Multiple slot modules for high field magnetic resonance imaging array coils.

PURPOSE: Mitigating coupling effects between coil elements represents a continuing challenge. Here, we present a 16-bowtie slot volume coil arranged in eight independent dual-slot modules without the use of any decoupling circuits. METHODS: Two electrically short "bowtie" slot antennas were used to form a "module." A bowtie configuration was chosen because electromagnetic modeling results show that bowtie slots exhibit improved B 1 + P in $$ \frac{B_1^{+}}{\sqrt{P_{in}}} $$ efficiency when compared to thin rectangular slots. An eight-module volume coil was evaluated through electromagnetic modeling, bench tests, and MRI experiments at 4.7 T. RESULTS: Bench tests indicate that worst-case coupling between modules did not exceed -14.5 dB. MR images demonstrate well-localized patterns about single excited modules confirming the low coupling between modules. Homogeneous MR images were acquired from a synthesized quadrature birdcage transmit mode. MRI experiments show that the RF power requirements for the proposed coil are 9.2 times more than a birdcage coil. Whereas from simulations performed to assess the proposed coil losses, the total power dissipated in the phantom was 1.1 times more for the birdcage. Simulation results at 7 T reveal an equivalent B1 + homogeneity when compared with an eight-dipole coil. CONCLUSION: Although exhibiting higher RF power requirements, as a transmit coil when the power availability is not a restriction, the inherently low coupling between electrically short slots should enable the use of many slot elements around the imaging volume. The slot module described in this paper should be useful in the design of multi-channel transmit coils.

Wideband receive-coil array design using high-impedance amplifiers for broadband decoupling.

PURPOSE: Multinuclear MRI/S is of increasing interest. Currently, most multinuclear receive array coils are constructed by nesting multiple single-tuned array coils or using switching elements to control the operating frequency, in which case more than one set of conventional isolation preamplifiers and associated decoupling circuits is required. These conventional configurations rapidly become complicated when greater numbers of channels or nuclei are needed. In this work, a novel coil decoupling mechanism is proposed to enable broadband decoupling for array coils with one set of preamplifiers. METHODS: Instead of using conventional isolation preamplifiers, a high-input impedance preamplifier is proposed to create broadband decoupling of the array elements. A matching network consisting of a single inductor-capacitor-capacitor multi-tuned network and a wire-wound transformer was used to interface the surface coil to the high-impedance preamplifier. To validate the concept, the proposed configuration was compared to the conventional preamplifier decoupling configuration on both bench and scanner. RESULTS: 2 The approach can provide more than 15dB decoupling over a range of 25MHz, covering the Larmor frequencies of 23 Na and 2 H at 4.7T. This multi-tuned prototype obtained 61% and 76% of the imaging SNR at 2 H and 23 Na respectively, 76 and 89% in a higher loading test phantom, when compared to the conventional single-tuned preamplifier decoupling configuration. CONCLUSION: With the multinuclear array operation and decoupling achieved using only one layer of array coil and preamplifiers, this work provides a simple approach of building high element-count arrays to enable accelerated imaging or SNR improvement from multiple nuclei.

Dynamic 13 C MR spectroscopy as an alternative to imaging for assessing cerebral metabolism using hyperpolarized pyruvate in humans.

