Case study on user knowledge and design knowledge in product form design

2003-2004 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Biosensor Based on Ultrasmall MoS2 Nanoparticles for Electrochemical Detection of H2O2 Released by Cells at the Nanomolar Level

Monodispersed surfactant-free MoS2 nanoparticles with sizes of less than 2 nm were prepared from bulk MoS2 by simple ultrasonication and gradient centrifugation. The ultrasmall MoS2 nanoparticles expose a large fraction of edge sites, along with their high surface area, which lead to attractive electrocatalytic activity for reduction of H2O2. An extremely sensitive H2O2 biosensor based on MoS2 nanoparticles with a real determination limit as low as 2.5 nM and wide linear range of 5 orders of magnitude was constructed. On the basis of this biosensor, the trace amount of H2O2 released from Raw 264.7 cells was successfully recorded, and an efficient glucose biosensor was also fabricated. Since H2O2 is a byproduct of many oxidative biological reactions, this work serves as a pathway for the application of MoS2 in the fields of electrochemical sensing and bioanalysis.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000326711400047&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Chemistry, AnalyticalSCI(E)EIPubMed75ARTICLE2110289-102958

Expression of a diverse array of Ca²⁺-activated K⁺ channels (SK1/3, IK1, BK) that functionally couple to the mechanosensitive TRPV4 channel in the collecting duct system of kidney

The voltage- and Ca2+-activated, large conductance K+ channel (BK, maxi-K) is expressed in the collecting duct system of kidney where it underlies flow- and Ca2+-dependent K+ excretion. To determine if other Ca2+-activated K+ channels (KCa) may participate in this process, mouse kidney and the K+-secreting mouse cortical collecting duct (CCD) cell line, mCCDcl1, were assessed for TRPV4 and KCa channel expression and cross-talk. qPCR mRNA analysis and immunocytochemical staining demonstrated TRPV4 and KCa expression in mCCDcl1 cells and kidney connecting tubule (CNT) and CCD. Three subfamilies of KCa channels were revealed: the high Ca2+-binding affinity small-conductance SK channels, SK1and SK3, the intermediate conductance channel, IK1, and the low Ca2+-binding affinity, BK channel (BKα subunit). Apparent expression levels varied in CNT/CCD where analysis of CCD principal cells (PC) and intercalated cells (IC) demonstrated differential staining: SK1:PCIC, IK1:PC>IC, BKα:PC = IC, and TRPV4:PC>IC. Patch clamp analysis and fluorescence Ca2+ imaging of mCCDcl1 cells demonstrated potent TRPV4-mediated Ca2+ entry and strong functional cross-talk between TRPV4 and KCa channels. TRPV4-mediated Ca2+ influx activated each KCa channel, as evidenced by selective inhibition of KCa channels, with each active KCa channel enhancing Ca2+ entry (due to membrane hyperpolarization). Transepithelial electrical resistance (TEER) analysis of confluent mCCDcl1 cells grown on permeable supports further demonstrated this cross-talk where TRPV4 activation induce a decrease in TEER which was partially restored upon selective inhibition of each KCa channel. It is concluded that SK1/SK3 and IK1 are highly expressed along with BKα in CNT and CCD and are closely coupled to TRPV4 activation as observed in mCCDcl1 cells. The data support a model in CNT/CCD segments where strong cross talk between TRPV4-mediated Ca2+ influx and each KCa channel leads to enhance Ca2+ entry which will support activation of the low Ca2+-binding affinity BK channel to promote BK-mediated K+ secretion

Use of moxibustion to treat primary dysmenorrhea at two interventional times: study protocol for a randomized controlled trial

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The TRPV5/6 calcium channels contain multiple calmodulin binding sites with differential binding properties

The epithelial Ca2+ channels TRPV5/6 (transient receptor potential vanilloid 5/6) are thoroughly regulated in order to fine-tune the amount of Ca2+ reabsorption. Calmodulin has been shown to be involved into calcium-dependent inactivation of TRPV5/6 channels by binding directly to the distal C-terminal fragment of the channels (de Groot et al. in Mol Cell Biol 31:2845–2853, 12). Here, we investigate this binding in detail and find significant differences between TRPV5 and TRPV6. We also identify and characterize in vitro four other CaM binding fragments of TRPV5/6, which likely are also involved in TRPV5/6 channel regulation. The five CaM binding sites display diversity in binding modes, binding stoichiometries and binding affinities, which may fine-tune the response of the channels to varying Ca2+-concentrations

