Social Well-Being, Psychological Factors, and Chronic Conditions Among Older Adults

Background

Aging is characterized by the decline in physical health, functional status, and loss of social roles and relationships that can challenge the quality of life. Social well-being may help explain how aging individuals experience declining physical health and social relationships. Despite the high prevalence of chronic conditions among older adults, research exploring the relationship between social well-being and chronic disease is sparse.

Objectives

The study aims were to investigate the relationship between social well-being and psychological factors (e.g., perceived control, life satisfaction, self-esteem, active coping, optimism, and religious coping) by chronic condition in older adults.

Design

Cross-sectional study.

Participants

The current study comprises older adults (N = 1,251, aged ≥ 65 y) who participated in the third wave of the National Survey of Midlife in the United States (i.e., MIDUS).

Setting

MIDUS was conducted on a random-digit-dial sample of community-dwelling, English-speaking adults.

Measurements

Six instruments representing psychological resources (life satisfaction, perceived control, self-esteem, optimism, active coping, and religious coping) and five dimensions of social well-being (social actualization, social coherence, social acceptance, social contribution, social integration) were measured. An index of chronic disease comprised of self-reported data whether they had received a physician's diagnosis for any chronic conditions over the past year.

Results

The findings indicated that the individuals without chronic conditions had significantly higher social integration, social acceptance, and social contribution scores than the individuals with chronic conditions (t = 2.26, p < 0.05, t = 2.85, p < 0.01, and t = 2.23, p < 0.05, respectively). For individuals diagnosed with more than one chronic condition, perceived control, self-esteem, and optimism were positively related to their social well-being (β = .33, p < .001, β = .17, p < .001, and β = .33, p < .001, respectively).

Conclusion

Findings suggested that older adults with multiple chronic conditions have a decrease in social well-being. Chronic disease management programs may help increase social well-being among individuals with multiple chronic conditions.

Improving Biosensors by the Use of Different Nanomaterials: Case Study with Microcystins as Target Analytes

The eutrophication of lakes and rivers without adequate rainfall leads to excessive growth of cyanobacterial harmful algal blooms (CyanoHABs) that produce toxicants, green tides, and unpleasant odors. The rapid growth of CyanoHABs owing to global warming, climate change, and the development of rainforests and dams without considering the environmental concern towards lakes and rivers is a serious issue. Humans and livestock consuming the toxicant-contaminated water that originated from CyanoHABs suffer severe health problems. Among the various toxicants produced by CyanoHABs, microcystins (MCs) are the most harmful. Excess accumulation of MC within living organisms can result in liver failure and hepatocirrhosis, eventually leading to death. Therefore, it is essential to precisely detect MCs in water samples. To date, the liquid chromatography-mass spectrometry (LC-MS) and enzyme-linked immunosorbent assay (ELISA) have been the standard methods for the detection of MC and provide precise results with high reliability. However, these methods require heavy instruments and complicated operation steps that could hamper the portability and field-readiness of the detection system. Therefore, in order for this goal to be achieved, the biosensor has been attracted to a powerful alternative for MC detection. Thus far, several types of MC biosensor have been proposed to detect MC in freshwater sample. The introduction of material is a useful option in order to improve the biosensor performance and construct new types of biosensors. Introducing nanomaterials to the biosensor interface provides new phenomena or enhances the sensitivity. In recent times, different types of nanomaterials, such as metallic, carbon-based, and transition metal dichalcogenide-based nanomaterials, have been developed and used to fabricate biosensors for MC detection. This study reviews the recent advancements in different nanomaterial-based MC biosensors.

Facile and foldable point-of-care biochip for nucleic acid based-colorimetric detection of murine norovirus in fecal samples using G-quadruplex and graphene oxide coated microbeads

Norovirus is one of the most common causes of gastroenteritis, a disease characterized by diarrhea, vomiting, and stomach pain. A rapid on-site identification of the virus from fecal samples of patients is a prerequisite for accurate medical management. Here, we demonstrate a rapid nucleic acid-based detection platform as an on-site biosensing tool that can concentrate viruses from fecal samples. Moreover, it can perform RNA extraction and identification, and signal amplification using G-quadruplex and hemin containing DNA probes (G-DNA probes) and graphene oxide (GO)-coated microbeads. Briefly, murine noroviruses are lysed without chemicals on the surface of the GO microbeads. Subsequently, the target RNA is hybridized with G-DNA probes, and the resultant RNA/G-DNA probe complex is separated from unbound G-DNA probes using GO beads and is mixed with the detection buffer (ABTS/H₂O₂). Presence of murine noroviruses causes a colorimetric change of the buffer from colorless to green. Thus, we integrated all processes required to detect murine noroviruses in stool samples in a simple foldable microfluidic chip. Moreover, it can detect 10¹ pfu of the virus in 30 min in a fecal sample.