PURPOSE: This study is to investigate time-resolved 13 C MR spectroscopy (MRS) as an alternative to imaging for assessing pyruvate metabolism using hyperpolarized (HP) [1-13 C]pyruvate in the human brain. METHODS: Time-resolved 13 C spectra were acquired from four axial brain slices of healthy human participants (n = 4) after a bolus injection of HP [1-13 C]pyruvate. 13 C MRS with low flip-angle excitations and a multichannel 13 C/1 H dual-frequency radiofrequency (RF) coil were exploited for reliable and unperturbed assessment of HP pyruvate metabolism. Slice-wise areas under the curve (AUCs) of 13 C-metabolites were measured and kinetic analysis was performed to estimate the production rates of lactate and HCO3- . Linear regression analysis between brain volumes and HP signals was performed. Region-focused pyruvate metabolism was estimated using coil-wise 13 C reconstruction. Reproducibility of HP pyruvate exams was presented by performing two consecutive injections with a 45-minutes interval. RESULTS: [1-13 C]Lactate relative to the total 13 C signal (tC) was 0.21-0.24 in all slices. [13 C] HCO3- /tC was 0.065-0.091. Apparent conversion rate constants from pyruvate to lactate and HCO3- were calculated as 0.014-0.018 s-1 and 0.0043-0.0056 s-1 , respectively. Pyruvate/tC and lactate/tC were in moderate linear relationships with fractional gray matter volume within each slice. White matter presented poor linear regression fit with HP signals, and moderate correlations of the fractional cerebrospinal fluid volume with pyruvate/tC and lactate/tC were measured. Measured HP signals were comparable between two consecutive exams with HP [1-13 C]pyruvate. CONCLUSIONS: Dynamic MRS in combination with multichannel RF coils is an affordable and reliable alternative to imaging methods in investigating cerebral metabolism using HP [1-13 C]pyruvate.

A retrofit to enable dynamic B1+ steering for transmit arrays without multiple amplifiers.

PURPOSE: B1+ shimming is an important method for mitigating B1 inhomogeneity in high-field MRI. Using independent power amplifiers for each transmit (Tx) element is the preferred method for B1 shimming but comes with a high cost. Conversely, the simplest approach to control a Tx array is by using coaxial cables of varying length in the Tx chain, but this approach is cumbersome and impractical for dynamic shimming. In this article, a system is described that enables dynamic, phase-only, eight-channel B1+ steering on a 7T MR scanner with only two power amplifiers. METHODS: Power dividers were utilized to first split the existing two-channel Tx signal into eight channels. Digitally controlled phase shifters on each channel were designed to provide independent phase shifts with a resolution of 22.5° (from 0°, 22.5° … 337.5°). To validate the system, an eight-channel body dipole array was simulated and constructed for bench and 7T imaging and evaluation. RESULTS: The phase conjugate B1+ steering method was employed at three different spatial positions in simulation, bench measurements, and scanner measurements-all with matching results. At the desired points, regions with homogenous B1+ were generated, indicating good Tx steering to the selected region. CONCLUSION: The described system can be used as a simple retrofit to existing hardware to provide phase control while avoiding the need to manually switch cables and without requiring independent power amplifiers for each channel, thus demonstrating the ability to perform dynamic B1+ shimming with increased degrees of freedom but without significantly increased hardware cost.

A 32-channel receive array coil for bilateral breast imaging and spectroscopy at 7T.

PURPOSE: This work describes the construction and evaluation of a bilateral 32-channel receive array for breast imaging at 7T. METHODS: The receive array consisted of 32 receive coils, placed on two 3D-printed hemispherical formers. Each side of the receive array consisted of 16 receive loops, each loop having a corresponding detachable board with match/tune capacitors, active detuning circuitry, and a balun. Coil performance was evaluated on homogeneous canola oil phantoms using a Philips Achieva 7T system. Array coil performance was compared with a bilateral forced current excitation volume coil in transmit/receive mode and with a previously reported 16-channel unilateral coil with a similar design. RESULTS: The 32-channel array had an increase in average SNR throughout both phantoms by a factor of five as compared with the volume coil, with SNR increases up to 10 times along the periphery and three times in the center. Noise measurements showed low interelement noise correlation (average: 5.4%; maximum: 16.8%). Geometry factor maps were acquired for various acceleration factors and showed mean geometry factors <1.2, for combined acceleration factors of up to six. CONCLUSIONS: The improvements achieved demonstrate the clear potential for use in dynamic contrast-enhanced or diffusion-weighted MR studies, while maintaining diagnostically relevant spatial and temporal resolutions.

