Detection of dimethyl methylphosphonate (DMMP) with an interband cascade laser sensor

We demonstrate the sensitive detection of dimethyl methylphosphonate (DMMP, a hydrogen-bond (HB) basic phosphonate ester) using additional optical loss induced in an interband cascade laser with top optical cladding layer replaced by an exposed sensing window coated by a HB acidic sorbent layer. Thin coatings of the sorbents HCSFA2 and oapBPAF were deposited on the sensing window to allow reversible capture and concentration of DMMP for optical interrogation. Analyte levels down to 0.1 mg/m3 (∼20 ppb) were tested and successfully detected by monitoring the laser's threshold or its output power at a fixed bias as a function of DMMP delivery concentration.

Genetically engineered bacteriophages as novel nanomaterials: applications beyond antimicrobial agents

Bacteriophages, also known as phages, are viruses that replicate in bacteria and archaea. Phages were initially discovered as antimicrobial agents, and they have been used as therapeutic agents for bacterial infection in a process known as "phage therapy." Recently, phages have been investigated as functional nanomaterials in a variety of areas, as they can function not only as therapeutic agents but also as biosensors and tissue regenerative materials. Phages are nontoxic to humans, and they possess self-assembled nanostructures and functional properties. Additionally, phages can be easily genetically modified to display specific peptides or to screen for functional peptides via phage display. Here, we demonstrated the application of phage nanomaterials in the context of tissue engineering, sensing, and probing.

A colorimetric lateral flow immunoassay based on oriented antibody immobilization for sensitive detection of SARS-CoV-2

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19). The high human-to-human transmission and rapid evolution of SARS-CoV-2 have resulted in a worldwide pandemic. To contain SARS-CoV-2, it is essential to efficiently control the transmission of the virus through the early diagnosis of infected individuals, including asymptomatic people. Therefore, a rapid and accurate assay is vital for the early diagnosis of SARS-CoV-2 in suspected individuals. In this study, we developed a colorimetric lateral flow immunoassay (LFIA) in which a CBP31-BC linker was used to immobilize antibodies on a cellulose membrane in an oriented manner. The developed LFIA enabled sensitive detection of cultured SARS-CoV-2 in 15 min with a detection limit of 5 × 10⁴ copies/mL. The clinical performance of the LFIA for detecting SARS-CoV-2 was evaluated using 19 clinical samples validated by reverse transcription-polymerase chain reaction (RT-PCR). The LFIA detected all the positive and negative samples accurately, corresponding to 100% accuracy. Importantly, patient samples with low viral loads were accurately identified. Thus, the proposed method can provide a useful platform for rapid and accurate point-of-care testing of SARS-CoV-2 in infected individuals to efficiently control the COVID-19 pandemic.

Virus-like nanoparticles as a theranostic platform for cancer

Virus-like nanoparticles (VLPs) are natural polymer-based nanomaterials that mimic viral structures through the hierarchical assembly of viral coat proteins, while lacking viral genomes. VLPs have received enormous attention in a wide range of nanotechnology-based medical diagnostics and therapies, including cancer therapy, imaging, and theranostics. VLPs are biocompatible and biodegradable and have a uniform structure and controllable assembly. They can encapsulate a wide range of therapeutic and diagnostic agents, and can be genetically or chemically modified. These properties have led to sophisticated multifunctional theranostic platforms. This article reviews the current progress in developing and applying engineered VLPs for molecular imaging, drug delivery, and multifunctional theranostics in cancer research.

Glycan chip based on structure-switchable DNA linker for on-chip biosynthesis of cancer-associated complex glycans

On-chip glycan biosynthesis is an effective strategy for preparing useful complex glycan sources and for preparing glycan-involved applications simultaneously. However, current methods have some limitations when analyzing biosynthesized glycans and optimizing enzymatic reactions, which could result in undefined glycan structures on a surface, leading to unequal and unreliable results. In this work, a glycan chip is developed by introducing a pH-responsive i-motif DNA linker to control the immobilization and isolation of glycans on chip surfaces in a pH-dependent manner. On-chip enzymatic glycosylations are optimized for uniform biosynthesis of cancer-associated Globo H hexasaccharide and its related complex glycans through stepwise quantitative analyses of isolated products from the surface. Successful interaction analyses of the anti-Globo H antibody and MCF-7 breast cancer cells with on-chip biosynthesized Globo H-related glycans demonstrate the feasibility of the structure-switchable DNA linker-based glycan chip platform for on-chip complex glycan biosynthesis and glycan-involved applications.

