Controlled Synthesis of Polyaniline-Based Nanomaterials with Self-Assembly and Interface Manipulation.

Versatile nanostructures of conducting polymers are highly relevant based on unique properties, including electrical, optical, and thermal, with changes in morphology. This contribution reports a facile and reproducible synthesis approach for the design of conducting polymer nanostructures from zero- to three-dimensional composites. Two polymerization steps, namely, self-assembly-directed and interface thin layer-templated polymerizations in this synthesis, were kinetically controlled to fabricate such nanostructures directly. The uniquely designed bicontinuous nanoreactor offers an easy synthesis technique for fabricating 3D multifunctional conducting polymer composites. Self-assembly-directed polymerization could be controlled to form nanorods and further directed to form nanobowl/hollow spherical structures. The interface thin layer template process was tuned to produce hollow spherical and 2D film nanostructures. Kinetic control of polymerization was able to provide access to unprecedented nanostructures of the conducting polymers ranging from DNA origami to gecko-inspired nanostructures, with potential applications in drug delivery, energy storage, and adhesive materials. For example, this is the first conducting polymer material that can demonstrate similar adhesiveness (around 8 N/cm2) to gecko finger hairs.

Age-related smartphone use patterns among individuals with moderate-to-severe traumatic brain injury.

OBJECTIVE: With mobile health technologies serving as an alternative means of providing healthcare, evaluating patients' abilities to navigate digital infrastructures is becoming increasingly relevant. The goal of this study is to investigate smartphone use patterns among individuals with history of moderate-to-severe traumatic brain injury (TBI). METHODS: An anonymous survey was delivered via e-mail or text message to eligible participants who had a history of moderate-to-severe TBI and were prospectively followed at one of the eight participating Traumatic Brain Injury Model Systems centers for at least 1-year post-injury. The survey captured demographic data and included a questionnaire to evaluate smartphone use (calling, texting, web browsing, etc.). RESULTS: A total of 2665 eligible individuals were contacted to complete the survey, 472 of which responded. 441 of them reported smartphone use. Individuals ages 45 and older were significantly less likely to use their phones for functions other than calling and texting when compared to individuals ages 18-44 (p < 0.05). CONCLUSIONS: Most individuals with moderate-to-severe TBI in this cohort demonstrated intentional smartphone use, suggesting that mobile health technologies may be feasible as a cost-effective healthcare alternative. However, doing so will require additional interventions to provide further technological education especially in older individuals with TBI.

Physicochemical Characterization, Antioxidant and Tyrosinase Inhibitory Activities of Coffea Robusta Monofloral Honey from Dak Lak Province, Vietnam.

Robusta coffee blossom honey stands as a key regional product in Dak Lak province, Vietnam. Despite its significance, there exists a dearth of scientific data for assessing its quality. This study aims to fill this gap by characterizing the physicochemical properties and biological activities of coffee blossom honeys from three distinct sub-regions within Dak Lak province, Vietnam. These activities include ferric reducing power (FRP), DPPH and ABTS radical scavenging, as well as tyrosinase inhibitory activities. Moreover, the study compares these honey samples with other popular varieties in Vietnam, such as Lychee and Longan honeys. The physicochemical parameters of the honey samples meet the standards set by Codex Alimentarius 2001. Through UPLC analysis, eleven compounds were identified, with caffeine serving as a marker for coffee honey. Furthermore, by employing multiple factor analysis (MFA), it was observed that certain physicochemical properties correlate positively with tyrosinase inhibitory, DPPH, ABTS free radicals scavenging activities, and FRP. Notably, tyrosinase inhibitory activity exhibited a positive correlation with antioxidant activity. These findings underscore the high quality of Coffea robusta honey, showcasing its potent antioxidant and tyrosinase inhibitory activities.

Dynamic Measurement of a Cancer Biomarker: Towards In Situ Application of a Fiber-Optic Ball Resonator Biosensor in CD44 Protein Detection.

