen‐activated protein kinase/extracellular signal‐regulated kinase(IL9r/MEK/ERK) pathway, while also acting as a physical barrier to prevent the formation of tendon adhesion.
Research Advances in Magnetic Field‐Assisted Photocatalysis
Authors: Li Ru , Qiu Li‐Peng , Cao Shi‐Ze , Li Zhi , Gao Shi‐Long , Zhang Jun , Ramakrishna Seeram , Long Yun‐Ze
Published: March 2024

Solar‐to‐chemical energy conversion thorugh photocatalytic technology has garnered significant attention due to its potential for clean hydrogen pro duction, pollutant degradation, and carbon dioxide reduction. However, its relatively low solar‐to‐chemical conversion efficiency hinders its industrial development. External fields have currently emerged as a supplementary energy source to augment the overall catalytic efficiency. Recently, the photocatalytic performance has been considerably enhanced through magnetic field modulation, which promotes the separation and transfer of photoexcited charge carriers. This article systematically reviews the recent research progress of magnetic field–assisted photocatalysis, discussing phenomena such as the negative magnetoresistance effect, Lorentz force, and spin polarization. It comprehensively analyzes the effect of magnetic fields on critical processes in photocatalysis: light absorption, charge‐carrier separation, and surface reactions. In particular, this review focuses on the spin‐relaxation mechanism, explains how the electron lifetime is extended through spin polarization, and proposes design strategies for spin‐polarized materials. Finally, this review discusses the challenges and potential opportunities for enhancing photocatalytic efficiency. The ultimate objective of this review is to offer notable theoretical and experimental insights that can guide the design and development of high‐performance photocatalysts and photocatalytic systems.
[2.2]Paracyclophane‐Substituted Chiral Multiresonant Thermally Activated Delayed Fluorescence Emitters for Efficient Organic Light‐Emitting Diodes
Authors: Xu Yan , Hafeez Hassan , Seibert Jasmin , Wu Sen , Ortiz Jhon Sebastian Oviedo , Crassous Jeanne , Bräse Stefan , Samuel Ifor D. W. , Zysman‐Colman Eli
Published: March 2024

The study reports two pairs of chiral multi‐resonant thermally activated delayed fluorescence (MR‐TADF) materials PCP‐DiKTa and Czp‐DiKTa by decorating a known MR‐TADF core, DiKTa, with different [2.2]paracyclophane (PCP) based planar chiral groups. PCP‐DiKTa shows narrow sky‐blue emission with a full width at half maximum (FWHM) of 44 nm, while the emission of Czp‐DiKTa is slightly broader with a FWHM of 66 nm and redshifted. Both emitters show high photoluminescence quantum yields of 93 and 99% for PCP‐DiKTa and Czp‐DiKTa, respectively. Enantiomerically pure samples of both compounds show chiroptical properties in the ground state while only Czp‐DiKTa exhibits chiroptical activity in the excited state, with dissymmetry factors (|gPL|) of 4 × 10−4. Organic light‐emitting diodes (OLEDs) with PCP‐DiKTa and Czp‐DiKTa show maximum external quantum efficiencies (EQEmax) of 25.7 and 29.2%, with λEL of 489 and 518 nm, and FWHMs of 53 and 69 nm, respectively. These EQEmax values are higher than those of other reported devices employing PCP‐based D‐A type emitters. This work demonstrates that the PCP moiety is not only a powerful building block to develop planar chiral emitters but one that is compatible with the fabrication of high efficiency devices.
Synergistic Regulation of Crystallization Kinetics of Donor/Acceptor by New Volatile Additives for High Performance Organic Solar Cells
Authors: Xie Jiaping , Deng Jiawei , Pei Yaqi , Jeong Sang Young , Huang Bin , Zhou Dan , Woo Han Young , Xu Junying , Wu Feiyan , Chen Lie
Published: March 2024