Thickness measurement of nm HfO2 films

A pilot study for the thickness measurement of HfO2 films was performed by the Surface Analysis Working Group (SAWG) of the Consultative Committee for Amount of Substance (CCQM). The aim of this pilot study was to ensure the equivalency in the measurement capability of national metrology institutes for the thickness measurement of HfO2 films. In this pilot study, the thicknesses of six HfO2 films with nominal thickness from 1 nm to 4 nm were measured by X-ray Photoelectron Spectroscopy (XPS), X-ray Reflectometry(XRR), X-ray Fluorescence Analysis (XRF), Transmission Electron Spectroscopy (TEM), Spectroscopic Ellipsometry (SE) and Rutherford Backscattering Spectrometry (RBS). The reference thicknesses were determined by mutual calibration of a zero-offset method (Medium Energy Ion Scattering Spectroscopy (MEIS) of KRISS) and a method traceable to the length unit (the average thicknesses of three XRR data except the thinnest film). These reference thicknesses are traceable to the length unit because they are based on the traceability of XRR. For the thickness measurement by XPS, the effective attenuation length of Hf 4f electrons was determined. In the cases of XRR and TEM, the offset values were determined from a linear fitting between the reference thicknesses and the individual data by XRR and TEM. The amount of substance of HfO2, expressed as thickness of HfO2 films (in both linear and areal density units), was found to be a good subject for a CCQM key comparison.

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Expression and purification of the full-length N-acetylgalactosaminyltransferase and galactosyltransferase from Campylobacter jejuni in Escherichia coli

The successful enzymatic synthesis of various ganglioside-related oligosaccharides requires many available glycan-processing enzymes. However, the number of available glycan-processing enzymes remains limited. In this study, the full-length CgtA43456 (β-(1→4)-N-acetylgalactosaminyltransferase) and CgtB11168 (β-(1→3)-galactosyltransferase) were successfully produced from Escherichia coli through the optimization of E. coli-preferable codon usage, selection of E. coli strain, and use of the molecular chaperone GroEL-GroES (GroEL/ES). The CgtA43456 enzyme was produced as a soluble form in E. coli C41(DE3) co-expressed with codon-optimized CgtA43456 and GroEL/ES. However, soluble CgtB11168 was well expressed in E. coli C41(DE3) with only the codon-optimized CgtB11168. Rather, when co-expressed with GroEL/ES, total production of CgtB11168 was reduced. Using immobilized-metal affinity chromatography, the CgtA43456 and CgtB11168 proteins were obtained with approximately 75-78 % purity. The purified CgtA43456 showed a specific activity of 21 mU/mg using UDP-N-acetylgalactosamine and GM3 trisaccharide as donor and acceptor, respectively. The purified CgtB11168 catalyzed the transfer of galactose from UDP-Gal to GM2 tetrasaccharide with a specific activity of 16 mU/mg. We propose that they could be used as catalysts for enzymatic synthesis of GM1 ganglioside-related oligosaccharides.

Determination of Ginsenosides (Ginseng Saponins) in Dry Root Powder from Panax ginseng, Panax quinquefolius, and Selected Commercial Products by Liquid Chromatography: Interlaboratory Study

