A novel paper-based lysis strip for SARS-CoV-2 RNA detection at low resource settings.

Infectious respiratory diseases such as COVID-19 are serious and global concerns from the past to the present. To isolate the spread of infectious diseases even in the absence of a health system, a simple, inexpensive, reliable, sensitive, and selective molecular diagnosis platform for Point of Care Test (POCT) is required. Especially, the nucleic acid extraction step is difficult to perform out of laboratory. Here, we propose a paper-based lysis (PBL) strip for nucleic acid extraction, especially in low-resource settings (LRS). PBL strips are suitable for isolating RNA from viruses with biological interference and inhibitors. We optimized the buffer compositions and membranes of the strip. A simple preparation method using a PBL strip could obtain an eluent for downstream inspection within 20 min. Overall, 104 copies/swaps were detected for 20 min for amplification in combination with Reverse Transcription Loop-Mediated Amplification (RT-LAMP).

Changes in masticatory performance during the retention period following 4-premolar extraction and non-extraction orthodontic treatment.

OBJECTIVES: To evaluate changes in masticatory performance (MP) during the retention period after extraction and non-extraction treatment and compare it with MP in individuals with normal occlusion. MATERIALS AND METHODS: Adult patients who had completed orthodontic fixed appliance treatment comprised the extraction and non-extraction treatment groups, and those with normal occlusion comprised the control group. Their mixing ability (MA), maximum bite force (MBF), and occlusal contact area (OCA) were recorded immediately after the fixed appliance was removed and at 1 month, 6 months, and 1 year post-treatment. The MA was measured via the two-color chewing gum MA test using ViewGum software, and the MBF and OCA were measured using Dental Prescale II system. RESULTS: MA immediately after orthodontic treatment was lower than that in the normal group but showed a time-dependent gradual increase during a 1-year retention period (P < 0.01). The MA at 1 month post-treatment was not significantly different between the three groups (P > 0.05). The MA revealed a significant correlation with the MBF and OCA (P < 0.01). CONCLUSIONS: The MP immediately after orthodontic treatment was lower than that in the normal group but increased gradually, with levels comparable to those of the normal occlusion group at 1 month post-treatment. Further, extraction did not affect the recovery of the MP after orthodontic treatment. CLINICAL RELEVANCE: No other study has evaluated the changes in MP during the retention period after orthodontic treatment. The findings show that compared with MBF and OCA, the patients' MP improved faster to levels found in normal occlusion.

Sprayable nanomicelle hydrogels and inflammatory bowel disease patient cell chips for development of intestinal lesion-specific therapy.

All-in-one treatments represent a paradigm shift in future medicine. For example, inflammatory bowel disease (IBD) is mainly diagnosed by endoscopy, which could be applied for not only on-site monitoring but also the intestinal lesion-targeted spray of injectable hydrogels. Furthermore, molecular conjugation to the hydrogels would program both lesion-specific adhesion and drug-free therapy. This study validated this concept of all-in-one treatment by first utilizing a well-known injectable hydrogel that underwent efficient solution-to-gel transition and nanomicelle formation as a translatable component. These properties enabled spraying of the hydrogel onto the intestinal walls during endoscopy. Next, peptide conjugation to the hydrogel guided endoscopic monitoring of IBD progress upon adhesive gelation with subsequent moisturization of inflammatory lesions, specifically by nanomicelles. The peptide was designed to mimic the major component that mediates intestinal interaction with Bacillus subtilis flagellin during IBD initiation. Hence, the peptide-guided efficient adhesion of the hydrogel nanomicelles onto Toll-like receptor 5 (TLR5) as the main target of flagellin binding and Notch-1. The peptide binding potently suppressed inflammatory signaling without drug loading, where TLR5 and Notch-1 operated collaboratively through downstream actions of tumor necrosis factor-alpha. The results were produced using a human colorectal cell line, clinical IBD patient cells, gut-on-a-chip, a mouse IBD model, and pig experiments to validate the translational utility.

Three-Dimensional Axotomy and Regeneration on Open-Access Microfluidic Platform.