Ideal nanoscale morphology of heterojunction active layer is important for the development of organic solar cells (OSCs). However, the mismatched crystalline kinetic between the polymer donor and small molecular acceptor often leads to the difficulties in controlling the morphology of the active layer. Herein, polar 1,2‐dibromo‐4,5‐difluorobenzene (DFB) and non‐polar 1,4‐dibromotetrafluorobenzene (TFB) are developed as the volatile additives for OSCs. More attractively, different from the reported volatile additives, both new volatile additives can simultaneously interact with donor and acceptor, synergistic regulating the crystallization kinetic and well‐balancing the crystallization behaviors between the polymer donor and small molecular acceptor during film formation process. Notably, due to the stronger dipole‐dipole interactions with active layer, polar DFB induces the more favorable film morphology than non‐polar TFB. As a result, the two additives‐treated PM6:Y6 devices both outperform the CN‐treated device (16.13%), and the polar DFB‐treated device deliver a higher efficiency of 17.15% than non‐polar TFB‐treated one (16.30%). With polar DFB additive, PM6:L8‐BO and PM6: BTP‐eC9 also achieve superior efficiency of 18.46% and 18.17%, respectively. This work deepens the insights of regulating crystallization kinetics and optimizing nanoscale morphology by developing simple volatile additives for further achieving high‐efficient OSCs.
One Stone Three Birds: Silver Sulfadiazine Modulates the Stability and Dynamics of Hydrogels for Infected Wound Healing
Authors: Huang Ye , Kang Haifei , Wang Yue , Liu Kun , Wei Wenying , Dai Honglian
Published: March 2024

Dynamic covalent bond hydrogels have demonstrated significant application potential in biomedical fields for their dynamic reversibility. However, the contradiction between the stability and dynamics of the hydrogel restricts its application. Here, utilizing silver sulfadiazine (AgSD) as a catalyst, hyaluronic acid‐based hydrogels are constructed through imine bond crosslinking and incorporated disulfide bonds within the same crosslinking chain. It is found that AgSD can accelerate the formation of imine crosslinking bonds to improve the stability of hydrogels, thereby shortening the gelation time by ≈36.9 times, enhancing compression strength and adhesion strength by ≈2.4 times and 1.7 times, respectively, while inhibiting swelling and degradation rates to ≈2.1 times and 3.7 times. Besides, AgSD can coordinate with disulfide bonds to enhance the dynamics of hydrogel, enhancing the hydrogel self‐healing efficiency by ≈2.3 times while reducing the relaxation time by ≈25.1 times. Significantly, AgSD imparts remarkable antibacterial properties to the hydrogel, thereby effectively facilitating the healing of bacterial infected wounds. Consequently, introducing AgSD enables hydrogels to possess concurrent stability, dynamics, and antibacterial properties. This strategy of regulating hydrogels by introducing AgSD provides a valuable reference for the application of dynamic covalent bonds.
Polymerizing M‐Series Acceptors for Efficient Polymer Solar Cells: Effect of the Molecular Shape
Authors: Zhu Yuhang , Guo Hui , Xiong Xiaoying , Cai Dongdong , Ma Yunlong , Zheng Qingdong
Published: March 2024

Currently, high‐performance polymerized small‐molecule acceptors (PSMAs) based on ADA‐type SMAs are still rare and greatly demanded for polymer solar cells (PSCs). Herein, two novel regioregular PSMAs (PW‐Se and PS‐Se) are designed and synthesized by using centrosymmetric (linear‐shaped) and axisymmetric (banana‐shaped) ADA‐type SMAs as the main building blocks, respectively. It is demonstrated that photovoltaic performance of the PSMAs can be significantly improved by optimizing the configuration of ADA‐type SMAs. Compared to the axisymmetric SMA‐based polymer (PS‐Se), PW‐Se using a centrosymmetric SMA as the main building block exhibits better backbone coplanarity thereby resulting in bathochromically shifted absorption with a higher absorption coefficient, tighter interchain π–π stacking, and more favorable blend film morphology. As a result, enhanced and more‐balanced charge transport, better exciton dissociation, and reduced charge recombination are achieved for PW‐Se‐based devices with PM6 as polymer donor. Benefiting from these positive factors, the optimal PM6:PW‐Se‐based device exhibits a higher power conversion efficiency (PCE) of 15.65% compared to the PM6:PS‐Se‐based device (8.90%). Furthermore, incorporation of PW‐Se as a third component in the binary active layer of PM6:M36 yields ternary devices with an outstanding PCE of 18.0%, which is the highest value for PSCs based on ADA‐type SMAs, to the best of the knowledge.
Memristive Explainable Artificial Intelligence Hardware
Authors: Song Hanchan , Park Woojoon , Kim Gwangmin , Choi Moon Gu , In Jae Hyun , Rhee Hakseung , Kim Kyung Min
Published: March 2024

