Detection of lactate in human sweat via surface-modified, screen-printed carbon electrodes.

Real-time and continuous monitoring of lactate levels in sweat has been used as an indicator of physiological information to evaluate exercise outcomes and sports performance. We developed an optimal enzyme-based biosensor to detect the concentrations of lactate in different fluids (i.e., a buffer solution and human sweat). The surface of the screen-printed carbon electrode (SPCE) was first treated with oxygen plasma and then surface-modified by lactate dehydrogenase (LDH). The optimal sensing surface of the LDH-modified SPCE was identified by Fourier transform infrared spectroscopy and electron spectroscopy for chemical analysis. After connecting the LDH-modified SPCE to a benchtop E4980A precision LCR meter, our results showed that the measured response was dependent on the lactate concentration. The recorded data exhibited a broad dynamic range of 0.1-100 mM (R2 = 0.95) and a limit of detection of 0.1 mM, which was unachievable without the incorporation of redox species. A state-of-the-art electrochemical impedance spectroscopy (EIS) chip was developed to integrate the LDH-modified SPCE for a portable bioelectronic platform in the detection of lactate in human sweat. We believe the optimal sensing surface can improve the sensitivity of lactate sensing in a portable bioelectronic EIS platform for early diagnosis or real-time monitoring during different physical activities.

A Multimodality Electrochemical and Impedance Spectroscopy System-on-a-Chip With Temperature Sensing and Impedance-Boosting Techniques.

This article presents a multimodal electrochemical sensing system-on-chip (SoC), including the functions of cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and temperature sensing. CV readout circuitry achieves an adaptive readout current range of 145.5 dB through an automatic range adjustment and resolution scaling technique. EIS has an impedance resolution of 9.2 m Ω/√ Hz at a sweep frequency of 10 kHz and an output current of up to 120 µA. With an impedance boost mechanism, the maximum detectable load impedance is extended to 22.95 k Ω, while the total harmonic distortion is less than 1%. A resistor-based temperature sensor using a swing-boosted relaxation oscillator can achieve a resolution of 31 mK in 0-85 °C. The design is implemented in a 0.18 µm CMOS process. The total power consumption is 1 mW.

Cobalt-Catalyzed Cyclization of 2-Bromobenzamides with Carbodiimides: A New Route for the Synthesis of 3-(Imino)isoindolin-1-ones.

A novel synthetic pathway to approach 3-(imino)isoindolin-1-ones by the Co-catalyzed cyclization reaction of 2-bromobenzamides with carbodiimides has been developed. This catalytic reaction can tolerate a variety of substituents and provide corresponding products in moderate yields for most cases. According to the literature, the reaction mechanism is proposed through the formation of a five-membered aza-cobalacycle complex, which carries out the following reaction subsequence, including nucleophilic addition and substitution, to furnish the desired structures.

Efficient Defect Healing of Transition Metal Dichalcogenides by Metallophthalocyanine.

Two-dimensional (2D) transition metal dichalcogenides (TMDCs) have attracted great attention as alternatives to graphene with semiconducting band gaps. Mono- or few-layer TMDCs can be prepared by various methods, but regardless of the fabrication methods [such as mechanical exfoliation and chemical vapor deposition (CVD)], TMDCs contain many structural defects, which significantly affect their physical properties and limit their performance in applications. Metallophthalocyanines (MPcs) are organic semiconductors, and as dopants, they are capable of modulating the optical and electrical properties of other semiconducting materials. Here, we report that besides the ability to modulate the optoelectronic properties of 2D TMDCs, MPc molecules can be used to heal defects and improve the physicochemical properties of TMDCs. Doping of planar MPc molecules to TMDCs is achieved by a simple solution dip-coating method and results in a significant improvement in the optical properties and thermal responses of CVD-grown TMDCs, even comparable to those of mechanically exfoliated counterparts. Study of carrier dynamics shows that the adsorption of MPc on the TMDC surface leads to the complete suppression of the mid-gap defect-induced absorption in TMDCs. Furthermore, MPc molecules with a large lateral size are found to effectively reduce the point defects in mechanically exfoliated TMDCs introduced during the preparation process. Our results not only clarify the optoelectronic modulation mechanism of chemical doping but also offer a simple method to control the nanosized defects in 2D TMDCs.

New insight into the catalytic properties of rice sucrose synthase.

