Understanding intercalative modulation of G-rich sequence folding: solution structure of a TINA-conjugated antiparallel DNA triplex.

We present here the high-resolution structure of an antiparallel DNA triplex in which a monomer of para-twisted intercalating nucleic acid (para-TINA: (R)-1-O-[4-(1-pyrenylethynyl)phenylmethyl]glycerol) is covalently inserted as a bulge in the third strand of the triplex. TINA is a potent modulator of the hybridization properties of DNA sequences with extremely useful properties when conjugated in G-rich oligonucleotides. The insertion of para-TINA between two guanines of the triplex imparts a high thermal stabilization (ΔTM = 9ºC) to the structure and enhances the quality of NMR spectra by increasing the chemical shift dispersion of proton signals near the TINA location. The structural determination reveals that TINA intercalates between two consecutive triads, causing only local distortions in the structure. The two aromatic moieties of TINA are nearly coplanar, with the phenyl ring intercalating between the flanking guanine bases in the sequence, and the pyrene moiety situated between the Watson-Crick base pair of the two first strands. The precise position of TINA within the triplex structure reveals key TINA-DNA interactions, which explains the high stabilization observed and will aid in the design of new and more efficient binders to DNA.

Does harvesting age matter? Changes in structure and rheology of a shear-thickening polysaccharide from Cyathea medullaris as a function of age.

A shear-thickening polysaccharide from the New Zealand Black tree fern (Cyathea medullaris, commonly known as mamaku) extracted from different age fronds (stage 1: young, stage 2: fully grown and stage 3: old) was characterised in terms of structure and rheological properties. Constituent sugar analysis and 1H and 13C NMR revealed a repeating backbone of -4)-ß-D-GlcpA-(1 â†’ 2)-α-D-Manp-(1→, for all mamaku polysaccharide (MP) samples from different age fronds without any alterations in molecular structure. However, the molecular weight (Mw) was reduced with increasing age, from ~4.1 × 106 to ~2.1 × 106 Da from stage 1 to stage 3, respectively. This decrease in Mw (and size) consequently reduced the shear viscosity (ηs-Stage 1 > Î·s-Stage 2 > Î·s-Stage 3). However, the extent of shear-thickening and uniaxial extensional viscosity of MP stage 2 was greater than MP stage 1, which was attributed to a greater intermolecular interaction occurring in the former. Shear-thickening behaviour was not observed in MP stage 3.

NMR Shows Why a Small Chemical Change Almost Abolishes the Antimicrobial Activity of Glycocin F.

Glycocin F (GccF), a ribosomally synthesized, post-translationally modified peptide secreted by Lactobacillus plantarum KW30, rapidly inhibits the growth of susceptible bacteria at nanomolar concentrations. Previous studies have highlighted structural features important for its activity and have shown the absolute requirement for the Ser18 O-linked GlcNAc on the eight-residue loop linking the two short helices of the (C-X6-C)2 structure. Here, we show that an ostensibly very small chemical modification to Ser18, the substitution of the Cα proton with a methyl group, reduces the antimicrobial activity of GccF 1000-fold (IC50 1.5 µM cf. 1.5 nM). A comparison of the GccFα-methylSer18 NMR structure (PDB 8DFZ) with that of the native protein (PDB 2KUY) showed a marked difference in the orientation and mobility of the loop, as well as a markedly different positioning of the GlcNAc, suggesting that loop conformation, dynamics, and glycan presentation play an important role in the interaction of GccF with as yet unknown but essential physiological target molecules.

Substrate-Selective Adhesion of Metal Nanoparticles to Graphene Devices.

Nanostructured electronic devices, such as those based on graphene, are typically grown on top of the insulator SiO2. Their exposure to a flux of small size-selected silver nanoparticles has revealed remarkably selective adhesion: the graphene channel can be made fully metallized, while the insulating substrate remains coverage-free. This conspicuous contrast derives from the low binding energy between the metal nanoparticles and a contaminant-free passivated silica surface. In addition to providing physical insight into nanoparticle adhesion, this effect may be of value in applications involving deposition of metallic layers on device working surfaces: it eliminates the need for masking the insulating region and the associated extensive and potentially deleterious pre- and postprocessing.