Twelve collaborating laboratories assayed 4 products, namely, Panax ginseng, Panax quinquefolius, and 2 ginseng products, for 6 ginsenosides: Rb1, Rb2, Rc, Rd, Re, andRg1. Collaborators also received a negative control for the recovery study. Pure ginsenosides were provided as reference standards for the liquid chromatography (LC) analysis and the system suitability tests. The LC analyses were performed on the methanol extract using UV detection at 203 nm. For P. ginseng, individual ginsenosides were consistent in their means; repeatability standard deviations (RSDr)rangedfrom4.17to5.09% and reproducibility standard deviations (RSDR) ranged from 7.27 to 11.3%. For P. quinquefolius, the Rb1 and Rb2 ginsenosides were higher and lower in concentration than P. ginseng, with RSDr values of 3.44 and 6.60% and RSDR values of 5.91 and 12.6% respectively, and other analytes at intermediate precisions. For ginseng commercial products, RSDr values ranged from 3.39 to 8.12%, andRSDR values ranged from 7.65 to 16.5%. A recovery study was also conducted for 3 ginsenosides: Rg1, Re, andRb1. The average recoveries were 99.9, 96.2, and 92.3%, respectively. The method is not applicable for the determination of Rg1 and Re in ginseng product at levels <300 mg/kg.

Coexpression of CMP-sialic acid transporter reduces N-glycolylneuraminic acid levels of recombinant glycoproteins in Chinese hamster ovary cells

Recombinant glycoproteins expressed in Chinese hamster ovary (CHO) cells contain two forms of sialic acids; N-acetylneuraminic acid (Neu5Ac) as a major type and N-glycolylneuraminic acid (Neu5Gc) as a minor type. The Neu5Gc glycan moieties in therapeutic glycoproteins can elicit immune responses because they do not exist in human. In the present work, to reduce Neu5Gc levels of recombinant glycoproteins from CHO cell cultures, we coexpressed cytidine-5'-monophosphate-sialic acid transporter (CMP-SAT) that is an antiporter and transports cytosolic CMP-sialic acids (both forms) into Golgi lumen. When human erythropoietin was used as a target human glycoprotein, coexpression of CMP-SAT resulted in a significant decrease of Neu5Gc level by 41.4% and a notable increase of Neu5Ac level by 21.2%. This result could be reasonably explained by our hypothesis that the turnover rate of Neu5Ac to Neu5Gc catalyzed by CMP-Neu5Ac hydroxylase would be reduced through facilitated transportation of Neu5Ac into Golgi apparatus by coexpression of CMP-SAT. We confirmed the effects of CMP-SAT coexpression on the decrease of Neu5Gc level and the increase of Neu5Ac level using another glycoprotein human DNase I. Therefore, CMP-SAT coexpression might be an effective strategy to reduce the levels of undesired Neu5Gc in recombinant therapeutic glycoproteins from CHO cell cultures.

Systemic lupus erythematosus is a risk factor for cancer: a nationwide population-based study in Korea

OBJECTIVE

Specific differences in cancer risk have been observed between systemic lupus erythematosus patients and the general population. Although meta-analyses have estimated cancer incidence in systemic lupus erythematosus patients, results have been inconclusive. Hence, we aimed to assess malignancy risk in systemic lupus erythematosus patients, compared to the risk in the general population.

METHODS

Systemic lupus erythematosus patients ( n = 21,016; mean age 41.67 ± 13.14 years; female 90.22%) were selected from the Korean National Health Insurance Service database between 2008 and 2014. Age- and sex-matched controls were randomly sampled in a 5:1 ratio ( n = 105,080).

RESULTS

During the 7 years of follow up, malignancy was detected in 763 (3.63%) systemic lupus erythematosus patients and 2667 (2.54%) controls. Systemic lupus erythematosus patients had a higher risk of malignancy than controls (odds ratio 1.44; 95% confidence interval 1.327-1.559), after multivariate adjustment. Systemic lupus erythematosus patients had a higher odds ratio for developing cervical, thyroid, ovarian, and oral cancer, as well as lymphoma, leukemia, and multiple myeloma than controls. Based on subgroup analysis, male systemic lupus erythematosus patients and patients younger than 40 years showed the highest lymphoma risk.

CONCLUSIONS

Systemic lupus erythematosus might be an independent risk factor for cancer. Therefore, the importance of cancer screening programs should be emphasized in systemic lupus erythematosus patients. Our study is the first large nationwide cohort study for evaluating the risk of cancer in systemic lupus erythematosus patients.

