Cost-effectiveness of physical activity interventions for prevention and management of cognitive decline and dementia-a systematic review.

BACKGROUND: Although increasing physical activity (PA) has been suggested to prevent and manage cognitive decline and dementia, its economic impact on healthcare systems and society is largely unknown. This study aimed to summarize evidence on the cost-effectiveness of PA interventions to prevent and manage cognitive decline and dementia. METHODS: Electronic databases, including PubMed/MEDLINE, Embase, and ScienceDirect, were searched from January 2000 to July 2023. The search strategy was driven by a combination of subject-heading terms related to physical activity, cognitive function, dementia, and cost-effectiveness. Selected studies were included in narrative synthesis, and extracted data were presented in narrative and tabular forms. The risk of bias in each study was assessed using the Consolidated Health Economic Evaluation Reporting Standards and Consensus on Health Economic Criteria list. RESULTS: Five of the 11 identified studies focused on individuals with existing dementia. Six of the 11 identified studies focused on individuals with no existing dementia, including 3 on those with mild cognitive impairment (MCI), and 3 on those with no existing MCI or dementia. PA interventions focused on individuals with no existing dementia were found to be cost-effective compared to the control group. Findings were mixed for PA interventions implemented in individuals with existing dementia. CONCLUSIONS: PA interventions implemented before or during the early stage of cognitive impairment may be cost-effective in reducing the burden of dementia. More research is needed to investigate the cost-effectiveness of PA interventions in managing dementia. Most existing studies used short-term outcomes in evaluating the cost-effectiveness of PA interventions in the prevention and management of dementia; future research should consider adding long-term outcomes to strengthen the study design.

Facet Connectivity-Based Estimation Algorithm for Manufacturability of Supportless Parts Fabricated via LPBF.

Recent advances in additive manufacturing have provided more freedom in the design of metal parts; hence, the prototyping of fluid machines featuring extremely complex geometries has been investigated extensively. The fabrication of fluid machines via additive manufacturing requires significant attention to part stability; however, studies that predict regions with a high risk of collapse are few. Therefore, a novel algorithm that can detect collapse regions precisely is proposed herein. The algorithm reflects the support span over the faceted surface via propagation and invalidates overestimated collapse regions based on the overhang angle. A heat exchanger model with an extremely complex internal space is adopted to validate the algorithm. Three samples from the model are extracted and their prototypes are fabricated via laser powder bed fusion. The results yielded by the fabricated samples and algorithm with respect to the sample domain are compared. Regions of visible collapse identified on the surface of the fabricated samples are predicted precisely by the algorithm. Thus, the supporting span reflected by the algorithm provides an extremely precise prediction of collapse.

Comparison of methods for evaluation of upper esophageal sphincter (UES) relaxation duration: Videofluoroscopic swallow study versus high-resolution manometry.

This study aims to compare the 2 methods of upper esophageal sphincter (UES) relaxation measurement and determine which method has better diagnostic value in UES relaxation impairment The study included 140 patients with pharyngeal dysphagia who underwent both videofluoroscopic swallow study (VFSS) and high-resolution manometry (HRM). Feeding method was determined to oral or non-oral feeding based on the severity of dysphagia; 103 patients were in oral feeding group and 37 were in non-oral feeding group. UES relaxation duration was measured using VFSS and HRM, respectively. Receiver-operating characteristic curve analysis was conducted to validate the UES relaxation duration in determination of feeding method. UES relaxation duration was more decreased in non-oral feeding group than in oral feeding group on both VFSS and HRM. Receiver-operating characteristic analysis revealed that the optimal cutoff value of UES relaxation duration to determine feeding method (oral or non-oral feeding) was 0.42 seconds on VFSS and 0.44 seconds on HRM. The sensitivity for feeding method was higher in VFSS than HRM (83.5% vs 70.9%), while the specificity was higher in HRM than VFSS (48.6% vs 54.1%). VFSS and HRM have complementary ability in evaluating UES relaxation duration in patients with oropharyngeal dysphagia.

The impact of fine particulate matter (PM) on various beneficial functions of human endometrial stem cells through its key regulator SERPINB2.

