Sine-Gordon solitons, auxiliary fields, and singular limit of a double pendulums chain

We consider the continuum version of an elastic chain supporting topological and non-topological degrees of freedom; this generalizes a model for the dynamics of DNA recently proposed and investigated by ourselves. In a certain limit, the non-topological degrees of freedom are frozen, and the model reduces to the sine-Gordon equations and thus supports well-known topological soliton solutions. We consider a (singular) perturbative expansion around this limit and study in particular how the non-topological field assume the role of an auxiliary field. This provides a more general framework for the slaving of this degree of freedom on the topological one, already observed elsewhere in the context of the mentioned DNA model; in this framework one expects such phenomenon to arise in a quite large class of field-theoretical models.Comment: 18 pages, 2 figure

Intra- and inter-operator variability of refractometric total proteins measurement of canine plasma

Refractometric total proteins are commonly used in practice as a quick and inexpensive way to measure total protein concentration in bodily fluids. Little information is available about how the operator performing the measurement affects the results. The aim of our study was to determine the inter- and intra-operator variability of refractometric total proteins measured on canine plasma using a temperature-compensated handheld refractometer. A pooled sample of canine lithium-heparin plasma was created using leftover samples from dogs presented to our hospital. The sample was then divided into three aliquots. Total proteins of these aliquots were measured by veterinary nurses, interns, residents and specialists working at our hospital. Statistical analysis revealed excellent inter-operator (ICC 0.99, CI 95% 0.971–1.00) and intra-operator (ICC 0.997, CI 95% 0.990–0.999) variability. Having different operators measuring refractometric total plasma proteins in practice should not affect the results. This suggests different operators can be used when monitoring total plasma proteins of a patient over time and when designing a study that involves this test

Penta-block copolymer microspheres: Impact of polymer characteristics and process parameters on protein release

Here, we aimed to develop protein loaded microspheres (MSs) using penta-block PLGA-based copolymers to obtain sustained and complete protein release. We varied MS morphology and studied the control of protein release. Lysozyme was used as a model protein and MSs were prepared using the solid-in-oil-in-water emulsion solvent extraction method. We synthesized and studied various penta-block PLGA-based copolymers. Copolymer characteristics (LA/GA ratio and molecular weight of PLGA blocks) influenced MS morphology. MS porosity was influenced by process parameters (such as solvent type, polymer concentration, emulsifying speed), whereas the aqueous volume for extraction and stabilizer did not have a significant effect. MSs of the same size, but different morphologies, exhibited different protein release behavior, with porous structures being essential for the continuous and complete release of encapsulated protein. These findings suggest strategies to engineer the morphology of MSs produced from PLGA-based multi-block copolymers to achieve appropriate release rates for a protein delivery system

“Things Have Changed”—Laparoscopic Cytoreduction for Advanced and Recurrent Ovarian Cancer: The Experience of a Referral Center on 108 Patients

Objective: To report the feasibility of laparoscopic cytoreduction surgery for primary and recurrent ovarian cancer in a select group of patients. Methods: A retrospective analysis was conducted on a cohort of patients with FIGO stage IIIA-IV advanced ovarian cancer who underwent laparoscopic primary debulking surgery (PDS), interval debulking surgery (IDS), or secondary debulking surgery (SDS) between June 2008 and January 2020. The primary endpoint was achieving optimal cytoreduction, defined as residual tumor less than 1 cm. Secondary endpoints included evaluating surgical complications and long-term survival, assessed at three-month intervals during the initial two years and then every six months. Results: This study included a total of 108 patients, among whom, 40 underwent PDS, 44 underwent IDS, and 24 underwent SDS. Optimal cytoreduction rates were found to be 95.0%, 97.7%, and 95.8% for the PDS, ISD, and SDS groups, respectively. Early postoperative complications (<30 days from surgery) occurred in 19.2% of cases, with 7.4% of these cases requiring reintervention. One patient died following postoperative respiratory failure. Late postoperative complications (<30 days from surgery) occurred in 9.3% of cases, and they required surgical reintervention only in one case. After laparoscopic optimal cytoreduction with a median follow-up time of 25 months, the overall recurrence rates were 45.7%, 38.5%, and 39.3% for PDS, ISD, and SDS, respectively. The three-year overall survival rates were 84%, 66%, and 63%, respectively, while the three-year disease-free survival rates were 48%, 51%, and 71%, respectively. Conclusions: Laparoscopic cytoreduction surgery is feasible for advanced ovarian cancer in carefully selected patients, resulting in high rates of optimal cytoreduction, satisfactory peri-operative morbidity, and encouraging survival outcomes. Future studies should focus on establishing standardized selection criteria and conducting well-designed investigations to further refine patient selection and evaluate long-term outcomes

Analysis of salinity tolerance of Vitis vinifera 'Thompson Seedless' transformed with AtNHX1

