794 research outputs found
Metabolism of methylated osmolytes by aerobic Mono Lake, a moderately hypersaline, alkaline
Abstract Three strains of aerobic bacteria were isolated from water and sediment samples of Mono Lake, a moderately hypersaline (90 ppt), alkaline (pH 9.7) lake in California. The organisms, Gram-negative rods, grew fastest at about pH 9.7 with no growth or much slower growth at pH 7.0. All three isolates grew on glycine betaine (GB) and respirometric experiments indicated that catabolism was by sequential demethylation with dimethyl glycine and sarcosine as intermediates. Two of the isolates also grew on dimethylsulfoniopropionate (DMSP), one with cleavage of the DMSP to yield dimethyl sulfide (DMS) and acrylate, and the other by demethylation with 3-methiolpropionate (MMPA) as an intermediate and the production of methanethiol from MMPA. The methylated osmolytes supported growth at salinities similar to those in Mono Lake, but, at higher salinities. catabolism was suppressed and GB and DMSP functioned as osmolytes. GB and DMSP probably originate from cyanobacteria and/or phytoplankton in Mono Lake and this report is the first indication of both the DMS and demethylation/methanethiol-producing pathways for DMSP degradation in a nonmarine environment
Passerini chemistries for synthesis of polymer pro-drug and polymersome drug delivery nanoparticles
New materials chemistries are urgently needed to overcome the limitations of existing biomedical materials in terms of preparation, functionality and versatility, and also in regards to their compatibility with biological environments. Here, we show that Passerini reactions are especially suited for the preparation of drug delivery materials, as with relatively few steps, polymers can be synthesized with functionality installed enabling drug conjugation and encapsulation, self-assembly into micellar or vesicular architectures, and with facile attachment triggerable chemistries. The polymers can be made with a variety of building blocks and assemble into nanoparticles, which are rapidly internalized in triple negative breast cancer (TNBC) cells. In addition, the polymers transport drug molecules efficiently through 3D cell cultures, and when designed with chemistries allowing pH-mediated release, exhibit greater efficacy against TNBC cells compared to the parent drug
An internet-based intervention with brief nurse support to manage obesity in primary care (POWeR+): a pragmatic, parallel-group, randomised controlled trial
Background
The obesity epidemic has major public health consequences. Expert dietetic and behavioural counselling with intensive follow-up is effective, but resource requirements severely restrict widespread implementation in primary care, where most patients are managed. We aimed to estimate the effectiveness and cost-effectiveness of an internet-based behavioural intervention (POWeR+) combined with brief practice nurse support in primary care.
Methods
We did this pragmatic, parallel-group, randomised controlled trial at 56 primary care practices in central and south England. Eligible adults aged 18 years or older with a BMI of 30 kg/m2 or more (or ≥28 kg/m2 with hypertension, hypercholesterolaemia, or diabetes) registered online with POWeR+—a 24 session, web-based, weight management intervention lasting 6 months. After registration, the website automatically randomly assigned patients (1:1:1), via computer-generated random numbers, to receive evidence-based dietetic advice to swap foods for similar, but healthier, choices and increase fruit and vegetable intake, in addition to 6 monthly nurse follow-up (control group); web-based intervention and face-to-face nurse support (POWeR+Face-to-face [POWeR+F]; up to seven nurse contacts over 6 months); or web-based intervention and remote nurse support (POWeR+Remote [POWeR+R]; up to five emails or brief phone calls over 6 months). Participants and investigators were masked to group allocation at the point of randomisation; masking of participants was not possible after randomisation. The primary outcome was weight loss averaged over 12 months. We did a secondary analysis of weight to measure maintenance of 5% weight loss at months 6 and 12. We modelled the cost-effectiveness of each intervention. We did analysis by intention to treat, with multiple imputation for missing data. This trial is registered as an International Standard Randomised Controlled Trial, number ISRCTN21244703.
