JURNAL AGROTEKNOLOGI
Not a member yet
63896 research outputs found
Sort by
Heterodinuclear catalysts Zn(II)/M and Mg(II)/M, where M = Na(I), Ca(II) or Cd(II), for phthalic anhydride/cyclohexene oxide ring opening copolymerisation
No full textAnhydride and epoxide ring opening copolymerisation is a useful and controlled route to aliphatic, semi-aromatic and functionalised polyesters. Building upon our prior investigations of synergic Zn(II)/Mg(II) and Mg(II)/Co(II) polymerisation catalysts, here, a series of heterodinuclear catalysts for phthalic anhydride/cyclohexene oxide ROCOP are reported. The complexes feature either Zn(II)/M or Mg(II)/M combinations, where M = Na(I), Ca(II) or Cd(II), and are coordinated by an ‘open’ dinucleating ortho-vanillin derived Schiff-base ligand. The ligand features two binding ‘pockets’: 1) a coordination site comprising diphenolate and dimine moieties and 2) a site featuring diphenolate and diether groups. Heterodinuclear complex syntheses are high yielding due in part to the different coordination chemistries of the binding ‘pockets’. All new complexes are fully characterised including by multi-nuclear NMR spectroscopy and X-ray diffraction experiments; several solid state structures are Lewis base adducts with the crystallisation solvents (THF or acetonitrile) and provide insights into the structures of catalytic cycle intermediates. The catalysts show good performances and quantitative formation of ester linkages. They show equivalent activity to the widely investigated [(salen)Cr(III)Cl]/PPNCl systems (TOF = 67 h−1, 0.1 mol%, 100 °C, 17.6 kg mol−1) but lower activity than previously reported Zn(II)/Mg(II) catalysts or than tethered metal-salen catalysts. All the complexes are less active than the Zn(II)/Zn(II) homodinuclear complex proving that catalytic synergy is not provided only by heterodinuclear complexes with different functions; these findings underscore the need for continued exploration of the factors underpinning synergic heterometallic combinations
Significant performance improvement in n-channel organic field-effect transistors with C60:C70 co-crystals induced by poly(2-ethyl-2-oxazoline) nanodots
No full textSolution-processed organic field-effect transistors (OFETs) have attracted great interest due to their potential as logic devices for bendable and flexible electronics. In relation to n-channel structures, soluble fullerene semiconductors have been widely studied. However, they have not yet met the essential requirements for commercialization, primarily because of low charge carrier mobility, immature large-scale fabrication processes, and insufficient long-term operational stability. Interfacial engineering of the carrier-injecting source/drain (S/D) electrodes has been proposed as an effective approach to improve charge injection, leading also to overall improved device characteristics. Here, it is demonstrated that a non-conjugated neutral dipolar polymer, poly(2-ethyl-2-oxazoline) (PEOz), formed as a nanodot structure on the S/D electrodes, enhances electron mobility in n-channel OFETs using a range of soluble fullerenes. Overall performance is especially notable for (C60-Ih)[5,6]fullerene (C60) and (C70-D5h(6))[5,6]fullerene (C70) blend films, with an increase from 0.1 to 2.1 cm2 V−1 s−1. The high relative mobility and eighteen-fold improvement are attributed not only to the anticipated reduction in S/D electrode work function but also to the beneficial effects of PEOz on the formation of a face-centered-cubic C60:C70 co-crystal structure within the blend films
Discovery and characterization of selective and ligand-efficient DYRK inhibitors
No full textDual-specificity tyrosine-regulated kinase 1A (DYRK1A) regulates the proliferation and differentiation of neuronal progenitor cells during brain development. Consequently, DYRK1A has attracted interest as a target for the treatment of neurodegenerative diseases, including Alzheimer’s disease (AD) and Down’s syndrome. Recently, the inhibition of DYRK1A has been investigated as a potential treatment for diabetes, while DYRK1A’s role as a mediator in the cell cycle has garnered interest in oncologic indications. Structure–activity relationship (SAR) analysis in combination with high-resolution X-ray crystallography leads to a series of pyrazolo[1,5-b]pyridazine inhibitors with excellent ligand efficiencies, good physicochemical properties, and a high degree of selectivity over the kinome. Compound 11 exhibited good permeability and cellular activity without P-glycoprotein liability, extending the utility of 11 in an in vivo setting. These pyrazolo[1,5-b]pyridazines are a viable lead series in the discovery of new therapies for the treatment of diseases linked to DYRK1A function
Phase segregation in mixed-halide perovskites affects charge-carrier dynamics while preserving mobility
No full textMixed halide perovskites can provide optimal bandgaps for tandem solar cells which are key to improved cost-efficiencies, but can still suffer from detrimental illumination-induced phase segregation. Here we employ optical-pump terahertz-probe spectroscopy to investigate the impact of halide segregation on the charge-carrier dynamics and transport properties of mixed halide perovskite films. We reveal that, surprisingly, halide segregation results in negligible impact to the THz charge-carrier mobilities, and that charge carriers within the I-rich phase are not strongly localised. We further demonstrate enhanced lattice anharmonicity in the segregated I-rich domains, which is likely to support ionic migration. These phonon anharmonicity effects also serve as evidence of a remarkably fast, picosecond charge funnelling into the narrow-bandgap I-rich domains. Our analysis demonstrates how minimal structural transformations during phase segregation have a dramatic effect on the charge-carrier dynamics as a result of charge funnelling. We suggest that because such enhanced recombination is radiative, performance losses may be mitigated by deployment of careful light management strategies in solar cells
Bringing seascape ecology to the deep seabed: A review and framework for its application
