An optical fiber chlorogenic acid sensor using a Chitosan membrane coated bent optical fiber probe.

Hydrogel polymers have hydrophilic function groups bonded on the polymer's backbone network. Water molecules and compounds soluble in aqueous solution can permeate into hydrogel's network. This property was employed in this work in developing an optical fiber chemical sensor for detecting chlorogenic acid (CGA). A Chitosan membrane was coated on a bent optical fiber probe (BOFP) by simply dipping the BOFP into a Chitosan solution, which was made by dissolving solid Chitosan in a 2 % acetic acid solution, and pulling out. When such a Chitosan-coated BOFP was exposed to CGA in an aqueous sample solution, CGA molecules permeate into the Chitosan membrane, and were detected through monitoring the compound's intrinsic optical absorption signal at 400 nm. Chitosan has one amine group on each of its glucose rings, which helps the membrane concentrating CGA (a weak acid) from aqueous sample solution. Therefore, the sensor shows high sensitivity in detecting CGA with a detection limit of 0.018 µg/mL. The sensor's response to CGA is reversible, because CGA permeation into/out of the polymer network is a reversible process. The effectiveness of the developed sensor for detecting CGA was verified though analyzing CGA in green coffee extract products. The analytical results obtained with the developed sensor agree well with results obtained with a traditional UV/Vis optical absorption spectrometric method. The effectiveness of the sensor for analyzing CGA in green coffee extract samples was also verified through standard addition and recovery experiment with obtained recovery rate ranging from 97 % to 100 %.

Digitisation and Sovereignty in Humanitarian Space: Technologies, Territories and Tensions.

Debates are ongoing on the limits of - and possibilities for - sovereignty in the digital era. While most observers spotlight the implications of the Internet, cryptocurrencies, artificial intelligence/machine learning and advanced data analytics for the sovereignty of nation states, a critical yet under examined question concerns what digital innovations mean for authority, power and control in the humanitarian sphere in which different rules, values and expectations are thought to apply. This forum brings together practitioners and scholars to explore both conceptually and empirically how digitisation and datafication in aid are (re)shaping notions of sovereign power in humanitarian space. The forum's contributors challenge established understandings of sovereignty in new forms of digital humanitarian action. Among other focus areas, the forum draws attention to how cyber dependencies threaten international humanitarian organisations' purported digital sovereignty. It also contests the potential of technologies like blockchain to revolutionise notions of sovereignty in humanitarian assistance and hypothesises about the ineluctable parasitic qualities of humanitarian technology. The forum concludes by proposing that digital technologies deployed in migration contexts might be understood as 'sovereignty experiments'. We invite readers from scholarly, policy and practitioner communities alike to engage closely with these critical perspectives on digitisation and sovereignty in humanitarian space.

Mechanistic insights into consumption of the food additive xanthan gum by the human gut microbiota.

Processed foods often include food additives such as xanthan gum, a complex polysaccharide with unique rheological properties, that has established widespread use as a stabilizer and thickening agent. Xanthan gum's chemical structure is distinct from those of host and dietary polysaccharides that are more commonly expected to transit the gastrointestinal tract, and little is known about its direct interaction with the gut microbiota, which plays a central role in digestion of other dietary fibre polysaccharides. Here we show that the ability to digest xanthan gum is common in human gut microbiomes from industrialized countries and appears contingent on a single uncultured bacterium in the family Ruminococcaceae. Our data reveal that this primary degrader cleaves the xanthan gum backbone before processing the released oligosaccharides using additional enzymes. Some individuals harbour Bacteroides intestinalis that is incapable of consuming polymeric xanthan gum but grows on oligosaccharide products generated by the Ruminococcaceae. Feeding xanthan gum to germfree mice colonized with a human microbiota containing the uncultured Ruminococcaceae supports the idea that the additive xanthan gum can drive expansion of the primary degrader Ruminococcaceae, along with exogenously introduced B. intestinalis. Our work demonstrates the existence of a potential xanthan gum food chain involving at least two members of different phyla of gut bacteria and provides an initial framework for understanding how widespread consumption of a recently introduced food additive influences human microbiomes.

Characterization of Stereolithography Printed Soft Tooling for Micro Injection Molding.

