71 research outputs found
A Dynamically Diluted Alignment Model Reveals the Impact of Cell Turnover on the Plasticity of Tissue Polarity Patterns
The polarisation of cells and tissues is fundamental for tissue morphogenesis
during biological development and regeneration. A deeper understanding of
biological polarity pattern formation can be gained from the consideration of
pattern reorganisation in response to an opposing instructive cue, which we
here consider by example of experimentally inducible body axis inversions in
planarian flatworms. Our dynamically diluted alignment model represents three
processes: entrainment of cell polarity by a global signal, local cell-cell
coupling aligning polarity among neighbours and cell turnover inserting
initially unpolarised cells. We show that a persistent global orienting signal
determines the final mean polarity orientation in this stochastic model.
Combining numerical and analytical approaches, we find that neighbour coupling
retards polarity pattern reorganisation, whereas cell turnover accelerates it.
We derive a formula for an effective neighbour coupling strength integrating
both effects and find that the time of polarity reorganisation depends linearly
on this effective parameter and no abrupt transitions are observed. This allows
to determine neighbour coupling strengths from experimental observations. Our
model is related to a dynamic -Potts model with annealed site-dilution and
makes testable predictions regarding the polarisation of dynamic systems, such
as the planarian epithelium.Comment: Preprint as prior to first submission to Journal of the Royal Society
Interface. 25 pages, 6 figures, plus supplement (18 pages, contains 1 table
and 7 figures). A supplementary movie is available from
https://dx.doi.org/10.6084/m9.figshare.c388781
Oncologic long-term outcome of single-incision laparoscopic surgery (SILS) for colorectal cancer
Purpose
Single-incision laparoscopic surgery (SILS) has been introduced as a less invasive alternative to multi-port laparoscopic surgery (MLS). MLS is widely accepted for the treatment of colorectal cancer, but there remains minimal evidence for the use of SILS. Thus, we compared both short- and long-term outcomes of SILS and open surgery (OS) in matched cohorts of colorectal cancer patients.
Methods
Some 910 patients had colorectal resections for cancer between 2006 and 2013, and 134 of them were operated on using SILS. Eighty of these SILS patients were compared to a cohort of patients who had open surgery that were matching in tumour stage and location, type of resection, sex, age and ASA Score. Disease-free survival at 5 years (5y-DFS) was the primary endpoint; morbidity and hospitalization were secondary parameters. The role of surgical training in SILS was also investigated.
Results
Clavien Dindo ≥ IIIb complications occurred in 13.8% in both groups. 5y-DSF were 82% after SILS and 70% after OS (p = 0.11). Local recurrence after rectal cancer tended to be lower after SILS (0/43 (SILS) vs. 4/35 (OS), p = 0.117). Length of stay was significantly shorter after SILS (10 vs. 14 days, p = 0.0004). The rate of operations performed by surgical residents was equivalent in both groups (44/80 (SILS) vs. 46/80 (OS), p = 0.75).
Conclusion
The data demonstrates that SILS results in similar long-term oncological outcomes when compared to open surgery as well as morbidity rates. The hospital stay in the SILS group was shorter. SILS can also be incorporated in surgical training programmes
A Novel Approach Towards Waste Treatment in FBC
Abstract Waste combustion has the potential to play an important role in the energy production despite its contribution to heavy metals emissions. A new multi-zone temperature combustion technique, known as a Low-High-Low (LHL) temperature method, was developed to reduce pollutant emissions, particularly heavy metals, from FBCs. This paper focuses on the environmental impacts of biowaste combustion at different FBC conditions with emphasis on gas and solid emissions. The biowaste (de-inking sludge) studied contained 15% moisture, 27% carbon, 18% oxygen, and 35% ash. Ash elemental analysis shows a dominance of SiO 2 , Al 2 O 3 and CaO (38%, 28% and 19%, respectively) with selected alkalis Na 2 O and K 2 O (0.3% and 0.2%, respectively). The used biowaste material had a heating value of 10,000 kJ/kg, which indicates that its combustion may be used to treat a portion of the total solid waste produced, while generating energy. The paper reports the following results of LHL vs. Classical FBC: (1) average axial profiles of gas concentrations (NO, NO x , and CO 2 ) as well as their final averages at the exhaust, (2) final heavy metals leachability from generated fly ash. During the multi-temperature combustion experiments (LHL), the final average gas measurements for NO, NO x , and CO 2 were 91 ppm, 175 ppm, and 6.1%, respectively. As for the classical FBC experiments, the final average gas measurements were similar (94 ppm, 141 ppm and 5.9% for NO, NO x and CO 2 , respectively). The final fly ash sample had leachability rates of 0.14 ppm and 0.061 ppm for Cd and Cr, respectively. Such low leachability rates are due to the LHL's ability to form dense and compact final fly ash structures. On the contrary, 30.7 ppm and 14.3 ppm of Cd and Cr leached out of the porous no-LHL final fly ash structures, respectively. These results confirm that the LHL combustion could be considered as an effective waste-to-energy approach
STUDI PERILAKU SEKSUAL PADA KELOMPOK GAY :PENGETAHUAN, SIKAP DAN NILAI DI GUBUG SEBAYA KABUPATEN JOMBANG
<p><b>Objectives:</b> Recent research suggested an influence of diminished central nervous serotonin (5-HT) synthesis on the leptin axis via immunological mechanisms in healthy adult females. However, studies assessing immunological parameters in combination with dietary challenge techniques that impact brain 5-HT synthesis in humans are lacking. </p> <p><b>Methods:</b> In the present trial, a pilot analysis was conducted on data obtained in healthy adult humans receiving either different dietary acute tryptophan depletion (ATD) challenge or tryptophan (TRP)-balanced control conditions (BAL) to study the effects of reduced central nervous 5-HT synthesis on serum tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β) and IL-6 concentrations. The data of <i>N</i> = 35 healthy adults were analysed who were randomly subjected to one of the following two dietary conditions in a double-blind between-subject approach: (1) The Moja-De ATD challenge (ATD), or (2) TRP-balanced control condition for ATD Moja-De (BAL). Serum concentrations for the assessment of relevant parameters (TNF-α, IL-1β and IL-6) and relevant TRP-related characteristics after the respective challenge procedures were assessed at baseline (T0) and in hourly intervals after administration over a period of 6 h (T1–T6). </p> <p><b>Results:</b> The ATD condition did not result in significant changes to cytokine concentrations for the entire study sample, or in male and female subgroups. Depletion of CNS 5-HT via dietary TRP depletion appears to have no statistically significant short-term impact on cytokine concentrations in healthy adults. </p> <p><b>Conclusions:</b> Future research on immunological stressors in combination with challenge techniques will be of value in order to further disentangle the complex interplay between brain 5-HT synthesis and immunological pathways.</p
PANC Study (Pancreatitis: A National Cohort Study): national cohort study examining the first 30 days from presentation of acute pancreatitis in the UK
Abstract
Background
Acute pancreatitis is a common, yet complex, emergency surgical presentation. Multiple guidelines exist and management can vary significantly. The aim of this first UK, multicentre, prospective cohort study was to assess the variation in management of acute pancreatitis to guide resource planning and optimize treatment.
