A pilot study on non-invasive in situ detection of phytochemicals and plant endogenous status using fiber optic infrared spectroscopy.

Traditional methods for assessing plant health often lack the necessary attributes for continuous and non-destructive monitoring. In this pilot study, we present a novel technique utilizing a customized fiber optic probe based on attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) with a contact force control unit for non-invasive and continuous plant health monitoring. We also developed a normalized difference mid-infrared reflectance index through statistical analysis of spectral features, enabling differentiation of drought and age conditions in plants. Our research aims to characterize phytochemicals and plant endogenous status optically, addressing the need for improved analytical measurement methods for in situ plant health assessment. The probe configuration was optimized with a triple-loop tip and a 3 N contact force, allowing sensitive measurements while minimizing leaf damage. By combining polycrystalline and chalcogenide fiber probes, a comprehensive wavenumber range analysis (4000-900 cm-1) was achieved. Results revealed significant variations in phytochemical composition among plant species, for example, red spinach with the highest polyphenolic content and green kale with the highest lignin content. Petioles displayed higher lignin and cellulose absorbance values compared to veins. The technique effectively monitored drought stress on potted green bok choy plants in situ, facilitating the quantification of changes in water content, antioxidant activity, lignin, and cellulose levels. This research represents the first demonstration of the potential of fiber optic ATR-FTIR probes for non-invasive and rapid plant health measurements, providing insights into plant health and advancements in quantitative monitoring for indoor farming practices, bioanalytical chemistry, and environmental sciences.

Classification of Plant Endogenous States Using Machine Learning-Derived Agricultural Indices.

Leaf color patterns vary depending on leaf age, pathogen infection, and environmental and nutritional stresses; thus, they are widely used to diagnose plant health statuses in agricultural fields. The visible-near infrared-shortwave infrared (VIS-NIR-SWIR) sensor measures the leaf color pattern from a wide spectral range with high spectral resolution. However, spectral information has only been employed to understand general plant health statuses (e.g., vegetation index) or phytopigment contents, rather than pinpointing defects of specific metabolic or signaling pathways in plants. Here, we report feature engineering and machine learning methods that utilize VIS-NIR-SWIR leaf reflectance for robust plant health diagnostics, pinpointing physiological alterations associated with the stress hormone, abscisic acid (ABA). Leaf reflectance spectra of wild-type, ABA2-overexpression, and deficient plants were collected under watered and drought conditions. Drought- and ABA-associated normalized reflectance indices (NRIs) were screened from all possible pairs of wavelength bands. Drought associated NRIs showed only a partial overlap with those related to ABA deficiency, but more NRIs were associated with drought due to additional spectral changes within the NIR wavelength range. Interpretable support vector machine classifiers built with 20 NRIs predicted treatment or genotype groups with an accuracy greater than those with conventional vegetation indices. Major selected NRIs were independent from leaf water content and chlorophyll content, 2 well-characterized physiological changes under drought. The screening of NRIs, streamlined with the development of simple classifiers, serves as the most efficient means of detecting reflectance bands that are highly relevant to characteristics of interest.

Miniaturized Vis-NIR handheld spectrometer for non-invasive pigment quantification in agritech applications.

Advanced precision agriculture requires the objective measurement of the structural and functional properties of plants. Biochemical profiles in leaves can differ depending on plant growing conditions. By quantitatively detecting these changes, farm production processes can be optimized to achieve high-yield, high-quality, and nutrient dense agricultural products. To enable the rapid and non-destructive detection on site, this study demonstrates the development of a new custom-designed portable handheld Vis-NIR spectrometer that collects leaf reflectance spectra, wirelessly transfers the spectral data through Bluetooth, and provides both raw spectral data and processed information. The spectrometer has two preprogramed methods: anthocyanin and chlorophyll quantification. Anthocyanin content of red and green lettuce estimated with the new spectrometer showed an excellent correlation coefficient of 0.84 with those determined by a destructive gold standard biochemical method. The differences in chlorophyll content were measured using leaf senescence as a case study. Chlorophyll Index calculated with the handheld spectrometer gradually decreased with leaf age as chlorophyll degrades during the process of senescence. The estimated chlorophyll values were highly correlated with those obtained from a commercial fluorescence-based chlorophyll meter with a correlation coefficient of 0.77. The developed portable handheld Vis-NIR spectrometer could be a simple, cost-effective, and easy to operate tool that can be used to non-invasively monitor plant pigment and nutrient content efficiently.

