Poststroke Depression: An Update.

The presence of neuropsychiatric disorders after stroke has been recognized for more than 100 years, but controlled systematic studies did not begin until the 1970s. The most clinically important advances, however, have been in the treatment and prevention of poststroke depression (PSD). Recent meta-analyses of randomized controlled trials (RCTs) for the treatment of PSD have demonstrated the efficacy of antidepressants. Similarly, RCTs for the prevention of PSD have shown that antidepressants significantly decrease the incidence of PSD compared with placebo. Early treatment of PSD with antidepressants also appears to enhance both physical and cognitive recovery from stroke and may increase survival up to 10 years. Genetic and epigenetic variations, white matter disease, cerebrovascular deregulation, altered neuroplasticity, and changes in glutamate neurotransmission may be relevant etiological factors.

Rates and Predictors of Rapid Eye Movement Sleep Behavior Disorder Symptoms Among Post-9/11 Veterans.

OBJECTIVE: Posttraumatic stress disorder (PTSD) and traumatic brain injury (TBI), which are prevalent conditions among post-9/11 veterans, increase risks of rapid eye movement (REM) sleep behavior disorder (RBD) and degenerative synucleinopathy. Rates and predictors of RBD symptoms were investigated by screening post-9/11 veterans for RBD with a validated questionnaire. METHODS: In this cross-sectional analysis, consecutive patients in the Houston Translational Research Center for TBI and Stress Disorders (TRACTS) were screened with the English translation of the RBD Questionnaire-Hong Kong (RBDQ-HK). In addition to data from the standard TRACTS battery, systematic chart review was used to identify known sleep disorders mimicking or manifesting RBD. RESULTS: Of the 119 patients with available RBDQ-HK scores, 71 (60%) and 65 (55%) screened positive for RBD, when a total score ≥21 and a factor 2 score ≥8 were used as cutoff scores, respectively. Univariable analyses with both cutoffs showed consistent associations between a positive RBDQ-HK screen and global sleep quality, number of TBI exposures, and PTSD severity. Multivariable logistic regression with total score ≥21 as a cutoff indicated that PTSD severity (odds ratio=1.06, 95% CI=1.02-1.10) and number of TBIs (odds ratio=1.63, 95% CI=1.16-2.41) were independent predictors of a positive screen, whereas global sleep quality was no longer significant. Multivariable logistic regression with factor 2 score ≥8 as a cutoff showed similar results. CONCLUSIONS: Interdisciplinary parasomnia assessment, further validation of RBD screens, and standardized reporting of REM sleep without atonia could provide necessary information on the pathophysiological relationships linking PTSD, TBI, RBD symptoms, and ultimately synucleinopathy risk among post-9/11 veterans.

Post-Traumatic Stress Disorder and Risk of Degenerative Synucleinopathies: Systematic Review and Meta-Analysis.

OBJECTIVE: A systematic review was conducted to answer whether adult-onset post-traumatic stress disorder (PTSD) is associated with increased risk of Parkinson's disease (PD) and related synucleinopathies. DESIGN: A systematic search of Medline (Ovid), Embase (Elsevier), PsycInfo (Ovid), Cochrane Library (Wiley), and Web of Science (Clarivate) was performed using MeSH headings and equivalent terms for PTSD, PD, DLB, and related disorders. SETTING: No restrictions. PARTICIPANTS: Eligible articles were published in peer-reviewed journals, sampled adult human populations, and treated PTSD and degenerative synucleinopathies as exposures and outcomes, respectively. MEASUREMENTS: Extracted data included diagnostic methods, sample characteristics, matching procedures, covariates, and effect estimates. Bias assessment was performed with the Newcastle-Ottawa scale. Hazard ratios were pooled using the random effects model, and the Hartung-Knapp adjustment was applied due to the small number of studies. RESULTS: A total of six articles comprising seven unique samples (total n = 1,747,378) met eligibility criteria. The risk of PD was reported in three retrospective cohort studies and one case-control study. Risk of DLB was reported in one retrospective cohort, one case-control, and one prospective cohort study. No studies addressed potential relationships with multiple system atrophy or pure autonomic failure. Meta-analysis of hazard ratios from four retrospective cohort studies supported the hypothesis that incident PTSD was associated with PD and DLB risk (pooled HR 1.88, 95% C.I. 1.08-3.24; p = 0.035). CONCLUSIONS: The sparse literature to-date supports further investigations on the association of mid- to late-life PTSD with Parkinson's and related neurodegenerative disorders.