Remifentanil vs. Lignocaine for Attenuating the Haemodynamic Response during Rapid Sequence Induction Using Propofol: Double-Blind Randomised Clinical Trial

This study was conducted to determine whether lignocaine or remifentanil effectively attenuate the response to endotracheal intubation during rapid sequence induction. Forty-eight patients were randomly divided into three groups: Group NS (n=16) received normal saline 0.1 ml/kg, Group L (n=16) received lignocaine 1.5 mg/kg, and Group R (n=16) received remifentanil 1 /μg/kg. Anaesthesia was induced with propofol 2 mg/kg after glycopyrrolate 0.2 mg IV. Each study drug was given intravenously over 30 seconds after loss of consciousness. Cricoid pressure was applied until intubation. Succinylcholine 1.0 mg/kg was administered to facilitate tracheal intubation. After intubation, the patient's lungs were ventilated with sevoflurane 1% and nitrous oxide 50% in oxygen. Mean arterial pressure and heart rate were recorded before induction, at loss of consciousness, immediately before laryngoscopy and every minute after intubation for 10 minutes. Mean arterial pressure fell following propofol in all groups. The maximum increase in mean arterial pressure in Group NS and Group L were 46% and 38% respectively above the baseline value one minute after intubation, whereas the mean arterial pressure in Group R increased only back to the baseline value. Heart rate in Group NS and Group L were increased by 27% and 33% above baseline value respectively one minute after intubation, while that in Group R was increased only to the baseline value. The results indicate that remifentanil 1 μg/kg, but not lignocaine 1.5 mg/kg, effectively attenuates the haemodynamic response to endotracheal intubation during rapid sequence induction using propofol.

On-chip biosynthesis of GM1 pentasaccharide-related complex glycans

A novel strategy for on-chip enzymatic glycosylation of complex glycans and direct analysis of glycan-related interactions is reported.

Survival outcome differences based on treatments used and knowledge of the primary tumour site for patients with cancer of unknown and known primary in Ontario

Introduction

Patients with cancer of unknown primary (cup) have pathologically confirmed metastatic tumours with unidentifiable primary tumours. Currently, very little is known about the relationship between the treatment of patients with cup and their survival outcomes. Thus, we compared oncologic treatment and survival outcomes for patients in Ontario with cup against those for a cohort of patients with metastatic cancer of known primary site.

Methods

Using the Ontario Cancer Registry and the Same-Day Surgery and Discharge Abstract databases maintained by the Canadian Institute for Health Information, we identified all Ontario patients diagnosed with metastatic cancer between 1 January 2000 and 31 December 2005. Ontario Health Insurance Plan treatment records were linked to identify codes for surgery, chemotherapy, or therapeutic radiation related to oncology. Multivariable Cox regression models were constructed, adjusting for histology, age, sex, and comorbidities.

Results

In 45,347 patients (96.3%), the primary tumour site was identifiable, and in 1743 patients (3.7%), cup was diagnosed. Among the main tumour sites, cup ranked as the 6th largest. The mean Charlson score was significantly higher (p < 0.0001) in patients with cup (1.88) than in those with a known primary (1.42). Overall median survival was 1.9 months for patients with cup compared with 11.9 months for all patients with a known-primary cancer. Receipt of treatment was more likely for patients with a known primary site (n= 35,012, 77.2%) than for those with cup (n = 891, 51.1%). Among patients with a known primary site, median survival was significantly higher for treated than for untreated patients (19.0 months vs. 2.2 months, p < 0.0001). Among patients with cup, median survival was also higher for treated than for untreated patients (3.6 months vs. 1.1 months, p < 0.0001).

Conclusions

In Ontario, patients with cup experience significantly lower survival than do patients with metastatic cancer of a known primary site. Treatment is associated with significantly increased survival both for patients with cup and for those with metastatic cancer of a known primary site.

Systemic lupus erythematosus is a risk factor for cardiovascular disease: a nationwide, population-based study in Korea

OBJECTIVE

To investigate the incidence and clinical significance of cardiovascular disease in systemic lupus erythematosus patients.

METHODS

We included systemic lupus erythematosus patients ( n = 18,575) without previous cardiovascular disease and age- and sex-matched individuals without systemic lupus erythematosus (controls; n = 92,875) from the Korean National Health Insurance Service database (2008-2014). Both cohorts were followed up for incident cardiovascular disease and death until 2015.