Observation of a ppb mass threshoud enhancement in \psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p}) decay

The decay channel $\psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p})$ is studied using a sample of $1.06\times 10^8$ $\psi^\prime$ events collected by the BESIII experiment at BEPCII. A strong enhancement at threshold is observed in the $p\bar{p}$ invariant mass spectrum. The enhancement can be fit with an $S$-wave Breit-Wigner resonance function with a resulting peak mass of $M=1861^{+6}_{-13} {\rm (stat)}^{+7}_{-26} {\rm (syst)} {\rm MeV/}c^2$ and a narrow width that is $\Gamma<38 {\rm MeV/}c^2$ at the 90% confidence level. These results are consistent with published BESII results. These mass and width values do not match with those of any known meson resonance.Comment: 5 pages, 3 figures, submitted to Chinese Physics

Patient-reported outcome measures for monitoring primary care patients with depression: the PROMDEP cluster RCT and economic evaluation.

BACKGROUND: Guidelines on the management of depression recommend that practitioners use patient-reported outcome measures for the follow-up monitoring of symptoms, but there is a lack of evidence of benefit in terms of patient outcomes. OBJECTIVE: To test using the Patient Health Questionnaire-9 questionnaire as a patient-reported outcome measure for monitoring depression, training practitioners in interpreting scores and giving patients feedback. DESIGN: Parallel-group, cluster-randomised superiority trial; 1 : 1 allocation to intervention and control. SETTING: UK primary care (141 group general practices in England and Wales). INCLUSION CRITERIA: Patients aged ≥ 18 years with a new episode of depressive disorder or symptoms, recruited mainly through medical record searches, plus opportunistically in consultations. EXCLUSIONS: Current depression treatment, dementia, psychosis, substance misuse and risk of suicide. INTERVENTION: Administration of the Patient Health Questionnaire-9 questionnaire with patient feedback soon after diagnosis, and at follow-up 10-35 days later, compared with usual care. PRIMARY OUTCOME: Beck Depression Inventory, 2nd edition, symptom scores at 12 weeks. SECONDARY OUTCOMES: Beck Depression Inventory, 2nd edition, scores at 26 weeks; antidepressant drug treatment and mental health service contacts; social functioning (Work and Social Adjustment Scale) and quality of life (EuroQol 5-Dimension, five-level) at 12 and 26 weeks; service use over 26 weeks to calculate NHS costs; patient satisfaction at 26 weeks (Medical Informant Satisfaction Scale); and adverse events. SAMPLE SIZE: The original target sample of 676 patients recruited was reduced to 554 due to finding a significant correlation between baseline and follow-up values for the primary outcome measure. RANDOMISATION: Remote computerised randomisation with minimisation by recruiting university, small/large practice and urban/rural location. BLINDING: Blinding of participants was impossible given the open cluster design, but self-report outcome measures prevented observer bias. Analysis was blind to allocation. ANALYSIS: Linear mixed models were used, adjusted for baseline depression, baseline anxiety, sociodemographic factors, and clustering including practice as random effect. Quality of life and costs were analysed over 26 weeks. QUALITATIVE INTERVIEWS: Practitioner and patient interviews were conducted to reflect on trial processes and use of the Patient Health Questionnaire-9 using the Normalization Process Theory framework. RESULTS: Three hundred and two patients were recruited in intervention arm practices and 227 patients were recruited in control practices. Primary outcome data were collected for 252 (83.4%) and 195 (85.9%), respectively. No significant difference in Beck Depression Inventory, 2nd edition, score was found at 12 weeks (adjusted mean difference -0.46, 95% confidence interval -2.16 to 1.26). Nor were significant differences found in Beck Depression Inventory, 2nd Edition, score at 26 weeks, social functioning, patient satisfaction or adverse events. EuroQol-5 Dimensions, five-level version, quality-of-life scores favoured the intervention arm at 26 weeks (adjusted mean difference 0.053, 95% confidence interval 0.013 to 0.093). However, quality-adjusted life-years over 26 weeks were not significantly greater (difference 0.0013, 95% confidence interval -0.0157 to 0.0182). Costs were lower in the intervention arm but, again, not significantly (-£163, 95% confidence interval -£349 to £28). Cost-effectiveness and cost-utility analyses, therefore, suggested that the intervention was dominant over usual care, but with considerable uncertainty around the point estimates. Patients valued using the Patient Health Questionnaire-9 to compare scores at baseline and follow-up, whereas practitioner views were more mixed, with some considering it too time-consuming. CONCLUSIONS: We found no evidence of improved depression management or outcome at 12 weeks from using the Patient Health Questionnaire-9, but patients' quality of life was better at 26 weeks, perhaps because feedback of Patient Health Questionnaire-9 scores increased their awareness of improvement in their depression and reduced their anxiety. Further research in primary care should evaluate patient-reported outcome measures including anxiety symptoms, administered remotely, with algorithms delivering clear recommendations for changes in treatment. STUDY REGISTRATION: This study is registered as IRAS250225 and ISRCTN17299295. FUNDING: This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 17/42/02) and is published in full in Health Technology Assessment; Vol. 28, No. 17. See the NIHR Funding and Awards website for further award information