Findings
Between Jan 30, 2013, and March 20, 2014, 818 participants were randomly assigned to the control group (n=279), the POWeR+F group (n=269), or the POWeR+R group (n=270). Weight loss averaged over 12 months was recorded in 666 (81%) participants. The control group lost almost 3 kg over 12 months (crude mean weight: baseline 104·38 kg [SD 21·11; n=279], 6 months 101·91 kg [19·35; n=136], 12 months 101·74 kg [19·57; n=227]). The primary imputed analysis showed that compared with the control group, patients in the POWeR+F group achieved an additional weight reduction of 1·5 kg (95% CI 0·6–2·4; p=0·001) averaged over 12 months, and patients in the POWeR+R group achieved an additional 1·3 kg (0·34–2·2; p=0·007). 21% of patients in the control group had maintained a clinically important 5% weight reduction at month 12, compared with 29% of patients in the POWeR+F group (risk ratio 1·56, 0·96–2·51; p=0·070) and 32% of patients in the POWeR+R group (1·82, 1·31–2·74; p=0·004). The incremental overall cost to the health service per kg weight lost with the POWeR+ interventions versus the control strategy was £18 (95% CI −129 to 195) for POWeR+F and –£25 (−268 to 157) for POWeR+R; the probability of being cost-effective at a threshold of £100 per kg lost was 88% and 98%, respectively. No adverse events were reported.
Interpretation
Weight loss can be maintained in some individuals by use of novel written material with occasional brief nurse follow-up. However, more people can maintain clinically important weight reductions with a web-based behavioural program and brief remote follow-up, with no increase in health service costs. Future research should assess the extent to which clinically important weight loss can be maintained beyond 1 year
An experimental investigation of yarn tension in simulated ring spinning
Yarn tension is a key factor that affects the efficiency of a ring spinning system. In this paper, a specially constructed rig, which can rotate a yarn at a high speed without inserting any real twist into the yarn, was used to simulate a ring spinning process. Yarn tension was measured at the guide-eye during the simulated spinning of different yarns at various balloon heights and with varying yarn length in the balloon. The effect of balloon shape, yarn hairiness and thickness, and yarn rotating speed, on the measured yarn tension, was examined. The results indicate that the collapse of balloon shape from single loop to double loop, or from double loop to triple etc, lead to sudden reduction in yarn tension. Under otherwise identical conditions, a longer length of yarn in the balloon gives a lower yarn tension at the guide-eye. In addition, thicker yarns and/or more hairy yarns generate a higher tension in the yarn, due to the increased air drag acting on the thicker or more hairy yarns
Antibiotics from rare actinomycetes, beyond the genus Streptomyces
Throughout the golden age of antibiotic discovery, Streptomyces have been unsurpassed for their ability to produce bioactive metabolites. Yet, this success has been hampered by rediscovery. As we enter a new stage of biodiscovery, omics data and existing scientific repositories can enable informed choices on the biodiversity that may yield novel antibiotics. Here, we focus on the chemical potential of rare actinomycetes, defined as bacteria within the order Actinomycetales, but not belonging to the genus Streptomyces. They are named as such due to their less-frequent isolation under standard laboratory practices, yet there is increasing evidence to suggest these biologically diverse genera harbour considerable biosynthetic and chemical diversity. In this review, we focus on examples of successful isolation and genera that have been the focus of more concentrated biodiscovery efforts, we survey the representation of rare actinomycete taxa, compared with Streptomyces, across natural product data repositories in addition to its biosynthetic potential. This is followed by an overview of clinically useful drugs produced by rare actinomycetes and considerations for future biodiscovery efforts. There is much to learn about these underexplored taxa, and mounting evidence suggests that they are a fruitful avenue for the discovery of novel antimicrobials
Early prehabilitation reduces admissions and time in hospital in patients with newly diagnosed lung cancer