Biotinylation of reducing and non-reducing termini to create plug-and-play polysaccharides.

Single-molecule studies continue to grow in popularity. In cases where biopolymer samples of interest exhibit variations in fine-structure between individual chains such single-molecule studies uniquely offer the promise of revealing deep structure-function relationships. Polysaccharides are typically studied in bulk and, as such, their study could greatly benefit from the application of single-molecule techniques. However, while for example single-molecule optical tweezers (OT) studies have become commonplace for DNA, studies of polysaccharides have lagged behind somewhat, complicated by the difficulty of studying molecules that amongst other things have more complex end-group chemistry. Recently, divalent streptavidin linkers have been shown to be capable of concatenating two pieces of biotin-terminated DNA to produce robust composite strings that run intact through conventional gels, and can be used in single-molecule OT experiments (Mohandas, Kent, Raudsepp, Jameson, & Williams, 2022). By using two such streptavidin linkers, biotin-terminated polymers could be inserted between two sections of DNA in order to facilitate single-molecule experiments on biopolymers that are currently difficult to address by other means. Here, we describe a generic approach for placing the required biotin moieties at both ends of polysaccharide chains, producing plug-and-play polysaccharide inserts that can be incorporated into composite polymer strings using streptavidin linking hubs.

Integrated Health Care Delivery for Adolescents Living with and at Risk of HIV Infection: A Review of Models and Actions for Implementation.

Integrated service delivery, providing coordinated services in a convenient manner, is important in HIV prevention and treatment for adolescents as they have interconnected health care needs related to HIV care, sexual and reproductive health and disease prevention. This review aimed to (1) identify key components of adolescent-responsive integrated service delivery in low and middle-income countries, (2) describe projects that have implemented integrated models of HIV care for adolescents, and (3) develop action steps to support the implementation of sustainable integrated models. We developed an implementation science-informed conceptual framework for integrated delivery of HIV care to adolescents and applied the framework to summarize key data elements in ten studies or programs across seven countries. Key pillars of the framework included (1) the socioecological perspective, (2) community and health care system linkages, and (3) components of adolescent-focused care. The conceptual framework and action steps outlined can catalyze design, implementation, and optimization of HIV care for adolescents.

Health worker perceptions of stigma towards Zambian adolescent girls and young women: a qualitative study.

BACKGROUND: The high prevalence of HIV among adolescent girls and young women aged 15-24 in Eastern and Southern Africa indicates a substantial need for accessible HIV prevention and treatment services in this population. Amidst this need, Zambia has yet to meet global testing and treatment targets among adolescent girls and young women living with HIV. Increasing access to timely, high-quality HIV services in this population requires addressing the intensified anticipated and experienced stigma that adolescent girls and young women often face when seeking HIV care, particularly stigma in the health facility setting. To better understand the multi-level drivers and manifestations of health facility stigma, we explored health workers' perceptions of clinic- and community-level stigma against adolescent girls and young women seeking sexual and reproductive health, including HIV, services in Lusaka, Zambia. METHODS: We conducted 18 in-depth interviews in August 2020 with clinical and non-clinical health workers across six health facilities in urban and peri-urban Lusaka. Data were coded in Dedoose and thematically analyzed. RESULTS: Health workers reported observing manifestations of stigma driven by attitudes, awareness, and institutional environment. Clinic-level stigma often mirrored community-level stigma. Health workers clearly described the negative impacts of stigma for adolescent girls and young women and seemed to generally express a desire to avoid stigmatization. Despite this lack of intent to stigmatize, results suggest that community influence perpetuates a lingering presence of stigma, although often unrecognized and unintended, in health workers and clinics. CONCLUSIONS: These findings demonstrate the overlap in health workers' clinic and community roles and suggest the need for multi-level stigma-reduction approaches that address the influence of community norms on health facility stigma. Stigma-reduction interventions should aim to move beyond fostering basic knowledge about stigma to encouraging critical thinking about internal beliefs and community influence and how these may manifest, often unconsciously, in service delivery to adolescent girls and young women.

