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Vibrational spectra of CO physisorbed onto well defined NaCl(100) surfaces were studied using a Fourier transform infrared interferometer. Structures of CO starting from the monolayer to multilayers were explored. At 31.5 K and a CO pressure of 1×10-6 mbar only the monolayer is formed. Polarization measurements confirm our earlier study that the monolayer CO molecules are aligned perpendicular to the NaCl(100) surface. Increasing the CO pressure to 7×10-6 mbar produces multilayer adsorption. The multilayer spectra closely resemble that of α-CO absorption previously reported. The near perfect match of crystal structures and lattice constants of α-CO and NaCl is reasoned to force the epitaxial growth of single crystal multilayers in our experiments. At 22 K the monolayer absorption is at 2155.01 cm-1 with a bandwidth (FWHH) of 0.26 cm-1. The two prominent features in the multilayer spectra at 22 K are assigned to the longitudinal optical (LO) mode at 2142.54 cm-1 and the transverse optical (TO) mode at 2138.51 cm-1. Their frequency separation is a consequence of the lowering of the cubic symmetry of the bulk α-CO crystal by the shape, in the form of thin slabs, of our multilayer samples. Their bandwidths depend on the thickness of the sample and are characterized by a bandwidth parameter of 0.25 cm-1 for the LO mode and 0.85 cm-1 for the TO mode. The relative absorbances of these modes depend on the polarization of the infrared radiation. Theoretical formalism to account for the band splitting and absorption profiles of the infrared absorption is reviewed and applied to our measurements. While many features of our data can be explained by the present theory, further work is required to account for all the experimental results. [ABSTRACT FROM AUTHOR]

Introduction: Forms of habitual substance use including cigarette smoking and alcohol consumption have been documented as risk factors of common mental disorders (CMDs). The effects of areca nut chewing on biophysiological tests, metabolic syndromes, and liver function have been reported previously; however, the relationship between areca nut chewing and CMDs remains unclear. This study examined the association between areca nut chewing and CMDs and explored the relationships between areca nut chewing and biophysiological indicators.Methods: A total of 4477 community dwellers who had enrolled in a cohort study and participated in health examinations in 2 consecutive years were selected for analysis in the present study. The community cohort was established in northern Taiwan during 2006-2012. The Chinese health questionnaire (CHQ-12) was used as a self-reported screening instrument to assess the potential for developing psychotic mental disorders (CHQ-12 score ≥ 3) among the community residents. Biophysiological tests performed 1 year before CMD assessment were analyzed to examine the causal pathways between areca nut chewing and CMDs. Multiple logistic regression and stratified analyses were performed.Results: A total of 18.23% of the participants were diagnosed as having CMDs. Factors including areca nut chewing [odds ratio (OR) 1.828; 95% confidence interval (CI) 1.165-2.869], sex (women; OR 1.828; 95% CI 1.165-2.869), age (30-49; OR 1.302; 95% CI 1.073-1.579), and socioeconomic status (lower status; OR 1.373; 95% CI 1.084-1.738) were associated with CMDs in a multiple logistic regression model. Areca nut chewers exhibited significantly more triglycerides (220.04 vs. 124.16 mg/dL) and white blood cells (65.17 102/μL vs. 60.36 102/μL) and significantly higher diastolic blood pressure (78.83 vs. 75.84 mmHg) and glutamic oxaloacetic transaminase (30.30 vs. 25.45 U/L) than did the controls.Conclusions: This study demonstrated the association between areca nut chewing and CMDs and its effects on biophysiological tests in a community-based population in Taiwan. The findings suggest the existence of mechanistic effects of areca nut chewing on CMDs exerted through multiple pathways that may interact with pre-existing biophysiological abnormalities. Lifestyle variables should be considered for the prevention and management of mental disorders in the future. [ABSTRACT FROM AUTHOR]

Chinese herbal medicines (CHMs) containing aristolochic acid (AA) are associated with chronic kidney disease (CKD), but some prescribed CHMs have been shown to possess renoprotective effects. We conducted a nationwide retrospective cohort study to delineate the role of prescribed CHMs on the CKD progression. Renoprotective CHM (RPCHM) was defined if a CHM contained dong chong xia cao (Cordyceps sinensis (Berk.) Sacc.), da huang (Rheum palmatum L), huang qi (Astragalus membranaceus), dan shen (Salvia miltiorrhiza Bge.), and dong quai (Angelica sinensis (Oliv.) Diels) or belonged to specific mixture herbal formulations (Yishen capsule, Saireito, or Wen Pi Tang). Subjects who had ever used AA-containing CHMs, had cancer or HIV prior to CKD diagnosis, or died within the first month of CKD diagnosis were excluded. A total of 11,625 patients were eligible subjects. The adjusted hazard ratio (aHR) for all-cause mortality was 0.6 (p < 0.001) and 0.6 (p = 0.013) among subjects receiving RPCHMs containing Angelica sinensis and those receiving other RPCHMs, respectively. For CKD-related mortality, the aHR among subjects receiving RPCHMs containing Angelica sinensis was 0.6 (p = 0.025). The use of specific RPCHMs, especially those that contained Angelica sinensis, was associated with a lower risk of mortality among CKD patients. [ABSTRACT FROM AUTHOR]

Room temperature optically detectedmagnetic resonance of a singlequantum object with nanoscale position control is an outstanding challengein many areas, particularly in the life sciences. We introduce a novelapproach to control the nitrogen-vacancy (NV) centers hosted in asingle fluorescent nanodiamond (FND) for which an anti-Brownian electrokinetictrap (ABEL) performs the position control and an integrated radiofrequency(RF) circuit provides enhanced magnetic flux density for ensemblespin-state control simultaneously. We demonstrate static magneticfield sensing in platforms compatible with ABEL trap. With the advancesin the synthesis and functionalization of stable arbitrarily smallFNDs, we foresee the use of our device for the trapping and manipulationof single molecular-sized FNDs in aqueous solution. [ABSTRACT FROM AUTHOR]