The accuracy and efficacy of medical treatment would be greatly improved by the continuous and real-time monitoring of protein biomarkers. Identification of cancer biomarkers in patients with solid malignant tumors is receiving increasing attention. Existing techniques for detecting cancer proteins, such as the enzyme-linked immunosorbent assay, require a lot of work, are not multiplexed, and only allow for single-time point observations. In order to get one step closer to clinical usage, a dynamic platform for biosensing the cancer biomarker CD44 using a single-mode optical fiber-based ball resonator biosensor was designed, constructed and evaluated in this work. The main novelty of the work is an in-depth study of the capability of an in-house fabricated optical fiber biosensor for in situ detection of a cancer biomarker (CD44 protein) by conducting several types of experiments. The main results of the work are as follows: (1) Calibration of the fabricated fiber-optic ball resonator sensors in both static and dynamic conditions showed similar sensitivity to the refractive index change demonstrating its usefulness as a biosensing platform for dynamic measurements; (2) The fabricated sensors were shown to be insensitive to pressure changes further confirming their utility as an in situ sensor; (3) The sensor's packaging and placement were optimized to create a better environment for the fabricated ball resonator's performance in blood-mimicking environment; (4) Incubating increasing protein concentrations with antibody-functionalized sensor resulted in nearly instantaneous signal change indicating a femtomolar detection limit in a dynamic range from 7.1 aM to 16.7 nM; (5) The consistency of the obtained signal change was confirmed by repeatability studies; (6) Specificity experiments conducted under dynamic conditions demonstrated that the biosensors are highly selective to the targeted protein; (7) Surface morphology studies by AFM measurements further confirm the biosensor's exceptional sensitivity by revealing a considerable shift in height but no change in surface roughness after detection. The biosensor's ability to analyze clinically relevant proteins in real time with high sensitivity offers an advancement in the detection and monitoring of malignant tumors, hence improving patient diagnosis and health status surveillance.

Rapid detection of carcinoembryonic antigen by means of an electrochemical aptasensor.

Carcinoembryonic antigen (CEA) is a critical biomarker for identifying colon cancer. This work presents an electrochemical impedance spectroscopy (EIS) based aptasensor for detecting CEA, utilizing a single-stranded DNA (ssDNA) aptamer previously selected and characterized by our research group. The surface of an interdigitated gold electrode (IDE) was successfully functionalized with an 18-HEG-modified aptamer sequence. The developed aptasensor demonstrated high specificity and sensitivity with detection limits of 2.4 pg/mL and 3.8 pg/mL for CEA in buffer and human serum samples, respectively. The optimal incubation time for the target protein was 20 min, and EIS measurements took less than 3 min. Atomic force microscopy (AFM) micrographs supported the EIS data, demonstrating a change in IDE surface roughness after each modification step, confirming the successful capture of the target. The potential of this developed EIS aptasensor in detecting CEA in complex samples holds promise.

Functionalized optical fiber ball-shaped biosensor for label-free, low-limit detection of IL-8 protein.

Detection of biomarkers for tracking disease progression is becoming increasingly important in biomedicine. Using saliva as a diagnostic sample appears to be a safe, cost-effective, and non-invasive approach. Salivary interleukin-8 levels demonstrate specific changes associated with diseases such as obstructive pulmonary disease, squamous cell carcinoma, oral cancer, and breast cancer. Traditional protein detection methods, such as enzyme-linked immunosorbent assay (ELISA), mass spectrometry, and Western blot are often expensive, complex, and time-consuming. In this study, an optical fiber-based biosensor was developed to detect salivary IL-8 protein in a label-free manner. The biosensor was able to achieve an ultra-low limit detection of 0.91 fM. Moreover, the tested concentration range was wide: from 273 aM to 59 fM. As a proof-of-concept for detecting the protein in real clinical samples, the detection was carried out in artificial saliva. It was possible to achieve high sensitivity for the target protein and minimal signal alterations for the control proteins.

Mechanism of the antimicrobial activity induced by phosphatase inhibitor sodium ortho-vanadate.

The present study describes a novel antimicrobial mechanism based on Sodium Orthovanadate (SOV), an alkaline phosphatase inhibitor. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and atomic force microscopy (AFM) were employed to examine the surface morphologies of the test organism, Escherichia coli (E. coli), during various antibacterial phases. Our results indicated that SOV kills bacteria by attacking cell wall growth and development, leaving E. coli's outer membrane intact. Our antimicrobial test indicated that the MIC of SOV for both E. coli and Lactococcus lactis (L. lactis) is 40 µM. A combination of quantum mechanical calculations and vibrational spectroscopy revealed that divanadate from SOV strongly coordinates with Ca2+ and Mg2+, which are the activity centers for the phosphatase that regulates bacterial cell wall synthesis. The current study is the first to propose the antibacterial mechanism caused by SOV attacking cell wall.

4-Nitrophenol reduction and antibacterial activity of Ag-doped TiO2 photocatalysts.