Methods
All patients aged greater than or equal to 18 years presenting with acute pancreatitis, as per the Atlanta criteria, from March to April 2021 were eligible for inclusion and followed up for 30 days. Anonymized data were uploaded to a secure electronic database in line with local governance approvals.
Results
A total of 113 hospitals contributed data on 2580 patients, with an equal sex distribution and a mean age of 57 years. The aetiology was gallstones in 50.6 per cent, with idiopathic the next most common (22.4 per cent). In addition to the 7.6 per cent with a diagnosis of chronic pancreatitis, 20.1 per cent of patients had a previous episode of acute pancreatitis. One in 20 patients were classed as having severe pancreatitis, as per the Atlanta criteria. The overall mortality rate was 2.3 per cent at 30 days, but rose to one in three in the severe group. Predictors of death included male sex, increased age, and frailty; previous acute pancreatitis and gallstones as aetiologies were protective. Smoking status and body mass index did not affect death.
Conclusion
Most patients presenting with acute pancreatitis have a mild, self-limiting disease. Rates of patients with idiopathic pancreatitis are high. Recurrent attacks of pancreatitis are common, but are likely to have reduced risk of death on subsequent admissions.
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Oncologic long-term outcome of single-incision laparoscopic surgery (SILS) for colorectal cancer
Purpose!#!Single-incision laparoscopic surgery (SILS) has been introduced as a less invasive alternative to multi-port laparoscopic surgery (MLS). MLS is widely accepted for the treatment of colorectal cancer, but there remains minimal evidence for the use of SILS. Thus, we compared both short- and long-term outcomes of SILS and open surgery (OS) in matched cohorts of colorectal cancer patients.!##!Methods!#!Some 910 patients had colorectal resections for cancer between 2006 and 2013, and 134 of them were operated on using SILS. Eighty of these SILS patients were compared to a cohort of patients who had open surgery that were matching in tumour stage and location, type of resection, sex, age and ASA Score. Disease-free survival at 5 years (5y-DFS) was the primary endpoint; morbidity and hospitalization were secondary parameters. The role of surgical training in SILS was also investigated.!##!Results!#!Clavien Dindo ≥ IIIb complications occurred in 13.8% in both groups. 5y-DSF were 82% after SILS and 70% after OS (p = 0.11). Local recurrence after rectal cancer tended to be lower after SILS (0/43 (SILS) vs. 4/35 (OS), p = 0.117). Length of stay was significantly shorter after SILS (10 vs. 14 days, p = 0.0004). The rate of operations performed by surgical residents was equivalent in both groups (44/80 (SILS) vs. 46/80 (OS), p = 0.75).!##!Conclusion!#!The data demonstrates that SILS results in similar long-term oncological outcomes when compared to open surgery as well as morbidity rates. The hospital stay in the SILS group was shorter. SILS can also be incorporated in surgical training programmes
Synthesis of nanocrystalline zinc ferrite powders from sulphuric pickling waste water
A low temperature method was used to synthesise nanocrystalline zinc ferrite powders from sulphuric pickling water (SPW), a waste
31 21 product of the steelmaking industry. The synthesis method consisted of coprecipitation of a bi-ionic Fe /Zn solution with 1M
31 21 n-butylamine. Fe from the SPW and Zn provided by ZnO were mixed at a molar ratio of 2.0. The precursor obtained in this manner
showed a 2-line X-ray diffraction pattern similar to that of ferrihydrite. Thermal treatment of the precursor at |375 8C led to the formation
of pure, fine-particle and stoichiometric ZnFe O powders. This process allows the total recovery of the iron in the SPW, as a product of 2 4
added value. The fine powders were characterised by XRD, FTIR, TG/DSC and SEM. The BET specific surface and the magnetic
properties of the powders were also determined.The authors would like to thank the European Commission
(Convention 7261/02/512) and the CICYT (project MAT94-0799 for funding of the study. They are also indebted to Dr. Patricia Crespo of the Facultad de Ciencias F´ısicas (UCM) for performing the magnetic determinations.Peer reviewe
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