Residue analytical method for the determination of trifluoroacetic acid and difluoroacetic acid in plant matrices by capillary electrophoresis tandem mass spectrometry (CE-MS/MS).

In the past years, the technology for trace residue analysis of plant protection compounds in plant and animal matrices, soil, and water has gradually changed to meet changing regulatory demands. Generally, from the '70s to the '90s of the last century, the active compounds and only a few major metabolites had to be determined in a typical "residue definition". Step by step and within the framework of product safety assessments of the enforcement of residues in dietary matrices and in the environment, further metabolites have come into the authorities focus. Many active substances were formerly determined via gas chromatography (GC) based detection techniques. The introduction of liquid chromatography tandem mass spectrometry (LC-MS/MS) technology in the '90s and the acceptance of this technique, by official bodies at the end of the '90s, has led to a major change for residue analytical laboratories all over the world. Most of the medium to non-polar active compounds as well as many of the more polar metabolites can be detected with this technique, and today LC-MS/MS is the "workhorse" in many residue analytical laboratories in the industry as well as official enforcement labs responsible for analyzing registration-related field studies. With the demand to analyze further breakdown products, more and more polar compounds, or even (permanently) charged target compounds, have now come into the focus of the registration authorities. This now brings standard LC-based techniques to their limits and requires the application of approaches such as hydrophilic interaction chromatography (HILIC) MS/MS or ion chromatography, however these techniques often incur related uncertainties and problems with matrix samples. The aim of this study was to develop a new CE-MS/MS-based approach to reduce the impact of matrix on the separation and detection of trifluoroacetic acid (TFA) and difluoroacetic acid (DFA) in agrochemical field trials. This project used 7 representative examples of fruit, grain and vegetables which had undergone homogenization and extraction with acetonitrile water and filtration before CE-MS/MS analysis. The CE-MS/MS developed reached the limit of quantitation (LOQ) requirement of current legislation for both TFA and DFA (0.01 mg/kg) in all 7 matrices tested. The mean relative standard deviation (RSD) obtained from the repeat analysis of control field trail samples in all matrices, for both TFA and DFA, was less than 10% meeting GLP guidelines. When compared with LC-MS/MS, using on column loading amounts, the CE-MS/MS was 17 - 43 times more sensitive than a standard method and less matrix effects were observed. The developed method was validated under GLP conditions to provide a GLP-validated residue analytical method for the charged metabolites TFA and DFA in matrix samples from GLP field residue trials.

Facilitators and Barriers to Post-partum Diabetes Screening Among Mothers With a History of Gestational Diabetes Mellitus-A Qualitative Study From Singapore.

Introduction: Gestational Diabetes Mellitus (GDM) affects one in six births worldwide. Mothers with GDM have an increased risk of developing post-partum Type-2 Diabetes Mellitus (T2DM). However, their uptake of post-partum diabetes screening is suboptimal, including those in Singapore. Literature reports that the patient-doctor relationship, mothers' concerns about diabetes, and family-related practicalities are key factors influencing the uptake of such screening. However, we postulate additional factors related to local society, healthcare system, and policies in influencing post-partum diabetes screening among mothers with GDM. Aim: The qualitative research study aimed to explore the facilitators and barriers to post-partum diabetes screening among mothers with GDM in an Asian community. Methods: In-depth interviews were carried out on mothers with GDM at a public primary care clinic in Singapore. Mothers were recruited from those who brought their child for vaccination appointments and their informed consent was obtained. Both mothers who completed post-partum diabetes screening within 12 weeks after childbirth and those who did not were purposively recruited. The social ecological model (SEM) provides the theoretical framework to identify facilitators and barriers at the individual, interpersonal, organizational, and policy levels. Results: Twenty multi-ethnic Asian mothers with GDM were interviewed. At the individual and interpersonal level, self-perceived risk of developing T2DM, understanding the need for screening and the benefits of early diagnosis, availability of confinement nanny in Chinese family, alternate caregivers, emotional, and peer support facilitated post-partum diabetes screening. Barriers included fear of the diagnosis and its consequences, preference for personal attention and care to child, failure to find trusted caregiver, competing priorities, and unpleasant experiences with the oral glucose tolerance test. At the organizational and public policy level, bundling of scheduled appointments, and standardization of procedure eased screening but uptake was hindered by inconvenient testing locations, variable post-partum care practices and advice in the recommendations for diabetes screening. Conclusion: Based on the SEM, facilitators and barriers towards post-partum diabetes screening exist at multiple levels, with some contextualized to local factors. Interventions to improve its uptake should be multi-pronged, targeting not only at personal but also familial, health system, and policy factors to ensure higher level of success.