The first demonstration of nanodiamonds (NDs) for cellular fluorescence imaging was reported in 2005. It has since then aroused considerable interest among scientists working in the field of diamond and related materials. A large number of researches have been conducted, aimed to develop this novel nanomaterial as diagnostic, imaging, and therapeutic agents in biomedicine. There have been more than 20 review articles and book chapters published on this topic in the past 8 years. With the recent development of nanotechnologies and photonics, the ND-based bioimaging has been taken to a new level. In this topic review, we will focus our attention on the recent advances in the development of NDs as versatile bioimaging agents for both in vitro and in vivo applications. Emerging new technologies including multiphoton excitation imaging, superresolution imaging, optically detected magnetic resonance imaging, cathodoluminescence imaging, and photoacoustic imaging are discussed. [ABSTRACT FROM AUTHOR]

Abstract: Theoretical calculations on electronic excitation energies and absorption cross sections of the H3 defect center in diamond were performed. We constructed model clusters with up to 180 atoms to imitate the local environment of the defect center and conducted first-principle calculations. TD-DFT predicted most accurately vertical excitation energy, whereas TD-HF and CIS provided rough estimations for one- and two-photon absorption cross sections. It was found that a model cluster with a diameter larger than ∼1.0nm is required, while relatively low-cost level of theory and basis set are sufficient for characterizing the excitation properties. [Copyright &y& Elsevier]

Objective Taiwan is the country where end-stage renal disease (ESRD) is most prevalent. The purpose of this study was to investigate whether the rising demand for dialysis or transplantation as a result of ESRD can be balanced by the supply of board-certified (B-C) nephrologists. Methods Two Markov processes were applied for the projection of the supply of B-C nephrologists in ESRD and for the projection of the demand from ESRD in 2020, assuming linear, exponential growth and no increase. Results The supply of B-C nephrologists was projected at 1346 in 2020. To make allowance for the share of total time of professional activities in full-time equivalent (FTE) for B-C nephrologists, the demand was 1556, 962 and 2652 with assumptions of steady, linear and exponential growth, respectively. By the year 2020, 210 and 1306 additional FTE nephrologists will be required to meet, respectively, a linear and an exponential increase in demand from ESRD. Conclusions The projection of the supply of and the demand for B-C nephrologists was made in this study using two Markov processes. The methods and results can be adopted as a reference for health manpower planning on B-C nephrologists. [ABSTRACT FROM AUTHOR]

Abstract: Oxidative-acid-treated nanodiamonds exhibit high affinity for proteins, a property well suited for immobilization of enzymes for biotechnological application. Using lysozyme as an example, this work demonstrates that the enzyme can retain much of its activity after physical adsorption to the surfaces of 100-nm diamond crystallites. The activity relative to that of free lysozyme in solution is ∼60% at the maximum surface coverage of 50% and pH 5. While the enzymatic activity decreases as the surface coverage is lowered, it can be recovered by blocking the empty sites on the surface with supplementary proteins such as cytochrome c to create a more “crowded” environment. A relative activity up to 70% can be attained at a partial coverage of 20%. [Copyright &y& Elsevier]

Background: Physical activity is related to health-related quality of life, but little evidence from multiple waves of panel data in Asian countries area available. This study aims to explore the impacts of different degree of regular exercise on the trajectories of physical and mental dimensions of health-related quality of life (HRQOL) for community-dwelling Taiwanese adults during 2006-2014.Methods: Data were derived from the "Landseed Integrated Outreaching Neighborhood Screening (LIONS)" study, with 6182 adults enrolled at the baseline and subsequently followed up to three times till 2014. Linear mixed-effects modeling approach was employed to evaluate the growth curve models of HRQOL (with 16,281 observations) by linear & quadratic time effects, regular exercise (5-level moderate-intensity physical activity), and major influential factors of HRQOL.Results: Regular exercise showed significantly positive dose-response effects on physical HRQOL (β =1.27~2.54), and regular exercise of 150 min or more showed positive effects on mental HRQOL (β = 1.55~2.03). Besides, irregular exercise could also improve both physical and mental HRQOL (β = 1.27 & β = 0.87). However, such effects were not significant over time (at time slope) on HRQOL. In addition, physical and mental HRQOL improved across time (β = 1.01 and 1.49, respectively), but the time quadratic effect would significantly offset a little bit on physical dimension (β = - 0.22). Moreover, being female, increasing age, living alone, or poorer health status were related to lower physical HRQOL; and being younger, living alone, or poorer health status were associated with lower mental HRQOL.Conclusions: The positive dose-response relationship between regular exercise and HRQOL or its domains was demonstrated for community-dwelling Taiwanese adults. Thus, a regular exercise habit (better ≧150 min per week) is advised for community-based healthcare professionals and the government to incorporate into health promotion strategies and plans. [ABSTRACT FROM AUTHOR]

Decoherence of Rabi oscillation in a two-level quantum system consists of two components, a simple exponential decay and a damped oscillation. In dense-ensemble spin systems like negatively charged nitrogen-vacancy (NV−) centers in diamond, fast quantum state decoherence often obscures clear observation of the Rabi nutation. On the other hand, the simple exponential decay (or baseline decay) of the oscillation in such spin systems can be readily detected but has not been thoroughly explored in the past. This study investigates in depth the baseline decay of dense spin ensembles in diamond under continuously driving microwave (MW). It is found that the baseline decay times of NV− spins decrease with the increasing MW field strength and the MW detuning dependence of the decay times shows a Lorentzian-like spectrum. The experimental findings are in good agreement with simulations based on the Bloch formalism for a simple two-level system in the low MW power region after taking into account the effect of inhomogeneous broadening. This combined investigation provides new insight into fundamental spin relaxation processes under continuous driving electromagnetic fields and paves ways to better understanding of this underexplored phenomena using single NV− centers, which have shown promising applications in quantum computing and quantum metrology. [ABSTRACT FROM AUTHOR]

