Correction: Vat photopolymerization-based 3D printing of polymer nanocomposites: current trends and applications.

[This corrects the article DOI: 10.1039/D2RA06522C.].

Vat photopolymerization-based 3D printing of polymer nanocomposites: current trends and applications.

The synthesis and manufacturing of polymer nanocomposites have garnered interest in recent research and development because of their superiority compared to traditionally employed industrial materials. Specifically, polymer nanocomposites offer higher strength, stronger resistance to corrosion or erosion, adaptable production techniques, and lower costs. The vat photopolymerization (VPP) process is a group of additive manufacturing (AM) techniques that provide the benefit of relatively low cost, maximum flexibility, high accuracy, and complexity of the printed parts. In the past few years, there has been a rapid increase in the understanding of VPP-based processes, such as high-resolution AM methods to print intricate polymer parts. The synergistic integration of nanocomposites and VPP-based 3D printing processes has opened a gateway to the future and is soon expected to surpass traditional manufacturing techniques. This review aims to provide a theoretical background and the engineering capabilities of VPP with a focus on the polymerization of nanocomposite polymer resins. Specifically, the configuration, classification, and factors affecting VPP are summarized in detail. Furthermore, different challenges in the preparation of polymer nanocomposites are discussed together with their pre- and post-processing, where several constraints and limitations that hinder their printability and photo curability are critically discussed. The main focus is the applications of printed polymer nanocomposites and the enhancement in their properties such as mechanical, biomedical, thermal, electrical, and magnetic properties. Recent literature, mainly in the past three years, is critically discussed and the main contributing results in terms of applications are summarized in the form of tables. The goal of this work is to provide researchers with a comprehensive and updated understanding of the underlying difficulties and potential benefits of VPP-based 3D printing of polymer nanocomposites. It will also help readers to systematically reveal the research problems, gaps, challenges, and promising future directions related to polymer nanocomposites and VPP processes.

Dysautonomia Causing Severe Orthostatic Hypotension: An Important, Early Finding in Neurodegenerative Disorders.

Orthostatic hypotension is common and dangerous; it has neurogenic and nonneurogenic causes. We present the case of a 40-year-old man with severe neurogenic hypotension, caused by young-onset multiple system atrophy. In patients presenting with neurogenic orthostatic hypotension, underlying neurodegenerative diseases should always be considered. (Level of Difficulty: Advanced.).

Attenuation of Splanchnic Autotransfusion Following Noninvasive Ultrasound Renal Denervation: A Novel Marker of Procedural Success.

BACKGROUND: Renal denervation has no validated marker of procedural success. We hypothesized that successful renal denervation would reduce renal sympathetic nerve signaling demonstrated by attenuation of α-1-adrenoceptor-mediated autotransfusion during the Valsalva maneuver. METHODS AND RESULTS: In this substudy of the Wave IV Study: Phase II Randomized Sham Controlled Study of Renal Denervation for Subjects With Uncontrolled Hypertension, we enrolled 23 subjects with resistant hypertension. They were randomized either to bilateral renal denervation using therapeutic levels of ultrasound energy (n=12) or sham application of diagnostic ultrasound (n=11). Within-group changes in autonomic parameters, office and ambulatory blood pressure were compared between baseline and 6 months in a double-blind manner. There was significant office blood pressure reduction in both treatment (16.1±27.3 mm Hg, P<0.05) and sham groups (27.9±15.0 mm Hg, P<0.01) because of which the study was discontinued prematurely. However, during the late phase II (Iii) of Valsalva maneuver, renal denervation resulted in substantial and significant reduction in mean arterial pressure (21.8±25.2 mm Hg, P<0.05) with no significant changes in the sham group. Moreover, there were significant reductions in heart rate in the actively treated group at rest (6.0±11.5 beats per minute, P<0.05) and during postural changes (supine 7.2±8.4 beats per minute, P<0.05, sit up 12.7±16.7 beats per minute, P<0.05), which were not observed in the sham group. CONCLUSIONS: Blood pressure reduction per se is not necessarily a marker of successful renal nerve ablation. Reduction in splanchnic autotransfusion following renal denervation has not been previously demonstrated and denotes attenuation of (renal) sympathetic efferent activity and could serve as a marker of procedural success. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02029885.

Recovery from Cogwheel Rigidity and Akinesia and Improvement in Vibration Sense and Olfactory Perception following Removal of an Epoxy-Oleic Acid DNA Adduct.

The epoxy fatty acid cis-12,13-epoxy-oleic acid, which acts as a DNA adduct, may be generated during long-term storage of many seed oils, including those used in cooking, with frying oils and fried foods being a major source in the modern human diet. Removal of this epoxy fatty acid from the locus of the N-formyl peptide receptors was associated with recovery from cogwheel rigidity and akinesia as well as with improvement in vibration sense and olfactory perception.