Operational Characteristics of Central Cancer Registries that Support the Generation of High-Quality Surveillance Data.

Objectives: We aim to assess external and internal attributes and operations of the Centers for Disease Control and Prevention (CDC)'s National Program of Cancer Registries (NPCR) central cancer registries by their consistency in meeting national data quality standards. Methods: The NPCR 2017 Program Evaluation Instrument (PEI) data were used to assess registry operational attributes, including adoption of electronic reporting, compliance with reporting, staffing, and software used among 46 NPCR registries. These factors were stratified by (1) registries that met the NPCR 12-month standards for all years 2014-2017; (2) registries that met the NPCR 12-month standards at least once in 2014-2017 and met the NPCR 24-month standards for all years 2014-2017; and (3) registries that did not meet the NPCR 24-month standards for all years 2014-2017. Statistical tests helped identify significant differences among registries that consistently, sometimes, or seldom/never achieved data standards. Results: Registries that always met the standards had a higher level of electronic reporting and a higher compliance with reporting among hospitals than registries that sometimes or seldom/never met the standards. Although not a statistically significant finding, the same registries also had a higher proportion of staffing positions filled, a higher proportion of certified tumor registrars, and more quality assurance and information technology staff. Conclusions: This information may be used to understand the importance of various factors and characteristics, including the adoption of electronic reporting, that may be associated with a registry's ability to consistently meet NPCR standards. The findings may be helpful in identifying best practices for processing high-quality cancer data.

Perspectives of Adolescent Girls and Young Women on Optimizing Youth-Friendly HIV and Sexual and Reproductive Health Care in Zambia.

Youth-friendly health care delivery models are needed to address the complex health care needs of adolescent girls and young women (AGYW). The aim of this study is to explore the lived experiences of AGYW seeking comprehensive HIV and sexual and reproductive health (SRH) care and to elicit their preferences for integrated health care services. We conducted in-depth interviews and focus group discussions in Lusaka, Zambia among 69 AGYW aged 10-20 who were HIV-negative or of unknown status and 40 AGYW aged 16-24 living with HIV. The data were coded through deductive and inductive processes and analyzed thematically using modified World Health Organization (WHO) dimensions of quality for youth-friendly services. AGYW expressed preference for one-stop clinics with integrated services that could provide HIV services along with other services such as pregnancy testing and family planning. AGYW also wanted information on staying healthy and approaches to prevent disease which could be delivered in the community setting such as youth clubs. An integrated clinic should address important attributes to AGYW including short wait time, flexible opening hours, assurance of confidentiality and positive staff attitudes. Youth-friendly, integrated care delivery models that incorporate AGYW preferences may foster linkages to care and improve outcomes among vulnerable AGYW.

Factors Affecting the Adoption of Electronic Data Reporting and Outcomes Among Selected Central Cancer Registries of the National Program of Cancer Registries.

PURPOSE: The CDC's National Program of Cancer Registries has expanded the use of electronic reporting to collect more timely information on newly diagnosed cancers. The adoption, implementation, and use of electronic reporting vary significantly among central cancer registries. We identify factors affecting the adoption of electronic reporting among these registries. METHODS: Directors and data managers of nine National Program of Cancer Registries took part in separate 1-hour telephone interviews in early 2019. Directors were asked about their registry's key data quality goals; staffing, resources, and tools used to aid processes; their definition and self-perception of electronic reporting adoption; key helpers and challenges; and cost and sustainability implications for adoption of electronic reporting. Data managers were asked about specific data collection processes, software applications, electronic reporting adoption and self-perception, information technology infrastructure, and helpers and challenges to data collection and processing, data quality, and sustainability of approach. RESULTS: Larger registries identified organizational capacity and technical expertise as key aides. Other help for implementing electronic reporting processes came from partnerships, funding availability, management support, legislation, and access to an interstate data exchange. Common challenges among lower adopters included lack of capacity at both registry and data source levels, insufficient staffing, and a lack of information technology or technical support. Other challenges consisted of automation and interoperability of software, volume of cases received, state political environment, and quality of data received. CONCLUSION: Feedback from the formative evaluation yielded several useful solutions that can guide implementation of electronic reporting and help refine the technical assistance provided to registries. Our findings may help guide future process and economic evaluations of electronic reporting and identify best practices to strengthen registry operations.