Background: Results from studies investigating the association between coffee consumption and osteoporosis or bone mineral density (BMD) have been inconsistent. This longitudinal study was performed to assess the effect of coffee drinking on bone health of Taiwanese adults.Methods: Data were retrieved from the Li-Shin (Landseed) Hospital in Taoyuan City. In 2006, 6152 participants completed a questionnaire on coffee drinking and other lifestyle factors. In 2014, 5077 of them were followed up. Nonetheless, a total of 2395 participants with incomplete data were excluded. The final analyses included 2682 participants comprising 1195 men and 1487 women (706 premenopausal and 781 postmenopausal). T-scores were derived from the osteo-sono assessment index (OSI) which is a surrogate of BMD. Coffee drinking was categorized as "no, medium, and high" based on the number of cups that were consumed per week in both 2006 and 2014.Results: In general, medium and high coffee drinking were associated with higher T-scores. However, significant results were observed only among high drinkers (β = 0.158; P = 0.0038). Nonetheless, the test for linear trend was significant (P = 0.0046). After stratification by sex, medium and high coffee drinking were associated with higher T-scores. However, significant results were prominent only among high male drinkers (β = 0.237; P = 0.0067) and the test for trend was significant (P = 0.0161). Based on menopausal status, coffee drinking was associated with higher T-scores. Nevertheless, significant results were found only among premenopausal women (β = 0.233; P = 0.0355 and β = 0.234; P = 0.0152 for medium and high coffee drinking, respectively. The test for linear trend was significant (P = 0.0108).Conclusion: Coffee drinking was significantly associated with higher T-scores hence, a lower risk of osteoporosis in men and premenopausal women. [ABSTRACT FROM AUTHOR]

Electron–photon temporal correlations in electron energy loss spectroscopy (EELS) and cathodoluminescence (CL) spectroscopies have recently been used to measure the relative quantum efficiency of materials. This combined spectroscopy, named cathodoluminescence excitation (CLE) spectroscopy, allows for the identification of excitation and decay channels, which are hidden in average measurements. Here, we demonstrate that CLE can also be used to measure excitations' decay time. In addition, the decay time as a function of the excitation energy is measured, as the energy for each electron–photon pair is probed. We used two well-known insulating materials to characterize this technique, nanodiamonds with NV0 defects and hexagonal boron nitride (h-BN) with 4.1 eV defects. Both also exhibit marked transition radiations, whose extremely short decay times can be used to characterize the instrumental response function. It is found to be typically 2 ns, in agreement with the expected limit of the EELS detector temporal resolution. The measured lifetimes of NV0 centers in diamond nanoparticles (20–40 ns) and 4.1 eV defect in h-BN flakes (<2 ns) match those reported previously. [ABSTRACT FROM AUTHOR]

Knowledge of temperature and temperature gradients with nanoscale resolution is critical for a variety of applications in medicine, nanoelectronics, biology, and solid‐state‐based devices. The number of existing nanothermometry techniques is remarkably large, varying for materials, mechanisms, sensitivity, and operating ranges. In this work, a selected group of prominent nanoscale thermosensors is reviewed, which are all‐optical and nanoparticle‐based. Specifically, the focus is on the analysis of their fundamental mechanism to identify absolute, intrinsic capabilities and limitations of each nanothermometry platform. Prominent applications as well as future challenges and opportunities in the field are discussed. [ABSTRACT FROM AUTHOR]

The purpose of this study was to explore the relationship between the metabolic syndrome severity Z -score and kidney function by gender. We also examined the estimated glomerular filtration rate in relation to other known risk factors. The study used was a population-based prospective longitudinal research design. A total of 4,838 participants (2,683 females and 2,155 males) included individuals aged >30 years who were undergoing a health examination from 2006 to 2014 in Pingzhen City, Taiwan. In the initial generalized estimated equation model analysis, which included the covariates of age of first visit, period between the first and current visit, and metabolic syndrome severity Z -score, the results indicated that the interaction between age and metabolic syndrome severity Z -score is significantly related to the estimated glomerular filtration rate for males (p =.040). For females, the interaction between age and metabolic syndrome severity Z -score was not significant, but a higher metabolic syndrome severity Z -score was significantly associated with lower estimated glomerular filtration rate (p =.001). After controlling for the confounders, unhealthy behaviors, and comorbidities, the metabolic syndrome severity Z -score was still a negative predictor of estimated glomerular filtration rate in both the male (p =.005) and female (p =.023) models. [ABSTRACT FROM AUTHOR]

The negatively charged nitrogen-vacancy defect center, (NV)–, in diamond has been investigated theoretically for its one- and two-photon absorption properties involving the first excited state with the 3A2→3E transition. Time-dependent density functional theory (TD-DFT), configuration interaction with single excitation (CIS), and complete active space self-consistent field (CASSCF) were employed in this investigation along with the 6-31G(d) basis set. Diamond lattice models containing 24–104 carbon atoms were constructed to imitate the local environment of the defect center. TD-DFT calculations in large molecular cluster models (with 85 or more carbon atoms) predicted the vertical excitation energy quite consistent with the experimental absorption maximum. CASSCF calculations were feasible only for small cluster models (less than 50 carbon atoms) but yielded one-photon absorption (OPA) and two-photon absorption (TPA) cross sections somewhat larger than the experimental values obtained with linearly polarized incident light [T.-L. Wee et al., J. Phys. Chem. A 111, 9379 (2007)]. CIS calculations in larger cluster models showed a systematic overestimation of the excitation energy while just slightly underestimated the OPA cross section and overestimated the TPA cross section. The agreements between calculations and measurements suggest that the computational approaches established in this work are applicable to explore the optical properties of related defect centers in diamond as well. [ABSTRACT FROM AUTHOR]

In studying ultrafast electron transfer from a dye molecule to a nanosized semiconductor particle, pump-probe experiments are commonly used. In this system the electron transfer (ET) rate is faster than vibrational relaxation so that the ET rate should be described by a single-level rate constant and the probing signal (often in the form of time-resolved spectra) contains the contribution from the dynamics of both population and coherence (i.e., wave packet). In this paper, we shall present the theoretical treatments for femtosecond time-resolved pump-probe experiment and the dynamics of population and coherence by the density matrix method, and the calculation of single-level ET rate constant involved in a pump-probe experiment. As an application, we show the theoretical results using parameters extracted from experiments on a specific dye/semiconductor system. [ABSTRACT FROM AUTHOR]