Dream Enactment Behaviors Associated With Posttraumatic Stress Disorder.

The investigators aimed to draw attention to current debates surrounding the etiologies of dream enactment behaviors in patients with posttraumatic stress disorder (PTSD). The phenomenological overlap between PTSD-related nocturnal symptoms, rapid eye movement sleep behavior disorder (RBD), and trauma-associated sleep disorder (TASD) is discussed. Strategies used to diagnose and manage dream enactment behaviors, whether due to RBD or another confounding sleep disorder, are considered. Finally, the need for further research on the pathophysiological overlap and integrated treatment of PTSD, RBD, and, possibly, TASD is highlighted.

Optimization of Magnetoplasmonic ε-Near-Zero Nanostructures Using a Genetic Algorithm.

Magnetoplasmonic permittivity-near-zero (ε-near-zero) nanostructures hold promise for novel highly integrated (bio)sensing devices. These platforms merge the high-resolution sensing from the magnetoplasmonic approach with the ε-near-zero-based light-to-plasmon coupling (instead of conventional gratings or bulky prism couplers), providing a way for sensing devices with higher miniaturization levels. However, the applications are mostly hindered by tedious and time-consuming numerical analyses, due to the lack of an analytical relation for the phase-matching condition. There is, therefore, a need to develop mechanisms that enable the exploitation of magnetoplasmonic ε-near-zero nanostructures' capabilities. In this work, we developed a genetic algorithm (GA) for the rapid design (in a few minutes) of magnetoplasmonic nanostructures with optimized TMOKE (transverse magneto-optical Kerr effect) signals and magnetoplasmonic sensing. Importantly, to illustrate the power and simplicity of our approach, we designed a magnetoplasmonic ε-near-zero sensing platform with a sensitivity higher than 56∘/RIU and a figure of merit in the order of 102. These last results, higher than any previous magnetoplasmonic ε-near-zero sensing approach, were obtained by the GA intelligent program in times ranging from 2 to 5 min (using a simple inexpensive dual-core CPU computer).

Magnetically Tunable Micro-Ring Resonators for Massive Magneto-Optical Modulation in Dense Wavelength Division Multiplexing Systems.

We demonstrate, numerically, a new concept for on-chip magneto-optical (MO) modulation in dense wavelength division multiplexing (DWDM) applications. Our idea uses materials and mechanisms that are compatible with current silicon-on-insulator fabrication and CMOS technologies for monolithic integration. The physics behind our idea stems in the exploitation of the enhanced MO activity of a micro-ring, made of cerium substituted yttrium iron garnet (Ce:YIG) material, to actively manipulate the resonance wavelengths of an adjacent micro-ring resonator (MRR) of silicon (Si). This active manipulation of the latter MO-MRR structure is used to modulate the optical signal traveling through a side-coupled Si bus waveguide. Moreover, by proper tailoring multiple MO-MRRs (side-coupled to the single Si bus waveguide) to match wavelength channels in DWDM across the entire C-band optical communications spectrum, we extend our proposal to massive and dynamic MO modulation in DWDM applications. Significantly, we noticed that the active MO shifting of the resonant wavelength (used for MO modulation here) can be used for improvements in the spectrum utilization efficiency in future elastic optical networks (EONs).

Design of Plasmonic Yagi-Uda Nanoantennas for Chip-Scale Optical Wireless Communications.