An increasing number of patients are suffering from central nervous system (CNS) injury, including spinal cord injury. However, no suitable treatment is available for such patients as yet. Various platforms have been utilized to recapitulate CNS injuries. However, animal models and in vitro two-dimensional (2D)-based cell culture platforms have limitations, such as genetic heterogeneity and loss of the neural-circuit ultrastructure. To overcome these limitations, we developed a method for performing axotomy on an open-access three-dimensional (3D) neuron-culture platform. In this platform, the 3D alignment of axons in the brain tissue was recapitulated. For direct access to the cultured axons, the bottom of the 3D neuron-culture device was disassembled, enabling exposure of the neuron-laden Matrigel to the outside. The mechanical damage to the axons was recapitulated by puncturing the neuron-laden Matrigel using a pin. Thus, precise axotomy of three-dimensionally aligned axons could be performed. Furthermore, it was possible to fill the punctuated area by re-injecting Matrigel. Consequently, neurites regenerated into re-injected Matrigel. Moreover, it was confirmed that astrocytes can be co-cultured on this open-access platform without interfering with the axon alignment. The proposed open-access platform is expected to be useful for developing treatment techniques for CNS injuries.

Quantifying Effects of Active Site Proximity on Rates of Methanol Dehydration to Dimethyl Ether over Chabazite Zeolites through Microkinetic Modeling.

Control of the spatial proximity of Brønsted acid sites within the zeolite framework can result in materials with properties that are distinct from materials synthesized through conventional crystallization methods or available from commercial sources. Recent experimental evidence has shown that turnover rates of different acid-catalyzed reactions increase with the fraction of proximal sites in chabazite (CHA) zeolites. The catalytic conversion of oxygenates is an important research area, and the dehydration of methanol to dimethyl ether (DME) is a well-studied reaction as part of methanol-to-olefin chemistry catalyzed by solid acids. Published experimental data have shown that DME formation rates (per acid site) increase systematically with the fraction of proximal acid sites in the six-membered ring of CHA. Here, we probe the effect of acid site proximity in CHA on methanol dehydration rates using electronic structure calculations and microkinetic modeling to identify the primary causes of this chemistry and their relationship to the local structure of the catalyst at the nanoscale. We report a density functional theory-parametrized microkinetic model of methanol dehydration to DME, catalyzed by acidic CHA zeolite with direct comparison to experimental data. Effects of proximal acid sites on reaction rates were captured quantitatively for a range of operating conditions and catalyst compositions, with a focus on total paired acid site concentration and reactant clustering to form higher nuclearity complexes. Next-nearest neighbor paired acid sites were identified as promoting the formation of methanol trimer clusters rather than the inhibiting tetramer or pentamer clusters, resulting in large increases in the rate for DME production due to the lower energy barriers present in the concerted methanol trimer reaction pathway. The model framework developed in this study can be extended to other zeolite materials and reaction chemistries toward the goal of rational design and development of next-generation catalytic materials and chemical processes.

A simple and innovative sample preparation method for on-site SARS-CoV-2 molecular diagnostics.

Nucleic acid amplification is a widely used diagnostic tool, although it requires a relatively time-consuming and complicated extraction step. To address this issue outside the laboratory, we investigated a sample preparation system and determined that a silica membrane and silica-coated beads are powerful tools for the extraction from raw samples: nucleic acids are kept in the silica membrane, retained during a single wash step, and released at the elution step. The eluent is appropriate for the quantitative real-time polymerase chain reaction (qPCR) and loop-mediated amplification (LAMP) assay in terms of purity and quantity. We also built an innovative equipment-free nucleic acid extraction squeeze system which requires less than 20 min. The sample with improved purity augments the specificity and sensitivity. This system is simple, user-friendly, low-cost, and equipment-free, thus making nucleic acid extraction more accessible and affordable for researchers and untrained users. Furthermore, when combined with the reverse-transcription quantitative real-time polymerase chain reaction method, the method will accelerate the detection of diseases. The same goes when combined with the LAMP assay, especially in developing countries.

Cell-Membrane-Derived Nanoparticles with Notch-1 Suppressor Delivery Promote Hypoxic Cell-Cell Packing and Inhibit Angiogenesis Acting as a Two-Edged Sword.