A Discussion on the Regulation of Blood Flow and Pressure.

This paper discusses two kinds of regulation essential to the circulatory system: namely the regulation of blood flow and that of (systemic) arterial blood pressure. It is pointed out that blood flow requirements sub-serve the nutritional needs of the tissues, adequately catered for by keeping blood flow sufficient for the individual oxygen needs. Individual tissue oxygen requirements vary between tissue types, while highly specific for a given individual tissue. Hence, blood flows are distributed between multiple tissues, each with a specific optimum relationship between the rate of oxygen delivery (DO2) and oxygen consumption (VO2). Previous work has illustrated that the individual tissue blood flows are adjusted proportionately, where there are variations in metabolic rate and where arterial oxygen content (CaO2) varies. While arterial blood pressure is essential for the provision of a sufficient pressure gradient to drive blood flow, it is applicable throughout the arterial system at any one time. Furthermore, It is regulated independently of the input resistance to individual tissues (local arterioles), since they are regulated locally, that being the means by which the highly specific adequate local requirement for DO2 is ensured. Since total blood flow is the summation of all the individually regulated tissue blood flows cardiac inflow (venous return) amounts to total tissue blood flow and as the heart puts out what it receives cardiac output is therefore determined at the tissues. Hence, regulation of arterial blood pressure is independent of the distributed independent regulation of individual tissues. It is proposed here that mechanical features of arterial blood pressure regulation will depend rather on the balance between blood volume and venous wall tension, determinants of venous pressure. The potential for this explanation is treated in some detail.

Hyperosmia in Lyme disease.

Neurological involvement in Lyme disease has been reported to include meningitis, cranial neuropathy and radiculoneuritis. While it is known that in some cases of asceptic meningitis patients may develop hyperosmia, the association between hyperosmia and Lyme disease has not previously been studied. Objective To carry out the first systematic study to ascertain whether hyperosmia is also a feature of Lyme disease. Method A questionnaire regarding abnormal sensory sensitivity in respect of the sense of smell was administered to 16 serologically positive Lyme disease patients and to 18 control subjects. Results The two groups were matched in respect of age, sex and body mass. None of the 34 subjects was suffering from migraine. Eight (50%) of the Lyme patients and none (0%) of the controls suffered from hyperosmia (p=0.0007). Conclusion This first systematic controlled study showed that Lyme disease is associated with hyperosmia.

Hyperosmia in Lyme disease / Hyperosmia na doença de Lyme

Neurological involvement in Lyme disease has been reported to include meningitis, cranial neuropathy and radiculoneuritis. While it is known that in some cases of asceptic meningitis patients may develop hyperosmia, the association between hyperosmia and Lyme disease has not previously been studied. Objective To carry out the first systematic study to ascertain whether hyperosmia is also a feature of Lyme disease. Method A questionnaire regarding abnormal sensory sensitivity in respect of the sense of smell was administered to 16 serologically positive Lyme disease patients and to 18 control subjects. Results The two groups were matched in respect of age, sex and body mass. None of the 34 subjects was suffering from migraine. Eight (50%) of the Lyme patients and none (0%) of the controls suffered from hyperosmia (p=0.0007). Conclusion This first systematic controlled study showed that Lyme disease is associated with hyperosmia. .

Tem sido descrito acometimento neurológico na doença de Lyme: meningite, neuropatia de nervos cranianos, e radiculoneurite. É bem conhecida a ocorrência de hiperosmia em alguns casos de meningites assépticas, mas a associação de hiperosmia com doença de Lyme ainda não foi relatada. Objetivo Conduzir um estudo sistemático para investigar se a hiperosmia é característica também da doença de Lyme. Método Foi aplicado um questionário pesquisando a ocorrência de sensibilidade anormal em relação ao sentido da olfação a 16 pacientes com sorologia positiva para doença de Lyme e a 18 controles normais. Os dois grupos foram pareados em relação a idade, sexo e massa corporal. Nenhum dos 34 sujeitos sofria de enxaqueca. Resultados Foi detectada hiperosmia em 8 sujeitos com doença de Lyme (50%) enquanto que a hiperosmia não apareceu em nenhum sujeito do grupo controle (p=0,0007). Conclusão Doença de Lyme está associada à hiperosmia. .

Respiratory modulation of cardiac vagal tone in Lyme disease.

AIM: To conduct the first systematic test of the hypothesis that modulation of cardiac vagal tone is impaired in Lyme disease. METHODS: The response of cardiac vagal tone to respiratory modulation was measured in 18 serologically positive Lyme disease patients and in 18 controls. RESULTS: The two groups were matched in respect of age, sex, body mass, mean arterial blood pressure, mean resting heart rate and mean resting cardiac vagal tone. The mean maximum cardiac vagal tone during deep breathing in the Lyme disease patients [11.2 (standard error 1.3)] was lower than in the matched controls [16.5 (standard error 1.7); P = 0.02]. CONCLUSION: Respiratory modulation of cardiac vagal tone is impaired in Lyme disease, which suggests that Lyme disease may directly affect the vagus nerve or the brainstem.