Rapid Diagnostic Tests for the Detection of the Four Dengue Virus Serotypes in Clinically Relevant Matrices.

The efficient and accurate diagnosis of dengue, a major mosquito-borne disease, is of primary importance for clinical care, surveillance, and outbreak control. The identification of specific dengue virus serotype 1 (DENV-1) to DENV-4 can help in understanding the transmission dynamics and spread of dengue disease. The four rapid low-resource serotype-specific dengue tests use a simple sample preparation reagent followed by reverse transcription-isothermal recombinase polymerase amplification (RT-RPA) combined with lateral flow detection (LFD) technology. Results are obtained directly from clinical sample matrices in 35 min, requiring only a heating block and pipettes for liquid handling. In addition, we demonstrate that the rapid sample preparation step inactivates DENV, improving laboratory safety. Human plasma and serum were spiked with DENV, and DENV was detected with analytical sensitivities of 333 to 22,500 median tissue culture infectious doses (TCID50)/mL. The analytical sensitivities in blood were 94,000 to 333,000 TCID50/mL. Analytical specificity testing confirmed that each test could detect multiple serotype-specific strains but did not respond to strains of other serotypes, closely related flaviviruses, or chikungunya virus. Clinical testing on 80 human serum samples demonstrated test specificities of between 94 and 100%, with a DENV-2 test sensitivity of 100%, detecting down to 0.004 PFU/µL, similar to the sensitivity of the PCR test; the other DENV tests detected down to 0.03 to 10.9 PFU/µL. Collectively, our data suggest that some of our rapid dengue serotyping tests provide a potential alternative to conventional labor-intensive RT-quantitative PCR (RT-qPCR) detection, which requires expensive thermal cycling instrumentation, technical expertise, and prolonged testing times. Our tests provide performance and speed without compromising specificity in human plasma and serum and could become promising tools for the detection of high DENV loads in resource-limited settings. IMPORTANCE The efficient and accurate diagnosis of dengue, a major mosquito-borne disease, is of primary importance for clinical care, surveillance, and outbreak control. This study describes the evaluation of four rapid low-resource serotype-specific dengue tests for the detection of specific DENV serotypes in clinical sample matrices. The tests use a simple sample preparation reagent followed by reverse transcription-isothermal recombinase polymerase amplification (RT-RPA) combined with lateral flow detection (LFD) technology. These tests have several advantages compared to RT-qPCR detection, such as a simple workflow, rapid sample processing and turnaround times (35 min from sample preparation to detection), minimal equipment needs, and improved laboratory safety through the inactivation of the virus during the sample preparation step. The low-resource formats of these rapid dengue serotyping tests have the potential to support effective dengue disease surveillance and enhance the diagnostic testing capacity in resource-limited countries with both endemic dengue and intense coronavirus disease 2019 (COVID-19) transmission.

G protein signaling and metabolic pathways as evolutionarily conserved mechanisms to combat calcium deficiency.