Discrimination and isolation of the virus from free RNA fragments for the highly sensitive measurement of SARS-CoV-2 abundance on surfaces using a graphene oxide nano surface

It is highly important to sensitively measure the abundance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on various surfaces. Here, we present a nucleic acid-based detection method consisting of a new sample preparation protocol that isolates only viruses, not the free RNA fragments already present on the surfaces of indoor human-inhabited environments, using a graphene oxide-coated microbead filter. Wet wipes (100 cm2), not cotton swabs, were used to collect viruses from environmental surfaces with large areas, and viruses were concentrated and separated with a graphene oxide-coated microbead filter. Viral RNA from virus was recovered 88.10 ± 8.03% from the surface and free RNA fragment was removed by 99.75 ± 0.19% from the final eluted solution. When we tested the developed method under laboratory conditions, a 10-fold higher viral detection sensitivity (Detection limit: 1 pfu/100 cm2) than the current commercial protocol was observed. Using our new sample preparation protocol, we also confirmed that the virus was effectively removed from surfaces after chemical disinfection; we were unable to measure the disinfection efficiency using the current commercial protocol because it cannot distinguish between viral RNA and free RNA fragments. Finally, we investigated the presence of SARS-CoV-2 and bacteria in 12 individual negative pressure wards in which patients with SARS-CoV-2 infection had been hospitalized. Bacteria (based on 16 S DNA) were found in all samples collected from patient rooms; however, SARS-CoV-2 was mainly detected in rooms shared by two patients.

Mix-and-read, one-minute SARS-CoV-2 diagnostic assay: development of PIFE-based aptasensor

We developed a one-minute, one-step SARS-CoV-2 antigen assay based on protein-induced fluorescence enhancement of a DNA aptamer. The system showed significant selectivity and sensitivity towards both nucleocapsid protein and SARS-CoV-2 virus lysate, but with marked improvements in speed and manufacturability. We hence propose this platform as a mix-and-read testing strategy for SARS-CoV-2 that can be applied to POC diagnostics in clinical settings, especially in low- and middle-income countries.

Fabrication of electrochemical biosensor composed of multi-functional DNA 4 way junction for TNF-α detection in human serum

Tumor necrosis factor (TNF-α) is a representative cytokine family known to induce multiple signaling cascades leading to various cellular responses, such as cell death, survival, and differentiation. It has been reported that blocking the action of TNF-α in various diseases can improve disease prognosis. Therefore, it is important to monitor TNF-α in patient plasma and properly regulate its action. In this study, we report a label-free electrochemical biosensor consisting of a multifunctional DNA 4-way junction (MF-4WJ) for TNF-α detection in human serum. MF-4WJ does not require additional labeling and signal amplification processes. The electrochemical properties of functionalized MF-4WJ were evaluated by cyclic voltammetry (CV) in the presence of Ag⁺ intercalated between the mismatched sequences of MF-aptamers as redox-active species. Afterward, CV was carried out to evaluate the performance of the fabricated biosensor. The proposed label-free electrochemical biosensor was able to effectively detect TNF-α in a dynamic range of 0.15 pg/ml to 150 ng/ml. Limit of detection (LOD) was at 0.07 pg/ml in HEPES. Moreover, it was confirmed that even in 10% diluted human serum, TNF-α could be detected in an excellent dynamic range of 0.15 pg/ml to ∼ 15 ng/ml and LOD was at 0.14 pg/ml in 10% diluted human serum.