Local Policy and Programmatic Activity to Address the US Opioid Crisis: A Cross-Sectional Survey of County Governments.

CONTEXT: Despite attention to federal and state governments' response to the US opioid crisis, few studies have systematically examined local governments' role in tackling this problem. OBJECTIVES: To determine what opioid policy and programmatic activities local governments are implementing, which activities are more challenging and require a greater latent ability to implement, and what community, environmental, and institutional factors shape such ability. DESIGN: A cross-sectional survey and multistage sampling procedure. SETTING/PARTICIPANTS: Of all 358 county governments in 5 purposively selected states (Colorado, North Carolina, Ohio, Pennsylvania, and Washington) surveyed, 171 counties (response rate = 47.8%) with complete data on self-reported policy and programmatic activities and predictor variables were eligible for analysis. MAIN OUTCOME MEASURES: Nineteen opioid policy and programmatic activities were analyzed individually and combined into a latent implementation ability index using empirical Bayes means estimates. RESULTS: Item response theory and bivariate analysis were applied. Item response theory estimates suggested that having police officers carry naloxone and establishing a task force of community leaders were easier to implement than more challenging activities such as establishing needle exchanges and allowing arrest alternatives for opioid offenses. Covering individuals' treatment costs was predicted to involve the highest ability. County population size (r = 0.34; 95% confidence interval [CI], 0.20-0.47), population density (r = 0.35; 95% CI, 0.21-0.47), and being a Pennsylvania county (r = 0.45; 95% CI, 0.32-0.56) showed the strongest associations with latent implementation ability. CONCLUSIONS: Counties appear engaged in opioid policy and programmatic activity, although some activities are likely more difficult and may require greater ability to implement than others. More sparsely populated counties appear more disadvantaged in implementing activities for tackling the opioid crisis and may need additional assistance to leverage their ability to build a comprehensive policy and programmatic infrastructure.

Chemical Modifications of Porous Shape Memory Polymers for Enhanced X-ray and MRI Visibility.

The goal of this work was to develop a shape memory polymer (SMP) foam with visibility under both X-ray and magnetic resonance imaging (MRI) modalities. A porous polymeric material with these properties is desirable in medical device development for applications requiring thermoresponsive tissue scaffolds with clinical imaging capabilities. Dual modality visibility was achieved by chemically incorporating monomers with X-ray visible iodine-motifs and MRI visible monomers with gadolinium content. Physical and thermomechanical characterization showed the effect of increased gadopentetic acid (GPA) on shape memory behavior. Multiple compositions showed brightening effects in pilot, T1-weighted MR imaging. There was a correlation between the polymeric density and X-ray visibility on expanded and compressed SMP foams. Additionally, extractions and indirect cytocompatibility studies were performed to address toxicity concerns of gadolinium-based contrast agents (GBCAs). This material platform has the potential to be used in a variety of medical devices.

Microbiota in Exhaled Breath Condensate and the Lung.

