368 research outputs found

    Innovation in crystal engineering

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    The first CrystEngComm discussion meeting on crystal engineering has demonstrated that the field has reached maturity in some areas (for example: design strategies, characterization of solid compounds, topological analysis of weak and strong non-covalent interactions), while the quest for novel properties engineered at molecular and supramolecular levels has only recently begun and the need for further research efforts is strongly felt. This Highlight article aims to provide a forward look and a constructive discussion of the prospects for future developments of crystal engineering as a bridge between supramolecular and molecular materials chemistry

    Keck Hires Observations of the QSO First J104459.6+365605: Evidence for a Large Scale Outflow

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    This paper presents an analysis of a Keck HIRES spectrum of the QSO FIRST J104459.6+365605. The line of sight towards the QSO contains two clusters of outflowing clouds that give rise to broad blue shifted absorption lines. The outflow velocities of the clouds range from -200 to -1200 km/s and from -3400 to -5200 km/s, respectively. The width of the individual absorption lines ranges from 50 to more than 1000 km/s. The most prominent absorption lines are those of Mg II, Mg I, and Fe II. The low ionization absorption lines occur at the same velocities as the most saturated Mg II lines, showing that the Fe II, Mg I and Mg II line forming regions must be closely associated. Many absorption lines from excited states of Fe II are present, allowing a determination of the population of several low lying energy levels. From this we determine an electron density in the Fe II line forming regions of 4000 per cubic cm. Modelling the ionization state of the absorbing gas with this value of the electron density as a constraint, we find that the distance between the Fe II and Mg I line forming region and the continuum source is of order 700 parsec. From the correspondence in velocity between the Fe II, Mg I and Mg II lines we infer that the Mg II lines must be formed at the same distance. The Mg II absorption fulfills the criteria for Broad Absorption Lines defined by Weymann et al. (1991). This large distance is surprising, since BALs are generally thought to be formed in outflows at a much smaller distance from the nucleus.Comment: 34 pages, 11 figures. Accepted by The Astrophysical Journa

    Comparative expression of the extracellular calcium sensing receptor in rat, mouse and human kidney

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    The calcium sensing receptor (CaSR) was cloned over 20 years ago and functionally demonstrated to regulate circulating levels of parathyroid hormone by maintaining physiological serum ionized calcium (Ca2+) concentration. The receptor is highly expressed in the kidney; however, intra-renal and intra-species distribution remains controversial. Recently, additional functions of the CaSR receptor in the kidney have emerged, including parathyroid hormone independent effects. It is therefore critical to establish unequivocally the localization of the CaSR in the kidney in order to relate this to its proposed physiological roles. In this study we determined CaSR expression in mouse, rat and human kidney using in situ hybridisation, immunohistochemistry (using eight different commercially available and custom-made antibodies) and proximity ligation assays. Both in situ hybridisation and immunohistochemistry showed CaSR expression in the thick ascending limb, distal tubule and collecting duct of all species, with the thick ascending limb showing the highest levels. Within the collecting ducts there was significant heterogeneity of expression between cell types. In the proximal tubule, lower levels of immunoreactivity were detected by immunohistochemistry and proximity ligation assays. Proximity ligation assays were the only technique to demonstrate expression within glomeruli. This study demonstrated CaSR expression throughout the kidney with minimal discrepancy between species but with significant variation in the levels of expression between cell and tubule types. These findings clarify the intra-renal distribution of the CaSR and enable elucidation of the full physiological roles of the receptor within this organ

    Use of name recognition software, census data and multiple imputation to predict missing data on ethnicity: application to cancer registry records