This paper describes a systematic study on the clathrate structure of H+(H2O)21 using tandem mass spectrometry, vibrational predissociation spectroscopy, Monte Carlo simulations, and density functional theory calculations. We produced H+(H2O)n from a continuous corona-discharged supersonic expansion and observed three anomalies simultaneously at the cluster temperature near 150 K, including (1) the peak at n=21 is more intense than its neighboring ions in the mass spectrum, (2) the size-dependent dissociation fractions show a distinct drop for the 21-mer, and (3) the infrared spectrum of H+(H2O)21 exhibits only a single feature at 3699 cm-1, corresponding to the free-OH stretching of three-coordinated water molecules. Interestingly, the anomalies appear or disappear together with cluster temperature, indicating close correlation of these three observations. The observations, together with Monte Carlo simulations and density functional theory calculations, corroborate the notion for the formation of a distorted pentagonal dodecahedral (512) cage with a H2O molecule in the cage and a H3O+ ion on the surface for this “magic number” water cluster ion. The dodecahedral cage melts at higher temperatures, as evidenced by the emergence of a free-OH stretching feature at 3717 cm-1 for the two-coordinated water in H+(H2O)21 produced in a warmer molecular beam. Extension of this study to larger clusters strongly suggests that the experimentally observed isomer of H+(H2O)28 is most likely to consist of a distorted protonated pentakaidecahedral (51263) cage enclosing two neutral water molecules. [ABSTRACT FROM AUTHOR]

Cathodoluminescence (CL) and correlative light‐electron microscopy (CLEM) are two useful analytical tools in diverse research areas. Recently, fluorescent nanodiamonds (FNDs) have emerged as promising imaging agents for both CL and CLEM owing to their exceptional photophysical and chemical properties. However, to realize their practical applications in the life sciences, surface modification and functionalization of the nanomaterials with bioactive molecules are critical and essential. Here we provide a comprehensive review on the methods of synthesizing biohybrid FNDs as well as recent advances of CL and CLEM imaging of cells with these carbon nanoparticles as dual‐contrast markers. [ABSTRACT FROM AUTHOR]

Understanding the conformational changes of a protein upon adsorption to a substrate is central to the development and application of modem protein chip technology. Spatial confinement such as that occurring on surfaces may raise the barriers of all dynamic processes in the protein, eliminate some extended configurations, and shift the equilibrium from the unfolded state toward the native state. Spectroscopic studies of proteins tethered on a flat surface provide the most stringent test for the theory.

Sodium hypochlorite (NaOCl) and ethylenediaminetetraacetic acid (EDTA) are commonly recommended for effectively removing organic and inorganic components in the smear layer. This layer is found on root canal walls after root canal instrumentation. However, high-concentration EDTA reduces the strength of dentin and the dissolution efficacy of organic substances in NaOCl solution. The objective of this study was to investigate the efficacy of applying nano and submicron diamonds in irrigation solutions with sonic and ultrasonic oscillation for removing the smear layer during endodontic treatment. Extracted single-rooted human teeth were instrumented with ProTaper® Gold (Dentsply Sirona) nickel–titanium rotary instruments. Subsequently, each canal was irrigated with 3% NaOCl, 17% EDTA, distilled water, and 10–1000 nm-sized nano and submicron diamond irrigation solutions, respectively. Sonic and ultrasonic instruments were compared for oscillating the irrigation solutions. The teeth were processed for scanning electron microscopy to observe the efficiency of smear layer removal on the canal walls. Our results indicated that diamond sizes of 50 nm and above irrigation solutions showed significant effectiveness in removing the smear layer following the oscillation of sonic instruments for 10 s. Ultrasonic assisted 500 nm and 1000 nm diamond solutions significantly differed from the other diamond-sized solution in their ability to remove the smear layer. These results suggest that sonic and ultrasonic oscillation with specific sizes of nano and submicron diamond irrigation solution can be used as an alternative approach to removing the smear layer during endodontic treatment. The potential clinical application of root canal treatments can be expected. [ABSTRACT FROM AUTHOR]

Review: 75 refs. [ABSTRACT FROM AUTHOR]

The neutral nitrogen‐vacancy (NV0) defects in diamond are photostable color centers, suitable for a wide range of applications in science and engineering. However, the photophysical properties of the centers have not yet been fully characterized. This work measured the stimulated emission cross sections of NV0 in a single‐crystal diamond by two‐photon excitation of its matrix at 344 nm. From the measured photoluminescence spectrum and the fluorescence lifetime of 20 ± 1 ns, we determined a peak stimulated emission cross section of 1.43 ± 0.07 × 10−17 cm2 at 650 nm for the NV0 centers. In addition, we have also examined the thermal shifts of the zero‐phonon line of NV0 centers in nanoscale diamonds (~100 nm in diameter) over the temperature range of 30–120°C. A temperature measurement sensitivity of 0.2 K·Hz−1/2 was achieved, which is about two‐fold better than that of NV−, despite that the fluorescence intensity of NV0 is about six‐fold lower than that of NV− in the same nanoparticles. The result is attributed to the smaller electron–phonon coupling strength of the neutral center, compared with its negatively charged counterpart. [ABSTRACT FROM AUTHOR]

In order to better understand the effect of non‐covalent weak interactions on molecules, we have explored a variety of weak interactions, such as improper H‐bonding (HB), tetrel bonds (TBs) and halogen bonds, in fluorinated chiral zinc complexes. High resolution neutron diffraction studies revealed a methylene carbon‐hydrogen bond elongation and shortening due to TB and improper HB interactions, respectively. To show the accumulative effects of multiple weak interactions on the C−H bond, three types of tetrel bonds have been carefully examined. We have also shown how C−H bond elongation can be easily offset by forming an improper HB with the H atom from this C−H bond. Non‐covalent interaction and electrostatic potential analysis investigations have been used to affirm the nature of the interactions based on density functional theory (DFT) and other related calculations. [ABSTRACT FROM AUTHOR]

In order to better understand the effect of non‐covalent weak interactions on molecules, we have explored a variety of weak interactions, such as improper H‐bonding (HB), tetrel bonds (TBs) and halogen bonds, in fluorinated chiral zinc complexes. High resolution neutron diffraction studies revealed a methylene carbon‐hydrogen bond elongation and shortening due to TB and improper HB interactions, respectively. To show the accumulative effects of multiple weak interactions on the C−H bond, three types of tetrel bonds have been carefully examined. We have also shown how C−H bond elongation can be easily offset by forming an improper HB with the H atom from this C−H bond. Non‐covalent interaction and electrostatic potential analysis investigations have been used to affirm the nature of the interactions based on density functional theory (DFT) and other related calculations. [ABSTRACT FROM AUTHOR]