Fine particulate matter (PM) has a small diameter but a large surface area; thus, it may have broad toxic effects that subsequently damage many tissues of the human body. Interestingly, many studies have suggested that the recent decline in female fertility could be associated with increased PM exposure. However, the precise mechanisms underlying the negative effects of PM exposure on female fertility are still a matter of debate. A previous study demonstrated that resident stem cell deficiency limits the cyclic regenerative capacity of the endometrium and subsequently increases the pregnancy failure rate. Therefore, we hypothesized that PM exposure induces endometrial tissue damage and subsequently reduces the pregnancy rate by inhibiting various beneficial functions of local endometrial stem cells. Consistent with our hypothesis, we showed for the first time that PM exposure significantly inhibits various beneficial functions of endometrial stem cells, such as their self-renewal, transdifferentiation, and migratory capacities, in vitro and in vivo through the PM target gene SERPINB2, which has recently been shown to be involved in multiple stem cell functions. In addition, the PM-induced inhibitory effects on the beneficial functions of endometrial stem cells were significantly diminished by SERPINB2 depletion. Our findings may facilitate the development of promising therapeutic strategies for improving reproductive outcomes in infertile women.

Noncanonical functions of glucocorticoids: A novel role for glucocorticoids in performing multiple beneficial functions in endometrial stem cells.

Chronic stress has a negative impact on many fertility-related functions; thus, the recent decline in female fertility seems to be at least partially associated with increased stress. The secretion of glucocorticoids is a typical endocrine response to chronic stress and indirectly reduces uterine receptivity through the hypothalamus-pituitary-gonadal (HPG) axis. However, in addition to its well-known canonical role, the direct effects of chronic stress-induced glucocorticoids on various uterine functions and their underlying molecular mechanisms are complex and have not yet been revealed. Recent studies have found that resident stem cell deficiency is responsible for the limited regenerative potential of the endometrium (the innermost lining of the uterine cavity) during each menstrual cycle, which subsequently increases infertility rates. In this context, we hypothesized that stress-induced glucocorticoids directly damage endometrial stem cells and consequently negatively affect endometrial reconstruction, which is important for uterine receptivity. In addition to its well-known canonical roles, we identified for the first time that cortisol, the most abundant and potent glucocorticoid in humans, directly suppresses the multiple beneficial functions (self-renewal, transdifferentiation, and migratory potential) of human endometrial stem cells through its functional receptor, glucocorticoid receptor (GR). Glucocorticoids inhibit well-known survival signals, such as the PI3K/Akt and FAK/ERK1/2 pathways. More importantly, we also found that immobilization of stress-induced glucocorticoids suppresses the various beneficial functions of tissue resident stem cells in vivo. To the best of our knowledge, this is the first study to investigate the direct effects of glucocorticoids on the regenerative capacity of endometrial stem cells, and the findings will facilitate the development of more promising therapeutic approaches to increase female fertility.

Mattertronics for programmable manipulation and multiplex storage of pseudo-diamagnetic holes and label-free cells.

Manipulating and separating single label-free cells without biomarker conjugation have attracted significant interest in the field of single-cell research, but digital circuitry control and multiplexed individual storage of single label-free cells remain a challenge. Herein, by analogy with the electrical circuitry elements and electronical holes, we develop a pseudo-diamagnetophoresis (PsD) mattertronic approach in the presence of biocompatible ferrofluids for programmable manipulation and local storage of single PsD holes and label-free cells. The PsD holes conduct along linear negative micro-magnetic patterns. Further, eclipse diode patterns similar to the electrical diode can implement directional and selective switching of different PsD holes and label-free cells based on the diode geometry. Different eclipse heights and junction gaps influence the switching efficiency of PsD holes for mattertronic circuitry manipulation and separation. Moreover, single PsD holes are stored at each potential well as in an electrical storage capacitor, preventing multiple occupancies of PsD holes in the array of individual compartments due to magnetic Coulomb-like interaction. This approach may enable the development of large programmable arrays of label-free matters with high throughput, efficiency, and reliability as multiplex cell research platforms.

