Authors: Fiona Watt

Topics: Biological Science Disciplines; History, 20th Century; History, 21st Century; Portraits as Topic; Stem Cells; Women, Working

PubMed: 19350675
DOI: 10.1002/stem.53

Authors: Long-Chang Hsieh, Tzu-Hsia Chen, Po-Cheng Lai...

INTRODUCTION

The mode clamping mechanism is the most important part of forming section for the plastic injection molding machine. If this mechanism has double-toggle effects at the close position, it will get a larger clamping force and have higher safety. This study focuses on the optimal design of the Watt-chain mechanism with double-toggle effects at the close position.

METHODS

The Watt-chain double-toggle mechanism is chosen to be the mold clamping mechanism by referring to the existing patents. Then, the kinematic characteristics of the Watt-chain double-toggle mechanism are analyzed by the vector loop method. Finally, based on the kinematic requirements and the proposed optimal design process according to the objective function, the optimal design on Watt-chain double-toggle mechanism is accomplished in this study.

RESULTS

This study proposes an optimal design process on Watt-chain double-toggle mold clamping mechanism. By following the optimal design process, the optimal Watt-chain double-toggle mold clamping mechanism has a maximum acceleration 3418 mm/s ( = 3418 mm/s) and a force ratio is 2.24 (/ = 2.24).

DISCUSSION

According to the studies on the optimal designs of mechanisms, the optimal Watt-chain double-toggle mechanism, which is better than the multiple-joint double-toggle mold clamping mechanism in the existing patent by reducing 19.5% of acceleration and 30% of a driving force, is proposed. The results of this study could be the design reference in engineering when designing mold clamping mechanisms for plastic injection molding machines.

Topics: Biomechanical Phenomena; Constriction; Injections; Plastics

PubMed: 34606397
DOI: 10.1177/00368504211041488

Comparative Study

Comparison of the efficiency, safety and pain scores of holmium laser devices working with 20 watt and 30 watt using in retrograde intrarenal surgery: One center prospective study.

Authors: Sercan Sari, Mehmet Çaglar Çakici, Ibrahim Güven Kartal...

OBJECTIVES

Holmium:Yttrium Aluminum Garnet laser lithotripsy is used in Retrograde Intrarenal Surgery. Fragmentation is made with a certain value of pulse energy (Joule) and frequency (Hertz) in Holmium laser lithotripsy and the multiplication of these values gives us total power (Watt). Devices with maximum power of 20 Watt and 30 Watt are used in clinical practice. We want to compare the efficiency, safety and pain scores of the lithotripsy made below 20 Watt and over 30 Watt with 30 Watt laser device.

MATERIALS AND METHODS

60 patients who had 2-3 cm sized kidney stones and operation planned were prospectively divided into three groups. Groups were random identified. In the first group, fragmentation was performed below 20 Watt power with 20 Watt laser device. In the second group, fragmentation was performed below 20 Watt power with 30 Watt laser device. In the third group, fragmentation was performed over 20 Watt power with 30 Watt laser device. Demographic, stone, intraoperative and postoperative data were recorded. We compared these groups regarding efficiency, safety and pain score.

RESULTS

For demographic and stone data, there was a statistically significant difference only for stone number. For intraoperative and postoperative data, there was a statistically significant difference only for ureteral access sheath usage between the groups. Success was lower than the other groups in Group 1.

CONCLUSIONS

Success was higher in groups using 30 Watt laser device. There was not statistically significantly difference between complications and pain. 30 Watt laser device is safe and efficient in Retrograde Intrarenal Surgery.

Topics: Adult; Aged; Female; Fiber Optic Technology; Humans; Kidney Calculi; Lasers, Solid-State; Lithotripsy, Laser; Male; Middle Aged; Pain Measurement; Pain, Procedural; Prospective Studies; Treatment Outcome; Ureteroscopy

PubMed: 32597122
DOI: 10.4081/aiua.2020.2.149

Authors: Jacqueline G Gerhart, Fernando O Carreño, Jennifer L Ford...