Optical wireless transmission has recently become a major cutting-edge alternative for on-chip/inter-chip communications with higher transmission speeds and improved power efficiency. Plasmonic nanoantennas, the building blocks of this new nanoscale communication paradigm, require precise design to have directional radiation and improved communication ranges. Particular interest has been paid to plasmonic Yagi-Uda, i.e., the optical analog of the conventional Radio Frequency (RF) Yagi-Uda design, which may allow directional radiation of plasmonic fields. However, in contrast to the RF model, an overall design strategy for the directional and optimized front-to-back ratio of the radiated far-field patterns is lacking. In this work, a guide for the optimized design of Yagi-Uda plasmonic nanoantennas is shown. In particular, five different design conditions are used to study the effects of sizes and spacing between the constituent parts (made of Au). Importantly, it is numerically demonstrated (using the scattered fields) that closely spaced nanoantenna elements are not appropriated for directional light-to-plasmon conversion/radiation. In contrast, if the elements of the nanoantenna are widely spaced, the structure behaves like a one-dimensional array of nanodipoles, producing a funnel-like radiation pattern (not suitable for on-chip wireless optical transmission). Therefore, based on the results here, it can be concluded that the constituent metallic rib lengths must be optimized to exhibit the resonance at the working wavelength, whilst their separations should follow the relation λeff/π, where λeff indicates the effective wavelength scaling for plasmonic nanostructures.

Eddy Current Measurement for Planar Structures.

Eddy current (EC) testing has become one of the most common techniques for measuring metallic planar structures in various industrial scenarios such as infrastructures, automotive, manufacturing, and chemical engineering. There has been significant progress in measuring the geometry, electromagnetic properties, and defects of metallic planar structures based on electromagnetic principles. In this review, we summarize recent developments in EC computational models, systems, algorithms, and measurement approaches for planar structures. First, the computational models including analytical models, numerical methods, and plate property estimation algorithms are introduced. Subsequently, the impedance measurement system and probes are presented. In plate measurements, sensor signals are sensitive to probe lift-off, and various algorithms for reducing the lift-off effect are reviewed. These approaches can be used for measureing thickness and electromagnetic properties. Furthermore, defect detection for metallic plates is also discussed.

Effect of Vagus Nerve Stimulation on Attention and Working Memory in Neuropsychiatric Disorders: A Systematic Review.

BACKGROUND: It has been suggested that vagus nerve stimulation (VNS) may enhance attention and working memory. The neuromodulator effects of VNS are thought to activate the release of neurotransmitters involving cognition and to promote neuronal plasticity. Therefore, VNS has been studied for its effects on attention and working memory impairment in neuropsychiatric disorders. OBJECTIVES: This study aimed to assess the effects of VNS on attention and working memory among patients with neuropsychiatric disorders, examine stimulation parameters, provide mechanistic hypotheses, and propose future studies using VNS. MATERIALS AND METHODS: We conducted a systematic review using electronic databases MEDLINE (Ovid), Embase (Ovid), Cochrane library, and PsycINFO (Ovid). Narrative analysis was used to describe the therapeutic effects of VNS on attention and working memory, describe stimulation parameters, and propose explanatory mechanisms. RESULTS: We identified 20 studies reporting VNS effects on attention and working memory in patients with epilepsy or mood disorders. For epilepsy, there was one randomized controlled trial from all 18 studies. It demonstrated no statistically significant differences in the cognitive tasks between active and control VNS. From a within-subject experimental design, significant improvement of working memory after VNS was demonstrated. One of three nonrandomized controlled trials found significantly improved attentional performance after VNS. The cohort studies compared VNS and surgery and found attentional improvement in both groups. Nine of 12 pretest-posttest studies showed improvement of attention or working memory after VNS. For mood disorders, although one study showed significant improvement of attention following VNS, the other did not. CONCLUSIONS: This review suggests that, although we identified some positive results from eligible studies, there is insufficient good-quality evidence to establish VNS as an effective intervention to enhance attention and working memory in persons with neuropsychiatric disorders. Further studies assessing the efficacy of such intervention are needed.