Kiwifruit (Actinidia deliciosa), compared with cellulose and psyllium, influences the histology and mucus layer of the gastrointestinal tract in the growing pig.

Kiwifruit (KF) fiber, a mixture of soluble and insoluble fibers, elicits mucosal changes in the gastrointestinal tract (GIT). This study aimed to define the nature of these changes in mucosal features throughout the GIT of the growing pig in response to semi-synthetic iso-fiber diets containing cellulose (CEL, low GIT luminal functionality) as the sole fiber source (4.5%), or diets where half of the CEL was replaced by either PSY fiber (PSY husk, high GIT luminal functionality) or KF fiber (consumed as intact fruit). Entire male growing pigs (n = 24, 21 kg bodyweight) received the three diets (n = 8) for 42 d. GIT tissues, digesta, and feces were sampled. The partial replacement of CEL increased (P≤ 0.05) the ileal (KF 22% and PSY 33%) and colonic (PSY 86%) mucus layer thickness, whereas it decreased the rectal crypt depth (KF -26%), and small intestinal (duodenum to ileum) villus length (PSY -17%). The number of duodenal goblet cells was 77% higher (P≤ 0.05) for KF than CEL. Pigs fed the KF-containing diet had greater (P≤ 0.05) apparent ileal organic matter digestibility and apparent total tract organic matter digestibility compared with CEL, but the lowest amount of fermented organic matter in the large intestine. In conclusion, partial substitution of CEL with PSY or KF at a constant, practically-relevant dietary fiber intake, affected several measures of GIT functionality with effects being specific to the added fiber.

Utility of linking survey and registry data to evaluate interventions and policies to address disparities in breast cancer survivorship among young women.

PURPOSE: There is limited research linking data sources to evaluate the multifactorial impacts on the quality of treatment received and financial burden among young women with breast cancer. To address this gap and support future evaluation efforts, we examined the utility of combining patient survey and cancer registry data. PATIENT AND METHODS: We administered a survey to women, aged 18-39 years, with breast cancer from four U.S. states. We conducted a systematic response-rate analysis and evaluated differences between racial groups. Survey responses were linked with cancer registry data to assess whether surveys could reliably supplement registry data. RESULTS: A total of 830 women completed the survey for a response rate of 28.4 %. Blacks and Asian/Pacific Islanders were half as likely to respond as white women. Concordance between survey and registry data was high for demographic variables (Cohen's kappa [k]: 0.879 to 0.949), moderate to high for treatments received (k: 0.467 to 0.854), and low for hormone receptor status (k: 0.167 to 0.553). Survey items related to insurance status, employment, and symptoms revealed racial differences. CONCLUSION: Cancer registry data, supplemented by patient surveys, can provide a broader understanding of the quality of care and financial impacts of breast cancer among young women.

Preparation of drip samples from leg of lamb with extended shelf life for nuclear magnetic resonance metabolomics studies.

Metabolomics has been used for the analysis of meat samples for different applications. Using drip as a proxy for meat could offer an easy and non-invasive way of sampling meat, yielding a homogenous liquid sample easy to prepare for metabolomics analysis. There is currently no standard method for the preparation of drip samples for quantitative metabolomics. The aim of this study was to evaluate six different sample preparation methods for quantitative Nuclear Magnetic Resonance (NMR) metabolomics analysis of drip from a lamb leg with extended shelf life: centrifugation, ultrafiltration, and solvent precipitation using four different solvents or solvent mixtures. The six methods were evaluated based on protein removal efficiency, ability to quantify metabolites, metabolite concentrations, reproducibility, speed and relative cost. Three methods (ultrafiltration, solvent precipitation with either acetonitrile/acetone/methanol or chloroform/methanol) resulted in excellent protein removal, high concentrations of metabolites and high reproducibility and are therefore recommended for preparation of extended shelf life lamb leg drip samples for NMR metabolomics.