Lateral flow immunoassay (LFIA) is a widely used tool for point‐of‐care testing (POCT). Although the method is fast and inexpensive, it provides only qualitative or semi‐quantitative information, which limits the scope of its applications in POCT. Here, we report the development of a low‐cost, portable LFIA reader based on photothermal detection of reporters (such as colloidal gold and colored latex beads) captured on LFIA strips using a low‐power green laser as the heating source and a single‐element infrared sensor as the detector. For 40‐nm colloidal gold, we measured a detection limit of 3 × 105 particles/mm2 by laser irradiation of the reporters at 532 nm with an intensity of 20 W/cm2. The photothermal detection enables a 10‐fold enhancement in sensitivity over color visualization with the naked eye. More importantly, with the use of the control line intensities as internal calibrants, the results so obtained are quantitative and useful to support critical decision‐making in POCT, as demonstrated by gold‐based assays for human chorionic gonadotropin and human immunodeficiency virus as well as latex‐based assays for nucleocapsid protein of the SARS‐CoV‐2 virus. [ABSTRACT FROM AUTHOR]

A recentadvance in nanotechnology is the scale-up production ofsmall and nonaggregated diamond nanoparticles suitable for biologicalapplications. Using detonation nanodiamonds (NDs) with an averagediameter of ∼4 nm as the adsorbents, we have studied the staticattachment of three proteins (myoglobin, bovine serum albumin, andinsulin) onto the nanoparticles by optical spectroscopy, mass spectrometry,and dynamic light scattering, and electrophoretic zeta potential measurements.Results show that the protein surface coverage is predominantly determinedby the competition between protein–protein and protein–NDinteractions, giving each protein a unique and characteristic structuralconfiguration in its own complex. Specifically, both myoglobin andbovine serum albumin show a Langmuir-type adsorption behavior, forming1:1 complexes at saturation, whereas insulin folds into a tightlybound multimer before adsorption. The markedly different adsorptionpatterns appear to be independent of the protein concentration andare closely related to the affinity of the individual proteins forthe NDs. The present study provides a fundamental understanding forthe use of NDs as a platform for nanomedical drug delivery. [ABSTRACT FROM AUTHOR]

Temperature sensing is a promising method of enhancing the detection sensitivity of lateral flow immunoassay (LFIA) for point-of-care testing. A temperature increase of more than 100 °C can be readily achieved by photoexcitation of reporters like gold nanoparticles (GNPs) or colored latex beads (CLBs) on LFIA strips with a laser power below 100 mW. Despite its promise, processes involved in the photothermal detection have not yet been well-characterized. Here, we provide a fundamental understanding of this thermometric assay using non-fluorescent CLBs as the reporters deposited on nitrocellulose membrane. From a measurement for the dependence of temperature rises on the number density of membrane-bound CLBs, we found a 1.3-fold (and 3.2-fold) enhancement of the light absorption by red (and black) latex beads at 520 nm. The enhancement was attributed to the multiple scattering of light in this highly porous medium, a mechanism that could make a significant impact on the sensitivity improvement of LFIA. The limit of detection was measured to be 1 × 105 particles/mm2. In line with previous studies using GNPs as the reporters, the CLB-based thermometric assay provides a 10× higher sensitivity than color visualization. We demonstrated a practical use of this thermometric immunoassay with rapid antigen tests for COVID-19. [ABSTRACT FROM AUTHOR]

Abstract: A facile and sensitive fluorescent probe for hydrazine was successfully constructed, displaying excellent colorimetric and ratiometric responses towards hydrazine via Ing–Manske hydrazinolysis conditions in semi-aqueous buffer solution. Semi-empirical calculations as well as spectroscopic results revealed the signalling mechanism of the current probe under hydrazinolysis conditions, in which hydrazine exclusively deprotected the phthalimide group by an intermediate of phthalhydrazide. Extensive screening of pH effects on the probe with the aid of proton nuclear magnetic resonance and mass spectrometry supported the distinctive and diverse ratiometric responses under hydrazinolysis and basic hydrolysis conditions. Time resolved photoluminescence measurements of the probe further confirmed its discernible ratiometric responses probed at respective wavelengths. A distinctive ratiometric response under basic hydrolysis conditions and a successful utilization of probe towards hydrazine detection in living cells are demonstrated. [Copyright &y& Elsevier]

We adopt an orthogonal wavelet packet decomposition (OWPD) filtering approach to cancel harmonic interference noises arising from an AC power source in time domain and remove the resulting rf voltage interference noise from the mass spectra acquired by using a charge detection frequency-scan quadrupole ion trap mass spectrometer. With the use of a phase lock resampling technique, the transform coefficients of the rf interference in signals become a constant, exhibiting a shift of the baseline in different rf phases. The rf interference is therefore removable by shifting the baselines back to zero in OWPD coefficients. The approach successfully reduces the time-domain background noise from 1367 electrons (rms) to 408 electrons (rms) (an improvement of 70 %) and removes the high frequency noise components in the charge detection ion trap mass spectrometry. Unlike other smoothing or averaging methods commonly used in the mass-to-charge ( m/Ze) domain, our approach does not cause any distortion of original signals. [ABSTRACT FROM AUTHOR]

Purpose: Gender differences in colorectal cancer (CRC) incidence have been previously reported. We designed this population-based study to determine if this gender difference was restricted to specific patient subgroups. Methods: Using the Taiwan Cancer Registry database, we identified a total of 124,314 CRCs registered from 1988 to 2007. We compared the incidence of CRCs by gender in all CRCs, in colon and rectal cancers considered separately, and in right-sided versus left-sided colon cancers. Results: In individuals aged 50 years and older, the incidence of CRCs was lower in females compared with males. For right-sided colon cancers, the incidence in both genders was similar. Because the proportion of right-sided colon cancer accounted for only one fourth of the total CRCs, its influence on the incidence of total CRCs is reduced. Conclusions: Although the incidence of total CRCs is male dominant, the actual gender difference in CRC incidence in Taiwan is limited to the left side of the colon. [ABSTRACT FROM AUTHOR]