Bulk Plasmon Polariton Modes in Hyperbolic Metamaterials for Giant Enhancement of the Transverse Magneto-Optical Kerr Effect.

We demonstrate a concept for the giant enhancement of the transverse magneto-optical Kerr effect (TMOKE) using bulk plasmon polariton (BPP) modes in non-magnetic multilayer hyperbolic metamaterials (HMMs). Since the BPP modes are excited through the attenuated total reflection (ATR) mechanism, using a Si-based prism-coupler, we considered a single dielectric magneto-optical (MO) spacer between the prism and the HMM. The working wavelength was estimated, using the effective medium approach for a semi-infinite dielectric-plasmonic multilayer, considering the region where the system exhibits type II HMM dispersion relations. Analytical results, by means of the scattering matrix method (SMM), were used to explain the physical principle behind our concept. Numerical results for giant TMOKE values (close to their maximum theoretical values, ±1) were obtained using the finite element method (FEM), applying the commercial software COMSOL Multiphysics. Our proposal comprises a simple and experimentally feasible structure that enables the study of MO phenomena in HMMs, which may find application in future nanostructured magnetoplasmonic metamaterials for active nanophotonic devices.

Post-Traumatic Stress Disorder is Associated with further Increased Parkinson's Disease Risk in Veterans with Traumatic Brain Injury.

OBJECTIVE: Determining if traumatic brain injury (TBI) and post-traumatic stress disorder (PTSD) are risk factors for Parkinson's disease (PD). This constitutes a research priority for the Veterans Administration (VA) with implications for screening policy and prevention. METHODS: Population-based, matched case-control study among veterans using VA health care facilities from October 1, 1999, to September 30, 2013. We identified 176,871 PD cases and 707,484 randomly selected PD-free matched controls. PD, TBI, and PTSD were ascertained by validated International Classification of Disease 9th revision (ICD)-9 code-based algorithms. We examined the association between both risk factors and PD using race-adjusted conditional logistic regression. RESULTS: The overall study cohort prevalence for TBImild , TBInon-mild , and PTSD was 0.65%, 0.69%, and 5.5%, respectively. Both TBI and PTSD were significantly associated with PD in single-risk factor race-adjusted analyses (conditional odds ratio [cOR] = 2.99; 95% confidence interval [CI]: 2.69-3.32), 3.82 (95% CI: 3.67-3.97), and 2.71 (95% CI: 2.66-2.77) for TBImild , TBInon-mild , and PTSD, respectively). There was suggestive positive interaction observed with comorbid PTSD/TBI in dual-risk factor analyses, with significant 2.69-fold and 3.70-fold excess relative PD risk in veterans with TBImild and TBInon-mild versus those without TBI when PTSD was present versus 2.17-fold and 2.80-fold excess risk when PTSD was absent. INTERPRETATION: Our study was the first to demonstrate that both TBI and PTSD are independently associated with increased relative PD risk in a diverse nationwide cohort of military service veterans, and the first to suggest a potential modest synergistic excess risk in those with comorbid TBI/PTSD. Longitudinal research is needed to confirm these suggestive findings. ANN NEUROL 2020 ANN NEUROL 2020;88:33-41.

Chiral Dielectric Metasurfaces for Highly Integrated, Broadband Circularly Polarized Antenna.

We report on the design of a low-profile integrated millimeter-wave antenna for efficient and broadband circularly polarized electromagnetic radiation. The designed antenna comprises a chiral dielectric metasurface built with a 2×2 arrangement of dielectric cylinders with slanted-slots at the center. A broadbeam high-gain with wide axial ratio (AR)<3 dB bandwidth was reached by pairing the electric and magnetic resonances of the dielectric cylinders and the slanted slots when excited by an elliptically polarized driven-patch antenna. This electric-magnetic pairing can be tuned by varying the cylinders diameter and the tilting and rotation angles of the slanted slots. The simulation results indicate impedance-matching bandwidths up to 22.6% (25.3-31.6 GHz) with 3-dB AR bandwidths of 11.6% (26.9-30.2 GHz), which in terms of compactness (0.95λ0×0.95λ0) and performance are superior to previous antenna designs. Since the simulations were performed by assuming materials and geometries easily implementable experimentally, it is hoped that circularly polarized antennas based on chiral metasurfaces can be integrated into 5G and satellite communications.