Fabrication of a surface-enhanced Raman spectroscopy-based analytical method consisting of multifunctional DNA three-way junction-conjugated porous gold nanoparticles and Au-Te nanoworm for C-reactive protein detection

C-Reactive protein (CRP) is a biomarker of inflammatory responses and an index for assessing the risk of cardiovascular disease and estimating prognosis. In this study, we constructed a surface-enhanced Raman spectroscopy (SERS) biosensor composed of a multifunctional DNA three-way junction (DNA 3WJ), porous gold nanoplates (pAuNPs), and an Au-Te nanoworm structure for detection of CRP. The pAuNP and Au-Te nanostructures were synthesized by galvanic replacement reactions, and the morphology was confirmed by transmission electron microscopy, scanning electron microscopy, and dynamic light scattering (DLS). To generate the SERS signal, the Au-Te nanostructure was immobilized on an indium-tin oxide substrate, and the thiol-modified CRP aptamer was then self-assembled onto the modified substrate for CRP recognition. To amplify the SERS signal and identify the Raman tag, the multifunctional DNA 3WJ was conjugated with the pAuNPs, and each fragment of 3WJ was functionalized to biotin (pAuNP conjugation), methylene blue (Raman reporter), and CRP aptamer (target binding). The results were confirmed by gel electrophoresis. For conjugation between pAuNPs and DNA 3WJ, avidin was encapsulated in pAuNPs, and the conjugation structure was confirmed by DLS. The fabricated SERS biosensor showed detection limits of 2.23 pM in phosphate-buffered saline and 3.11 pM in diluted human serum. Overall, the proposed biosensor may have potential applications as a SERS biosensor platform.

Simple and portable on-site system for nucleic acid-based detection of Clostridium difficile in stool samples using two columns containing microbeads and loop-mediated isothermal amplification

It is challenging to employ nucleic acid-based diagnostics for the in situ detection of Clostridium difficile from complex fecal samples because essential sample preparation and amplification procedures require various experimental resources. In this study, a simple and effective on-site nucleic acid-based detection system was used to detect C. difficile in stool samples. Two columns containing different microbeads, namely, glass and functionalized graphene oxide-coated microbeads, were designed to remove relatively large impurities by filtration and concentrate bacteria, including C. difficile, from stool samples by adsorption. The bacterial nucleic acids were effectively extracted using a small bead beater. The effectiveness of enzyme inhibitors remaining in the sample was efficiently reduced by the direct buffer developed in this study. This sample preparation kit consisting of two simple columns showed better performance in real-time polymerase chain reaction (PCR) and equivalent performance in loop-mediated isothermal amplification (LAMP) than other sample preparation kits, despite 90% simplification of the process. The amplification-ready samples were introduced into two microtubes containing LAMP pre-mixtures (one each for E. coli as an external positive control and C. difficile) by a simple sample loader, which was operated using a syringe. LAMP, which indicates amplification based on color change, was performed at 65 °C in a small water bath. The limit of detection (L.O.D) and analytical sensitivity/specificity of our simple and effective kit were compared with those of a commercial kit. C. difficile in stool samples could be detected within 1 h with 10³ cfu/10 mg using LAMP combined simple on-site detection kit.

Electrospun Nanofibers Embedded with Copper Oxide Nanoparticles to Improve Antiviral Function

Many studies on anti-bacterial/antiviral surfaces have been conducted to prevent epidemic spread worldwide. Several nanoparticles such as those composed of silver and copper are known to have antiviral properties. In this study, we developed copper oxide (CuO) nanoparticle-incorporated nanofibers to inactivate or remove viruses. The CuO nanoparticle-incorporated nanofiber was fabricated with a hydrophobic polymer-polyvinylpyrrolidone (PVP)-using electrospinning, and CuO nanoparticles were exposed from the PVP polymer surface by etching the nanofiber with oxygen plasma. The fabrication conditions of electrospinning and oxygen plasma etching were investigated by scanning electron microscopy (SEM), and field emission transmission electron microscopy (FETEM)/ energy dispersive spectrometry (EDS). H1N1 virus was utilized as the target sample and quantified by RT-qPCR. The antiviral efficacy of CuO nanoparticle-incorporated nanofibers was compared against bare CuO nanoparticles. Overall, 70% of the viruses were inactivated after CuO nanoparticle-incorporated nanofibers were incubated with 10² pfu/mL of H1N1 virus solution for 4 h. This indicates that the developed CuO nanoparticle-incorporated nanofibers have noticeable antiviral efficacy. As the developed CuO nanoparticle-incorporated nanofibers exerted promising antiviral effects against H1N1 virus, it is expected to benefit global health by preventing epidemic spread.