Physical property and gas transport studies of ultrathin polysulfone membrane from 298.15 to 328.15 K and 2 to 50 bar: atomistic molecular simulation and empirical modelling.

Elucidation of ultrathin polymeric membrane at the laboratory scale is complicated at different operating conditions due to limitation of instruments to obtain in situ measurement data of membrane physical properties. This is essential since their effects are reversible. In addition, tedious experimental work is required to collect gas transport data at varying operating conditions. Recently, we have proposed a validated Soft Confining Methodology for Ultrathin Films that can be used to simulate ultrathin polysulfone (PSF) membranes upon confinement limited to 308.15 K and 2 bars. In industry application, these ultrathin membranes are operated within 298.15-328.15 K and up to 50 bars. Therefore, our proposed methodology using computational chemistry has been adapted to circumvent limitation in experimental study by simulating ultrathin PSF membranes upon confinement at different operating temperatures (298.15 to 328.15 K) and pressures (2 to 50 bar). The effect of operating parameters towards non-bonded and potential energy, free volume, specific volume and gas transport data (e.g. solubility and diffusivity) for oxygen and nitrogen of the ultrathin films has been simulated and collected using molecular simulation. Our previous empirical equations that have been confined to thickness dependent gas transport properties have been modified to accommodate the effect of operating parameters. The empirical equations are able to provide a good quantitative characterization with R 2 ≥ 0.99 consistently, and are able to be interpolated to predict gas transport properties within the range of operating conditions. The modified empirical model can be utilized in process optimization studies to determine optimal membrane design for typical membrane specifications and operating parameters used in industrial applications.

Mathematical modelling of thickness and temperature dependent physical aging to O2/N2 gas separation in polymeric membranes.

Polymeric membranes are glassy materials at non-equilibrium state and inherently undergo a spontaneous evolution towards equilibrium known as physical aging. Volume relaxation characteristic during the course of aging is governed by the surrounding temperature in which the polymeric material is aged. Although there are studies to understand how polymeric materials evolve over time towards equilibrium at different operating temperatures, the theories have been developed merely in response to experimental observations and phenomenological theory at bulk glassy state without the implementation of sample size effects. Limited work has been done to characterize the physical aging process to thin polymeric films using reasonable physical parameters and mathematical models with incorporation of thermodynamics and film thickness consideration. The current work applies the Tait equation of states and thickness dependent glass transition temperature, integrated within a simple linear correlation, to model the temperature and thickness dependent physical aging. The mathematical model has been validated with experimental aging data, whereby a small deviation is observed that has been explained by intuitive reasoning pertaining to the thermodynamic parameters. The mathematical model has been further employed to study the gas transport properties of O2 and N2, which is anticipated to be applied in oxygen enriched combustion for generation of cleaner and higher efficiency fuel in future work.

PORTAF - postoperative radiotherapy of non-small cell lung cancer: accelerated versus conventional fractionation - study protocol for a randomized controlled trial.