Objectives Lung cancer is the leading cause of cancer death in the UK. Prehabilitation aims to maximise patient fitness and minimise the negative impact of anticancer treatment. What constitutes prehabilitation before non-surgical anticancer treatment is not well established. We present data from a pilot project of Early prehabilitation In lung Cancer.Methods All new patients with likely advanced lung cancer were offered prehabilitation at respiratory clinic, if fit for further investigation. Prehabilitation included assessment and appropriate intervention from a consultant in palliative medicine, registered dietitian and rehabilitation physiotherapist. Four objective endpoints were identified, namely admissions to hospital, time spent in the hospital, treatment rates and overall survival. Outcomes were to be compared with 178 prehab eligible historical controls diagnosed from 2019 to 2021.Results From July 2021 to June 2023, 65 patients underwent prehabilitation and 72% of patients underwent all 3 interventions. 54 patients had a stage 3 or 4 lung cancer. In the prehab group, fewer patients attended Accident and Emergency (31.5 vs 37.4 attendances per 100 patients) and fewer were admitted (51.9 vs 67.9) when compared with historical controls. Those receiving prehab spent a lot less time in the hospital (129.7 vs 543.5 days per 100 patients) with shorter admissions (2.5 vs 8 days). Systemic anticancer treatment rates increased in the short term but were broadly similar overall. Median survival was higher in the prehabilitation group (0.73 vs 0.41 years, p=0.046).Conclusions Early prehabilitation appears to reduce time spent in the hospital. It may improve survival. Further work is required to understand its full effect on treatment rates.<br/
Incidence and risk factors of surgical site infections and related antibiotic resistance in Freetown, Sierra Leone: a prospective cohort study
BACKGROUND: There is limited information on surgical site infections (SSI) and the related antibiotic resistance needed to guide their management and prevention in Sierra Leone. In this study, we aimed to establish the incidence and risk factors of SSI and the related antibiotic resistance among adults attending a tertiary hospital, and a secondary health facility in Freetown, Sierra Leone. METHODS: This is a prospective cohort study designed to collect data from adult (18 years or older) patients who attended elective and emergency surgeries at two hospitals in Freetown between February and July, 2021. Data analysis was done using STATA version 16. RESULTS: Of 338 patients, 245 (72.5%) and 93 (27.5%) had their surgeries at the tertiary and secondary hospitals, respectively. Many were males 192 (56.8%), less than 35 years 164 (48.5%), and 39 (11.5%) developed an SSI. Of the 39 patients who acquired an SSI, 7 (17.9%) and 32 (82.1%) had their surgeries at the secondary and tertiary hospitals, respectively. The incidence of SSI is higher in contaminated 17 (43.6%) than in clean-contaminated 12 (30.8%) and clean 10 (25.6%) wounds. Wound swabs were collected in 29 (74.4%) patients, of which 18 (62.1%) had bacterial growth. In total, 49 isolates of 14 different bacteria including gram-negative 41 (83.7%) and gram-positive 8 (16.3%) isolates were identified. Of these, 32 (65.3%) were Enterobacteriaceae, 9 (18.4%) were Non-fermenting gram-negative bacilli and 10 (12.2%) were Enterococci. The most common isolates were Escherichia coli (12, 24.5%), Klebsiella pneumoniae (10, 20.4%), Acinetobacter baumannii (5, 10.2%), Klebsiella oxytoca (4, 8.2%) and Enterococcus faecalis (4, 8.2%). The Enterobacteriaceae were either resistance to carbapenems (4, 8.2%) or were extended-spectrum beta-lactamase (ESBL) producing organisms (29, 59.2%). Male sex [p = 0.031], an ASA score >/= 2 [p = 0.020), administration of general anaesthesia [p = 0.018] and elevated fasting glucose [p = 0.033] were predictive of SSI. CONCLUSION: The incidence of SSI in this study is comparable to other low- and middle-income countries, but a substantial proportion of these postoperative wounds have an ESBL-producing Enterobacteriaceae. Therefore, routine surveillance of SSI and related antibiotic resistance is required in resource-limited settings
High levels of surgical antibiotic prophylaxis: implications for hospital-based antibiotic stewardship in Sierra Leone