Clinical Practice Guidelines for Prenatal Aneuploidy Screening and Diagnostic Testing from Korean Society of Maternal-Fetal Medicine: (2) Invasive Diagnostic Testing for Fetal Chromosomal Abnormalities.

The Korean Society of Maternal Fetal Medicine proposed the first Korean guideline on prenatal aneuploidy screening and diagnostic testing, in April 2019. The clinical practice guideline (CPG) was developed for Korean women using an adaptation process based on good-quality practice guidelines, previously developed in other countries, on prenatal screening and invasive diagnostic testing for fetal chromosome abnormalities. We reviewed current guidelines and developed a Korean CPG on invasive diagnostic testing for fetal chromosome abnormalities according to the adaptation process. Recommendations for selected 11 key questions are: 1) Considering the increased risk of fetal loss in invasive prenatal diagnostic testing for fetal genetic disorders, it is not recommended for all pregnant women aged over 35 years. 2) Because early amniocentesis performed before 14 weeks of pregnancy increases the risk of fetal loss and malformation, chorionic villus sampling (CVS) is recommended for pregnant women who will undergo invasive prenatal diagnostic testing for fetal genetic disorders in the first trimester of pregnancy. However, CVS before 9 weeks of pregnancy also increases the risk of fetal loss and deformity. Thus, CVS is recommended after 9 weeks of pregnancy. 3) Amniocentesis is recommended to distinguish true fetal mosaicism from confined placental mosaicism. 4) Anti-immunoglobulin should be administered within 72 hours after the invasive diagnostic testing. 5) Since there is a high risk of vertical transmission, an invasive prenatal diagnostic testing is recommended according to the clinician's discretion with consideration of the condition of the pregnant woman. 6) The use of antibiotics is not recommended before or after an invasive diagnostic testing. 7) The chromosomal microarray test as an alternative to the conventional cytogenetic test is not recommended for all pregnant women who will undergo an invasive diagnostic testing. 8) Amniocentesis before 14 weeks of gestation is not recommended because it increases the risk of fetal loss and malformation. 9) CVS before 9 weeks of gestation is not recommended because it increases the risk of fetal loss and malformation. 10) Although the risk of fetal loss associated with invasive prenatal diagnostic testing (amniocentesis and CVS) may vary based on the proficiency of the operator, the risk of fetal loss due to invasive prenatal diagnostic testing is higher in twin pregnancies than in singleton pregnancies. 11) When a monochorionic twin is identified in early pregnancy and the growth and structure of both fetuses are consistent, an invasive prenatal diagnostic testing can be performed on one fetus alone. However, an invasive prenatal diagnostic testing is recommended for each fetus in cases of pregnancy conceived via in vitro fertilization, or in cases in which the growth of both fetuses differs, or in those in which at least one fetus has a structural abnormality. The guidelines were established and approved by the Korean Academy of Medical Sciences. This guideline is revised and presented every 5 years.

Clinical Practice Guidelines for Prenatal Aneuploidy Screening and Diagnostic Testing from Korean Society of Maternal-Fetal Medicine: (1) Prenatal Aneuploidy Screening.

In 2019, the Korean Society of Maternal-Fetal Medicine developed the first Korean clinical practice guidelines for prenatal aneuploidy screening and diagnostic testing. These guidelines were developed by adapting established clinical practice guidelines in other countries that were searched systematically, and the guidelines aim to assist in decision making of healthcare providers providing prenatal care and to be used as a source for education and communication with pregnant women in Korea. This article delineates clinical practice guidelines specifically for maternal serum screening for fetal aneuploidy and cell-free DNA (cfDNA) screening. A total of 19 key questions (12 for maternal serum and 7 for cfDNA screening) were defined. The main recommendations are: 1) Pregnant women should be informed of common fetal aneuploidy that can be detected, risks for chromosomal abnormality according to the maternal age, detection rate and false positive rate for common fetal aneuploidy with each screening test, limitations, as well as the benefits and risks of invasive diagnostic testing, 2) It is ideal to give counseling about prenatal aneuploidy screening and diagnostic testing at the first prenatal visit, and counseling is recommended to be given early in pregnancy, 3) All pregnant women should be informed about maternal serum screening regardless of their age, 4) cfDNA screening can be used for the screening of trisomy 21, 18, 13 and sex-chromosome aneuploidy. It is not recommended for the screening of microdeletion, 5) The optimal timing of cfDNA screening is 10 weeks of gestation and beyond, and 6) cfDNA screening is not recommended for women with multiple gestations. The guideline was reviewed and approved by the Korean Academy of Medical Sciences.

