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Controlled titration-based ZnO formation.

ABSTRACT: Hexamethylenetetramine (HMTA) is commonly used as a base releasing agent for the synthesis of ZnO under mild aqueous conditions. HMTA hydrolysis leads to gradual formation of a base during the reaction. Use of HMTA, however, does have limitations: HMTA hydrolysis yields both formaldehyde and ammonia, it provides no direct control over the ammonia addition rate or the total amount of ammonia added during the reaction, it results in a limited applicable pH range and it dictates the accessible reaction temperatures. To overcome these restrictions, this work presents a direct base titration strategy for ZnO synthesis in which a continuous base addition rate is maintained. Using this highly flexible strategy, wurtzite ZnO can be synthesized at a pH >5.5 using either KOH or ammonia as a base source at various addition rates and reaction pH values. In situ pH measurements suggest a similar reaction mechanism to HMTA-based synthesis, independent of the varied conditions. The type and concentration of the base used for titration affect the reaction product, with ammonia showing evidence of capping behaviour. Optimizing this strategy, we are able to influence and direct the crystal shape and significantly increase the product yield to 74% compared to the ∼13% obtained by the reference HMTA reaction.

SUBMITTER: van Rijt MMJ

PROVIDER: S-EPMC8107948 | biostudies-literature | 2021 Mar

REPOSITORIES: biostudies-literature

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Controlled titration-based ZnO formation.

van Rijt Mark M J MMJ Oosterlaken Bernette M BM Friedrich Heiner H de With Gijsbertus G

CrystEngComm 20210324 18

Hexamethylenetetramine (HMTA) is commonly used as a base releasing agent for the synthesis of ZnO under mild aqueous conditions. HMTA hydrolysis leads to gradual formation of a base during the reaction. Use of HMTA, however, does have limitations: HMTA hydrolysis yields both formaldehyde and ammonia, it provides no direct control over the ammonia addition rate or the total amount of ammonia added during the reaction, it results in a limited applicable pH range and it dictates the accessible reac ...[more]

PMID: 34093087

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Project description:BackgroundPositive end-expiratory pressure (PEEP) at minimum respiratory elastance during mechanical ventilation (MV) in patients with acute respiratory distress syndrome (ARDS) may improve patient care and outcome. The Clinical utilisation of respiratory elastance (CURE) trial is a two-arm, randomised controlled trial (RCT) investigating the performance of PEEP selected at an objective, model-based minimal respiratory system elastance in patients with ARDS.Methods and designThe CURE RCT compares two groups of patients requiring invasive MV with a partial pressure of arterial oxygen/fraction of inspired oxygen (PaO2/FiO2) ratio ≤ 200; one criterion of the Berlin consensus definition of moderate (≤ 200) or severe (≤ 100) ARDS. All patients are ventilated using pressure controlled (bi-level) ventilation with tidal volume = 6-8 ml/kg. Patients randomised to the control group will have PEEP selected per standard practice (SPV). Patients randomised to the intervention will have PEEP selected based on a minimal elastance using a model-based computerised method. The CURE RCT is a single-centre trial in the intensive care unit (ICU) of Christchurch hospital, New Zealand, with a target sample size of 320 patients over a maximum of 3 years. The primary outcome is the area under the curve (AUC) ratio of arterial blood oxygenation to the fraction of inspired oxygen over time. Secondary outcomes include length of time of MV, ventilator-free days (VFD) up to 28 days, ICU and hospital length of stay, AUC of oxygen saturation (SpO2)/FiO2 during MV, number of desaturation events (SpO2 < 88%), changes in respiratory mechanics and chest x-ray index scores, rescue therapies (prone positioning, nitric oxide use, extracorporeal membrane oxygenation) and hospital and 90-day mortality.DiscussionThe CURE RCT is the first trial comparing significant clinical outcomes in patients with ARDS in whom PEEP is selected at minimum elastance using an objective model-based method able to quantify and consider both inter-patient and intra-patient variability. CURE aims to demonstrate the hypothesized benefit of patient-specific PEEP and attest to the significance of real-time monitoring and decision-support for MV in the critical care environment.Trial registrationAustralian New Zealand Clinical Trial Registry, ACTRN12614001069640. Registered on 22 September 2014. (https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=366838&isReview=true) The CURE RCT clinical protocol and data usage has been granted by the New Zealand South Regional Ethics Committee (Reference number: 14/STH/132).