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    <p>Abstract</p> <p>Background</p> <p>Information on ethnicity is commonly used by health services and researchers to plan services, ensure equality of access, and for epidemiological studies. In common with other important demographic and clinical data it is often incompletely recorded. This paper presents a method for imputing missing data on the ethnicity of cancer patients, developed for a regional cancer registry in the UK.</p> <p>Methods</p> <p>Routine records from cancer screening services, name recognition software (Nam Pehchan and Onomap), 2001 national Census data, and multiple imputation were used to predict the ethnicity of the 23% of cases that were still missing following linkage with self-reported ethnicity from inpatient hospital records.</p> <p>Results</p> <p>The name recognition software were good predictors of ethnicity for South Asian cancer cases when compared with data on ethnicity derived from hospital inpatient records, especially when combined (sensitivity 90.5%; specificity 99.9%; PPV 93.3%). Onomap was a poor predictor of ethnicity for other minority ethnic groups (sensitivity 4.4% for Black cases and 0.0% for Chinese/Other ethnic groups). Area-based data derived from the national Census was also a poor predictor non-White ethnicity (sensitivity: South Asian 7.4%; Black 2.3%; Chinese/Other 0.0%; Mixed 0.0%).</p> <p>Conclusions</p> <p>Currently, neither method for assigning individuals to an ethnic group (name recognition and ethnic distribution of area of residence) performs well across all ethnic groups. We recommend further development of name recognition applications and the identification of additional methods for predicting ethnicity to improve their precision and accuracy for comparisons of health outcomes. However, real improvements can only come from better recording of ethnicity by health services.</p

    Patient-Relevant Outcomes Following First Revision Total Knee Arthroplasty, by Diagnosis: An Analysis of Implant Survivorship, Mortality, Serious Medical Complications, and Patient-Reported Outcome Measures Utilizing the National Joint Registry Data Set.

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    BackgroundThe purpose of this study was to investigate patient-relevant outcomes following first revision total knee arthroplasties (rTKAs) performed for different indications.MethodsThis population-based cohort study utilized data from the United Kingdom National Joint Registry, Hospital Episode Statistics Admitted Patient Care, National Health Service Patient-Reported Outcome Measures, and the Civil Registrations of Death. Patients undergoing a first rTKA between January 1, 2009, and June 30, 2019, were included in our data set. Patient-relevant outcomes included implant survivorship (up to 11 years postoperatively), mortality and serious medical complications (up to 90 days postoperatively), and patient-reported outcome measures (at 6 months postoperatively).ResultsA total of 24,540 first rTKAs were analyzed. The patient population was 54% female and 62% White, with a mean age at the first rTKA of 69 years. At 2 years postoperatively, the cumulative incidence of re-revision surgery ranged from 2.7% (95% confidence interval [CI], 1.9% to 3.4%) following rTKA for progressive arthritis to 16.3% (95% CI, 15.2% to 17.4%) following rTKA for infection. The mortality rate at 90 days was highest following rTKA for fracture (3.6% [95% CI, 2.5% to 5.1%]) and for infection (1.8% [95% CI, 1.5% to 2.2%]) but was ConclusionsThis study found large differences in patient-relevant outcomes among different indications for first rTKA. The rate of complications was highest following rTKA for fracture or infection. Although rTKA resulted in large improvements in joint function for most patients, those who underwent surgery for stiffness and unexplained pain had worse outcomes.Level of evidenceTherapeutic Level III. See Instructions for Authors for a complete description of levels of evidence

    Polymorphisms in Plasmodium falciparum chloroquine resistance transporter and multidrug resistance 1 genes: parasite risk factors that affect treatment outcomes for P. falciparum malaria after artemether-lumefantrine and artesunate-amodiaquine.