No full textSeascape ecology is an emerging pattern-oriented and integrative science conceptually linked to landscape ecology. It aims to quantify multidimensional spatial structure in the sea and reveal its ecological consequences. The seascape ecology approach has made important advances in shallow coastal environments, and increasing exploration and mapping of the deep seabed provides opportunities for application in the deep ocean. We argue that seascape ecology, with its integrative and multiscale perspective, can generate new scientific insights at spatial and temporal scales relevant to ecosystem-based management. Seascape ecology provides a conceptual and operational framework that integrates and builds on existing benthic ecology and habitat mapping research by providing additional pattern-oriented concepts, tools and techniques to (1) quantify complex ecological patterns across multiple scales; (2) link spatial patterns to biodiversity and ecological processes; and (3) provide ecologically meaningful information that is operationally relevant to spatial management. This review introduces seascape ecology and provides a framework for its application to deep-seabed environments. Research areas are highlighted where seascape ecology can advance the ecological understanding of deep benthic environments
Burden of disease among the world’s poorest billion people: An expert-informed secondary analysis of Global Burden of Disease estimates
No full textBackground
The health of populations living in extreme poverty has been a long-standing focus of global development efforts, and continues to be a priority during the Sustainable Development Goal era. However, there has not been a systematic attempt to quantify the magnitude and causes of the burden in this specific population for almost two decades. We estimated disease rates by cause for the world’s poorest billion and compared these rates to those in high-income populations.
Methods
We defined the population in extreme poverty using a multidimensional poverty index. We used national-level disease burden estimates from the 2017 Global Burden of Disease Study and adjusted these to account for within-country variation in rates. To adjust for within-country variation, we looked to the relationship between rates of extreme poverty and disease rates across countries. In our main modeling approach, we used these relationships when there was consistency with expert opinion from a survey we conducted of disease experts regarding the associations between household poverty and the incidence and fatality of conditions. Otherwise, no within-country variation was assumed. We compared results across multiple approaches for estimating the burden in the poorest billion, including aggregating national-level burden from the countries with the highest poverty rates. We examined the composition of the estimated disease burden among the poorest billion and made comparisons with estimates for high-income countries.
Results
The composition of disease burden among the poorest billion, as measured by disability-adjusted life years (DALYs), was 65% communicable, maternal, neonatal, and nutritional (CMNN) diseases, 29% non-communicable diseases (NCDs), and 6% injuries. Age-standardized DALY rates from NCDs were 44% higher in the poorest billion (23,583 DALYs per 100,000) compared to high-income regions (16,344 DALYs per 100,000). Age-standardized DALY rates were 2,147% higher for CMNN conditions (32,334 DALYs per 100,000) and 86% higher for injuries (4,182 DALYs per 100,000) in the poorest billion, compared to high-income regions.
Conclusion
The disease burden among the poorest people globally compared to that in high income countries is highly influenced by demographics as well as large disparities in burden from many conditions. The comparisons show that the largest disparities remain in communicable, maternal, neonatal, and nutritional diseases, though NCDs and injuries are an important part of the “unfinished agenda” of poor health among those living in extreme poverty
Ultrasound versus computed tomography assessment of focal lung aeration in invasively ventilated ICU patients
No full textIt is unknown whether and to what extent the penetration depth of lung ultrasound (LUS) influences the accuracy of LUS findings. The current study evaluated and compared the LUS aeration score and two frequently used B-line scores with focal lung aeration assessed by chest computed tomography (CT) at different levels of depth in invasively ventilated intensive care unit (ICU) patients. In this prospective observational study, patients with a clinical indication for chest CT underwent a 12-region LUS examination shortly before CT scanning. LUS images were compared with corresponding regions on the chest CT scan at different subpleural depths. For each LUS image, the LUS aeration score was calculated. LUS images with B-lines were scored as the number of separately spaced B-lines (B-line count score) and the percentage of the screen covered by B-lines divided by 10 (B-line percentage score). The fixed-effect correlation coefficient (β) was presented per 100 Hounsfield units. A total of 40 patients were included, and 372 regions were analyzed. The best association between the LUS aeration score and CT was found at a subpleural depth of 5 cm for all LUS patterns (β = 0.30, p < 0.001), 1 cm for A- and B1-patterns (β = 0.10, p < 0.001), 6 cm for B1- and B2-patterns (β = 0.11, p < 0.001) and 4 cm for B2- and C-patterns (β = 0.07, p = 0.001). The B-line percentage score was associated with CT (β = 0.46, p = 0.001), while the B-line count score was not (β = 0.07, p = 0.305). In conclusion, the subpleural penetration depth of ultrasound increased with decreased aeration reflected by the LUS pattern. The LUS aeration score and the B-line percentage score accurately reflect lung aeration in ICU patients, but should be interpreted while accounting for the subpleural penetration depth of ultrasound
Chinese women’s attitudes towards postpartum interventions to prevent type 2 diabetes after gestational diabetes: a semi-structured qualitative study
No full textBackground
Gestational diabetes (GDM) is a global problem affecting millions of pregnant women, including in mainland China. These women are at high risk of Type II diabetes (T2DM). Cost-effective and clinically effective interventions are needed. We aimed to explore Chinese women’s perspectives, concerns and motivations towards participation in early postpartum interventions and/or research to prevent the development of T2DM after a GDM-affected pregnancy.