3D-Printed Quasi-Cylindrical Bragg Reflector to Boost the Gain and Directivity of cm- and mm-Wave Antennas.

We demonstrate a concept for a large enhancement of the directivity and gain of readily available cm- and mm-wave antennas, i.e., without altering any property of the antenna design. Our concept exploits the high reflectivity of a Bragg reflector composed of three bilayers made of transparent materials. The cavity has a triangular aperture in order to resemble the idea of a horn-like, highly directive antenna. Importantly, we report gain enhancements of more than 400% in relation to the gain of the antenna without the Bragg structure, accompanied by a highly directive radiation pattern. The proposed structure is cost-effective and easy to fabricate with 3D-printing. Our results are presented for frequencies within the conventional WiFi frequencies, based on IEEE 802.11 standards, thus, enabling easily implementation by non-experts and needing only to be placed around the antenna to improve the directivity and gain of the signal.

Clinical Correlates of Dream Enactment Behaviors in Previously Deployed OEF/OIF/OND Veterans: An Exploratory Analysis.

OBJECTIVE: Veterans with posttraumatic stress disorder (PTSD) frequently report dream enactment behavior (DEB). Although DEBs are associated with PTSD symptoms, their relationship with other sleep disorders, including REM behavior disorder, warrants reexamination of their clinical correlates. METHODS: The investigators used a cross-sectional, exploratory analysis to compare demographic and clinical characteristics of veterans endorsing regularly occurring DEB compared with those endorsing no or infrequent DEB. The participants comprised a convenience sample of servicemembers who were previously deployed to Operation Enduring Freedom/Operation Iraqi Freedom/Operation New Dawn (OEF/OIF/OND) and enrolled in an ongoing cohort study. RESULTS: Of the 78 eligible participants, 19 (24.4%) endorsed DEBs occurring at least once per week in the past month. Compared with participants who reported no or infrequent DEBs, participants with regularly occurring DEBs had poorer sleep quality, greater PTSD severity, a higher number of reported mild traumatic brain injuries (mTBI) with loss of consciousness, and a higher likelihood of being diagnosed with sleep disorders. After adjustment for global sleep quality, a significant association persisted between DEBs and the number of mTBI with loss of consciousness but not between DEBs and the severity of PTSD symptoms. CONCLUSIONS: These results suggest that mTBI may disrupt neural circuits regulating sleep among OIF/OEF/OND veterans. Prospective, polysomnographic assessment of muscle tone and behavioral events during REM sleep is needed to characterize the physiology of DEBs in this population.

Selective block of grey communicantes in upper thoracic sympathectomy. A feasibility study on human cadaveric specimens.

Background: Sympathetic chain interruption is the gold standard treatment for essential hyperhidrosis. Postoperative compensatory hyperhidrosis, the main reason for patients' dissatisfaction, is reduced by selectively lesioning white and grey rami communicantes (ramicotomy).Objective: To develop an endoscopic surgical technique that interrupts only T3 and T4 grey rami communicantes to minimize compensatory hyperhidrosis.Material and Methods: T3 and T4 grey rami communicantes ramicotomy in fifteen cold-preserved cadavers through a uniportal axillary endoscopic approach. The sympathetic chain, its ganglia, and white rami communicantes were left intact. On opening the chest, the sympathetic chain, rami communicantes and ganglia were dissected, photographed, measured and excised for histological examination.Results: Dissecting the grey rami communicantes is feasible as they consistently lie between the intercostal nerve and the homonymous sympathetic ganglion. At some levels, Kuntz nerves, as well as more than one grey ramus communicans, can be found. White rami communicantes are more medial, therefore damaging them can be avoided. Intercostal veins can be obstructive, but these can be controlled via coagulation or clipping if necessary.Conclusion: Uniportal endoscopic selective excision of the T3 and T4 grey rami communicantes is feasible without damaging the white rami communicantes, the sympathetic chain or its ganglia. Clipping the grey rami communicantes is technically possible but not reliable due to their thin diameter. This study confirms that T3 and T4 grey rami sympathetic block is technically feasible. Its application might reduce compensatory hyperhidrosis, but clinical studies are needed.