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    Adequate clinical and parasitologic cure by artemisinin combination therapies relies on the artemisinin component and the partner drug. Polymorphisms in the Plasmodium falciparum chloroquine resistance transporter (pfcrt) and P. falciparum multidrug resistance 1 (pfmdr1) genes are associated with decreased sensitivity to amodiaquine and lumefantrine, but effects of these polymorphisms on therapeutic responses to artesunate-amodiaquine (ASAQ) and artemether-lumefantrine (AL) have not been clearly defined. Individual patient data from 31 clinical trials were harmonized and pooled by using standardized methods from the WorldWide Antimalarial Resistance Network. Data for more than 7,000 patients were analyzed to assess relationships between parasite polymorphisms in pfcrt and pfmdr1 and clinically relevant outcomes after treatment with AL or ASAQ. Presence of the pfmdr1 gene N86 (adjusted hazards ratio = 4.74, 95% confidence interval = 2.29 - 9.78, P < 0.001) and increased pfmdr1 copy number (adjusted hazards ratio = 6.52, 95% confidence interval = 2.36-17.97, P < 0.001 : were significant independent risk factors for recrudescence in patients treated with AL. AL and ASAQ exerted opposing selective effects on single-nucleotide polymorphisms in pfcrt and pfmdr1. Monitoring selection and responding to emerging signs of drug resistance are critical tools for preserving efficacy of artemisinin combination therapies; determination of the prevalence of at least pfcrt K76T and pfmdr1 N86Y should now be routine

    Mechanistic insight into the pathology of polyalanine expansion disorders revealed by a mouse model for x linked hypopituitarism

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    Extent: 9 p.Polyalanine expansions in transcription factors have been associated with eight distinct congenital human diseases. It is thought that in each case the polyalanine expansion causes misfolding of the protein that abrogates protein function. Misfolded proteins form aggregates when expressed in vitro; however, it is less clear whether aggregation is of relevance to these diseases in vivo. To investigate this issue, we used targeted mutagenesis of embryonic stem (ES) cells to generate mice with a polyalanine expansion mutation in Sox3 (Sox3-26ala) that is associated with X-linked Hypopituitarism (XH) in humans. By investigating both ES cells and chimeric mice, we show that endogenous polyalanine expanded SOX3 does not form protein aggregates in vivo but rather is present at dramatically reduced levels within the nucleus of mutant cells. Importantly, the residual mutant protein of chimeric embryos is able to rescue a block in gastrulation but is not sufficient for normal development of the hypothalamus, a region that is functionally compromised in Sox3 null embryos and individuals with XH. Together, these data provide the first definitive example of a disease-relevant PA mutant protein that is both nuclear and functional, thereby manifesting as a partial loss-of-function allele.James Hughes Sandra Piltz, Nicholas Rogers, Dale McAninch, Lynn Rowley and Paul Thoma

    Impaired Mineral Ion Metabolism in a Mouse Model of Targeted Calcium-Sensing Receptor (CaSR) Deletion from Vascular Smooth Muscle Cells

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    Background Impaired mineral ion metabolism is a hallmark of CKD–metabolic bone disorder. It can lead to pathologic vascular calcification and is associated with an increased risk of cardiovascular mortality. Loss of calcium-sensing receptor (CaSR) expression in vascular smooth muscle cells exacerbates vascular calcification in vitro. Conversely, vascular calcification can be reduced by calcimimetics, which function as allosteric activators of CaSR. Methods To determine the role of the CaSR in vascular calcification, we characterized mice with targeted Casr gene knockout in vascular smooth muscle cells (SM22αCaSRΔflox/Δflox). Results Vascular smooth muscle cells cultured from the knockout (KO) mice calcified more readily than those from control (wild-type) mice in vitro. However, mice did not show ectopic calcifications in vivo but they did display a profound mineral ion imbalance. Specifically, KO mice exhibited hypercalcemia, hypercalciuria, hyperphosphaturia, and osteopenia, with elevated circulating fibroblast growth factor 23 (FGF23), calcitriol (1,25-D3), and parathyroid hormone levels. Renal tubular α-Klotho protein expression was increased in KO mice but vascular α-Klotho protein expression was not. Altered CaSR expression in the kidney or the parathyroid glands could not account for the observed phenotype of the KO mice. Conclusions These results suggest that, in addition to CaSR’s established role in the parathyroid-kidney-bone axis, expression of CaSR in vascular smooth muscle cells directly contributes to total body mineral ion homeostasis
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