The use of microfeature-enabled devices, such as microfluidic platforms and anti-fouling surfaces, has grown in both potential and application in recent years. Injection molding is an attractive method of manufacturing these devices due to its excellent process throughput and commodity-priced raw materials. Still, the manufacture of micro-structured tooling remains a slow and expensive endeavor. This work investigated the feasibility of utilizing additive manufacturing, specifically a Digital Light Processing (DLP)-based inverted stereolithography process, to produce thermoset polymer-based tooling for micro injection molding. Inserts were created with an array of 100-µm wide micro-features, having different heights and thus aspect ratios. These inserts were molded with high flow polypropylene to investigate print process resolution capabilities, channel replication abilities, and insert wear and longevity. Samples were characterized using contact profilometry as well as optical and scanning electron microscopies. Overall, the inserts exhibited a maximum lifetime of 78 molding cycles and failed by cracking of the entire insert. Damage was observed for the higher aspect ratio features but not the lower aspect ratio features. The effect of the tool material on mold temperature distribution was modeled to analyze the impact of processing and mold design.

Validation of a single-step, single-tube reverse transcription loop-mediated isothermal amplification assay for rapid detection of SARS-CoV-2 RNA.

Introduction. The SARS-CoV-2 pandemic of 2020 has resulted in unparalleled requirements for RNA extraction kits and enzymes required for virus detection, leading to global shortages. This has necessitated the exploration of alternative diagnostic options to alleviate supply chain issues.Aim. To establish and validate a reverse transcription loop-mediated isothermal amplification (RT- LAMP) assay for the detection of SARS-CoV-2 from nasopharyngeal swabs.Methodology. We used a commercial RT-LAMP mastermix from OptiGene in combination with a primer set designed to detect the CDC N1 region of the SARS-CoV-2 nucleocapsid (N) gene. A single-tube, single-step fluorescence assay was implemented whereby 1 µl of universal transport medium (UTM) directly from a nasopharyngeal swab could be used as template, bypassing the requirement for RNA purification. Amplification and detection could be conducted in any thermocycler capable of holding 65 °C for 30 min and measure fluorescence in the FAM channel at 1 min intervals.Results. Assay evaluation by assessment of 157 clinical specimens previously screened by E-gene RT-qPCR revealed assay sensitivity and specificity of 87 and 100%, respectively. Results were fast, with an average time-to-positive (Tp) for 93 clinical samples of 14 min (sd±7 min). Using dilutions of SARS-CoV-2 virus spiked into UTM, we also evaluated assay performance against FDA guidelines for implementation of emergency-use diagnostics and established a limit-of-detection of 54 Tissue Culture Infectious Dose 50 per ml (TCID50 ml-1), with satisfactory assay sensitivity and specificity. A comparison of 20 clinical specimens between four laboratories showed excellent interlaboratory concordance; performing equally well on three different, commonly used thermocyclers, pointing to the robustness of the assay.Conclusion. With a simplified workflow, The N1 gene Single Tube Optigene LAMP assay (N1-STOP-LAMP) is a powerful, scalable option for specific and rapid detection of SARS-CoV-2 and an additional resource in the diagnostic armamentarium against COVID-19.

Evaluation of the Efficacy of BI 425809 Pharmacotherapy in Patients with Schizophrenia Receiving Computerized Cognitive Training: Methodology for a Double-blind, Randomized, Parallel-group Trial.