Project description:BACKGROUND:Hypertension is a major cause of mortality in cardiac, vascular, and renal disease. Effective control of elevated blood pressure has been shown to reduce target organ damage. A Web-based self-titration program may empower patients to control their own disease, share decisions about antihypertensive dose titration, and improve self-management, ultimately improving health-related quality of life. OBJECTIVE:Our primary aim was to evaluate the effects of a Web-based self-titration program for improving blood pressure control in patients with primary hypertension. Our secondary aim was to evaluate the effects of that program on improving health-related quality of life. METHODS:This was a parallel-group, double-blind, randomized controlled trial with assessments at baseline, 3 months, and 6 months. We included patients with primary hypertension (blood pressure>130/80 mm Hg) from a cardiology outpatient department in northern Taiwan and divided them randomly into intervention and control groups. The intervention group received the Web-based self-titration program, while the control group received usual care. The random allocation was concealed from participants and outcome evaluators. Health-related quality of life was measured by the EuroQol five-dimension self-report questionnaire. We used generalized estimating equations to evaluate the effects of the intervention. RESULTS:We included 222 patients and divided them equally into intervention (n=111) and control (n=111) groups. Patients receiving the Web-based self-titration program showed significantly greater improvement in the systolic and diastolic blood pressure control than those who did not receive this program, at 3 months (-21.4 mm Hg and -5.4 mm Hg, respectively; P<.001) and 6 months (-27.8 mm Hg and -9.7 mm Hg, respectively; P<.001). Compared with the control group, the intervention group showed a significant decrease in the overall defined daily dose at both 3 (-0.202, P=.003) and 6 (-0.236, P=.001) months. Finally, health-related quality of life improved significantly in the intervention group compared with the control group at both 3 and 6 months (both, P<.001). CONCLUSIONS:A Web-based self-titration program can provide immediate feedback to patients about how to control their blood pressure and manage their disease at home. This program not only decreases mean blood pressure but also increases health-related quality of life in patients with primary hypertension. TRIAL REGISTRATION:ClinicalTrials.gov NCT03470974; https://clinicaltrials.gov/ct2/show/NCT03470974.

Project description:BACKGROUND:Patients on insulin glargine typically visit a clinician to obtain advice on how to adjust their insulin dose. These multiple clinic visits can be costly and time-consuming, particularly for low-income patients. It may be feasible to achieve insulin titration through text messages and phone calls with patients instead of face-to-face clinic visits. OBJECTIVE:The objectives of this study are to (1) evaluate if the Mobile Insulin Titration Intervention (MITI) is clinically effective by helping patients reach their optimal dose of insulin glargine, (2) determine if the intervention is feasible within the setting and population, (3) assess patient satisfaction with the intervention, and (4) measure the costs associated with this intervention. METHODS:This is a pilot study evaluating an approach to insulin titration using text messages and phone calls among patients with insulin-dependent type 2 diabetes in the outpatient medical clinic of Bellevue Hospital Center, a safety-net hospital in New York City. Patients will be randomized in a 1:1 ratio to either the MITI arm (texting/phone call intervention) or the usual-care arm (in-person clinic visits). Using a Web-based platform, weekday text messages will be sent to patients in the MITI arm, asking them to text back their fasting blood glucose values. In addition to daily reviews for alarm values, a clinician will rereview the texted values weekly, consult our physician-approved titration algorithm, and call the patients with advice on how to adjust their insulin dose. The primary outcome will be whether or not a patient reaches his/her optimal dose of insulin glargine within 12 weeks. RESULTS:Recruitment for this study occurred between June 2013 and December 2014. We are continuing to collect intervention and follow-up data from our patients who are currently enrolled. The results of our data analysis are expected to be available in 2015. CONCLUSIONS:This study explores the use of widely-available text messaging and voice technologies for insulin titration. We aim to show that remote insulin titration is clinically effective, feasible, satisfactory, and cost saving for low-income patients in a busy, urban clinic. TRIAL REGISTRATION:Clinicaltrials.gov NCT01879579; http://clinicaltrials.gov/ct2/show/NCT01879579 (Archived by WebCite at http://www.webcitation.org/6WUEgjZUO).

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Controlled titration-based ZnO formation.

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Controlled titration-based ZnO formation.

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