Calcium (Ca) deficiency causes necrotic symptoms of foliar edges known as tipburn; however, the underlying cellular mechanisms have been poorly understood due to the lack of an ideal plant model and research platform. Using a phenotyping system that quantitates growth and tipburn traits in the model bryophyte Marchantia polymorpha, we evaluated metabolic compounds and the Gß-null mutant (gpb1) that modulate the occurrence and expansion of the tipburn. Transcriptomic comparisons between wild-type and gpb1 plants revealed the phenylalanine/phenylpropanoid biosynthesis pathway and reactive oxygen species (ROS) important for Ca deficiency responses. gpb1 plants reduced ROS production possibly through transcriptomic regulations of class III peroxidases and induced the expression of phenylpropanoid pathway enzymes without changing downstream lignin contents. Supplementation of intermediate metabolites and chemical inhibitors further confirmed the cell-protective mechanisms of the phenylpropanoid and ROS pathways. Marchantia polymorpha, Arabidopsis thaliana, and Lactuca sativa showed comparable transcriptomic changes where genes related to phenylpropanoid and ROS pathways were enriched in response to Ca deficiency. In conclusion, our study demonstrated unresolved signaling and metabolic pathways of Ca deficiency response. The phenotyping platform can speed up the discovery of chemical and genetic pathways, which could be widely conserved between M. polymorpha and angiosperms.

Drug Delivery in Plants Using Silk Microneedles.

New systems for agrochemical delivery in plants will foster precise agricultural practices and provide new tools to study plants and design crop traits, as standard spray methods suffer from elevated loss and limited access to remote plant tissues. Silk-based microneedles can circumvent these limitations by deploying a known amount of payloads directly in plants' deep tissues. However, plant response to microneedles' application and microneedles' efficacy in deploying physiologically relevant biomolecules are unknown. Here, it is shown that gene expression associated with Arabidopsis thaliana wounding response decreases within 24 h post microneedles' application. Additionally, microinjection of gibberellic acid (GA3 ) in A. thaliana mutant ft-10 provides a more effective and efficient mean than spray to activate GA3 pathways, accelerating bolting and inhibiting flower formation. Microneedle efficacy in delivering GA3 is also observed in several monocot and dicot crop species, i.e., tomato (Solanum lycopersicum), lettuce (Lactuca sativa), spinach (Spinacia oleracea), rice (Oryza Sativa), maize (Zea mays), barley (Hordeum vulgare), and soybean (Glycine max). The wide range of plants that can be successfully targeted with microinjectors opens the doors to their use in plant science and agriculture.

Post graduate remediation programs in medicine: a scoping review.

BACKGROUND: Recognizing that physicians may struggle to achieve knowledge, skills, attitudes and or conduct at one or more stages during their training has highlighted the importance of the 'deliberate practice of improving performance through practising beyond one's comfort level under guidance'. However, variations in physician, program, contextual and healthcare and educational systems complicate efforts to create a consistent approach to remediation. Balancing the inevitable disparities in approaches and settings with the need for continuity and effective oversight of the remediation process, as well as the context and population specific nature of remediation, this review will scrutinise the remediation of physicians in training to better guide the design, structuring and oversight of new remediation programs. METHODS: Krishna's Systematic Evidence Based Approach is adopted to guide this Systematic Scoping Review (SSR in SEBA) to enhance the transparency and reproducibility of this review. A structured search for articles on remediation programs for licenced physicians who have completed their pre-registration postings and who are in training positions published between 1st January 1990 and 31st December 2021 in PubMed, Scopus, ERIC, Google Scholar, PsycINFO, ASSIA, HMIC, DARE and Web of Science databases was carried out. The included articles were concurrently thematically and content analysed using SEBA's Split Approach. Similarities in the identified themes and categories were combined in the Jigsaw Perspective and compared with the tabulated summaries of included articles in the Funnelling Process to create the domains that will guide discussions. RESULTS: The research team retrieved 5512 abstracts, reviewed 304 full-text articles and included 101 articles. The domains identified were characteristics, indications, frameworks, domains, enablers and barriers and unique features of remediation in licenced physicians in training programs. CONCLUSION: Building upon our findings and guided by Hauer et al. approach to remediation and Taylor and Hamdy's Multi-theories Model, we proffer a theoretically grounded 7-stage evidence-based remediation framework to enhance understanding of remediation in licenced physicians in training programs. We believe this framework can guide program design and reframe remediation's role as an integral part of training programs and a source of support and professional, academic, research, interprofessional and personal development.