Abstract: Eu doped nanocrystalline Y2O3 with different sizes were prepared by combustion synthesis. Dependences of particle size, crystal status and fluorescence characteristic on ratio of glycine/Y(NO3)3 and annealing temperature were studied. It was observed that the peaks of charge transfer (CT) band do not shift with different size in low-doped concentration. With the increasing of concentration and annealing temperature, the peaks of CT band blue shift distinctly. It can be concluded that the CT band in cubic nanocrystalline Y2O3:Eu3+ has no direct connection with size, but depends on local structure, especially crystal status. [Copyright &y& Elsevier]

Mesenchymal stem/stromal cells (MSCs) are a promising resource for cell-based therapy because of their high immunomodulation ability, tropism towards inflamed and injured tissues, and their easy access and isolation. Currently, there are more than 1200 registered MSC clinical trials globally. However, a lack of standardized methods to characterize cell safety, efficacy, and biodistribution dramatically hinders the progress of MSC utility in clinical practice. In this review, we summarize the current state of MSC-based cell therapy, focusing on the systemic safety and biodistribution of MSCs. MSC-associated risks of tumor initiation and promotion and the underlying mechanisms of these risks are discussed. In addition, MSC biodistribution methodology and the pharmacokinetics and pharmacodynamics of cell therapies are addressed. Better understanding of the systemic safety and biodistribution of MSCs will facilitate future clinical applications of precision medicine using stem cells. [ABSTRACT FROM AUTHOR]

Avian influenza virus (AIV) is a zoonotic virus that can be transmitted from animals to humans. Although human infections are rare, the virus has a high mortality rate when contracted. Appropriate detection methods are thus crucial for combatting this pathogen. There is a growing demand for rapid, selective, and accurate methods of identifying the virus. Numerous biosensors have been designed and commercialized to detect AIV. However, they all have considerable shortcomings. Nanotechnology offers a new way forward. Nanomaterials produce more eco-friendly, rapid, and portable diagnostic systems. They also exhibit high sensitivity and selectivity while achieving a low detection limit (LOD). This paper reviews state-of-the-art nanomaterial-based biosensors for AIV detection, such as those composed of quantum dots, gold, silver, carbon, silica, nanodiamond, and other nanoparticles. It also offers insight into potential trial protocols for creating more effective methods of identifying AIV and discusses key issues associated with developing nanomaterial-based biosensors. [Display omitted] • A comprehensive review of biomarkers, techniques, and challenges associated with identifying Avian Influenza Virus (AIV). • Nanomaterial-based biosensors present a resolution to the obstacles encountered in detecting AIV. • A concise exploration of cutting-edge biosensors using nanomaterials for AIV detection. • Valuable information regarding prospective diagnostic tests in developing nanomaterial-based biosensors for AIV. [ABSTRACT FROM AUTHOR]

Fixing a diamond containing a high density of Nitrogen-Vacancy (NV) center ensembles on the apex of a multimode optical fiber (MMF) extends the applications of NV-based endoscope sensors. Replacing the normal MMF with a tapered MMF (MMF-taper) has enhanced the fluorescence (FL) collection efficiency from the diamond and achieved a high spatial resolution NV-based endoscope. The MMF-taper's high FL collection efficiency is the direct result of multiple internal reflections in the tapered region caused by silica, which has a higher refractive index (RI) than the surrounding air. However, for applications involving fluidic environments whose RI is close to or higher than that of the silica, the MMF-taper loses its FL collection significantly. Here, to overcome this challenge and achieve a high spatial resolution NV-based endoscope in a fluidic environment, we conceptually proposed a tapered ultra-high numerical aperture microstructured optical fiber (MOF) whose air capillaries at the tapered end are sealed. Since the end-sealed air capillaries along the tapered MOF (MOF-taper) have isolated the MOF core from the surrounding medium, the core retains its high FL collection and NV excitation efficiency in liquids regardless of their RI values. Replacing the MMF-taper with the MOF-taper will achieve a versatile NV-based endoscope that could potentially find widespread applications in fluidic environments where many biological processes and chemical reactions occur. [ABSTRACT FROM AUTHOR]

Cationic polymers are often employed in conjugation with nanomaterials, and the resultant hybrids are useful for various bioapplications. Here, a single-step metal-free method for the synthesis of fluorescent nanodiamonds (FNDs) conjugated with cationic polymer brushes is reported. Distinct from the common methods such as atom transfer radical polymerization and reversible addition fragmentation chain transfer, our ring-opening-polymerization-based method is simple and less time consuming and hazardous. Infrared spectroscopy, thermogravimetric analysis, zeta potential, and dynamic light scattering confirmed the synthesis. The produced FND-polymer brushes showed markedly higher cell labeling and internalization efficiency without noticeable cytotoxicity. Our method is general and applicable to other nanoparticles as well for uses in diverse research areas. [ABSTRACT FROM AUTHOR]

We experimentally demonstrate a simple and robust optical fiber based method to achieve simultaneously efficient excitation and fluorescence collection from Nitrogen-Vacancy (NV) defects containing micro-crystalline diamond. We fabricate a suitable micro-concave mirror that focuses scattered excitation laser light into the diamond located at the focal point of the mirror. At the same instance, the mirror also couples the fluorescence light exiting out of the diamond crystal in the opposite direction of the optical fiber back into the optical fiber within its light acceptance cone. This part of fluorescence would have been otherwise lost from reaching the detector. Our proof-of-principle demonstration achieves a 25 times improvement in fluorescence collection compared to the case of not using any mirrors. The increase in light collection favors getting high signal-to-noise ratio optically detected magnetic resonance signals and hence offers a practical advantage in fiber-based NV quantum sensors. Additionally, we compacted the NV sensor system by replacing some bulky optical elements in the optical path with a 1 × 2 fiber optical coupler in our optical system. This reduces the complexity of the system and provides portability and robustness needed for applications like magnetic endoscopy and remote-magnetic sensing. [ABSTRACT FROM AUTHOR]