Several transgenic plant species expressing AtNHX1, coding for a vacuolar Na+/H+ antiporter from Arabidopsis thaliana, have shown their ability to cope with salinity. The aim of this study was to analyze the response of Vitis vinifera cv. 'Thompson Seedless' transformed with AtNHX1 to salt stress, using soil substrate or hydroponic media, and to compare the response with untransformed 'Thompson Seedless' and allegedly tolerant 'Criolla' cultivars: 'Pedro Giménez' and 'Criolla Chica'. 'Thompson Seedless' embryogenic calli were transformed with Agrobacterium tumefaciens carrying AtNHX1 under the control of CaMV 35S promoter. Transgenic and untransformed plants were grown in a greenhouse under hydroponics or in pots with soil, and were subjected to increasing concentrations of sodium chloride (NaCl) up to 150 mM for a period of 7 weeks. Growth and toxicity symptoms were less affected in transgenics as compared to the untransformed grapevines, and transgenic lines had higher shoot length, leaf area and dry weights at the end of the experiment. Root concentrations of Na in transgenics were similar or lower than that observed in untransformed genotypes. Growth impairment and toxicity symptoms were observed in all genotypes under both conditions, but effects were more severe in plants growing with hydroponic culture. Potassium content and shoot to root dry weight ratio decreased with NaCl in hydroponics but not in pots. 'Criolla' cultivars grew less than the other genotypes, although 'Pedro Giménez' always exhibited highest shoot/root ratios

Elastic properties of grafted microtubules

We use single-particle tracking to study the elastic properties of single microtubules grafted to a substrate. Thermal fluctuations of the free microtubule's end are recorded, in order to measure position distribution functions from which we calculate the persistence length of microtubules with contour lengths between 2.6 and 48 micrometers. We find the persistence length to vary by more than a factor of 20 over the total range of contour lengths. Our results support the hypothesis that shearing between protofilaments contributes significantly to the mechanics of microtubules.Comment: 9 pages, 3 figure

Release kinetics of 5-fluorouracil-loaded microspheres on an experimental rat glioma.

BACKGROUND: Biodegradable loaded systems are promising devices for controlled and sustained release of anticancer drugs to brain tumours. We investigated the influence of drug-release profiles of 5-fluorouracil-loaded microspheres designed for the treatment of malignant gliomas. MATERIALS AND METHODS: 2.5 mg 5-FU delivered by either fast. (1 formulation) or slow-(2 formulations) 5-FU release microspheres (MS) were tested in C6-glioma rat brains. Tumor response was assessed by T2-weighted MRI. RESULTS: All treated animals, whatever the release profile considered, displayed a comparable 50% increase in life span versus controls. Delays in C6-glioma development appeared to correspond to the in vitro release periods of MS. In terms of curative prospect, complete remission was only observed in 11% of 5-FU-treated animals (4 out of 38). CONCLUSION: Formulation was unambiguously implicated in the response observed after local delivery of 5-FU to glioma

Bayesian inference on compact binary inspiral gravitational radiation signals in interferometric data

Presented is a description of a Markov chain Monte Carlo (MCMC) parameter estimation routine for use with interferometric gravitational radiational data in searches for binary neutron star inspiral signals. Five parameters associated with the inspiral can be estimated, and summary statistics are produced. Advanced MCMC methods were implemented, including importance resampling and prior distributions based on detection probability, in order to increase the efficiency of the code. An example is presented from an application using realistic, albeit fictitious, data.Comment: submitted to Classical and Quantum Gravity. 14 pages, 5 figure

Pharmacologically active microcarriers associated with thermosensitive hydrogel as a growth factor releasing biomimetic 3D scaffold for cardiac tissue-engineering

International audienceThe challenge of tissue engineering of the infarcted heart is how to improve stem cell engraftment, survival, homing, and differentiation for myocardial repair. We here propose to integrate human adipose-derived stem cells (ADSCs) and pharmacologically active microcarriers (PAMs), a three-dimensional (3D) carrier of cells and growth factors, into an injectable hydrogel (HG), to obtain a system that stimulates the survival and/or differentiation of the grafted cells toward a cardiac phenotype. PAMs are biodegradable and non-cytotoxic poly(lactic-co-glycolic acid) (PLGA) microspheres conveying cells on their 3D surface that deliver continuously and in a controlled manner a growth factor (GF) acting on the transported cells and on the microenvironment to improve engraftment. The choice of the appropriate GF and its protection during the formulation process and delivery are essential. In this study two GFs, hepatocyte growth factor (HGF) and insulin-like growth factor (IGF-1), have been encapsulated under a solid state in order to limit their interaction with the polymer and conserve their integrity. GF precipitation conditions and release profile from PAMs have been first investigated before combining them to ADSCs. The released IGF-1 and HGF induced the protein synthesis of cardiac differentiation markers GATA4, Nkx2.5, cTnI and CX43 after 1 week in vitro. Moreover, the GFs accelerated cell cycle progression, as suggested by the increased expression of Cyclin D1 mRNA and the widespread distribution of Ki67 protein. Integrating PAMs within the thermosensitive P407 hydrogel increased their elastic properties but decreased the transcription of most cardiac markers. In contrast, CX43 expression increased in ADSC–PAM–GF complexes embedded within the hydrogel compared to the ADSCs cultured alone in the absence of P407. These results suggest that particulate scaffolds releasing HGF and IGF-1 may be beneficial for applications in tissue-engineering strategies for myocardial repair and the association with a P407 hydrogel can increase substrate elasticity and junction connections in ADSCs