A Study on the Mechanical Properties of an Automobile Part Additively Printed through Periodic Layer Rotation Strategies.

In metal product manufacturing, additive manufacturing (AM) is a method that has the advantage of fabricating complex shapes and customized production, unlike existing machining methods. However, owing to the characteristics of the AM process, anisotropy of macrostructure occurs because of various causes such as the scan direction, melting, fusion, and cooling of the powdered material. The macrostructure anisotropy is realized from the scan direction, and when a single layer is stacked in one direction, it is expressed as orthogonal anisotropy. Here, the classical lamination theory is applied to simply calculate the individual orthotropic layers by superimposing them. Through this, the authors analyzed whether the mechanical properties of the product are isotropically expressed with a periodic layer rotation strategy. To determine if the mechanical properties can be reasonably considered to be isotropic, a shock absorber mount for a vehicle was manufactured by AM. The tensile and vibration test performed on the product was compared with the finite element analysis and experimental results. As a result of the comparison, it was confirmed that the macroscopically of the product was considered isotropic as the load-displacement diagram and the fracture location coincided, as well as the natural frequency and mode shape.

Synthesis and Structure of Multinuclear Pd(II) Complexes Bridged by Phosphide or Azide Ligands.

The synthesis and structure of phosphide- and azide-bridged multinuclear Pd(II) complexes bearing phosphine ligands [PdX(µ-X')(PR3)] n (X = Cl and N3; X' = PR2 ' and N3; n = 2 and 4) are reported. The oxidative addition of R2 'PCl to Pd(PMe3)2 furnished the phosphide-bridged dinuclear Pd(II) complexes [PdCl(µ-PR2 ')(PMe3)]2 [R' = i Pr (1a) and Cy (1b)]. However, the oxidative addition of (o-tolyl)2PCl to Pd(PMe3)2 produced a nonbridged mononuclear Pd(II) complex with the bis(o-tolyl)phosphinic ligand, trans-[Pd(PMe3)2{P(O)(o-tolyl)2}] (2), via oxidation of the phosphinyl ligand. The reaction of the chloride-bridged dinuclear Pd(II) complexes [PdCl(µ-Cl)(PR3)]2 [PR3 = PEt3 (3a) and PPhMe2 (3b)] with NaN3 afforded the azide-bridged dinuclear and tetranuclear Pd(II) complexes [Pd(N3)(µ-N3)(PEt3)]2 (4) and [Pd(N3)(µ-N3)(PPhMe2)]4 (5). Comparisons of the X-ray structures of 4 and 5 show that the square-planar molecular geometry of the Pd(II) centers of 4 are more distorted than those of 5. Density functional theory calculations suggest that the tetranuclear eight-membered ring structure like 5 is more stable than the dinuclear four-membered ring structure like 4 in the gas phase in both PEt3 and PPhMe2 systems. However, because the relative energy difference between the four-membered and eight-membered ring structures is small in the PEt3 system with smaller steric hindrance compared with PPhMe2, it is assumed that this difference is compensated by the crystal packing energy, and the dinuclear four-membered ring complex 4 is actually obtained.

Deletion mutant of PGE2 receptor using CRISPR-Cas9 exhibits larval immunosuppression and adult infertility in a lepidopteran insect, Spodoptera exigua.