Fabrication of an Electrochemical Aptasensor Composed of Multifunctional DNA Three-Way Junction on Au Microgap Electrode for Interferon Gamma Detection in Human Serum

Interferon gamma (IFN-γ) is an important cytokine with antiviral, antibacterial, and immunosuppressive properties. It has been used as a biomarker for the early detection of several diseases, including cancer, human immunodeficiency virus (HIV), tuberculosis, and paratuberculosis. In this study, we developed an electrochemical biosensor composed of multifunctional DNA 3WJ to detect IFN-γ level with high sensitivity. Each multifunctional triple-stranded aptamer (MF-3WJ) was designed to have an IFN-γ aptamer sequence, anchoring region (thiol group), and 4C-C (cytosine-cytosine) mismatch sequence (signal generation), which could introduce silver ions. To generate the electrochemical signal, four Ag⁺ ions were intercalated (3wj b-3wj c) in the 4C-C mismatch sequence. MF-3WJ was assembled through the annealing step, and the assembly of MF-3WJ was confirmed by 8% tris-boric-EDTA native polyacrylamide gel electrophoresis. The Au microgap electrode was manufactured to load sample volumes of 5 µL. The reliability of electrochemical biosensor measurement was established by enabling the measurement of seven samples from one Au microgap electrode. MF-3WJ was immobilized on the Au microgap electrode. Then, cyclic voltammetry and electrochemical impedance spectroscopy were performed to confirm the electrochemical properties of MF-3WJ. To test the electrochemical biosensor's ability to detect IFN-γ, the limit of detection (LOD) and selectivity tests were performed by square wave voltammetry. A linear region was observed in the concentration range of 1 pg/mL-10 ng/mL of IFN-γ. The LOD of the fabricated electrochemical biosensor was 0.67 pg/mL. In addition, for the clinical test, the LOD test was carried out for IFN-γ diluted in 10% human serum samples in the concentration range of 1 pg/mL-10 ng/mL, and the LOD was obtained at 0.42 pg/mL.

Reasons why patients with tuberculosis in South Korea stop anti-TB treatment: a cross-sectional study

BACKGROUND: As there had been no reduction in the TB burden in South Korea since 2000, a public-private mix (PPM) strategy was launched in 2011. The purpose of this study was to investigate the reasons for lost to follow-up (LTFU) among TB patients and their clinical characteristics.METHOD: A multicentre, cross-sectional study based on in-depth interviews with patients and their families by TB specialist nurses was conducted. Patients who were reported with a final outcome of LTFU in 2015-2017 at all PPM hospitals across the country were enrolled. Enrolled patients were classified into six subgroups by age and three major reasons for LTFU (adverse effects, refusal of treatment, marginalisation) and their clinical features were compared.RESULTS: Among 780 patients, those who were lost to follow-up due to adverse effects accounted for the largest proportion (n = 387). LTFU in those aged <65 years who refused treatment (n = 189) and those aged <65 years who were marginalised (n = 108) were related to having smear-positive TB and a previous history of unfavourable outcomes.CONCLUSION: To reduce LTFU in South Korea, comprehensive strategies, including management of adverse effects, systematic counselling and education, should be implemented.

Suppressed Degradation and Enhanced Performance of CsPbI3 Perovskite Quantum Dot Solar Cells via Engineering of Electron Transport Layers

CsPbI₃ perovskite quantum dots (CsPbI₃-PQDs) have recently come into focus as a light-harvesting material that can act as a platform through which to combine the material advantages of both perovskites and QDs. However, the low cubic-phase stability of CsPbI₃-PQDs in ambient conditions has been recognized as a factor that inhibits device stability. TiO₂ nanoparticles are the most regularly used materials as an electron transport layer (ETL) in CsPbI₃-PQD photovoltaics; however, we found that TiO₂ can facilitate the cubic-phase degradation of CsPbI₃-PQDs due to its vigorous photocatalytic activity. To address these issues, we have developed chloride-passivated SnO₂ QDs (Cl@SnO₂ QDs), which have low photocatalytic activity and few surface traps, to suppress the cubic-phase degradation of CsPbI₃-PQDs. Given these advantages, the CsPbI₃-PQD solar cells based on Cl@SnO₂ ETLs show significantly improved device operational stability (under conditions of 50% relative humidity and 1-sun illumination), compared to those based on TiO₂ ETLs. In addition, the Cl@SnO₂-based devices showed improved open circuit voltage and photocurrent density, resulting in enhanced power conversion efficiency (PCE) up to 14.5% compared to that of TiO₂-based control devices (PCE of 13.8%).