Microfluidic Point-of-Care Devices: New Trends and Future Prospects for eHealth Diagnostics.

Point-of-care (PoC) diagnostics is promising for early detection of a number of diseases, including cancer, diabetes, and cardiovascular diseases, in addition to serving for monitoring health conditions. To be efficient and cost-effective, portable PoC devices are made with microfluidic technologies, with which laboratory analysis can be made with small-volume samples. Recent years have witnessed considerable progress in this area with "epidermal electronics", including miniaturized wearable diagnosis devices. These wearable devices allow for continuous real-time transmission of biological data to the Internet for further processing and transformation into clinical knowledge. Other approaches include bluetooth and WiFi technology for data transmission from portable (non-wearable) diagnosis devices to cellphones or computers, and then to the Internet for communication with centralized healthcare structures. There are, however, considerable challenges to be faced before PoC devices become routine in the clinical practice. For instance, the implementation of this technology requires integration of detection components with other fluid regulatory elements at the microscale, where fluid-flow properties become increasingly controlled by viscous forces rather than inertial forces. Another challenge is to develop new materials for environmentally friendly, cheap, and portable microfluidic devices. In this review paper, we first revisit the progress made in the last few years and discuss trends and strategies for the fabrication of microfluidic devices. Then, we discuss the challenges in lab-on-a-chip biosensing devices, including colorimetric sensors coupled to smartphones, plasmonic sensors, and electronic tongues. The latter ones use statistical and big data analysis for proper classification. The increasing use of big data and artificial intelligence methods is then commented upon in the context of wearable and handled biosensing platforms for the Internet of things and futuristic healthcare systems.

Bulk pH and Carbon Source Are Key Factors for Calcium Phosphate Granulation.

Recovery of calcium phosphate granules (CaP granules) from high-strength wastewater is an opportunity to reduce the natural phosphorus (P) scarcity, geographic imbalances of P reserves, and eutrophication. Formation of CaP granules was previously observed in an upflow anaerobic sludge bed (UASB) reactor treating source separated black water and is enhanced by Ca2+ addition. However, the required operating conditions and influent composition for CaP granulation are still unknown. In this study, we have experimentally demonstrated that the carbon source and bulk pH are crucial parameters for the formation and growth of CaP granules in a UASB reactor, operating at relatively low upflow velocity (<1 cm h-1). Degradation of glucose yielded sufficient biomass (microbial cells and extracellular biopolymers) to cover crystal and amorphous calcium phosphate [Ca x(PO4) y], forming CaP granules. Influent only containing volatile fatty acids as the carbon source did not generate CaP granules. Moreover, bulk pH between 7.0 and 7.5 was crucial for the enrichment of Ca x(PO4) y in the granules over bulk precipitation. Bulk pH 8 reduced the Ca x(PO4) y enrichment in granules of >1.4 mm diameter from 9 to 5 wt % P. Moreover, for bulk pH 7.5, co-precipitation of CaCO3 with Ca x(PO4) y was reduced.

Treating Alcohol Use Disorder in U.S. Veterans: The Role of Traumatic Brain Injury.