OBJECTIVE: Despite the impact of inappropriate prescribing on antibiotic resistance, data on surgical antibiotic prophylaxis in sub-Saharan Africa are limited. In this study, we evaluated antibiotic use and consumption in surgical prophylaxis in 4 hospitals located in 2 geographic regions of Sierra Leone. METHODS: We used a prospective cohort design to collect data from surgical patients aged 18 years or older between February and October 2021. Data were analyzed using Stata version 16 software. RESULTS: Of the 753 surgical patients, 439 (58.3%) were females, and 723 (96%) had received at least 1 dose of antibiotics. Only 410 (54.4%) patients had indications for surgical antibiotic prophylaxis consistent with local guidelines. Factors associated with preoperative antibiotic prophylaxis were the type of surgery, wound class, and consistency of surgical antibiotic prophylaxis with local guidelines. Postoperatively, type of surgery, wound class, and consistency of antibiotic use with local guidelines were important factors associated with antibiotic use. Of the 2,482 doses administered, 1,410 (56.8%) were given postoperatively. Preoperative and intraoperative antibiotic use was reported in 645 (26%) and 427 (17.2%) cases, respectively. The most commonly used antibiotic was ceftriaxone 949 (38.2%) with a consumption of 41.6 defined daily doses (DDD) per 100 bed days. Overall, antibiotic consumption was 117.9 DDD per 100 bed days. The Access antibiotics had 72.7 DDD per 100 bed days (61.7%). CONCLUSIONS: We report a high rate of antibiotic consumption for surgical prophylaxis, most of which was not based on local guidelines. To address this growing threat, urgent action is needed to reduce irrational antibiotic prescribing for surgical prophylaxis
Redox-freezing and nucleation of diamond via magnetite formation in the Earth’s mantle
Diamonds and their inclusions are unique probes into the deep Earth, tracking the deep carbon cycle to >800 km. Understanding the mechanisms of carbon mobilization and freezing is a prerequisite for quantifying the fluxes of carbon in the deep Earth. Here we show direct evidence for the formation of diamond by redox reactions involving FeNi sulfides. Transmission Kikuchi Diffraction identifies an arrested redox reaction from pyrrhotite to magnetite included in diamond. The magnetite corona shows coherent epitaxy with relict pyrrhotite and diamond, indicating that diamond nucleated on magnetite. Furthermore, structures inherited from h-Fe3O4 define a phase transformation at depths of 320–330 km, the base of the Kaapvaal lithosphere. The oxidation of pyrrhotite to magnetite is an important trigger of diamond precipitation in the upper mantle, explaining the presence of these phases in diamonds
Improved outcomes for hepatic trauma in England and Wales over a decade of trauma and hepatobiliary surgery centralisation
Background: Over the last decade trauma services have undergone a reconfiguration in England and Wales. The objective is to describe the epidemiology, management and outcomes for liver trauma over this period and examine factors predicting survival. Methods: Patients sustaining hepatic trauma were identified using the Trauma Audit and Research Network database. Demographics, management and outcomes were assessed between January 2005 and December 2014 and analysed over five, 2-year study periods. Independent predictor variables for the outcome of liver trauma were analysed using multiple logistic regression. Results: 4368 Patients sustained hepatic trauma (with known outcome) between January 2005 and December 2014. Median age was 34 years (interquartile range 23–49). 81% were due to blunt and 19% to penetrating trauma. Road traffic collisions were the main mechanism of injury (58.2%). 241 patients (5.5%) underwent liver-specific surgery. The overall 30-day mortality rate was 16.4%. Improvements were seen in early consultant input, frequency and timing of computed tomography (CT) scanning, use of tranexamic acid and 30-day mortality over the five time periods. Being treated in a unit with an on-site HPB service increased the odds of survival (odds ratio 3.5, 95% confidence intervals 2.7–4.5). Conclusions: Our study has shown that being treated in a unit with an on-site HPB service increased the odds of survival. Further evaluation of the benefits of trauma and HPB surgery centralisation is warranted
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