BACKGROUND: In early-stage non-small cell lung cancer (NSCLC) without affected lymph nodes detected at staging, surgical resection is still the mainstay of treatment. However, in patients with metastatic mediastinal lymph nodes (pN2) or non-radically resected primary tumors (R1/R2), postoperative radiotherapy (possibly combined with chemotherapy) is indicated. So far, investigations about time factors affecting postoperative radiotherapy have only examined the waiting time defined as interval between surgery and start of radiotherapy, but not the overall treatment time (OTT) itself. Conversely, results from trials on primary radio(chemo)therapy in NSCLC show that longer OTT correlates with significantly worse local tumor control and overall survival rates. This time factor of primary radio(chemo)therapy is thought to mainly be based on repopulation of surviving tumor cells between irradiation fractions. It remains to be elucidated if such an effect also occurs when patients with NSCLC are treated with postoperative radiotherapy after surgery (and chemotherapy). Our own retrospective data suggest an advantage of shorter OTT also for postoperative radiotherapy in this patient group. METHODS/DESIGN: This is a multicenter, prospective randomized trial investigating whether an accelerated course of postoperative radiotherapy with photons or protons (7 fractions per week, 2 Gy fractions) improves locoregional tumor control in NSCLC patients in comparison to conventional fractionation (5 fractions per week, 2 Gy fractions). Target volumes and total radiation doses will be stratified in both treatment arms based on individual risk factors. DISCUSSION: For the primary endpoint of the study we postulate an increase in local tumor control from 70% to 85% after 36 months. Secondary endpoints are overall survival of patients; local recurrence-free and distant metastases-free survival after 36 months; acute and late toxicity and quality of life for both treatment methods. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02189967 . Registered on 22 May 2014.

Delayed insemination of nonestrous cows improves pregnancy rates when using sex-sorted semen in timed artificial insemination of suckled beef cows.

This experiment was designed to test the hypothesis that delayed insemination of nonestrous cows would increase pregnancy rates when using sex-sorted semen in conjunction with fixed-time artificial insemination (FTAI). Estrus was synchronized for 656 suckled beef cows with the 7-d CO-Synch + controlled internal drug release (CIDR) protocol (100 µg GnRH + CIDR [1.38 g progesterone] on d 0, 25 mg PGF2α at CIDR removal on d 7, and 100 µg GnRH on d 10, 66 h after CIDR removal). Estrus detection aids (Estrotect) were applied at PGF2α and CIDR removal on d 7, and estrous expression was recorded at GnRH on d 10. Cows were assigned to 1 of 3 treatments: 1) FTAI (concurrent with GnRH, 66 h after CIDR removal) with conventional semen regardless of estrous expression, 2) FTAI with sex-sorted semen regardless of estrous expression, or 3) FTAI with sex-sorted semen for cows having expressed estrus and delayed AI 20 h after final GnRH for cows failing to express estrus. A treatment × estrous expression interaction was found (P < 0.0001). Higher pregnancy rates (P < 0.0001) were achieved with conventional semen (Treatment 1; 77%) than with sex-sorted semen (Treatments 2 and 3; 51 and 42%, respectively) among cows that expressed estrus. However, among cows that failed to express estrus, delayed insemination with sex-sorted semen yielded higher (P < 0.0001) pregnancy rates than with sex-sorted semen at the standard time (Treatments 2 and 3; 3 versus 36%, respectively). Furthermore, among cows that failed to express estrus, FTAI pregnancy rates when using sex-sorted semen at the delayed time (36%) were comparable (P = 0.9) to those achieved using conventional semen at the standard time (Treatment 1; 37%). These results indicate that delaying AI of nonestrous cows by 20 h from the standard FTAI improves pregnancy rates when sex-sorted semen is used with FTAI.

Potential clinical predictors of outcome after postoperative radiotherapy of non-small cell lung cancer.

AIM: The aim of this analysis was to investigate the impact of tumour-, treatment- and patient-related cofactors on local control and survival after postoperative adjuvant radiotherapy in patients with non-small cell lung cancer (NSCLC), with special focus on waiting and overall treatment times. PATIENTS AND METHODS: For 100 NSCLC patients who had received postoperative radiotherapy, overall, relapse-free and metastases-free survival was retrospectively analysed using Kaplan-Meier methods. The impact of tumour-, treatment- and patient-related cofactors on treatment outcome was evaluated in uni- and multivariate Cox regression analysis. RESULTS: No statistically significant difference between the survival curves of the groups with a short versus a long time interval between surgery and radiotherapy could be shown in uni- or multivariate analysis. Multivariate analysis revealed a significant decrease in overall survival times for patients with prolonged overall radiotherapy treatment times exceeding 42 days (16 vs. 36 months) and for patients with radiation-induced pneumonitis (8 vs. 29 months). CONCLUSION: Radiation-induced pneumonitis and prolonged radiation treatment times significantly reduced overall survival after adjuvant radiotherapy in NSCLC patients. The negative impact of a longer radiotherapy treatment time could be shown for the first time in an adjuvant setting. The hypothesis of a negative impact of longer waiting times prior to commencement of adjuvant radiotherapy could not be confirmed.