Cell-cell interactions regulate intracellular signaling via reciprocal contacts of cell membranes in tissue regeneration and cancer growth, indicating a critical need of membrane-derived tools in studying these processes. Hence, cell-membrane-derived nanoparticles (CMNPs) are produced using tonsil-derived mesenchymal stem cells (TMSCs) from children owing to their short doubling time. As target cell types, laryngeal cancer cells are compared to bone-marrow-derived MSCs (BMSCs) because of their cartilage damaging and chondrogenic characteristics, respectively. Treating spheroids of these cell types with CMNPs exacerbates interspheroid hypoxia with robust maintenance of the cell-cell interaction signature for 7 days. Both cell types prefer a hypoxic environment, as opposed to blood vessel formation that is absent in cartilage but is required for cancer growth. Hence, angiogenesis is inhibited by displaying the Notch-1 aptamer on CMNPs. Consequently, laryngeal cancer growth is suppressed efficiently in contrast to improved chondroprotection observed in a series of cell and animal experiments using a xenograft mouse model of laryngeal cancer. Altogether, CMNPs execute a two-edged sword function of inducing hypoxic cell-cell packing, followed by suppressing angiogenesis to promote laryngeal cancer death and chondrogenesis simultaneously. This study presents a previously unexplored therapeutic strategy for anti-cancer and chondroprotective treatment using CMNPs.

Emerging Brain-Pathophysiology-Mimetic Platforms for Studying Neurodegenerative Diseases: Brain Organoids and Brains-on-a-Chip.

Neurodegenerative diseases are a group of disorders characterized by progressive degeneration of the structural and functional integrity of the central and peripheral nervous systems. Millions of people suffer from degenerative brain diseases worldwide, and the mortality continues to increase every year, causing a growing demand for knowledge of the underlying mechanisms and development of therapeutic targets. Conventional 2D-based cell culture platforms and animal models cannot fully recapitulate the pathophysiology, and this has limited the capability for estimating drug efficacy. Recently, engineered platforms, including brain organoids and brain-on-a-chip, have emerged. They mimic the physiology of brain tissue and reflect the fundamental pathophysiological signatures of neurodegenerative diseases, such as the accumulation of neurotoxic proteins, structural abnormalities, and functional loss. In this paper, recent advances in brain-mimetic platforms and their potential for modeling features of neurodegenerative diseases in vitro are reviewed. The development of a physiologically relevant model should help overcome unresolved neurodegenerative diseases.

Tailoring a Dynamic Metal-Polymer Interaction to Improve Catalyst Selectivity and Longevity in Hydrogenation.

Controlling metal-support interactions is important for tuning the catalytic properties of supported metal catalysts. Here, premade Pd particles are supported on stable polymers containing different ligating functionalities to control the metal-polymer interactions and their catalytic properties in industrially relevant acetylene partial hydrogenation. The polymers containing strongly ligating groups (e.g., Ar-SH and Ar-S-Ar) can form a polymer overlayer on the Pd surface, which enables selective acetylene adsorption and partial hydrogenation to ethylene without deactivation. In contrast, polymers with weakly ligating groups (e.g., Ar-O-Ar) do not form an overlayer, resulting in non-selective hydrogenation and fast deactivation, similar to Pd catalysts on conventional inorganic supports. The results imply that tuning the metal-polymer interactions via rational polymer design can provide an efficient way of synthesizing selective and stable catalysts for hydrogenation.

Dynamic metal-polymer interaction for the design of chemoselective and long-lived hydrogenation catalysts.

Metal catalysts are generally supported on hard inorganic materials because of their high thermochemical stabilities. Here, we support Pd catalysts on a thermochemically stable but "soft" engineering plastic, polyphenylene sulfide (PPS), for acetylene partial hydrogenation. Near the glass transition temperature (~353 K), the mobile PPS chains cover the entire surface of Pd particles via strong metal-polymer interactions. The Pd-PPS interface enables H2 activation only in the presence of acetylene that has a strong binding affinity to Pd and thus can disturb the Pd-PPS interface. Once acetylene is hydrogenated to weakly binding ethylene, re-adsorption of PPS on the Pd surface repels ethylene before it is further hydrogenated to ethane. The Pd-PPS interaction enables selective partial hydrogenation of acetylene to ethylene even in an ethylene-rich stream and suppresses catalyst deactivation due to coke formation. The results manifest the unique possibility of harnessing dynamic metal-polymer interaction for designing chemoselective and long-lived catalysts.