BACKGROUND AND OBJECTIVE: Cognitive impairments associated with schizophrenia (CIAS) predict poor functional outcomes, but there are currently no approved pharmacological treatments for patients with CIAS. Additional cognitive stimulation may be required for pro-cognitive medications to improve efficacy, and computerized cognitive training (CCT) can be used to increase cognitive activity. A trial evaluating the effects of the novel glycine transporter inhibitor BI 425809 compared with placebo, on a background of regularly self-administered CCT in clinically stable patients with schizophrenia has commenced and its methodology is described here. METHODS: This Phase II, multinational, randomized, double-blind, placebo-controlled, parallel-group trial will randomize 200 clinically stable outpatients, aged 18-50 years with established schizophrenia and no other major psychiatric disorder, 1:1 to BI 425809 or placebo once daily for 12 weeks. Following screening, which included a 2-week CCT run-in period, patients sufficiently compliant with CCT (target: ≥ 2 h of CCT per week during CCT run-in) will be randomized. During the 12-week treatment period, all patients should complete a total of approximately 30 h of CCT. The primary endpoint is change from baseline in neurocognitive function as measured by the neurocognitive composite score of the Measurement and Treatment Research to Improve Cognition in Schizophrenia Consensus Cognitive Battery (MCCB), after 12 weeks of treatment. Secondary endpoints include change from baseline in overall MCCB score, Schizophrenia Cognition Rating Scale, Positive and Negative Syndrome Scale, and safety (adverse events [AEs]) and serious AEs. Primary and secondary endpoints will be analyzed using the Restricted Maximum Likelihood-based mixed model for repeated measures. Novel endpoints include the Balloon Effort Task to evaluate patients' motivation and the Virtual Reality Functional Capacity Assessment Tool to assess skills for daily functioning. DISCUSSION: This is one of the largest and longest trials to date to combine pharmacological therapy with CCT in patients with schizophrenia and will determine the benefit of combining BI 425809 pharmacotherapy with cognitive stimulation through self-administered CCT. This trial will further evaluate whether improvements in neurocognition translate into improved everyday functioning, whether self-administered CCT can be effectively implemented in a large multinational trial, and the role of motivation in neurocognitive and functional improvements. TRIAL REGISTRATION: Registered on Clinicaltrials.gov on March 1, 2019 (NCT03859973).

Rapid point-of-care diagnostics for the detection of Chlamydia pecorum in koalas (Phascolarctos cinereus) using loop-mediated isothermal amplification without nucleic acid purification.

Infectious disease, predominately chlamydiosis, contributes significantly to the decline in health of wild koala (Phascolarctos cinereus) populations in some regions of Australia. In this study, we describe the development and evaluation of a simple, sensitive, and specific loop-mediated isothermal amplification (LAMP) assay for the detection of Chlamydia pecorum in koalas as a point-of-care diagnostic tool that can be used in any wildlife hospital and in the field on specialized instrumentation. A set of primers targeting a 188-bp region of the C. pecorum genome was designed. 100% specificity of the LAMP assay was revealed by demonstrating no cross-reactivity with 33 nontarget pathogens, and complete correlation with qPCR results for 43 clinical swabs collected opportunistically from wildlife hospitals. In sensitivity evaluations, the technique successfully detected serial dilutions of extracted C. pecorum DNA with a detection limit of 44 IFU/ml.

Thermal and Photolytic Transformation of NHC-B,N-Heterocycles: Controlled Generation of Blue Fluorescent 1,3-Azaborinine Derivatives and 1H-Imidazo[1,2-a]indoles by External Stimuli.

NHC-B,N-heterocyclic compounds have been found to act as convenient precursors for obtaining either 1,3-azaborinine or 1H-imidazo[1,2-a]indole derivatives, which are two different and rare classes of compounds. The formation of these two classes of compounds from the NHC-B,N-heterocycles is highly selective depending on the external stimuli employed, and the resulting products have been studied for their interesting chemical and photophysical properties. The mechanism and possible reaction pathways of the unusual transformation are established by computational studies.

Application of the donor-acceptor concept to intercept low oxidation state group 14 element hydrides using a Wittig reagent as a Lewis base.

This article outlines our attempts to stabilize the Group 14 element dihydrides, GeH2 and SnH2, using commonly employed phosphine and pyridine donors; in each case, elemental Ge and Sn extrusion was noted. However, when these phosphorus and nitrogen donors were replaced with the ylidic Wittig ligand Ph3P═CMe2, stable inorganic methylene complexes (EH2) were obtained, demonstrating the utility of this under-explored ligand class in advancing main group element coordination chemistry.

Synthesis and Mössbauer spectroscopy of formal tin(II) dichloride and dihydride species supported by Lewis acids and bases.

(119)Sn Mössbauer spectroscopy was performed on a series of formal Sn(II) dichloride and dihydride adducts bound by either carbon- or phosphorus-based electron pair donors. Upon binding electron-withdrawing metal pentacarbonyl units to the tin centers in LB·SnCl2·M(CO)5 (LB = Lewis base; M = Cr or W), a significant decrease in isomer shift (IS) was noted relative to the unbound Sn(II) complexes, LB·SnCl2, consistent with removal of nonbonding s-electron density from tin upon forming Sn-M linkages (M = Cr and W). Interestingly, when the nature of the Lewis base in the series LB·SnCl2·W(CO)5 was altered, very little change in the IS values was noted, implying that the LB-Sn bonds were constructed with tin-based orbitals of large p-character (as supported by prior theoretical studies). In addition, variable temperature Mössbauer measurements were used to determine the mean displacement of the tin atoms in the solid state, a parameter that can be correlated with the degree of covalent bonding involving tin in these species.