Artificial intelligence (AI) is often considered a black box because it provides optimal answers without clear insight into its decision‐making process. To address this black box problem, explainable artificial intelligence (XAI) has emerged, which provides an explanation and interpretation of its decisions, thereby promoting the trustworthiness of AI systems. Here, a memristive XAI hardware framework is presented. This framework incorporates three distinct types of memristors (Mott memristor, valence change memristor, and charge trap memristor), each responsible for performing three essential functions (perturbation, analog multiplication, and integration) required for the XAI hardware implementation. Three memristor arrays with high robustness are fabricated and the image recognition of 3 × 3 testing patterns and their explanation map generation are experimentally demonstrated. Then, a software‐based extended system based on the characteristics of this hardware is built, simulating a large‐scale image recognition task. The proposed system can perform the XAI operations with only 4.32% of the energy compared to conventional digital systems, enlightening its strong potential for the XAI accelerator.
Chain‐Like Semiconductive Fillers for Dielectric Enhancement and Loss Reduction of Polymer Composites
Authors: Wu Xudong , Karlin Anat , Beilin Vadim , Shter Gennady E. , Grader Gideon S. , Ivry Yachin , Lin Shuheng , Tan Daniel Q.
Published: March 2024

Dielectric loss is a crucial factor in determining the long‐term endurance for security and energy loss of dielectric composites. Here, chain‐like semiconductive fibers of titanium oxide, indium, and niobium‐doped titanium oxide are used for enhancing the complex dielectric properties of a polymer through composite construction, which involves significant interface enhancements. The chain‐like fibers significantly enhance the dielectric constant owing to the special morphology of the fillers and their interfacial polarization, especially at higher temperatures. The dielectric loss and electrical conductivity of the composites are substantially reduced across the entire investigated temperature range, achieved by passivating the fiber surface with an alumina shell using atomic layer deposition. The as‐deposited alumina shell transformed from an amorphous to a crystalline phase through thermal annealing results in a porous shell and more effective suppression of the loss tangent and electrical conductivity. A plausible mechanism for loss suppression is associated with carrier movement along the surface of the fibers and bulk, leading to a higher loss tangent. The alumina shell blocks the carrier transport path, particularly at the interfaces, resulting in a reduced interfacial polarization contribution and energy storage loss. This study provides a method for inhibiting dielectric loss by fabricating fillers with special surfaces.
Porous Titanium/SF Sponge Composite Scaffold with Loads of Gentamicin and Small Extracellular Vesicles to Improve Antibacterial and Osteogenesis Properties
Authors: Li Xiang , Zhang Hanxu , Xiong Yin‐Ze , Wang Bibo
Published: March 2024

Additive manufacturing has been widely used for producing porous titanium orthopedic implants. However, the higher surface area inherent to porous structures increases the risk of bacterial colonization. In this work, composite scaffolds with dual functions of the antibacterial and osteogenesis promotion properties are developed. The porous titanium is fabricated using a selective laser melting process to provide mechanical support. Silk fibrin (SF) sponge‐loading gentamicin and extracellular vesicles (EVs) are prepared in the pores of the porous titanium. The developed composite scaffolds are investigated for their antibacterial and osteogenesis effects. The samples exhibit well antibacterial activity against Escherichia coli. The samples also show good cytocompatibility, effectively promoting the adhesion and proliferation of the bone marrow mesenchymal stem cells (rBMSCs). EVs significantly promote the expression of osteogenesis‐related genes in rBMCSs and the superior extracellular matrix mineralization reveals that EVs have a remarkable role in enhancing osteogenic differentiation. Therefore, the composite scaffolds with dual functions of antibacterial and osteogenesis promotion properties have excellent potential for orthopedic implant applications.