Methods
We conducted a qualitative study in two hospitals in Chengdu, Southwest China. Face-to-face semi-structured interviews were conducted with 20 women with recent experience of GDM: 16 postpartum women and 4 pregnant women. Women were asked about their attitudes towards postpartum screening for type 2 diabetes, lifestyle interventions, mHealth delivered interventions and pharmacologic interventions (specifically metformin). An inductive approach to analysis was used. Interviews were recorded, transcribed, and coded using NVivo 12 Pro.
Results
Most women held positive attitudes towards participating in T2DM screening, and were willing to participate in postpartum interventions to prevent T2DM through lifestyle change or mHealth interventions. Women were less likely to agree to pharmacological intervention, unless they had family members with diabetes or needed medication themselves during pregnancy. We identified seven domains influencing women’s attitudes towards future interventions: (1) experiences with the health system during pregnancy; (2) living in an enabling environment; (3) the experience of T2DM in family members; (4) knowledge of diabetes and perception of risk; (5) concerns about personal and baby health; (6) feelings and emotions, and (7) lifestyle constraints. Those with more severe GDM, an enabling environment and health knowledge, and with experience of T2DM in family members expressed more favourable views of postpartum interventions and research participation to prevent T2DM after GDM. Those who perceived themselves as having mild GDM and those with time/lifestyle constraints were less likely to participate.
Conclusions
Women with experiences of GDM in Chengdu are generally willing to participate in early postpartum interventions and/or research to reduce their risk of T2DM, with a preference for non-drug, mHealth based interventions, integrating lifestyle change strategies, blood glucose monitoring, postpartum recovery and mental health
Microbial evolution and transitions along the parasite-mutualist continuum
No full textVirtually all plants and animals, including humans, are home to symbiotic microorganisms. Symbiotic interactions can be neutral, harmful or have beneficial effects on the host organism. However, growing evidence suggests that microbial symbionts can evolve rapidly, resulting in drastic transitions along the parasite–mutualist continuum. In this Review, we integrate theoretical and empirical findings to discuss the mechanisms underpinning these evolutionary shifts, as well as the ecological drivers and why some host–microorganism interactions may be stuck at the end of the continuum. In addition to having biomedical consequences, understanding the dynamic life of microorganisms reveals how symbioses can shape an organism’s biology and the entire community, particularly in a changing world
Systematic literature review of residual symptoms and an unmet need in patients with rheumatoid arthritis
No full textObjective
To evaluate the nature and burden of residual disease in rheumatoid arthritis (RA) in patients who meet treatment targets. Second, for those who did not meet targets, to evaluate how much is due to patient symptoms.
Methods
Prospective and retrospective studies were searched in Medline, Embase, and Cochrane Library in the English language from January 1, 2008 to April 18, 2018; conference abstracts (from January 2016 to April 2018) and reference lists of relevant studies were also screened.
Results
Of 8,339 records identified, 55 were included in the review; 53 were unique studies, including 10 randomized controlled trials. Of these, 48 reported on patients who achieved low disease activity (LDA) or remission. Studies varied in population, treatment goals, and outcome reporting. The proportions of patients with residual symptoms in these studies varied by the definitions used for LDA or remission and were more often reported in patients with LDA than those in remission. The most commonly reported outcome measures were functional disability (n = 34 studies), tender or swollen joints (n = 18), pain (n = 17), patient global assessment (n = 15), and fatigue (n = 14). However, few studies reported the percentage of patients achieving a specific threshold, which could then be used to easily define the presence of residual symptoms.
Conclusion
Residual symptoms are present in some patients despite their achieving LDA or remission, highlighting an unmet need, especially with respect to improving pain, fatigue, and function. Standardized reporting in future observational studies would facilitate better understanding of this issue in defined RA populations