Expanding the steric coverage offered by bis(amidosilyl) chelates: isolation of low-coordinate N-heterocyclic germylene complexes.

The synthesis and coordination chemistry of a series of dianionic bis(amido)silyl and bis(amido)disilyl, [NSiN] and [NSiSiN], chelates with N-bound aryl or sterically modified triarylsilyl (SiAr(3)) groups is reported. In order to provide a consistent comparison of the steric coverage afforded by each ligand construct, various two-coordinate N-heterocyclic germylene complexes featuring each ligand set were prepared and oxidative S-atom transfer chemistry was explored. In the cases where clean oxidation transpired, sulfido-bridged centrosymmetric germanium(IV) dimers of the general form [LGe(µ-S)](2) (L = bis(amidosilyl) ligands) were obtained in lieu of the target monomeric germanethiones with discrete Ge═S double bonds. These results indicate that the reported chelates possess sufficient conformational flexibility to allow for the dimerization of LGe═S units to occur. Notably, the new triarylsilyl groups (4-RC(6)H(4))(3)Si- (R = (t)Bu and (i)Pr) still offer considerably expanded degrees of steric coverage relative to the parent congener, -SiPh(3,) and thus the use of substituted triarylsilyl groups within ligand design strategies should be a generally useful concept in advancing low-coordination main group and transition-metal chemistry.

Characteristics of false allegation adult crimes.

The purpose of this study was to identify common factors in false allegation adult crimes, by examining the dynamics involved in 30 confirmed false allegation cases. The authors conducted a comprehensive review of these adjudicated cases and then completed a collection instrument to capture offender demographics, offense characteristics, and motive. The results indicated that most false allegation crimes were committed by women (73.3%) and Caucasians (93.3%). Data indicated that more interpersonally violent allegations were primarily motivated by attention/sympathy needs (50.0%), whereas more impersonal offenses involved other motivations such as providing an alibi (16.7%) or profit (13.3%). Offenders tended to be younger, high school graduates with no higher education (43.3%). A total of 23.3% of offenders had a prior criminal history. Male offenders appeared as likely as women to be motivated by attention/sympathy; however, men tended to select more violent, nonsexual offenses (e.g., attempted murder) than women.

Ethical dilemmas in community-based participatory research: recommendations for institutional review boards.

National and international codes of research conduct have been established in most industrialized nations to ensure greater adherence to ethical research practices. Despite these safeguards, however, traditional research approaches often continue to stigmatize marginalized and vulnerable communities. Community-based participatory research (CBPR) has evolved as an effective new research paradigm that attempts to make research a more inclusive and democratic process by fostering the development of partnerships between communities and academics to address community-relevant research priorities. As such, it attempts to redress ethical concerns that have emerged out of more traditional paradigms. Nevertheless, new and emerging ethical dilemmas are commonly associated with CBPR and are rarely addressed in traditional ethical reviews. We conducted a content analysis of forms and guidelines commonly used by institutional review boards (IRBs) in the USA and research ethics boards (REBs) in Canada. Our intent was to see if the forms used by boards reflected common CBPR experience. We drew our sample from affiliated members of the US-based Association of Schools of Public Health and from Canadian universities that offered graduate public health training. This convenience sample (n = 30) was garnered from programs where application forms were available online for download between July and August, 2004. Results show that ethical review forms and guidelines overwhelmingly operate within a biomedical framework that rarely takes into account common CBPR experience. They are primarily focused on the principle of assessing risk to individuals and not to communities and continue to perpetuate the notion that the domain of "knowledge production" is the sole right of academic researchers. Consequently, IRBs and REBs may be unintentionally placing communities at risk by continuing to use procedures inappropriate or unsuitable for CBPR. IRB/REB procedures require a new framework more suitable for CBPR, and we propose alternative questions and procedures that may be utilized when assessing the ethical appropriateness of CBPR.