Prostaglandins (PGs) mediate various physiological processes in insects and other invertebrates, but there is very little information on PG receptors. This study identified a PGE2 receptor (SePGE2R) in the lepidopteran insect, Spodoptera exigua, and addressed its functional association with cellular immunity, development, and reproduction. SePGE2R is expressed in most developmental stages and tissues. After SePGR2R expression knock down by RNA interference (RNAi), larval nodule formation (clears bacterial infections from circulating hemolymph) was severely suppressed coupled with reduced F-actin growth in hemocytes. Treating female adults with RNAi prevented nurse cell dumping in follicles and interfered with oocyte development. SePGE2R was heterologously expressed in Sf9 cells, in which the endogenous S. frugiperda PGE2R was knocked down by small interfering RNA. This transiently expressed SePGE2R responded to PGE2, but not other PGs, with dose-dependent up-regulation of intracellular cAMP concentrations. Treating S. exigua larvae with PGE2 led to activation of a trimeric Gαs subunit, protein kinase A (PKA), and Rho family small intracellular G proteins in hemocytes. A deletion mutant of SePGE2R was generated using CRISPR/Cas9 which exhibited severely retarded larval development and adult reproduction. We infer that PGE2R mediates insect immune and reproductive processes via a PKA signal pathway.

Multifarious Transit Gates for Programmable Delivery of Bio-functionalized Matters.

Programmable delivery of biological matter is indispensable for the massive arrays of individual objects in biochemical and biomedical applications. Although a digital manipulation of single cells has been implemented by the integrated circuits of micromagnetophoretic patterns with current wires, the complex fabrication process and multiple current operation steps restrict its practical application for biomolecule arrays. Here, a convenient approach using multifarious transit gates is proposed, for digital manipulation of biofunctionalized microrobotic particles that can pass through the local energy barriers by a time-dependent pulsed magnetic field instead of multiple current wires. The multifarious transit gates including return, delay, and resistance linear gates, as well as dividing, reversed, and rectifying T-junction gates, are investigated theoretically and experimentally for the programmable manipulation of microrobotic particles. The results demonstrate that, a suitable angle of the gating field at a suitable time zone is crucial to implement digital operations at integrated multifarious transit gates along bifurcation paths to trap microrobotic particles in specific apartments, paving the way for flexible on-chip arrays of biomolecules and cells.

Addition of Cervical Elastography May Increase Preterm Delivery Prediction Performance in Pregnant Women with Short Cervix: a Prospective Study.

BACKGROUND: We investigated whether there is a difference in elastographic parameters between pregnancies with and without spontaneous preterm delivery (sPTD) in women with a short cervix (≤ 25 mm), and examined the ability of elastographic parameters to predict sPTD in those women. METHODS: E-CervixTM (WS80A; Samsung Medison, Seoul, Korea) elastography was used to examine the cervical strain. Elastographic parameters were compared between pregnancies with and without sPTD. Diagnostic performance of elastographic parameters to predict sPTD ≤ 37 weeks, both alone and in combination with other parameters, was compared with that of cervical length (CL) using area under receiver operating characteristic curve (AUC) analysis. RESULTS: A total of 130 women were included. Median gestational age (GA) at examination was 24.4 weeks (interquartile range, 21.4-28.9), and the prevalence of sPTD was 20.0% (26/130). Both the elastographic parameters and CL did not show statistical difference between those with and without sPTD. However, when only patients with CL ≥ 1.5 cm (n = 110) were included in the analysis, there was a significant difference between two groups in elasticity contrast index (ECI) within 0.5/1.0/1.5 cm from the cervical canal (P < 0.05) which is one of elastographic parameters generated by E-Cervix. When AUC analysis was performed in women with CL ≥ 1.5 cm, the combination of parameters (CL + pre-pregnancy body mass index + GA at exam + ECI within 0.5/1.0/1.5 cm) showed a significantly higher AUC than CL alone (P < 0.05). CONCLUSION: An addition of cervical elastography may improve the ability to predict sPTD in women with a short CL between 1.5 and 2.5 cm.

Autonomous Magnetic Microrobots by Navigating Gates for Multiple Biomolecules Delivery.