The association of lyme disease with loss of sexual libido and the role of urinary bladder detrusor dysfunction.

PURPOSE: The primary aim was to carry out a pilot study to compare the loss of sexual libido between a group of Lyme disease patients and a group of matched controls. The secondary aim was to evaluate whether loss of libido in Lyme disease patients is associated with urinary bladder detrusor dysfunction. METHODS: A group of 16 serologically positive Lyme disease patients and 18 controls were queried directly about loss of libido. RESULTS: The 2 groups were matched with respect to age, sex, body mass index, and mean arterial blood pressure. None of the 34 subjects was taking medication that might affect sexual libido or had undergone a previous operative procedure involving the genitourinary tract. Of the 16 Lyme disease patients, 8 (50%) had no loss of libido, and of the 18 controls, none had loss of libido (P<0.001). In the Lyme disease patient group, there was no statistically significant relationship between loss of libido and urinary bladder detrusor dysfunction (P=0.61). CONCLUSIONS: This pilot study suggested an association between Lyme disease and loss of libido. Moreover, this loss of libido did not seem to be associated with urinary bladder detrusor dysfunction. Given these results, we recommend further studies to confirm the association.

Urinary bladder detrusor dysfunction symptoms in lyme disease.

PURPOSE: Symptoms of urinary bladder detrusor dysfunction have been rarely reported in Lyme disease. The aim was to carry out the first systematic study to compare the prevalence of such symptoms in a group of Lyme disease patients and a group of matched controls. METHODS: A questionnaire relating to detrusor function was administered to 17 serologically positive Lyme disease patients and to 18 control subjects. RESULTS: The two groups were matched in respect of age, sex, body mass, and mean arterial blood pressure. None of the 35 subjects was taking medication which might affect urinary function and none had undergone a previous operative procedure on the lower urinary tract. Six of the Lyme patients (35%) and none of the controls (0%) had symptoms of detrusor dysfunction (P<0.01). CONCLUSIONS: This first systematic controlled study confirms that Lyme disease is associated with urinary bladder detrusor dysfunction. Further evaluation of detrusor function is warranted in this disease.

Abnormality of taste and smell in Parkinson's disease.

BACKGROUND: Smell sense is impaired in classic Parkinson's disease (PD). An initial study found no change in taste threshold in non-demented PD subjects and pathological studies suggest that the first relay for taste, the nucleus of the solitary tract, is spared. We wished to determine if taste is abnormal in PD and whether it is associated with smell dysfunction. METHODS: Taste threshold was estimated using the Rion electrogustometer and olfaction by the University of Pennsylvania Smell Identification Test (UPSIT) in 75 non-demented PD patients and 74 controls. RESULTS: There was a significant impairment of taste threshold and severe disorder of smell identification in the PD group. Age, duration of symptoms, disability, and smoking had no important effect on threshold measurement and there was no correlation between taste and smell dysfunction. Sensitivity analysis suggested that a provisional diagnosis of PD would be confirmed if smell or taste were abnormal; conversely, the diagnosis would merit review if both modalities were normal. CONCLUSIONS: Impaired taste appreciation was found in about 27% of patients with clinically defined PD. There were no important effects from age, disease severity or smell sense. Given the sparing of the first and second order taste neurones in PD, disorder of taste in PD most likely signifies involvement of the frontal operculum or orbitofrontal cortex, in keeping with advanced disease, although confounding by drug effects and changes in salivary constitution could not be excluded completely.

Olfactory tests in the diagnosis of essential tremor.

Most patients with tremor-dominant Parkinson's disease (PD) have impaired smell function but it is unclear whether this is true for subjects with essential tremor (ET). If ET patients do not exhibit meaningful smell loss, then olfactory testing may help to distinguish PD from ET. We assessed olfactory function in 59 ET and 64 tremor-dominant PD patients using the University of Pennsylvania Smell Identification Test (UPSIT) and olfactory event-related potential (OERP). UPSIT scores were compared to those from 245 healthy controls, and OERPs were compared to those from 74 controls. Unlike the PD test scores, those of ET patients were indistinguishable from controls when the effects of age, age of onset, gender, and smoking were taken into account. ET patients with a family history of tremor scored significantly better than controls on the UPSIT, and their rate of decline with age was slower. The effect was not observed on OERP. Smell testing may help to distinguish between ET and tremor-predominant PD, and patients with family history of tremor may represent a subgroup whose olfactory function is enhanced by some unknown mechanism.