Family Support for Adolescent Girls and Young Women Living With HIV in Zambia: Benefits, Challenges, and Recommendations for Intervention Development.

ABSTRACT: Lack of family involvement is barrier to antiretroviral therapy adherence among adolescent girls and young women (AGYW). This study assessed family support for AGYW's engagement along the HIV care continuum to inform the design of a family-focused intervention in Lusaka, Zambia. We conducted 16 in-depth interviews and four focus group discussions with 40 AGYW living with HIV. Three strategies were identified to strengthen family support. First, emotional and instrumental support are highly valued by AGYW and should be further developed or reinforced. Second, AGYW wanted more informational support and open discussion of HIV from family, and an intervention should aim to enhance these types of support. Third, existing appraisal support reinforced anticipated stigma among AGYW and discouraged disclosure, yet participants wished for more interactions with peers living with HIV. Appraisal support should therefore be reframed to help AGYW decide to whom they should disclose and how to do so safely.

Cyclic peptides bearing the d-Phe-2-Abz turn motif: Structural characterization and antimicrobial potential.

The effect on secondary structure and antimicrobial activity of introducing different cyclic constraints in linear ß-hairpin antimicrobial peptides has been investigated with the intention of generating cyclic ß sheets as promising antimicrobials with improved therapeutic potential. The linear peptides were cyclized head to tail either directly or after the addition of either a second turn motif or a disulfide bridge. The propensity of these peptides to adopt a cyclic ß-sheet structure has been correlated to their antibacterial activity. All cyclic peptides showed enhanced activity, compared with their linear counterparts against methicillin-resistant Staphylococcus aureus. Scanning electron microscopy and transmission electron microscopy studies showed that this family kills bacteria through membrane lysis. The peptide that showed the best efficacy against all strains (exhibiting nanomolar activity), while retaining low haemolysis, bears two symmetrical, homochiral d-phe-2-Abz-d-ala turns and adopted a flexible structure. Its twin peptide that bears heterochiral turns (one with d-ala and one with L-Ala) showed reduced antibacterial activity and higher percentage of haemolysis. Circular dichroism and nuclear magnetic resonance spectroscopy indicate that heterochirality in the two turns leads to oligomerization of the peptide at higher concentrations, stabilizing the ß-sheet secondary structure. More rigid secondary structure is associated with lower activity against bacteria and loss of selectivity.

Experimentally based structural model of Yih1 provides insight into its function in controlling the key translational regulator Gcn2.

Yeast impact homolog 1 (Yih1), or IMPACT in mammals, is part of a conserved regulatory module controlling the activity of General Control Nonderepressible 2 (Gcn2), a protein kinase that regulates protein synthesis. Yih1/IMPACT is implicated not only in many essential cellular processes, such as neuronal development, immune system regulation and the cell cycle, but also in cancer. Gcn2 must bind to Gcn1 in order to impair the initiation of protein translation. Yih1 hinders this key Gcn1-Gcn2 interaction by binding to Gcn1, thus preventing Gcn2-mediated inhibition of protein synthesis. Here, we solved the structures of the two domains of Saccharomyces cerevisiae Yih1 separately using Nuclear Magnetic Resonance and determined the relative positions of the two domains using a range of biophysical methods. Our findings support a compact structural model of Yih1 in which the residues required for Gcn1 binding are buried in the interface. This model strongly implies that Yih1 undergoes a large conformational rearrangement from a latent closed state to a primed open state to bind Gcn1. Our study provides structural insight into the interactions of Yih1 with partner molecules.

Direct Measurement of Water-Assisted Ion Desorption and Solvation on Isolated Carbon Nanotubes.

We have investigated the change in mean residence time of gaseous ions adsorbed on the surface of suspended carbon nanotube field-effect transistors (CNT-FETs) with and without native surface water layers that exists in atmospheric conditions. Devices were characterized electrically before and after dehydration by thermal, dry gas, and vacuum desiccation and in each scenario were found to have substantially higher mean ion residence times. It is proposed that water molecules native to the CNT surface in ambient conditions provide a reduction pathway for incoming gaseous ions, yielding hydronium ions (H3O+). This is supported by the appearance of frequent clustered readsorption events in the presence of surface water, caused by the rapid hopping of H+ between the device surface and the lowest water layer, which are not present in data collected from desiccated devices. After desiccation of the device, a thermal trial was conducted to determine the adsorption energy of N2+ ions on the CNT surface. This work has profound implications for our understanding of wetting in one-dimensional systems and the chemistry of ion chemisorption and solvation on the surfaces of materials in general.