Obesity is an increasingly alarming public health threat, with nearly 20% of children classified as obese in the United States today. Children with obesity are commonly prescribed the opioids fentanyl and methadone, and accurate dosing is critical to reducing the risk of serious adverse events associated with overexposure. However, pharmacokinetic studies in children with obesity are challenging to conduct, so there is limited information to guide fentanyl and methadone dosing in these children. To address this clinical knowledge gap, physiologically-based pharmacokinetic models of fentanyl and methadone were developed in adults and scaled to children with and without obesity to explore the interplay of obesity, age, and pharmacogenomics. These models included key obesity-induced changes in physiology and pharmacogenomic effects. Model predictions captured observed concentrations in children with obesity well, with an overall average fold error of 0.72 and 1.08 for fentanyl and methadone, respectively. Model simulations support a reduced fentanyl dose (1 vs. 2 μg/kg/h) starting at an earlier age (6 years) in virtual children with obesity, highlighting the importance of considering both age and obesity status when selecting an infusion rate most likely to achieve steady-state concentrations within the target range. Methadone dosing simulations highlight the importance of considering genotype in addition to obesity status when possible, as cytochrome P450 (CYP)2B6*6/*6 virtual children with obesity required half the dose to match the exposure of wildtype children without obesity. This physiologically-based pharmacokinetic modeling approach can be applied to explore dosing of other critical drugs in children with obesity.

Topics: Adult; Analgesics, Opioid; Child; Fentanyl; Humans; Methadone; Obesity

PubMed: 35491971
DOI: 10.1002/psp4.12793

Authors: Graham Watt, Rita Giacaman, Huda Zurayk...

Topics: Arabs; Biomedical Research; Cooperative Behavior; Health Status; Health Surveys; Humans; Middle East; Periodicals as Topic

PubMed: 24315726
DOI: 10.1016/S0140-6736(13)62234-5

Authors: Graham Watt, Rita Giacaman, Huda Zurayk...

Topics: Arabs; Biomedical Research; Congresses as Topic; Cooperative Behavior; Evidence-Based Medicine; Health Status; Humans; Middle East; Periodicals as Topic

PubMed: 24315727
DOI: 10.1016/S0140-6736(13)62233-3

Authors: Richard G Watt

Topics: Betacoronavirus; COVID-19; Coronavirus Infections; Delivery of Health Care; Dental Care; Health Care Reform; Humans; Pandemics; Pneumonia, Viral; SARS-CoV-2

PubMed: 32798482
DOI: 10.1016/S0140-6736(20)31529-4

Observational Study

Authors: Sarah Phillips, Rachel Watt, Thomas Atkinson...

BACKGROUND

The early life period represents the first step in establishing a beneficial microbial ecosystem, which in turn affects both short and longer-term health. Changes during pregnancy influence the neonatal microbiome; through transmission of maternal microbes during childbirth, and beyond, through nutritional programming. However, in-depth exploration of longitudinal maternal-infant cohorts, with sampling of multiple body sites, complemented by clinical and nutritional metadata, and use of cutting-edge experimental systems are limited. The PEARL study will increase our knowledge of; how microbes (including viruses/phages, bacteria, fungi and archaea) change in composition and functional capacity during pregnancy; transmission pathways from mother to infant; the impact of various factors on microbial communities across pregnancy and early life (e.g. diet), and how these microbes interact with other microbes and modulate host processes, including links to disease onset.

METHODS

PEARL is a longitudinal observational prospective study of 250 pregnant women and their newborns, with stool and blood samples, questionnaires and routine clinical data collected during pregnancy, labour, birth and up to 24 months post birth. Metagenomic sequencing of samples will be used to define microbiome profiles, and allow for genus, species and strain-level taxonomic identification and corresponding functional analysis. A subset of samples will be analysed for host (immune/metabolite) molecules to identify factors that alter the host gut environment. Culturing will be used to identify new strains of health-promoting bacteria, and potential pathogens. Various in vitro and in vivo experiments will probe underlying mechanisms governing microbe-microbe and microbe-host interactions.

DISCUSSION

Longitudinal studies, like PEARL, are critical if we are to define biomarkers, determine mechanisms underlying microbiome profiles in health and disease, and develop new diet- and microbe-based therapies to be tested in future studies and clinical trials.

TRIAL REGISTRATION

This study is registered in the ClinicalTrials.gov Database with ID: NCT03916874 .

Topics: Bacteria; Female; Gastrointestinal Microbiome; Humans; Infant; Infant, Newborn; Longitudinal Studies; Microbiota; Pregnancy; Prospective Studies

PubMed: 34429088
DOI: 10.1186/s12887-021-02835-5

Authors: Kevin M Watt

Topics: Betacoronavirus; COVID-19; Child; Coronavirus; Coronavirus Infections; Humans; Pandemics; Pneumonia, Viral; SARS-CoV-2; Therapies, Investigational

PubMed: 32501513
DOI: 10.1001/jamapediatrics.2020.2435

Authors: Graham Watt

PubMed: 31345818
DOI: 10.3399/bjgp19X704885