Water contamination by organic pollutants is a serious environmental problem. 4-Nitrophenol (4-NP) is a potentially harmful chemical, which is commonly present in industrial effluents and can severely damage human health. Photocatalytic reduction of hazardous 4-NP by nano-sized materials to produce 4-aminophenol (4-AP), which is a commercially valuable product, is a promising alternative as the process is framed within the circular economy. In this context, Ag-doped TiO2 (AT) catalysts were synthesized by liquid impregnation and reduction techniques, and their structure, morphology, elemental composition, textural, and light absorption properties were evaluated by XRD, Raman spectroscopy, SEM, TEM, EDS, BET, and DRS spectroscopy. AT catalysts exhibited an enhanced photocatalytic reduction of 4-NP into 4-aminophenol (4-AP) in the presence of NaBH4. Among the tested catalysts, AT21 prepared by a simple aqueous reduction method showed the highest activity reaching about 98% 4-NP reduction within 10 min. Antibacterial tests of these catalysts against Bacillus subtilis, Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa revealed that AT21 also exhibited the lowest minimum inhibitory concentration, suggesting that it has the strongest antibacterial activity. These findings suggest that AT21 catalyst with improved catalytic and antibacterial properties can potentially be utilized for the remediation of 4-NP-contaminated water environment.

Osmoregulation by choline-based deep eutectic solvent induces electroactivity in Bacillus subtilis biofilms.

Gram-positive Bacillus subtilis is a model organism for the biotechnology industry and has recently been characterized as weakly electroactive in both planktonic cultures and biofilms. Increasing the extracellular electron transfer (EET) rate in B. subtilis biofilms will help to develop an efficient microbial electrochemical technology (MET) and improve the bioproduction of high-value metabolites under electrofermentative conditions. In our previous work, we have shown that the addition of compatible solute precursors such as choline chloride (ChCl) to the growth medium formulation increases current output and biofilm formation in B. subtilis. In this work, we utilized a low-carbon tryptone yeast extract medium with added salts to further expose B. subtilis to salt stress and observe the osmoregulatory and/or nutritional effects of a D-sorbitol/choline chloride (ChCl) (1:1 mol mol-1) deep eutectic solvents (DESs) on the electroactivity of the formed biofilm. The results show that ChCl and D-sorbitol alleviate the osmotic stress induced by the addition of NaH2PO4 and KH2PO4 salts and boost biofilm production. This is probably due to the osmoprotective effect of ChCl, a precursor of the osmoprotectant glycine betaine, and the induction of electroactive exopolymeric substances within the B. subtilis biofilm. Since high ionic strength media are commonly used in microbial biotechnology, the combination of ChCl-containing DESs and salt stress could enhance biofilm-based electrofermentation processes that bring significant benefits for biotechnological applications.

Electrofermentation increases concentration of poly γ-glutamic acid in Bacillus subtilis biofilms.

Fluctuations in redox conditions in bioprocesses can alter the end-products, reduce their concentration, and lengthen the process time. Electrofermentation enables rapid metabolic modulation of biosynthesis and allows control of redox imbalances in biofilm-based fermentation processes. In this study, electrofermentation is used to boost the production of the bacterial biopolymer poly-γ-glutamic acid (γ-PGA) from Bacillus subtilis ATCC 6051. When compared to control experiments (3.3 ± 0.99 g L-1 ), the application of an electrode potential E = 0.4 V versus Ag/AgCl results in a more than two-fold increase in the production of γ-PGA (9.13 ± 1.4 g L-1 ). Using an engineered B. subtilis strain, in which γ-PGA production is driven by isopropyl ß-d-1-thiogalactopyranoside, electrofermentation improves polymer concentrations from 15.4 ± 1.5 to 23.1 ± 1.6 versus g L-1 . These results confirm that electrofermentation conditions can be adopted to increase the concentration of γ-PGA and perhaps other extracellular biopolymers in industrial strains.

Community-based exercise program, self-reported health-related symptoms, and quality of life in persons with traumatic brain injury 45 + years old.

BACKGROUND: Individuals with moderate to severe traumatic brain injury (msTBI) have reported a lack of motivation, lack of time, and fatigue as perceived barriers to exercise. OBJECTIVE: To evaluate the effects of an exercise program on self-reported health-related symptoms and quality of life in persons 45-years and older with msTBI. METHODS: Post-hoc analysis of a prospective community-based 12-week exercise program of 20 adults, age 45-80 years, with msTBI. Ten were in aerobic exercise training (AET) program and 10 in a stretching and toning (SAT) program. The AET group was instructed to exercise based on their estimated maximal heart rate (HR) for 150 minutes weekly. The SAT group was to stretch for the same target time without significantly increasing HR or level of exertion. Outcome measures were Traumatic Brain Injury Quality of Life (TBI-QOL) for global, cognitive, emotional, and social health, Patient Health Questionnaire-9 (PHQ-9) for depressive symptoms, and Pittsburgh Sleep Quality Index (PSQI) for sleep quality. RESULTS: AET was associated with improved self-reported cognitive health and sleep compared to SAT. Moderate to large, positive effect sizes were also observed in the AET group in the QOL categories of global, emotional, and social health, and depressive symptoms. CONCLUSIONS: This study offers preliminary evidence that AET may improve health-related QOL, especially for cognition and sleep, in middle-aged and older adults with msTBI.