Development of a multi-channel NIRS-USG hybrid imaging system for detecting prostate cancer and improving the accuracy of imaging-based diagnosis: a phantom study.

PURPOSE: This study aimed to develop a multi-channel near-infrared spectroscopy (NIRS) and ultrasonography (USG) fusion imaging system for imaging prostate cancer and to verify its diagnostic capability by applying the hybrid imaging system to a prostate cancer phantom. METHODS: A multi-channel NIRS system using the near-infrared 785-nm wavelength with 12 channels and four detectors was developed. After arranging the optical fibers around a USG transducer, we performed NIRS imaging and grayscale USG imaging simultaneously. Fusion imaging was obtained by processing incoming signals and the spatial reconstruction of NIRS, which corresponded with grayscale USG acquired at the same time. The NIRS-USG hybrid system was applied to a silicone-based optical phantom of the prostate gland containing prostate cancer to verify its diagnostic capability qualitatively. RESULTS: The NIRS-USG hybrid imaging system for prostate cancer imaging simultaneously provided anatomical and optical information with 2-dimensional registration. The hybrid imaging system showed more NIR attenuation over the prostate cancer model than over the model of normal prostate tissue. Its diagnostic capability to discriminate a focal area mimicking the optical properties of prostate cancer from the surrounding background mimicking the optical properties of normal prostate tissue was verified by applying the hybrid system to a silicone-based optical phantom of prostate cancer. CONCLUSION: This study successfully demonstrated that the NIRS-USG hybrid system may serve as a new imaging method for improving the diagnostic accuracy of prostate cancer, with potential utility for future clinical applications.

Simultaneous Monitoring of Hemodynamic Response in the Pre-Frontal Cortex and Genital Organ During Sexual Arousal Using Near-Infrared Spectroscopy.

BACKGROUND: The monitoring of brain activity along with genital organ response to sexual stimulation can play an important role in understanding the under-lying mechanisms of sexual arousal as well as diagnosing erectile dysfunction. Several studies have observed brain activity corresponding to sexual stimuli, but only a few studies have shown a simultaneous measurement of brain activation and penile response. AIM: To introduce near-infrared spectroscopy (NIRS) as a portable, easily implemented, and low-cost technique to simultaneously record brain activity and hemodynamics in the genital organ during sexual arousal. METHODS: Hemodynamic measurements of 15 healthy men were obtained using a home-built NIRS system. In the initial experiment, hemodynamics in the pre-frontal cortex (N = 10) were measured during visual sexual stimulation (VSS) and neutral visual stimulation (NVS) to identify brain activity related to sexual arousal. In the subsequent experiment, cerebral and penile hemodynamics were simultaneously measured (N = 5) using NIRS during VSS and NVS. RESULTS: The pre-frontal cortex showed activity related to VSS but not to NVS. Simultaneous measurements showed a corresponding increase of penile oxygenated and deoxygenated hemoglobin concentration indicating an increase of blood volume associated with sexual arousal in healthy men. An average response delay of 4 seconds was observed in the hemodynamic changes between the brain and genital organ. CONCLUSION: In this preliminary study, we presented a NIRS system capable not only of detecting cerebral hemodynamic changes related to sexual arousal but also the simultaneous measurement of penile hemodynamics. We believe the NIRS system can be a potential technique to supplement the field of sexual medicine and can be expanded further to diagnose erectile dysfunction. Kim E, Kim S, Zephaniah PV, et al. Simultaneous Monitoring of Hemodynamic Response in the Pre-Frontal Cortex and Genital Organ During Sexual Arousal Using Near-Infrared Spectroscopy. Sex Med 2018;6:234-238.

Breast tumor hemodynamic response during a breath-hold as a biomarker to predict chemotherapeutic efficacy: preclinical study.