Treatment cost and access to care: experiences of young women diagnosed with breast cancer.

PURPOSE: Breast cancer is the leading cause of cancer-related deaths in women younger than 40 years. We aim to evaluate cost as a barrier to care among female breast cancer patients diagnosed between 18 to 39 years. METHODS: In early 2017, we distributed a survey to women diagnosed with breast cancer between the ages of 18 and 39 years, as identified by the central cancer registries of California, Georgia, North Carolina, and Florida. We used multivariable statistics to explore cost-related barriers to receiving breast cancer care for the 830 women that completed the survey. RESULTS: About half of the women (47.4%) reported spending more on breast cancer care than expected, and almost two-thirds (65.3%) had not discussed costs with their care team. A third of the patients (31.8%) indicated forgoing care due to cost. Factors associated with not receiving anticipated care due to cost included age less than35 years at diagnosis, self-insurance, comorbid conditions, and late-stage diagnosis. CONCLUSION: Previous studies using breast cancer registry data have not included detailed insurance information and care received by young women. Young women with breast cancer frequently forgo breast cancer care due to cost. Our results highlight the potential for policies that facilitate optimal care for young breast cancer patients which could include the provision of comprehensive insurance coverage.

Investigation of metabolites associated with confinement odour in chilled vacuum-packed lamb by proton nuclear magnetic resonance (1H NMR) spectroscopy.

This study aimed to determine the profiles of water-soluble metabolites in lamb drip and meat by Nuclear Magnetic Resonance (NMR) spectroscopy, in order to better understand the confinement odour (CO) phenomenon in lamb meat on a molecular level. Thirty-five lamb legs were obtained from two New Zealand meat processing plants and stored for 11 to 13 weeks at temperatures ranging from -1.5 °C to +4.0 °C. A sensorial test classified meat samples as having CO, no odour (NO) or persistent odour (PO). Sixty-three and sixty-two metabolites were identified and quantified in drip and meat samples, respectively. Partial least squares canonical analysis (PLS-CA) showed that CO was correlated with meat and drip metabolites tyramine, formate, alanine, carnosine, urea, proline, aspartate, glutathione and nicotinate. CO was also positively associated with appearance and bloom, but not directly associated with pH, size of the bacterial population or with processing plant. Metabolites associated with CO/PO are substrates or products of glucose fermentation and amino acid catabolism.

Costs and Resources Used by Population-based Cancer Registries in the US-Affiliated Pacific Islands.

Background: The costs of cancer registration have previously been estimated for registries in the continental United States and many international registries; however, to date, there has been no economic assessment of population-based registries in the US-Affiliated Pacific Islands. This study estimates the costs and factors affecting the operations of US-Affiliated Pacific Island population-based cancer registries. Methods: The web-based International Registry Costing Tool1 was used to collect costs, resources used, cancer cases processed, and other registry characteristics from the Pacific Regional Central Cancer Registry (PRCCR), Federated States of Micronesia National Cancer Registry, and nine satellite jurisdictional registries within the US Pacific Islands. The registries provided data on costs for June 30, 2016-June 29, 2017, and cases processed during 2014. Results: Local host institutions provided a vital source of support for US-Affiliated Pacific Islands registries, covering substantial fixed costs, such as management and overhead. The cost per cancer case processed had an almost tenfold variation across registries, with the average total cost per case of about $1,413. The average cost per inhabitant in the US-Affiliated Pacific Islands was about $1.77 per person. Discussion: The challenges of collecting data from dispersed populations spread across multiple islands of the US-Affiliated Pacific Islands are likely leading factors driving the magnitude of the registries' cost per case. The economic information from this study provides a valuable source of activity-based cost data that can both help guide cancer control initiatives and help registries improve operations and efficiency.