Hot topic: Comparison of sex-sorted and conventional semen within a fixed-time artificial insemination protocol designed for dairy heifers.

The objective was to compare pregnancy per AI (P/AI) with conventional (CON) or sex-sorted (SS) semen from a single sire within a fixed-time AI (FTAI) program designed for dairy heifers. Holstein heifers (n=240) were assigned to treatment (CON or SS) according to body weight and reproductive tract score. All heifers underwent FTAI by using the "Show-Me-Synch" protocol [controlled internal drug release (CIDR) insert from d 0 to 14 followed by PGF(2α) (25mg i.m.) 16d after insert removal (d 30) with GnRH (100 µg i.m.) and FTAI at 66 h after PGF(2α)]. A single professional technician performed the FTAI. Heifers were fitted with heat detection patches at PGF(2α) to characterize estrous response. Estrous response did not differ between CON (63/120; 53%) and SS (70/120; 58%) treatments. The CON heifers, however, achieved greater FTAI P/AI (82/120; 68%) compared with SS (45/120; 38%) heifers. The P/AI did not differ for CON heifers that exhibited or failed to exhibit estrus before FTAI [44/63 (70%) vs. 38/57(67%), respectively]. For SS heifers, however, those that exhibited estrus had greater P/AI compared with those that failed to exhibit estrus [32/70 (46%) vs. 13/50 (26%)]. Pregnancy per AI resulting from FTAI was greater for heifers that were inseminated with CON semen compared with those that received SS semen. The expression of estrus before FTAI did not affect P/AI when CON semen was used, whereas the P/AI with SS semen was greater for heifers detected in estrus. Further studies are required to develop strategies for using sex-sorted semen when inseminating heifers at predetermined fixed times on the basis of expression of estrus before FTAI.

Fracture liaison services for the evaluation and management of patients with osteoporotic fracture: a cost-effectiveness evaluation based on data collected over 8 years of service provision.

SUMMARY: The cost-effectiveness of Fracture Liaison Services (FLSs) for prevention of secondary fracture in osteoporosis patients in the United Kingdom (UK), and the cost associated with their widespread adoption, were evaluated. An estimated 18 fractures were prevented and £21,000 saved per 1,000 patients. Setup across the UK would cost an estimated £9.7 million. INTRODUCTION: Only 11% to 28% of patients with a fragility fracture receive osteoporosis treatment in the UK. FLSs provide an efficient means to identify patients and are endorsed by the Department of Health but have not been widely adopted. The objective of this study was to evaluate the cost-effectiveness of FLSs in the UK and the cost associated with their widespread adoption. METHODS: A cost-effectiveness and budget-impact model was developed, utilising detailed audit data collected by the West Glasgow FLS. RESULTS: For a hypothetical cohort of 1,000 fragility-fracture patients (740 requiring treatment), 686 received treatment in the FLS compared with 193 in usual care. Assessments and osteoporosis treatments cost an additional £83,598 and £206,544, respectively, in the FLS; 18 fractures (including 11 hip fractures) were prevented, giving an overall saving of £21,000. Setup costs for widespread adoption of FLSs across the UK were estimated at £9.7 million. CONCLUSIONS: FLSs are cost-effective for the prevention of further fractures in fragility-fracture patients. The cost of widespread adoption of FLS across the UK is small in comparison with other service provision and would be expected to result in important benefits in fractures avoided and reduced hospital bed occupancy.

Dynamical tunneling in mushroom billiards.

We study the fundamental question of dynamical tunneling in generic two-dimensional Hamiltonian systems by considering regular-to-chaotic tunneling rates. Experimentally, we use microwave spectra to investigate a mushroom billiard with adjustable foot height. Numerically, we obtain tunneling rates from high precision eigenvalues using the improved method of particular solutions. Analytically, a prediction is given by extending an approach using a fictitious integrable system to billiards. In contrast to previous approaches for billiards, we find agreement with experimental and numerical data without any free parameter.

Regular-to-chaotic tunneling rates using a fictitious integrable system.