Circulating Tumor Marker Isolation with the Chemically Stable and Instantly Degradable (CSID) Hydrogel ImmunoSpheres

Here, we present chemically stable and instantly degradable (CSID) hydrogel immunospheres for the isolation of circulating tumor cells (CTCs) and circulating tumor exosomes (CTXs). The CSID hydrogels, which are prepared by the hybridization of alginate and poly(vinyl alcohol), show an equilibrium swelling ratio (ESR) of at pH 7, with a highly stable pH-responsive property. The present hybrid hydrogel is not easily disassociated in the biological buffers, thus being suitable for use in "liquid biopsy", requiring a multistep, long-term incubation process with biological samples. Also, it is gradually degraded by the action of chelating agents; effortless retrieval of the circulating markers has been achieved. Then, we modified the CSID hydrogel spheres with the anti-EpCAM antibody ("C-CSID ImmunoSpheres") and the anti-CD63 antibody ("E-CSID ImmunoSpheres") to isolate two promising circulating markers in liquid biopsy: CTCs and CTXs. The immunospheres' capabilities for marker isolation and retrieval were confirmed by a fluorescence image, where the spheres successfully isolate and effortlessly retrieve the target circulating markers. Lastly, we applied the CSID hydrogel immunospheres to five blood samples from colorectal cancer patients and retrieved average 10.8 ± 5.9 CTCs/mL and average 96.5 × 10⁶ CTXs/mL. The present CSID hydrogel immunospheres represent a simple, versatile, and time-efficient assay platform for liquid biopsy in the practical setting, enabling us to gain a better understanding of disease-related circulating markers.

Bacterial Isolation by Adsorption on Graphene Oxide from Large Volume Sample

Graphene oxide (GO) is a well-known two-dimensional nanomaterial with broad applications in various fields. In particular, the functional groups of GO has demonstrated significance in the molecular binding interactions. GO is normally coated on a solid surface as it is difficult to handle due to its nano-scaled size. Therefore, chemical properties of surface-coated GO depend on the morphological structure of GO on the surface and the operating conditions during the coating process. Isolation of bacteria from environmental samples such as river and pond water is important for increasing the analytical sensitivity of sensor devices. The main issue in isolation of bacteria from an environmental sample is adsorption capacity per unit time. However, increasing the velocity of water sample to elevate the process rate induces high shear stress on the surface, such that the bacteria adsorption rate on the surface is reduced. In this study, we investigated the morphological and chemical properties of sonicated GO and GO-coated surface by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). The sonicated GO-coated beads were successfully used for concentrating bacteria from a large-volume sample as opposed to the conventional methods. It can be concluded that, GO-coated surfaces are prospective platforms for concentrating bacteria from various samples and play a major role in reducing the concentration time.

Improvement of Heat Sink Effect Using Zinc Oxide Nanostructure

Heat sinks that dissipate heat effectively play a significant role in devices with high-precision temperature control, such as thermal cyclers for polymerase chain reaction (PCR). This study was carried out to develop a heat sink with a high thermal conductivity to dissipate heat effectively. To increase the surface area of the heat sink, zinc oxide (ZnO) nanostructures were fabricated on an aluminum plate. ZnO nanostructures were fabricated by hydrothermal method and confirmed by scanning electron microscopy and X-ray diffraction. With the increase in the concentration of the precursors, the length of the nanorods increased, and with longer reaction time, nanostructures connected with higher stability and larger surface area. Thermal conductivity is increased by ZnO nanostructures and is affected by the concentration of precursors and the reaction time. Thermal conductivity of an optimal ZnO-coated Al plate is 2 times higher than that of a bare one. This technology can be applied to portable PCR devices to reduce weight, size, and power consumption.