Containing an ensemble of nitrogen-vacancy centers in crystal matrices, fluorescent nanodiamonds (FNDs) are a new type of photostable markers that have found wide applications in light microscopy. The nanomaterial also has a dense carbon core, making it visible to electron microscopy. Here, we show that FNDs encapsulated in biotinylated lipids (bLs) are useful for subdiffraction imaging of antigens on cell surface with correlative light-electron microscopy (CLEM). The lipid encapsulation enables not only good dispersion of the particles in biological buffers but also high specific labeling of live cells. By employing the bL-encapsulated FNDs to target CD44 on HeLa cell surface through biotin-mediated immunostaining, we obtained the spatial distribution of these antigens by CLEM with a localization accuracy of ~50 nm in routine operations. A comparative study with dual-color imaging, in which CD44 was labeled with FND and MICA/MICB was labeled with Alexa Fluor 488, demonstrated the superior performance of FNDs as fluorescent fiducial markers for CLEM of cell surface antigens. [ABSTRACT FROM AUTHOR]

Highly stable lipid-encapsulated fluorescent nanodiamonds (FNDs) are produced by photo-crosslinking of diacetylene-containing lipids physically attached to the FND surface. Not only is this coating method simple and fast, but also it gives the FND–lipid hybrids favorable properties for bioapplications. The hybrids are useful as fluorescent biolabels as well as fiducial markers for correlative light and electron microscopy. [ABSTRACT FROM AUTHOR]

The nitrogen-vacancy (NV) centers in diamond are among the most thoroughly investigated defects in solid-state matter; however, our understanding of their properties upon far-UV excitation of the host matrix is limited. This knowledge is crucial for the identification of NV as the carrier of extended red emission (ERE) bands detected in a wide range of astrophysical environments. Herein, we report a study on the photoluminescence spectra of NV-containing nanodiamonds excited with synchrotron radiation over the wavelength range of 125-350 nm. We observed, for the first time, an emission at 520-850 nm with a quantum yield greater than 20 %. Our results share multiple similarities with the ERE phenomena, suggesting that nanodiamonds are a common component of dust in space. [ABSTRACT FROM AUTHOR]

The nitrogen-vacancy (NV) centers in diamond are among the most thoroughly investigated defects in solid-state matter; however, our understanding of their properties upon far-UV excitation of the host matrix is limited. This knowledge is crucial for the identification of NV as the carrier of extended red emission (ERE) bands detected in a wide range of astrophysical environments. Herein, we report a study on the photoluminescence spectra of NV-containing nanodiamonds excited with synchrotron radiation over the wavelength range of 125-350 nm. We observed, for the first time, an emission at 520-850 nm with a quantum yield greater than 20 %. Our results share multiple similarities with the ERE phenomena, suggesting that nanodiamonds are a common component of dust in space. [ABSTRACT FROM AUTHOR]

Despite their name, nanodiamonds (ND) are comprised of a complex interplay of different carbon phases. The diamond core is surrounded by the shell consisting mostly of disordered sp 3 carbon and graphene-like carbon (GLC). The complex structure makes the characterization of nanodiamonds (ND) a difficult challenge. Recent development of many varieties of NDs for different applications demands quick and reliable characterization of the content of various carbon fragments, as well as the estimation of the diamond core size. In this work, we apply Raman spectroscopy to study the structure of nanodiamonds from different origins, including those produced by detonation (DND), high pressure high temperature synthesis (HPHT), and pulsed laser irradiation (LND). The relative content of GLC, disordered and surface carbon can be easily determined from Raman spectra. In particular, we show how the content of different structure fragments is changed upon de-agglutination, surface oxidation and ion irradiation. We also compare the different ND production methods in terms of the structural uniformity of the nanoparticles. Raman spectroscopy provides unique quantitative tool for ND characterization; we believe that the present data will be useful for understanding the structure of diamond nanoparticles, and will provide the background for obtaining the NDs with desired properties. [ABSTRACT FROM AUTHOR]

Much of the current understanding of thermal effects in biological systems is based on macroscopic measurements. There is little knowledge about the local thermostability or heat tolerance of subcellular components at the nanoscale. Herein, we show that gold nanorod-fluorescent nanodiamond (GNR-FND) hybrids are useful as a combined nanoheater/nanothermometer in living cells. With the use of a 594 nm laser for both heating and probing, we measure the temperature changes by recording the spectral shifts of the zero-phonon lines of negatively charged nitrogen-vacancy centers in FNDs. The technique allows us to determine the rupture temperatures of individual membrane nanotubes in human embryonic kidney cells, as well as to generate high temperature gradients on the cell membrane for photoporation and optically controlled hyperthermia. Our results demonstrate a new paradigm for hyperthermia research and application. [ABSTRACT FROM AUTHOR]

Much of the current understanding of thermal effects in biological systems is based on macroscopic measurements. There is little knowledge about the local thermostability or heat tolerance of subcellular components at the nanoscale. Herein, we show that gold nanorod-fluorescent nanodiamond (GNR-FND) hybrids are useful as a combined nanoheater/nanothermometer in living cells. With the use of a 594 nm laser for both heating and probing, we measure the temperature changes by recording the spectral shifts of the zero-phonon lines of negatively charged nitrogen-vacancy centers in FNDs. The technique allows us to determine the rupture temperatures of individual membrane nanotubes in human embryonic kidney cells, as well as to generate high temperature gradients on the cell membrane for photoporation and optically controlled hyperthermia. Our results demonstrate a new paradigm for hyperthermia research and application. [ABSTRACT FROM AUTHOR]

Ever since the discovery of fullerenes in 1985, nanocarbon has demonstrated a wide range of applications in various areas of science and engineering. Compared with metal, oxide, and semiconductor nanoparticles, the carbon-based nanomaterials have distinct advantages in both biotechnological and biomedical applications due to their inherent biocompatibility. Fluorescent nanodiamond (FND) joined the nanocarbon family in 2005. It was initially developed as a contrast agent for bioimaging because it can emit bright red photoluminescence from negatively charged nitrogen-vacancy centers built in the diamond matrix. A notable application of this technology is to study the cytoplasmic dynamics of living cells by tracking single bioconjugated FNDs in intracellular medium. This article provides a critical review on recent advances and developments of such single particle tracking (SPT) research. It summarizes SPT and related studies of FNDs in cells (such as cancer cell lines) and organisms (including zebrafish embryos, fruit fly embryos, whole nematodes, and mice) using assorted imaging techniques. [ABSTRACT FROM AUTHOR]