The lung microbiota is commonly sampled using relatively invasive bronchoscopic procedures. Exhaled breath condensate (EBC) collection potentially offers a less invasive alternative for lung microbiota sampling. We compared lung microbiota samples retrieved by protected specimen brushings (PSB) and exhaled breath condensate collection. We also sought to assess whether aerosolized antibiotic treatment would influence the lung microbiota and whether this change could be detected in EBC. EBC was collected from 6 conscious sheep and then from the same anesthetized sheep during mechanical ventilation. Following the latter EBC collection, PSB samples were collected from separate sites within each sheep lung. On the subsequent day, each sheep was then treated with nebulized colistimethate sodium. Two days after nebulization, EBC and PSB samples were again collected. Bacterial DNA was quantified using 16S rRNA gene quantitative PCR. The V2-V3 region of the 16S rRNA gene was amplified by PCR and sequenced using Illumina MiSeq. Quality control and operational taxonomic unit (OTU) clustering were performed with mothur. The EBC samples contained significantly less bacterial DNA than the PSB samples. The EBC samples from anesthetized animals clustered separately by their bacterial community compositions in comparison to the PSB samples, and 37 bacterial OTUs were identified as differentially abundant between the two sample types. Despite only low concentrations of colistin being detected in bronchoalveolar lavage fluid, PSB samples were found to differ by their bacterial compositions before and after colistimethate sodium treatment. Our findings indicate that microbiota in EBC samples and PSB samples are not equivalent.IMPORTANCE Sampling of the lung microbiota usually necessitates performing bronchoscopic procedures that involve a hospital visit for human participants and the use of trained staff. The inconvenience and perceived discomfort of participating in this kind of research may deter healthy volunteers and may not be a safe option for patients with advanced lung disease. This study set out to evaluate a less invasive method for collecting lung microbiota samples by comparing samples taken via protected specimen brushings (PSB) to those taken via exhaled breath condensate (EBC) collection. We found that there was less bacterial DNA in EBC samples compared with that in PSB samples and that there were differences between the bacterial communities in the two sample types. We conclude that while EBC and PSB samples do not produce equivalent microbiota samples, the study of the EBC microbiota may still be of interest.

Variability of the Sheep Lung Microbiota.

UNLABELLED: Sequencing technologies have recently facilitated the characterization of bacterial communities present in lungs during health and disease. However, there is currently a dearth of information concerning the variability of such data in health both between and within subjects. This study seeks to examine such variability using healthy adult sheep as our model system. Protected specimen brush samples were collected from three spatially disparate segmental bronchi of six adult sheep (age, 20 months) on three occasions (day 0, 1 month, and 3 months). To further explore the spatial variability of the microbiotas, more-extensive brushing samples (n = 16) and a throat swab were taken from a separate sheep. The V2 and V3 hypervariable regions of the bacterial 16S rRNA genes were amplified and sequenced via Illumina MiSeq. DNA sequences were analyzed using the mothur software package. Quantitative PCR was performed to quantify total bacterial DNA. Some sheep lungs contained dramatically different bacterial communities at different sampling sites, whereas in others, airway microbiotas appeared similar across the lung. In our spatial variability study, we observed clustering related to the depth within the lung from which samples were taken. Lung depth refers to increasing distance from the glottis, progressing in a caudal direction. We conclude that both host influence and local factors have impacts on the composition of the sheep lung microbiota. IMPORTANCE: Until recently, it was assumed that the lungs were a sterile environment which was colonized by microbes only during disease. However, recent studies using sequencing technologies have found that there is a small population of bacteria which exists in the lung during health, referred to as the "lung microbiota." In this study, we characterize the variability of the lung microbiotas of healthy sheep. Sheep not only are economically important animals but also are often used as large animal models of human respiratory disease. We conclude that, while host influence does play a role in dictating the types of microbes which colonize the airways, it is clear that local factors also play an important role in this regard. Understanding the nature and influence of these factors will be key to understanding the variability in, and functional relevance of, the lung microbiota.

Roxadustat (FG-4592) Versus Epoetin Alfa for Anemia in Patients Receiving Maintenance Hemodialysis: A Phase 2, Randomized, 6- to 19-Week, Open-Label, Active-Comparator, Dose-Ranging, Safety and Exploratory Efficacy Study.