Depression follow-up monitoring with the PHQ-9: open cluster-randomised controlled trial.

BACKGROUND: Outcome monitoring of depression is recommended but lacks evidence of patient benefit in primary care. AIM: To test monitoring depression using the PHQ-9 questionnaire with patient feedback. DESIGN AND SETTING: Open cluster-randomised controlled trial in 141 group practices. METHOD: Adults with new depressive episodes were recruited through records searches and opportunistically. EXCLUSION CRITERIA: dementia, psychosis, substance misuse, suicide risk. The PHQ-9 questionnaire was to be administered soon after diagnosis, and 10-35 days later. PRIMARY OUTCOME: Beck Depression Inventory (BDI-II) score at 12 weeks. SECONDARY OUTCOMES: BDI-II at 26 weeks; Work and Social Adjustment Scale and EuroQol EQ-5D-5L quality of life at 12 and 26 weeks; antidepressant treatment, mental health service use, adverse events, and Medical Informant Satisfaction Scale over 26 weeks. RESULTS: 302 intervention arm patients were recruited and 227 controls. At 12 weeks 252 (83.4%) and 195 (85.9%) were followed-up respectively. Only 41% of intervention arm patients had a GP follow-up PHQ-9 recorded. There was no significant difference in BDI-II score at 12 weeks (mean difference -0.46; 95% CI -2.16,1.26), adjusted for baseline depression, baseline anxiety, sociodemographic factors, and clustering by practice). EQ-5D-5L quality of life scores were higher in the intervention arm at 26 weeks (adjusted mean difference 0.053; 95% CI 0.093,0.013). A clinically significant difference in depression at 26 weeks could not be ruled out. No significant differences were found in social functioning, adverse events, or satisfaction. In a per-protocol analysis, antidepressant use and mental health contacts were significantly greater in intervention arm patients with a recorded follow-up PHQ-9. CONCLUSIONS: No evidence was found of improved depression outcome at 12 weeks from monitoring. The findings of possible benefits over 26 weeks warrant replication, investigating possible mechanisms, preferably with automated delivery of monitoring and more instructive feedback

Functional stacking of three resistance genes against Phytophthora infestans in potato

Functional stacking of broad spectrum resistance (R) genes could potentially be an effective strategy for more durable disease resistance, for example, to potato late blight caused by Phytophthora infestans (Pi). For this reason, three broad spectrum potato R genes (Rpi), Rpi-sto1 (Solanum stoloniferum), Rpi-vnt1.1 (S. venturii) and Rpi-blb3 (S. bulbocastanum) were selected, combined into a single binary vector pBINPLUS and transformed into the susceptible cultivar Desiree. Among the 550 kanamycin resistant regenerants, 28 were further investigated by gene specific PCRs. All regenerants were positive for the nptII gene and 23 of them contained the three Rpi genes, referred to as triple Rpi gene transformants. Detached leaf assay and agro-infiltration of avirulence (Avr) genes showed that the 23 triple Rpi gene transformants were resistant to the selected isolates and showed HR with the three Avr effectors indicating functional stacking of all the three Rpi genes. It is concluded that Avr genes, corresponding to the R genes to be stacked, must be available in order to assay for functionality of each stack component. No indications were found for silencing or any other negative effects affecting the function of the inserted Rpi genes. The resistance spectrum of these 23 triple Rpi gene transformants was, as expected, a sum of the spectra from the three individual Rpi genes. This is the first example of a one-step approach for the simultaneous domestication of three natural R genes against a single disease by genetic transformation