SARS-CoV-2 viruses, responsible for the COVID-19 pandemic, continues to evolve into new mutations, which poses a significant threat to public health. Current testing methods have some limitations, such as long turnaround times, high costs, and professional laboratory requirements. In this report, the novel Spin-Enhanced Lateral Flow Immunoassay (SELFIA) platform and fluorescent nanodiamond (FND) reporter were utilized for the rapid detection of SARS-CoV-2 nucleocapsid and spike antigens from different variants, including wild-type (Wuhan-1), Alpha (B.1.1.7), Delta (B.1.617.2), and Omicron (B.1.1.529). The SARS-CoV-2 antibodies were conjugated with FND via nonspecific binding, enabling the detection of SARS-CoV-2 antigens via both direct and competitive SELFIA format. Direct SELFIA was performed by directly adding the SARS-CoV-2 antibodies-conjugated FND on the antigens-immobilized nitrocellulose (NC) membrane. Conversely, the SARS-CoV-2 antigen-containing sample was first incubated with the antibodies-conjugated FND, and then dropped on the antigen-immobilized NC membrane to carry out the competitive SELFIA. The results suggested that S44F anti-S IgG antibody can be efficiently used for the detection of wild-type, Alpha, Delta, and Omicron variants spike antigens. Findings were comparable in direct SELFIA, competitive SELFIA, and ELISA. A detection limit of 1.94, 0.77, 1.14, 1.91, and 1.68 ng/mL can be achieved for SARS-CoV-2 N protein, wild-type, Alpha, Delta, and Omicron S proteins, respectively, via competitive SELFIA assay. These results suggest that a direct SELFIA assay can be used for antibody/antigen pair screening in diagnosis development, while the competitive SELFIA assay can serve as an accurate quantitative diagnostic tool. The simplicity and rapidity of the SELFIA platform were demonstrated, which can be leveraged in the detection of other infectious diseases in the near future. [Display omitted] • Sensitive detection of SARS-CoV-2 N and S antigens from wild-type, Alpha, Delta, and Omicron variants in artificial saliva. • Our direct SELFIA assay can be used for antibody/antigen pair screening. • Our competitive SELFIA assay serves as a precise quantitative diagnostic tool. [ABSTRACT FROM AUTHOR]

A new red-fluorescent mercury ion sensor material is designed and synthesized, which is composed of a tweezer-shaped hydrophilic probe containing bifurcated soft-base atoms N and S coupled with 2-dicyanomethylene-3-cyano-4,5,5-trimethyl-2,5-dihydrofuran (TCF) unit. By virtue of the strong electron-accepting nature of TCF unit (as a push–pull chromophore), this designed sensor material can selectively detect Hg 2+ over various tested metal ions in a 100% aqueous medium via naked-eye and photoluminescence (PL) observations. Theoretical and time-resolved photoluminescence measurements further confirmed the selectivity and reversibility of the probe towards Hg 2+ via intramolocular charge transfer mechanism in this sensor material. Moreover, the living cell tests by confocal fluorescence images of this sensor material towards Hg 2+ were also investigated. Finally, distinguished absorption changes and fluorescence quenching spectral appearances allowed us to present the selective optical indicator of Hg 2+ via TCF moiety for the first time. [ABSTRACT FROM AUTHOR]

Ultracompact directional optical nanoantennas are rapidly gaining popularity yet still challenging tasks to construct at the nanoscale. Here, we experimentally demonstrate unidirectional emission from a fluorescent nanodiamond coupled with a single gold nanorod. Different configurations of the assembled hybrid nanostructures were realized via step-by-step atomic force microscope nanomanipulation. The emission patterns can be controlled by adjusting the configurations, i.e., the gold nanorod orientation and separation with respect to the nanodiamond. Numerical simulation results reveal that the unidirectional emission can be ascribed to the interference between the electromagnetic fields produced by the dipole-like source and the out-of-phase dipole induced in the gold nanorod. The proposed hybrid nanostructures remarkably exhibit highly unidirectional emission even when the emitter is positioned up to 50 nm away from the nanorod antenna and present a broad working spectral bandwidth of ∼200 nm. The distinct features of this hybrid structure suggest potential applications for novel nanoscale light sources, sensing, and quantum information. [ABSTRACT FROM AUTHOR]

Detonation nanodiamonds (DNDs), a nanomaterial with an increasing range of industrial and biomedical applications, have previously been shown to induce a pro-inflammatory response in cultured human airway epithelial cells (HAECs). We now show that surface modifications induced by air oxidation of DND (AO-DND), including an increase in oxygen content, formation of carboxylic groups associated with the appearance of high negative zeta potential and a decrease in unpaired electron content, are accompanied by a significant loss of bioactivity, as measured by levels of interleukin-8 mRNA in HAEC. These findings are relevant to the identification of chemical determinants and molecular mechanisms of the inhalational toxicity of carbonaceous nanomaterials. [ABSTRACT FROM AUTHOR]

Fluorescent nanodiamond (FND) is attracting much attention as a bioimaging agent because of its inherent biocompatibility and superior optical properties (e.g., excellent photostability and far-red emission). However, for practical use in life science research, some issues such as higher brightness and ease of bioconjugation have to be solved. Here, it is shown that the 100-nm FND particles fabricated by using nitrogen-rich type Ib diamonds and high-energy proton irradiation are highly fluorescent and readily functionalizable with proteins for biological applications. In the first approach, acid-treated FND is noncovalently coated with glycoproteins or neoglycoproteins (i.e., proteins chemically modified with multiple sugar residues) for targeting hepatocytes via carbohydrate receptors. In the second approach, FND is first PEGylated and then covalently conjugated with streptavidin, to which biotin-labeled antibodies of interest are linked. High targeting specificity of the bioconjugated FND is demonstrated with the human hepatoma cell line, HepG2, and breast cancer cell lines, ASB145-1R, MCF-7, and MDA-MB-231 cells. These approaches should be widely applicable to a variety of situations for specific targeting and labeling of cells. [ABSTRACT FROM AUTHOR]