Continuous wave diffuse optical tomographic/spectroscopic system does not provide absolute concentrations of chromophores in tissue and monitor only the changes of chromophore concentration. Therefore, it requires a perturbation of physiological signals, such as blood flow and oxygenation. In that sense, a few groups reported that monitoring a relative hemodynamic change during a breast tissue compression or a breath-hold to a patient can provide good contrast between tumor and nontumor. However, no longitudinal study reports the utilization of a breath-hold to predict tumor response during chemotherapy. A continuous wave near-infrared spectroscopy was employed to monitor hemodynamics in rat breast tumor during a hyperoxic to normoxic inhalational gas intervention to mimic a breath-hold during tumor growth and chemotherapy. The reduced oxyhemoglobin concentration during inhalational gas intervention correlated well with tumor growth, and it responded one day earlier than the change of tumor volume after chemotherapy. In conclusion, monitoring tumor hemodynamics during a breath-hold may serve as a biomarker to predict chemotherapeutic efficacy of tumor.

Change of tumor vascular reactivity during tumor growth and postchemotherapy observed by near-infrared spectroscopy.

Breast cancer is one of the most common cancers in females. To monitor chemotherapeutic efficacy for breast cancer, medical imaging systems such as x-ray mammography, computed tomography, magnetic resonance imaging, and ultrasound imaging have been used. Currently, it can take up to 3 to 6 weeks to see the tumor response from chemotherapy by monitoring tumor volume changes. We used near-infrared spectroscopy (NIRS) to predict breast cancer treatment efficacy earlier than tumor volume changes by monitoring tumor vascular reactivity during inhalational gas interventions. The results show that the amplitude of oxy-hemoglobin changes (vascular reactivity) during hyperoxic gas inhalation is well correlated with tumor growth and responded one day earlier than tumor volume changes after chemotherapy. These results may imply that NIRS with respiratory challenges can be useful in early detection of tumor and in the prediction of tumor response to chemotherapy.

Single-tube nested PCR assay for the detection of avian botulism in cecal contents of chickens.

This paper describes a novel diagnostic method for the detection of avian botulism caused by Clostridium botulinum type C and C/D, using single-tube nested PCR assay. This assay was developed to overcome the disadvantages of bioassays used in experiments with mice. Three primer pairs including an antisense primer were designed to target the N-terminal of the toxin gene from C. botulinum types C and C/D. The specificity of the PCR assay was confirmed by using 33 bacterial strains and chicken cecal contents from farms that experienced botulism outbreaks. The detection limit for purified DNA was 1.1 fg/µl, and for bacterial spores was 4.3 spores/200 mg of cecal contents. While checking for specificity of the PCR assay, the reactions with the templates form C. botulinum type C and C/D which were tested became positive, but the rest of the reactions turned negative. However, the results for all clinical samples (n = 8) were positive. The PCR assay results for cecal samples obtained from 300 healthy chickens (150 Korean native chickens and 150 broilers) were all negative. This assay is rapid and straightforward and evades ethical issues associated with mouse bioassay. Moreover, it is more economical than real-time PCR.

A discrepancy of penile hemodynamics during visual sexual stimulation observed by near-infrared spectroscopy.

BACKGROUND: In this paper, we observed a discrepancy of penile hemodynamics dependent on location by using near infrared spectroscopy (NIRS) sensor, and showcase NIRS as a potentially suitable sensor in supplementing the diagnosis and treatment of erectile dysfunction. METHODS: To observe the effect that location has on penile hemodynamics, the NIRS sensor was placed on the top and the side of genital organ, and oxy- (HbO), deoxy-(RHb), and total (HbT) hemoglobin concentration changes were acquired. Our results from 6 healthy subjects show that hemodynamic changes vary depending on where the probe was placed. To observe a statistical difference between the signals, a Wilcoxon signed-rank test was performed. RESULTS: The result shows a significant difference (p < 0.05) between concentration changes of RHb and HbT depending on the probes' location. Moreover, the sensor placed on the top of the organ shows a rise of HbO and HbT concentration while RHb concentration decreased. However, hemodynamics from the side of the organ showed that RHb concentration increased along with HbO. CONCLUSIONS: The outcomes demonstrates an ability of NIRS to be sensitive enough to detect the different hemodynamic changes in various locations of a healthy male genital organ during visual sexual stimulation. The results also show the importance of sensor location on the genital organ for the resulting hemodynamic changes. We can foresee our results as a way for clinicians to obtain more accurate hemodynamic measurements from the penis, and also show the likelihood for NIRS enhanced diagnosis tool of male erectile dysfunction over the current standards.