We derive a formula predicting dynamical tunneling rates from regular states to the chaotic sea in systems with a mixed phase space. Our approach is based on the introduction of a fictitious integrable system that resembles the regular dynamics within the island. For the standard map and other kicked systems we find agreement with numerical results for all regular states in a regime where resonance-assisted tunneling is not relevant.

A feasibility study of remote monitoring of asthmatic patients.

We assessed the feasibility of a remote monitoring system for asthmatic patients to use in their own homes. Eighty-four patients were invited to participate following discharge from hospital after an acute exacerbation of their asthma. We remotely monitored 33 patients from two hospitals for two weeks. Their mean age was 34 years (range 17-50 years). Patient compliance with monitoring was 80% (range 45-231%) and compliance with transmitting the results using a modem was 52% (range 0-100%). The average time spent teaching patients how to perform measurements was 16 min (range 2-55 min) and time spent providing asthma education was 39 min (range 5-135 min). Ninety-six per cent of patients found the equipment easy or very easy to use and 92% said they would use the equipment again in the future. Medical intervention occurred in 48% of patients during the study period, which suggests that the use of remote monitoring could be important in reducing asthma morbidity and improving treatment outcomes.

Supporting Partners of People with Aphasia in Relationships and Cconversation (SPPARC).

This paper reviews new theoretical and practical developments in working with partners of people with aphasia and describes the development of a clinician's resource entitled 'SPPARC: Supporting Partners of People with Aphasia in Relationships and Conversation'. It focuses particularly on one part of that resource: the SPPARC Conversation Training Programme, which adapts conversation analysis for clinical use. The paper describes the stages involved in assessing and working on conversation in everyday life.

Evidence-based practice and the advanced practice nurse: a curriculum for the future.

The concept of evidence-based practice has gained increased attention throughout the 1990s as a strategy for linking the best scientific findings with clinical judgment to improve health outcomes. Because the concept implies finding, evaluating, summarizing, and using research results, a high level of clinical reasoning skills is required. Effective evidence-based practice also requires the incorporation of new practices into clinical and organizational settings, thereby demanding advanced leadership skills. Competencies in clinical reasoning, leadership, and clinical practice are critical for advanced practice nurses. This article describes a master's-level curriculum supportive of evidence-based practice and includes recommendations for developing curricula of this type.

Communication of sexual risk behavior among late adolescents.

A grounded theory approach was used to describe how males and females in late adolescence communicate with their sexual partners about sexual risk behaviors. Interviews were audiotaped with 18 women and 15 men from a university in the southeastern United States. Verbatim transcripts were analyzed using constant comparative analysis. Building trust was identified as the core variable for both men and women. For women, prerequisites for building trust were being involved in caring relationships and indirectly gathering information about potential sexual partners. For men, prerequisites were being involved in caring relationships and using their instincts. Women usually initiated safe-sex talk, but men were willing to discuss it, once the conversation was initiated. Findings can serve as a guide for developing nursing strategies that promote more effective communication about sexual risk behavior in this age group.

PIP: The characteristics of communication about sexual risk behaviors between adolescent sexual partners were investigated in interviews with 14 sexually active females and 18 males attending a public university in southeastern US. Mean age at first intercourse was 17 years; respondents had had an average of 3 sexual partners. A review of the interview transcripts led to development of a model of the communication process. Building trust in one's partner emerged as the core variable for both males and females. A prerequisite for building trust was being involved in a caring relationship. Women built trust by indirectly gathering information about potential sexual partners, while men tended to rely on their instincts about their partners' appearance and demeanor. Once trust was established, both men and women were more likely to talk about sexual risk issues. Although males were willing to engage in safe sex talk if their female partner raised the topic, they rarely initiated such discussions. Alcohol use, previous sexual experience, knowledge about reproduction and contraception, conversations with friends, and the media were intervening conditions for safe sex conversations. Some participants believed that discussing safer sex practices indicated a lack of trust. Moreover, many participants demonstrated trust in their partners by engaging in high-risk sexual practices. This model can serve as a guide for developing strategies for promoting more effective communication about sexuality in late adolescence. For example, the finding that women tend to initiate discussions of safer sex practices suggests a need to empower women with the skills needed to negotiate risk-reduction behaviors.