BACKGROUND: Roxadustat (FG-4592) is an oral hypoxia-inducible factor prolyl-hydroxylase inhibitor that promotes erythropoiesis through increasing endogenous erythropoietin, improving iron regulation, and reducing hepcidin. STUDY DESIGN: Phase 2, randomized (3:1), open-label, active-comparator, safety and efficacy study. SETTING & PARTICIPANTS: Patients with stable end-stage renal disease treated with hemodialysis who previously had hemoglobin (Hb) levels maintained with epoetin alfa. INTERVENTION: Part 1: 6-week dose-ranging study in 54 individuals of thrice-weekly oral roxadustat doses versus continuation of intravenous epoetin alfa. Part 2: 19-week treatment in 90 individuals in 6 cohorts with various starting doses and adjustment rules (1.0-2.0mg/kg or tiered weight based) in individuals with a range of epoetin alfa responsiveness. Intravenous iron was prohibited. OUTCOMES: Primary end point was Hb level response, defined as end-of-treatment Hb level change (ΔHb) of -0.5g/dL or greater from baseline (part 1) and as mean Hb level ≥ 11.0g/dL during the last 4 treatment weeks (part 2). MEASUREMENTS: Hepcidin, iron parameters, cholesterol, and plasma erythropoietin (the latter in a subset). RESULTS: Baseline epoetin alfa doses were 138.3±51.3 (SD) and 136.3±47.7U/kg/wk in part 1 and 152.8±80.6 and 173.4±83.7U/kg/wk in part 2, in individuals randomly assigned to roxadustat and epoetin alfa, respectively. Hb level responder rates in part 1 were 79% in pooled roxadustat 1.5 to 2.0mg/kg compared to 33% in the epoetin alfa control arm (P=0.03). Hepcidin level reduction was greater at roxadustat 2.0mg/kg versus epoetin alfa (P<0.05). In part 2, the average roxadustat dose requirement for Hb level maintenance was ∼1.7mg/kg. The least-squares-mean ΔHb in roxadustat-treated individuals was comparable to that in epoetin alfa-treated individuals (about -0.5g/dL) and the least-squares-mean difference in ΔHb between both treatment arms was -0.03 (95% CI, -0.39 to 0.33) g/dL (mixed effect model-repeated measure). Roxadustat significantly reduced mean total cholesterol levels, not observed with epoetin alfa. No safety concerns were raised. LIMITATIONS: Short treatment duration and small sample size. CONCLUSIONS: In this phase 2 study of anemia therapy in patients with end-stage renal disease on maintenance hemodialysis therapy, roxadustat was well tolerated and effectively maintained Hb levels.

Trap Design and Construction for High-Power Multinuclear Magnetic Resonance Experiments.

Performing multinuclear experiments requires one or more radiofrequency (RF) coils operating at both the proton and second-nucleus frequencies; however, inductive coupling between coils must be mitigated to retain proton sensitivity and coil tuning stability. The inclusion of trap circuits simplifies placement of multinuclear RF coils while maintaining inter-element isolation. Of the commonly investigated non-proton nuclei, perhaps the most technically demanding is carbon-13, particularly when applying a proton decoupling scheme to improve the resulting spectra. This work presents experimental data for trap circuits withstanding high-power broadband proton decoupling of carbon-13 at 7 T. The advantages and challenges of building trap circuits with various inductor and capacitor components are discussed. Multiple trap designs are evaluated on the bench and utilized on an RF coil at 7 T to detect broadband proton-decoupled carbon-13 spectra from a lipid phantom. A particular trap design, built from a coaxial stub inductor and high-voltage ceramic chip capacitors, is highlighted owing to both its performance and adaptability for planar array coil elements with diverse spatial orientations.

A microelectromechanical systems-enabled, miniature triple quadrupole mass spectrometer.

Miniaturized mass spectrometers are becoming increasingly capable, enabling the development of many novel field and laboratory applications. However, to date, triple quadrupole tandem mass spectrometers, the workhorses of quantitative analysis, have not been significantly reduced in size. Here, the basis of a field-deployable triple quadrupole is described. The key development is a highly miniaturized ion optical assembly in which a sequence of six microengineered components is employed to generate ions at atmospheric pressure, provide a vacuum interface, effect ion guiding, and perform fragmentation and mass analysis. Despite its small dimensions, the collision cell efficiently fragments precursor ions and yields product ion spectra that are very similar to those recorded using conventional instruments. The miniature triple quadrupole has been used to detect thiabendazole, a common pesticide, in apples at a level of 10 ng/g.