RESULTS

During follow up, myocardial infarction occurred in 203 systemic lupus erythematosus patients and 325 controls (incidence rate: 1.76 and 0.56 per 1000 person-years, respectively), stroke occurred in 289 patients and 403 controls (incidence rate: 2.51 and 0.70 per 1000 person-years, respectively), heart failure occurred in 358 patients and 354 controls (incidence rate 3.11 and 0.61 per 1000 person-years, respectively), and death occurred in 744 patients and 948 controls (incidence rate 6.54 and 1.64 per 1000 person-years, respectively). Patients with systemic lupus erythematosus had higher risks for myocardial infarction (hazard ratio: 2.74, 95% confidence interval: 2.28-3.37), stroke (hazard ratio: 3.31, 95% confidence interval: 2.84-3.86), heart failure (hazard ratio: 4.60, 95% confidence interval: 3.96-5.35), and cardiac death (hazard ratio: 3.98, 95% confidence interval: 3.61-4.39).

CONCLUSIONS

Here, systemic lupus erythematosus was an independent risk factor for cardiovascular disease, thus cardiac assessment and management are critical in systemic lupus erythematosus patients.

Gemigliptin, a novel dipeptidyl peptidase-IV inhibitor, exerts a synergistic cytotoxicity with the histone deacetylase inhibitor PXD101 in thyroid carcinoma cells

PURPOSE

The influence of the dipeptidyl peptidase-IV inhibitor gemigliptin alone or in combination with the histone deacetylase inhibitor PXD101 on survival of thyroid carcinoma cells was investigated.

METHODS

SW1736, TPC-1, 8505C and BCPAP human thyroid carcinoma cells were used. To assess cell survival, cell viability, the percentage of viable cells and dead cells, cytotoxic activity, ATP levels and FACS analysis were measured. To validate the impact of gemigliptin combined with PXD101, the interactions were estimated by obtaining combination index in cells treated with two agents.

RESULTS

In cells treated with gemigliptin or PXD101, cell viability, the percentage of viable cells and ATP levels were reduced, and the percentage of dead cells and cytotoxic activity were elevated. In cells treated with both gemigliptin and PXD101, compared with PXD101 alone, cell death was augmented, and all of the combination index values were lower than 1.0, suggesting the synergism between gemigliptin and PXD101. The percentage of apoptotic cells, and the protein levels of Bcl2 and cleaved poly (ADP-ribose) polymerase were elevated, and the protein levels of xIAP and survivin were reduced. The protein levels of phospho-Akt and phospho-AMPK were elevated, and cell migration was reduced.

CONCLUSIONS

Our results demonstrate that gemigliptin induces cytotoxicity in thyroid carcinoma cells. Moreover, gemigliptin has a synergistic activity with PXD101 in the induction of cell death through involvement of Bcl2 family proteins, xIAP and survivin as well as mediation of Akt and AMPK in thyroid carcinoma cells.

Two-dimensional plasmonic grating for increased quantum efficiency in midwave infrared nBn detectors with thin absorbers

We demonstrate a strategy for increasing the operating temperatures of nBn midwave infrared (MWIR) focal plane arrays, based on the use of two-dimensional plasmonic gratings to enhance the quantum efficiency (QE) of structures with very thin absorbers. Reducing the absorber volume correspondingly reduces the dark current in a diffusion-limited photodiode, while light trapping mediated by the plasmonic grating increases the net absorbance to maintain high QE. The plasmonically enhanced nBn MWIR sensors with absorber thicknesses of only 0.5 μm exhibit peak internal QEs as high as 57%, which enables a 5-fold reduction in dark current. Numerical simulations indicate the potential for further improvement.