The precise delivery of biofunctionalized matters is of great interest from the fundamental and applied viewpoints. In spite of significant progress achieved during the last decade, a parallel and automated isolation and manipulation of rare analyte, and their simultaneous on-chip separation and trapping, still remain challenging. Here, a universal micromagnet junction for self-navigating gates of microrobotic particles to deliver the biomolecules to specific sites using a remote magnetic field is described. In the proposed concept, the nonmagnetic gap between the lithographically defined donor and acceptor micromagnets creates a crucial energy barrier to restrict particle gating. It is shown that by carefully designing the geometry of the junctions, it becomes possible to deliver multiple protein-functionalized carriers in high resolution, as well as MCF-7 and THP-1 cells from the mixture, with high fidelity and trap them in individual apartments. Integration of such junctions with magnetophoretic circuitry elements could lead to novel platforms without retrieving for the synchronous digital manipulation of particles/biomolecules in microfluidic multiplex arrays for next-generation biochips.

Magnetically Characterized Molecular Lubrication between Biofunctionalized Surfaces.

We demonstrate an efficient approach for quantifying frictional forces (sub-piconewton) at nano-bio interfaces by controlled magnetic forces, which is based on simultaneous measurements of critical frequencies for streptavidin-coupled magnetic particles. The maximum phase angle, being corresponded with the critical frequency, is formulated in terms of magnetic, frictional, and viscous forces of the particles on DNA- and SiO2-functionalized micromagnet arrays. The streptavidin/DNA interface shows lower friction as an enhanced lubrication than the streptavidin/SiO2 interface, which is indicated by the lower transition field of quasi-static motion, the larger ratio of dynamic particles, and also the higher velocity of the particles. The friction coefficients at the streptavidin/DNA and streptavidin/SiO2 interfaces are evaluated numerically as 0.07 and 0.11, respectively, regardless of the vertical force and the velocity. The proposed method would open up new possibilities to study mechanical interactions at biological surfaces.

Quantitative Analysis of Swallowing Function Between Dysphagia Patients and Healthy Subjects Using High-Resolution Manometry.

OBJECTIVE: To compare swallowing function between healthy subjects and patients with pharyngeal dysphagia using high resolution manometry (HRM) and to evaluate the usefulness of HRM for detecting pharyngeal dysphagia. METHODS: Seventy-five patients with dysphagia and 28 healthy subjects were included in this study. Diagnosis of dysphagia was confirmed by a videofluoroscopy. HRM was performed to measure pressure and timing information at the velopharynx (VP), tongue base (TB), and upper esophageal sphincter (UES). HRM parameters were compared between dysphagia and healthy groups. Optimal threshold values of significant HRM parameters for dysphagia were determined. RESULTS: VP maximal pressure, TB maximal pressure, UES relaxation duration, and UES resting pressure were lower in the dysphagia group than those in healthy group. UES minimal pressure was higher in dysphagia group than in the healthy group. Receiver operating characteristic (ROC) analyses were conducted to validate optimal threshold values for significant HRM parameters to identify patients with pharyngeal dysphagia. With maximal VP pressure at a threshold value of 144.0 mmHg, dysphagia was identified with 96.4% sensitivity and 74.7% specificity. With maximal TB pressure at a threshold value of 158.0 mmHg, dysphagia was identified with 96.4% sensitivity and 77.3% specificity. At a threshold value of 2.0 mmHg for UES minimal pressure, dysphagia was diagnosed at 74.7% sensitivity and 60.7% specificity. Lastly, UES relaxation duration of <0.58 seconds had 85.7% sensitivity and 65.3% specificity, and UES resting pressure of <75.0 mmHg had 89.3% sensitivity and 90.7% specificity for identifying dysphagia. CONCLUSION: We present evidence that HRM could be a useful evaluation tool for detecting pharyngeal dysphagia.

Magnetic Susceptibility Study of Sub-Pico-emu Sample Using a Micromagnetometer: An Investigation through Bistable Spin-Crossover Materials.