Associations between provider designation and female-specific cancer screening in women Veterans.

BACKGROUND: In 2010, the Department of Veterans Affairs Healthcare System (VA) implemented policy to provide Comprehensive Primary Care (for acute, chronic, and female-specific care) from designated Women's Health providers (DWHPs) at all VA sites. However, since that time no comparisons of quality measures have been available to assess the level of care for women Veterans assigned to these providers. OBJECTIVES: To evaluate the associations between cervical and breast cancer screening rates among age-appropriate women Veterans and designation of primary-care provider (DWHP vs. non-DWHP). RESEARCH DESIGN: Cross-sectional analyses using the fiscal year 2012 data on VA women's health providers, administrative files, and patient-specific quality measures. SUBJECTS: The sample included 37,128 women Veterans aged 21 through 69 years. MEASURES: Variables included patient demographic and clinical factors (ie, age, race, ethnicity, mental health diagnoses, obesity, and site), and provider factors (ie, DWHP status, sex, and panel size). Screening measures were defined by age-appropriate subgroups using VA national guidelines. RESULTS: Female-specific cancer screening rates were higher among patients assigned to DWHPs (cervical cytology 94.4% vs. 91.9%, P<0.0001; mammography 86.3% vs. 83.3%, P<0.0001). In multivariable models with adjustment for patient and provider characteristics, patients assigned to DWHPs had higher odds of cervical cancer screening (odds ratio, 1.26; 95% confidence interval, 1.07-1.47; P<0.0001) and breast cancer screening (odds ratio, 1.24; 95% CI, 1.10-1.39; P<0.0001). CONCLUSIONS: As the proportion of women Veterans increases, assignment to DWHPs may raise rate of female-specific cancer screening within VA. Separate evaluation of sex neutral measures is needed to determine whether other measures accrue benefits for patients with DWHPs.

Are comparisons of patient experiences across hospitals fair? A study in Veterans Health Administration hospitals.

BACKGROUND: Surveys are increasingly used to assess patient experiences with health care. Comparisons of hospital scores based on patient experience surveys should be adjusted for patient characteristics that might affect survey results. Such characteristics are commonly drawn from patient surveys that collect little, if any, clinical information. Consequently some hospitals, especially those treating particularly complex patients, have been concerned that standard adjustment methods do not adequately reflect the challenges of treating their patients. OBJECTIVES: To compare scores for different types of hospitals after making adjustments using only survey-reported patient characteristics and using more complete clinical and hospital information. RESEARCH DESIGN: We used clinical and survey data from a national sample of 1858 veterans hospitalized for an initial acute myocardial infarction (AMI) in a Department of Veterans Affairs (VA) medical center during fiscal years 2003 and 2004. We used VA administrative data to characterize hospitals. The survey asked patients about their experiences with hospital care. The clinical data included 14 measures abstracted from medical records that are predictive of survival after an AMI. RESULTS: Comparisons of scores across hospitals adjusted only for patient-reported health status and sociodemographic characteristics were similar to those that also adjusted for patient clinical characteristics; the Spearman rank-order correlations between the 2 sets of adjusted scores were >0.97 across 9 dimensions of inpatient experience. CONCLUSIONS: This study did not support concerns that measures of patient care experiences are unfair because commonly used models do not adjust adequately for potentially confounding patient clinical characteristics.

Quadrature transmit coil for breast imaging at 7 tesla using forced current excitation for improved homogeneity.