OBJECTIVE: The authors examined the efficacy of valproate to reduce relapse to heavy drinking among veterans with alcohol use disorder (AUD) and neuropsychiatric comorbidities and whether antecedent traumatic brain injury (TBI) or posttraumatic stress disorder (PTSD) affected treatment response. METHODS: Participants were male veterans 18-60 years old with an AUD and no other substance use besides nicotine or cannabis. Sixty-two patients were randomly assigned to receive either valproate or naltrexone. Participants were evaluated at baseline and followed weekly for 24 weeks. All participants received standardized psychosocial interventions as well as treatment for coexistent psychiatric conditions. RESULTS: During the follow-up period, nine study subjects in the naltrexone group and 14 in the valproate group relapsed to heavy drinking, but the difference did not reach statistical significance. Participants with a history of moderate to severe TBI were more likely to relapse to heavy drinking compared with those with no TBI (hazard ratio=4.834, 95% CI=1.103-21.194, p=0.033). PTSD status did not significantly affect outcome. CONCLUSIONS: Intensive outpatient programs are efficacious alternatives to treat AUD in veterans, although the role of pharmacological treatment is not completely elucidated. Glutamatergic agents appear to be less effective than opiate antagonists to prevent relapse to heavy drinking and to increase cumulative abstinence. Future studies should examine novel pharmacological and nonpharmacological options.

Recovery of calcium phosphate granules from black water using a hybrid upflow anaerobic sludge bed and gas-lift reactor.

Adding calcium during anaerobic digestion of vacuum collected black water (BW) in an up-flow anaerobic sludge bed (UASB) reactor increased the retention of total phosphorus (P) in the reactor from 51% to 87%. However, the insufficient mixing in the reactor caused cementation and relatively high content of organics in the recovered calcium phosphate (CaP) granules, limiting the P recovery. In this study, the UASB reactor was mixed with an internal gas-lift (UASB-GL) to prevent cementation and to enhance the P content in CaP granules. The novel UASB-GL reactor operated for 300 days, treating concentrated BW. At steady state, the removal of total COD and P was 92% and 90%, respectively. The gas injection created a sludge bed with an average total suspended solids concentration of 73 ±â€¯16 g/L at the bottom and 31 ±â€¯5 g/L at the top of the reactor. The concentration of solid P at the bottom of the reactor was 4.58 ±â€¯1.34 gP/L, while at the top a much lower concentration was obtained (0.75 ±â€¯0.32 gP/L). 89% of the CaP granules was found at the bottom of the reactor. The harvested CaP granules (>0.4 mm diameter) contained on average 7.8 ±â€¯0.6 wt% of P. A potential recovery of 57% of P in BW as CaP granules was calculated, considering actual application of the UASB-GL reactor in source separated sanitation.

Designing Silver Nanoparticles for Detecting Levodopa (3,4-Dihydroxyphenylalanine, L-Dopa) Using Surface-Enhanced Raman Scattering (SERS).

Detection of the drug Levodopa (3,4-dihydroxyphenylalanine, L-Dopa) is essential for the medical treatment of several neural disorders, including Parkinson's disease. In this paper, we employed surface-enhanced Raman scattering (SERS) with three shapes of silver nanoparticles (nanostars, AgNS; nanospheres, AgNP; and nanoplates, AgNPL) to detect L-Dopa in the nanoparticle dispersions. The sensitivity of the L-Dopa SERS signal depended on both nanoparticle shape and L-Dopa concentration. The adsorption mechanisms of L-Dopa on the nanoparticles inferred from a detailed analysis of the Raman spectra allowed us to determine the chemical groups involved. For instance, at concentrations below/equivalent to the limit found in human plasma (between 10-7-10-8 mol/L), L-Dopa adsorbs on AgNP through its ring, while at 10-5-10-6 mol/L adsorption is driven by the amino group. At even higher concentrations, above 10-4 mol/L, L-Dopa polymerization predominates. Therefore, our results show that adsorption depends on both the type of Ag nanoparticles (shape and chemical groups surrounding the Ag surface) and the L-Dopa concentration. The overall strategy based on SERS is a step forward to the design of nanostructures to detect analytes of clinical interest with high specificity and at varied concentration ranges.