Perisomatic changes in h-channels regulate depressive behaviors following chronic unpredictable stress

Chronic stress can be a precipitating factor in the onset of depression. Lentiviral-mediated knockdown of HCN1 protein expression and reduction of functional I_h produce antidepressant behavior. However, whether h-channels are altered in an animal model of depression is not known. We found that perisomatic HCN1 protein expression and I_h-sensitive physiological measurements were significantly increased in dorsal but not in ventral CA1 region/neurons following chronic unpredictable stress (CUS), a widely accepted model for major depressive disorder. Cell-attached patch clamp recordings confirmed that perisomatic I_h was increased in dorsal CA1 neurons following CUS. Furthermore, when dorsal CA1 I_h was reduced by shRNA-HCN1, the CUS-induced behavioral deficits were prevented. Finally, rats infused in the dorsal CA1 region with thapsigargin, an irreversible inhibitor of the SERCA pump, exhibited anxiogenic-like behaviors and increased I_h, similar to that observed following CUS. Our results suggest that CUS, but not acute stress, leads to an increase in perisomatic I_h in dorsal CA1 neurons and that HCN channels represent a potential target for the treatment of major depressive disorder.

Evaluation of abundance of artificial radionuclides in food products in South Korea and sources

Food samples are collected nationwide from January 2016 to February 2017 and their contents of artificial radionuclides are measured to address the growing concerns regarding the radioactive contamination of food products in Korea. Specifically, 900 food samples are collected for this study and their contents of representative artificial radionuclides ¹³⁴Cs, ¹³⁷Cs, ^239,240Pu, and ⁹⁰Sr are analyzed. The analysis shows that the activity concentrations of ¹³⁷Cs in fish range from minimum detectable activity (MDA) to 340 mBq/kg of fresh weight. The concentration factor (CF) determined for ¹³⁷Cs as a measure of its bioavailability is calculated to be ca. 74 and found to be very similar to that (100) recommended by the International Atomic Energy Agency. With an MDA of <0.221 mBq/kg, the results reveal that ^239,240Pu values in fish are below the MDA. The activity concentrations of ¹³⁷Cs and ⁹⁰Sr are lower than the MDA in both shellfish and seaweed, while the activity concentrations of ^239,240Pu in shellfish range from 0.26 to 2.18 mBq/kg, and for seaweed samples range from 2.07 to 3.38 mBq/kg. The atom ratios of ²⁴⁰Pu/²³⁹Pu in shellfish caught at the Korean coast vary from 0.209 to 0.237, with a mean of 0.227. The higher ²⁴⁰Pu/²³⁹Pu atom ratio determined in shellfish is thought to be caused by the plutonium transported from the Pacific Proving Grounds rather than other sources such as the Fukushima nuclear power plant accident. The activity concentrations of ¹³⁷Cs in mushrooms are found to vary from 1.0 to 21.4 Bq/kg, with the highest concentrations observed in the Oak (shiitake) and Sarcodon asparatus. ¹³⁴Cs is detected in three mushroom specimens collected from Jeju Island and about 3-3.6% of ¹³⁷Cs present in the wild mushrooms native to the Jeju Island are introduced as a result of the Fukushima nuclear plant accident. The annual effective doses of ¹³⁷Cs received through consumption of mushrooms and fish are 2.0 × 10^-4 mSv yr^-1 and 3.9 × 10^-5 mSv yr^-1, and those values are negligible compared to the annual effective doses limit of 1 mSv yr^-1.

Diatom-Inspired Silica Nanostructure Coatings with Controllable Microroughness Using an Engineered Mussel Protein Glue to Accelerate Bone Growth on Titanium-Based Implants

Silica nanoparticles (SiNPs) have been utilized to construct bioactive nanostructures comprising surface topographic features and bioactivity that enhances the activity of bone cells onto titanium-based implants. However, there have been no previous attempts to create microrough surfaces based on SiNP nanostructures even though microroughness is established as a characteristic that provides beneficial effects in improving the biomechanical interlocking of titanium implants. Herein, a protein-based SiNP coating is proposed as an osteopromotive surface functionalization approach to create microroughness on titanium implant surfaces. A bioengineered recombinant mussel adhesive protein fused with a silica-precipitating R5 peptide (R5-MAP) enables direct control of the microroughness of the surface through the multilayer assembly of SiNP nanostructures under mild conditions. The assembled SiNP nanostructure significantly enhances the in vitro osteogenic cellular behaviors of preosteoblasts in a roughness-dependent manner and promotes the in vivo bone tissue formation on a titanium implant within a calvarial defect site. Thus, the R5-MAP-based SiNP nanostructure assembly could be practically applied to accelerate bone-tissue growth to improve the stability and prolong the lifetime of medical implantable devices.