PURPOSE: To demonstrate the use of forced current excitation (FCE) to create homogeneous excitation of the breast at 7 tesla, insensitive to the effects of asymmetries in the electrical environment. MATERIALS AND METHODS: FCE was implemented on two breast coils: one for quadrature (1) H imaging and one for proton-decoupled (13) C spectroscopy. Both were a Helmholtz-saddle combination, with the saddle tuned to 298 MHz for imaging and 75 MHz for spectroscopy. Bench measurements were acquired to demonstrate the ability to force equal currents on elements in the presence of asymmetric loading to improve homogeneity. Modeling and temperature measurements were conducted per safety protocol. B1 mapping, imaging, and proton-decoupled (13) C spectroscopy were demonstrated in vivo. RESULTS: Using FCE to ensure balanced currents on elements enabled straightforward tuning and maintaining of isolation between quadrature elements of the coil. Modeling and bench measurements confirmed homogeneity of the field, which resulted in images with excellent fat suppression and in broadband proton-decoupled carbon-13 spectra. CONCLUSION: FCE is a straightforward approach to ensure equal currents on multiple coil elements and a homogeneous excitation field, insensitive to the effects of asymmetries in the electrical environment. This enabled effective breast imaging and proton-decoupled carbon-13 spectroscopy at 7T.

Perceptions of a disability sport unit in general physical education.

The purpose of this qualitative study was to assess the effectiveness of a disability sport unit in shaping perceptions of disability. Data from interviews, observations, and documents were collected on 87 elementary-aged students, one physical education teacher, and one teaching intern. Comparisons were drawn between fifth graders engaged in a five-week disability sport unit to fourth graders participating in their standard physical education curriculum. Findings revealed differences in the way fourth and fifth graders came to view individuals with disabilities. The results support an analysis of curriculum development that underscores the significance of the social model in positively impacting constructions of disability. Recommendations include the use of disability sports in physical education as an effective strategy for educating students in game play, knowledge of the Paralympics, and the inclusion of individuals with disabilities in a variety of sporting venues.

A Review of Current Control and Decoupling Methods for MRI Transmit Arrays.

The shortened radio frequency wavelength in high field MRI makes it challenging to create a uniform excitation pattern over a large field of view, or to achieve satisfactory transmission efficiency at a local area. Transmit arrays are one tool that can be used to create a desired excitation pattern. To be effective, it is important to be able to control the current amplitude and phase at the array elements. The control of the current may get complicated by the coil coupling in many applications. Various methods have been proposed to achieve current control, either in the presence of coupling, or by effectively decouple the array elements. These methods are applied in different subsystems in the RF transmission chain: coil; coil-amplifier interface; amplifier, etc. In this review paper, we provide an overview of the various approaches and aspects of transmit current control and decoupling.

Prescribing and deprescribing guidance for benzodiazepine and benzodiazepine receptor agonist use in adults with depression, anxiety, and insomnia: an international scoping review.

Background: Clinical practice guidelines and guidance documents routinely offer prescribing clinicians' recommendations and instruction on the use of psychotropic drugs for mental illness. We sought to characterise parameters relevant to prescribing and deprescribing of benzodiazepine (BZD) and benzodiazepine receptor agonist (BZRA), in clinical practice guidelines and guidance documents internationally, for adult patients with unipolar depression, anxiety disorders and insomnia to understand similarities and discrepancies between evidence-based expert opinion. Methods: A Scoping Review was conducted to characterize documents that offered evidence-based and/or consensus pharmacologic guidance on the management of unipolar depression, anxiety disorders, obsessive-compulsive disorders, post-traumatic stress disorders and insomnia. A systematic search was conducted of PubMed, SCOPUS, PsycINFO and CINAHL from inception to October 13, 2023 and supplemented by a gray literature search. Documents were screened in Covidence for eligibility. Subsequent data-charting on eligible documents collected information on aspects of both prescribing and deprescribing. Findings: 113 documents offering guidance on BZD/BZRA use were data-charted. Overall, documents gathered were from Asia (n = 11), Europe (n = 34), North America (n = 37), Oceania (n = 7), and South America (n = 4) with the remainder being "International" (n = 20) and not representative to any particular region or country. By condition the documents reviewed covered unipolar depressive disorders (n = 28), anxiety disorders, obsessive-compulsive disorder and post-traumatic stress disorder (n = 42) and Insomnia (n = 25). Few documents (n = 18) were sufficiently specific and complete to consider as de-prescribing focused documents. Interpretation: Documents were in concordance in terms of BZD and BZRA not being used routinely as first-line pharmacologic agents. When used, it is advisable to restrict their duration to "short-term" use with the most commonly recommended duration being less than four weeks. Documents were less consistent in terms of prescriptive recommendations for specific drug, dosing and administration pattern (i.e regular or 'as needed') selection for each condition. Deprescribing documents were unanimously in favor of gradual dose reduction and patient shared decision-making. However, approaches towards dose-tapering differed substantially. Finally, there were inconsistencies and/or insufficiency of detail, among deprescribing documents, in terms of switching to a long-acting BZD, use of adjunctive pharmacotherapies and micro-tapering. Funding: The authors received no funding for this work.