Changing self-concept in the time of COVID-19: a close look at physician reflections on social media.

BACKGROUND: The COVID-19 pandemic has changed the healthcare landscape drastically. Stricken by sharp surges in morbidity and mortality with resource and manpower shortages confounding their efforts, the medical community has witnessed high rates of burnout and post-traumatic stress amongst themselves. Whilst the prevailing literature has offered glimpses into their professional war, no review thus far has collated the deeply personal reflections of physicians and ascertained how their self-concept, self-esteem and perceived self-worth has altered during this crisis. Without adequate intervention, this may have profound effects on their mental and physical health, personal relationships and professional efficacy. METHODS: With mentions of the coronavirus pervading social media by the millions, this paper set out to collate and thematically analyse social media posts containing first-person physician reflections on how COVID-19 affected their lives and their coping mechanisms. A consistent search strategy was employed and a PRISMA flowchart was used to map out the inclusion/exclusion criteria. RESULTS: A total of 590 social media posts were screened, 511 evaluated, and 108 included for analysis. Salient themes identified include Disruptions to Personal Psycho-Emotional State, Disruptions to Professional Care Delivery, Concern for Family, Response from Institution, Response from Society and Coping Mechanisms. CONCLUSION: It is evident that the distress experienced by physicians during this time has been manifold, multi-faceted and dominantly negative. Self-concepts were distorted with weakened self-esteem and perceived self-worth observed. The Ring Theory of Personhood (RToP) was adopted to explain COVID-19's impact on physician personhood as it considers existential, individual, relational and social concepts of the self. These entwined self-concepts serve as 'compensatory' to one another, with coping mechanisms buffering and fortifying the physician's overall personhood. With healthcare institutions playing a vital role in providing timely and targeted support, it was further proposed that a comprehensive assessment tool based on the RToP could be developed to detect at-risk physicians and evaluate the presence and effectiveness of established support structures.

A Scoping Review of Professional Identity Formation in Undergraduate Medical Education.

BACKGROUND: Professional identity formation (PIF) in medical students is a multifactorial phenomenon, shaped by ways that clinical and non-clinical experiences, expectations and environmental factors merge with individual values, beliefs and obligations. The relationship between students' evolving professional identity and self-identity or personhood remains ill-defined, making it challenging for medical schools to support PIF systematically and strategically. Primarily, to capture prevailing literature on PIF in medical school education, and secondarily, to ascertain how PIF influences on medical students may be viewed through the lens of the ring theory of personhood (RToP) and to identify ways that medical schools support PIF. METHODS: A systematic scoping review was conducted using the systematic evidence-based approach. Articles published between 1 January 2000 and 1 July 2020 related to PIF in medical students were searched using PubMed, Embase, PsycINFO, ERIC and Scopus. Articles of all study designs (quantitative and qualitative), published or translated into English, were included. Concurrent thematic and directed content analyses were used to evaluate the data. RESULTS: A total of 10443 abstracts were identified, 272 full-text articles evaluated, and 76 articles included. Thematic and directed content analyses revealed similar themes and categories as follows: characteristics of PIF in relation to professionalism, role of socialization in PIF, PIF enablers and barriers, and medical school approaches to supporting PIF. DISCUSSION: PIF involves iterative construction, deconstruction and inculcation of professional beliefs, values and behaviours into a pre-existent identity. Through the lens of RToP, factors were elucidated that promote or hinder students' identity development on individual, relational or societal levels. If inadequately or inappropriately supported, enabling factors become barriers to PIF. Medical schools employ an all-encompassing approach to support PIF, illuminating the need for distinct and deliberate longitudinal monitoring and mentoring to foster students' balanced integration of personal and professional identities over time.