A promising and original method to study the spin-transition in bistable spin-crossover (SCO) materials using a magnetoresistive multiring sensor and its self-generated magnetic field is reported. Qualitative and quantitative studies are carried out combining theoretical and experimental approaches. The results show that only a small part of matter dropped on the sensor surface is probed by the device. At a low bias-current range, the number of detected nanoparticles depends on the amplitude of the current. However, in agreement with the theoretical model, the stray voltage from the particles is proportional to the current squared. By changing both the bias current and the concentration of particle droplet, the thermal hysteresis of an ultrasmall volume, 1 × 10-4 mm3 , of SCO particles is measured. The local probe of the experimental setup allows a highest resolution of 4 × 10-14 emu to be reached, which is never achieved by experimental methods at room temperature.

An entomopathogenic bacterium, Xenorhabdus hominickii ANU101, produces oxindole and suppresses host insect immune response by inhibiting eicosanoid biosynthesis.

An entomopathogenic bacterium, Xenorhabdus hominickii ANU101, was isolated from an entomopathogenic nematode, Steinernema monticolum. X. hominickii exhibited significant insecticidal activities at ≥6.6×102 colony-forming units per larva against a lepidopteran insect, Spodoptera exigua with hemocoelic injection. The insecticidal activity of X. hominickii was reduced by an addition of arachidonic acid (AA, a catalytic product of PLA2), but enhanced by an addition by dexamethasone (DEX, a specific inhibitor of PLA2). S. exigua could defend the bacterial infection by forming hemocyte nodules. However, live X. hominickii significantly reduced the hemocytic nodulation compared to similar treatment with heat-killed X. hominickii. An addition of AA to live X. hominickii significantly rescued the immunosuppression. X. hominickii also inhibited phenoloxidase activity in hemolymph of S. exigua larvae. Furthermore, the bacteria suppressed gene expressions of antimicrobial peptides, such as attacin-1, attacin-2, defensin, gallerimycin and transferrin-1 of S. exigua. An organic extract of X. hominickii-cultured broth with ethyl acetate possessed oxindole and significantly suppressed hemocyte nodulation. Again, an addition of AA diminished the inhibitory activity of the organic extract against hemocyte nodulation. Oxindole alone inhibited hemocyte nodulation and PLA2 enzyme activity. These results suggest that the entomopathogenicity of X. hominickii comes from its inhibitory activity against eicosanoid biosynthesis of target insects.

An on-chip micromagnet frictionometer based on magnetically driven colloids for nano-bio interfaces.

A novel method based on remotely controlled magnetic forces of bio-functionalized superparamagnetic colloids using micromagnet arrays was devised to measure frictional force at the sub-picoNewton (pN) scale for bio-nano-/micro-electromechanical system (bio-NEMS/MEMS) interfaces in liquid. The circumferential motion of the colloids with phase-locked angles around the periphery of the micromagnets under an in-plane rotating magnetic field was governed by a balance between tangential magnetic force and drag force, which consists of viscous and frictional forces. A model correlating the phase-locked angles of the steady colloid rotation was formulated and validated by measuring the angles under controlled magnetic forces. Hence, the frictional forces on the streptavidin/Teflon interface between the colloids and the micromagnet arrays were obtained using the magnetic forces at the phase-locked angles. The friction coefficient for the streptavidin/Teflon interface was estimated to be approximately 0.036 regardless of both vertical force in the range of a few hundred pN and velocity in the range of a few tenths of µm s(-1).

Towards targeting anticancer drugs: ruthenium(ii)-arene complexes with biologically active naphthoquinone-derived ligand systems.

Anticancer active metal complexes with biologically active ligands have the potential to interact with more than one biological target, which could help to overcome acquired and/or intrinsic resistance of tumors to small molecule drugs. In this paper we present the preparation of 2-hydroxy-[1,4]-naphthoquinone-derived ligands and their coordination to a Ru(II)(η(6)-p-cymene)Cl moiety. The synthesis of oxime derivatives resulted in the surprising formation of nitroso-naphthalene complexes, as confirmed by X-ray diffraction analysis. The compounds were shown to be stable in aqueous solution but reacted with glutathione and ascorbic acid rather than undergoing reduction. One-electron reduction with pulse radiolysis revealed different behavior for the naphthoquinone and nitroso-naphthalene complexes, which was also observed in in vitro anticancer assays.