Inheritance and QTL mapping of Fusarium wilt race 4 resistance in cotton.

Diseases such as Fusarium wilt [Fusarium oxysporum f.sp. vasinfectum (FOV) Atk. Sny & Hans] represent expanding threats to cotton production. Integrating disease resistance into high-yielding, high-fiber quality cotton (Gossypium spp.) cultivars is one of the most important objectives in cotton breeding programs worldwide. In this study, we conducted a comprehensive analysis of gene action in cotton governing FOV race 4 resistance by combining conventional inheritance and quantitative trait loci (QTL) mapping with molecular markers. A set of diverse cotton populations was generated from crosses encompassing multiple genetic backgrounds. FOV race 4 resistance was investigated using seven parents and their derived populations: three intraspecific (G. hirsutum × G. hirsutum L. and G. barbadense × G. barbadense L.) F1 and F2; five interspecific (G. hirsutum × G. barbadense) F1 and F2; and one RIL. Parents and populations were evaluated for disease severity index (DSI) of leaves, and vascular stem and root staining (VRS) in four greenhouse and two field experiments. Initially, a single resistance gene (Fov4) model was observed in F2 populations based on inheritance of phenotypes. This single Fov4 gene had a major dominant gene action and conferred resistance to FOV race 4 in Pima-S6. The Fov4 gene appears to be located near a genome region on chromosome 14 marked with a QTL Fov4-C14 1 , which made the biggest contribution to the FOV race 4 resistance of the generated F2 progeny. Additional genetic and QTL analyses also identified a set of 11 SSR markers that indicated the involvement of more than one gene and gene interactions across six linkage groups/chromosomes (3, 6, 8, 14, 17, and 25) in the inheritance of FOV race 4 resistance. QTLs detected with minor effects in these populations explained 5-19 % of the DSI or VRS variation. Identified SSR markers for the resistance QTLs with major and minor effects will facilitate for the first time marker-assisted selection for the introgression of FOV race 4 resistance into elite cultivars during the breeding process.

Paper-based evaporation concentrators: Comparison of linear and radial geometries.

Paper-based evaporation concentrators with linear and radial geometries are compared. A new method of finding approximate analytic solutions of the advection-dispersion equation is proposed, based on the behavior of concentrators with infinite sources. Analytic approximations are compared with numerical solutions, and the advantage of radial concentration is highlighted: linear concentration rates scale with the square root of the Péclet number Pe while radial rates scale with Pe itself, leading to faster radial concentration beyond a critical value. Experiments are performed with Brilliant Blue FCF dye, using optical transmission and the Beer-Lambert law for quantitation. Dye concentrations are chosen for operation in the linear absorbance regime. Radial concentration is demonstrated under ambient conditions on filter paper disks with 60 mm diameter evaporation areas fed from a perimeter source, in a reverse of the well-known "coffee stain" experiment. Airflow enhanced concentration in strips and wedges is compared directly, using laser-patterned chromatography paper. The advantage of radial concentration is confirmed (and enhanced by diversion of concentrate to the corners of strips) and concentration factors greater than ∼ 500 (the dynamic range of measurement) are obtained in ∼2 h using 30 mm long columns.