Sucrose synthase (SuS), which catalyzes the reversible conversion of sucrose and uridine diphosphate (UDP) into fructose and UDP-glucose, is a key enzyme in sucrose metabolism in higher plants. SuS belongs to family 4 of the glycosyltransferases (GT4) and contains an E-X7-E motif that is conserved in members of GT4 and two other GT families. To gain insight into the roles of this motif in rice sucrose synthase 3 (RSuS3), the two conserved glutamate residues (E678 and E686) in this motif and a phenylalanine residue (F680) that resides between the two glutamate residues were changed by site-directed mutagenesis. All mutant proteins maintained their tetrameric conformation. The mutants E686D and F680Y retained partial enzymatic activity and the mutants E678D, E678Q, F680S, and E686Q were inactive. Substrate binding assays indicated that UDP and fructose, respectively, were the leading substrates in the sucrose degradation and synthesis reactions of RSuS3. Mutations on E678, F680, and E686 affected the binding of fructose, but not of UDP. The results indicated that E678, F680, and E686 in the E-X7-E motif of RSuS3 are essential for the activity of the enzyme and the sequential binding of substrates. The sequential binding of the substrates implied that the reaction catalyzed by RSuS can be controlled by the availability of fructose and UDP, depending on the metabolic status of a tissue.

Use of traditional medicine and complementary and alternative medicine in Taiwan: a multilevel analysis.

As the selection of a medical modality is not completely independent, environmental and sociocultural contexts of ecological validity are desired. This study aimed to apply a multilevel analysis using the Hierarchical Linear Modeling software to examine predictors of traditional medicine (TM)/complementary and alternative medicine (CAM) use in Taiwan on both individual and division levels. Individual-level data were obtained from the government database involving TM/CAM use and its impact on the population, whereas division-level data were obtained from a government annual report. A total of 2310 individuals from 22 administrative divisions of Taiwan were evaluated in the data analysis, of which 86.9% had used at least 1 TM/CAM modality in the past year. The average division of TM/CAM use was 2.86 modalities in the null model and 4.15 in the full model. Significant relationships were found between TM/CAM use and individual-level variables of gender, educational level, monthly income, perceived health status, experience with Western medical treatment, and the cost, effect, and degree of satisfaction with TM/CAM. At the division level, TM/CAM use was significantly related to aging population, employment status, and the number of medical institutions. With a simultaneous evaluation of the individual-level and division-level influences, it was found that the average division of TM/CAM use increased significantly. The place of residence is an important predictor of TM/CAM use. The age factor in predicting TM/CAM use in this study may be overestimated in the population of 26 to 60 years of age, whereas an aging population is important in the average division of TM/CAM use. Efforts to reform health insurance to completely cover the costs of TM/CAM and to better facilitate equality of access of health care in rural and remote areas are deemed necessary.

Insights into the catalytic properties of bamboo vacuolar invertase through mutational analysis of active site residues.

Plant acid invertases, which are either associated with the cell wall or present in vacuoles, belong to family 32 of glycoside hydrolases (GH32). Homology modeling of bamboo vacuolar invertase Bobetafruct3 using Arabidopsis cell-wall invertase AtcwINV1 as a template showed that its overall structure is similar to GH32 enzymes, and that the three highly conserved motifs, NDPNG, RDP and EC, are located in the active site. This study also used site-directed mutagenesis to examine the roles of the conserved amino acid residues in these three motifs, which include Asp135, Arg259, Asp260, Glu316 and Cys317, and a conserved Trp residue (Trp159) that resides between the NDPNG and RDP motifs. The mutants W159F, W159L, E316Q and C317A retained acid invertase activity, but no invertase activity was observed for the mutant E316A or mutants with changes at Asp135, Arg259, or Asp260. The apparent K(m) values of the four mutants with invertase activity were all higher than that of the wild-type enzyme. The mutants W159L and E316Q exhibited lower k(cat) values than the wild-type enzyme, but an increase in the k(cat) value was observed for the mutants W159F and C317A. The results of this study demonstrate that these residues have individual functions in catalyzing sucrose hydrolysis.

[Developments and trends in traditional medicine and complementary and alternative medicine].

With the rapid development of society, medical science and technology, although quality of life is enhanced and life expectancy is prolonged, aging, environmental changes and health problems are unavoidable. More and more people, therefore, are concerned about their health and place high demands on medical care. As modern medicine cannot meet all such demands, other medical care systems emerge. Trends in the seeking of medical care show that people are inclined towards natural approaches, so attention is being paid once again to traditional medicine, as well as complementary and alternative medicine. Under the patient-oriented concept, medical personnel have to recognize means of health care while thinking of the individualized and socioeconomic impacts. The purpose of this paper therefore is to provide medical personnel with information on the developments and trends in, knowledge and research with regard to traditional medicine as well as complementary and alternative medicine.