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1.
Clin Exp Med ; 24(1): 67, 2024 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-38568288

RESUMEN

Colorectal cancer (CRC) is the second most prevalent cancer type worldwide, which highlights the urgent need for non-invasive biomarkers for its early detection and improved prognosis. We aimed to investigate the patterns of long non-coding RNAs (lncRNAs) in small extracellular vesicles (sEVs) collected from low-volume blood serum specimens of CRC patients, focusing on their potential as diagnostic biomarkers. Our research comprised two phases: an initial exploratory phase involving RNA sequencing of sEVs from 76 CRC patients and 29 healthy controls, and a subsequent validation phase with a larger cohort of 159 CRC patients and 138 healthy controls. Techniques such as dynamic light scattering, transmission electron microscopy, and Western blotting were utilized for sEV characterization. Optimized protocol for sEV purification, RNA isolation and preamplification was applied to successfully sequence the RNA content of sEVs and validate the results by RT-qPCR. We successfully isolated sEVs from blood serum and prepared sequencing libraries from a low amount of RNA. High-throughput sequencing identified differential levels of 460 transcripts between CRC patients and healthy controls, including mRNAs, lncRNAs, and pseudogenes, with approximately 20% being lncRNAs, highlighting several tumor-specific lncRNAs that have not been associated with CRC development and progression. The validation phase confirmed the upregulation of three lncRNAs (NALT1, AL096828, and LINC01637) in blood serum of CRC patients. This study not only identified lncRNA profiles in a population of sEVs from low-volume blood serum specimens of CRC patients but also highlights the value of innovative techniques in biomolecular research, particularly for the detection and analysis of low-abundance biomolecules in clinical samples. The identification of specific lncRNAs associated with CRC provides a foundation for future research into their functional roles in cancer development and potential clinical applications.


Asunto(s)
Neoplasias Colorrectales , Vesículas Extracelulares , Neoplasias Primarias Secundarias , ARN Largo no Codificante , Humanos , ARN Largo no Codificante/genética , Suero , Vesículas Extracelulares/genética , Biomarcadores , Neoplasias Colorrectales/diagnóstico , Neoplasias Colorrectales/genética
2.
Vet Med (Praha) ; 69(1): 18-29, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38465000

RESUMEN

Salinomycin, belonging to ionophore antibiotics, has been used as a feed additive for poultry for its coccidiostatic effect. Poisoning by ionophore antibiotics has been reported in cattle and other sensitive animals due to the replacement of medicated feed and/or accidental overdoses. The aim of this paper is to report the toxicity of salinomycin for fallow deer and to describe the different levels of sensitivity of cervids to this substance. In the presented case study, a medicated feed containing ivermectin used for deworming red deer and fallow deer was accidentally contaminated with sodium salinomycinate in a concentration of 252.6 mg/kg. The contaminated feed was consumed by the animals over a period of four days. The mortality of fallow deer within 12 days was 58%. No mortality was recorded in the red deer. In the affected animals, clinical signs associated with acute and congestive heart failure were observed. The biochemical examination indicated prerenal azotaemia caused by circulatory insufficiency and ion imbalance. The histological examination revealed pronounced focal acute cardiomyopathy and massive subacute myopathy in the skeletal muscles.

3.
World J Surg Oncol ; 21(1): 384, 2023 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-38098074

RESUMEN

BACKGROUND: The aim of this prospective study was to evaluate the role of serum IL-6 as a potential predictive biomarker of postoperative complications (POC) in elective colorectal surgery. METHOD: A total of 115 patients underwent colorectal surgery for malignancy. IL-6 was measured on the first and third postoperative days (POD1, POD3), and C-reactive protein (CRP) was measured on the POD3. POC was analysed in subgroups according to Clavien‒Dindo (CD), antibiotic (ATB) treatment, intensive care unit (ICU) and hospital length of stay. The predictive power of variables for evaluated endpoints was analysed using receiver-operating characteristic (ROC) analysis and described by area under the curve (AUC). ROC analysis was adopted for the identification of optimal cut-offs. Histological analysis was performed to verify IL-6 production by the tumour. RESULTS: Out of 115 patients who were analysed, 42% had POC. Patients with POC had significantly higher serum levels of IL-6 on POD1 (p < 0.001) and POD3 (p < 0.001). IL-6 early on POD1 as a predictor of antibiotic treatment, ICU stay and hospital stay (AUC 0.818; 0.811; 0.771) did not significantly differ from the AUC of CRP late on POD3 (0.879; 0.838, 0.752). A cut-off IL-6 value of 113 pg/ml on POD1 and 180.5 pg/ml on POD3 in severe complications (CD > 3a) resulted in 75% and 72% sensitivity, 78.6% and 99% specificity, negative predictive value 96.4% and 97% and positive predictive value 29% and 88.9%. CONCLUSION: The serum level of interleukin-6 can predict severe (CD > 3a) POC early on POD1. On POD3, IL-6 is superior to CRP in terms of high positive predictive power of severe POC. Interestingly, the advantage of IL-6 on POD1 is early prediction of the need for antibiotic treatment, ICU stay and hospital stay, which is comparable to the CRP serum level late on the third POD.


Asunto(s)
Cirugía Colorrectal , Interleucina-6 , Humanos , Antibacterianos , Biomarcadores , Proteína C-Reactiva/análisis , Complicaciones Posoperatorias/etiología , Estudios Prospectivos , Curva ROC
4.
Sensors (Basel) ; 23(21)2023 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-37960520

RESUMEN

This article represents the first paper in a two-part series dealing with safety during tram-pedestrian collisions. This research is dedicated to the safety of trams for pedestrians during collisions and is motivated by the increased number of lethal cases. The first part of this paper includes an overview of tram face development from the earliest designs to the current ones in use and, at the same time, provides a synopsis and explanation of the technical context, including a link to current and forthcoming legislation. The historical design development can be characterised by three steps, from an almost vertical front face, to leaned and pointed shapes, to the current inclined low-edged windshield without a protruding coupler. However, since most major manufacturers now export their products worldwide and customisation is only of a technically insignificant nature, our conclusions are generalisable (supported by the example of Berlin). The most advantageous shape of the tram's front, minimising the effects on pedestrians in all collision phases, has evolved rather spontaneously and was unprompted, and it is now being built into the European Commission regulations. The goal of the second part of this paper is to conduct a series of tram-pedestrian collisions with a focus on the frontal and side impacts using a crash test dummy (anthropomorphic test device-ATD). Four tram types approaching the collision at four different impact speeds (5 km/h, 10 km/h, 15 km/h, and 20 km/h) were used. The primary outcome variable was the resultant head acceleration. The risk and severity of possible head injuries were assessed using the head injury criterion (HIC15) and its linkage to the injury level on the Abbreviated Injury Scale (AIS). The results showed increasing head impacts with an increasing speed for all tram types and collision scenarios. Higher values of head acceleration were reached during the frontal impact (17-124 g) compared to the side one (2-84 g). The HIC15 values did not exceed the value of 300 for any experimental setting, and the probability of AIS4+ injuries did not exceed 10%. The outcomes of tram-pedestrian collisions can be influenced by the ATD's position and orientation, the impact speed and front-end design of trams, and the site of initial contact.


Asunto(s)
Traumatismos Craneocerebrales , Peatones , Heridas y Lesiones , Humanos , Accidentes de Tránsito , Vehículos a Motor , Caminata
5.
Sensors (Basel) ; 23(21)2023 Nov 04.
Artículo en Inglés | MEDLINE | ID: mdl-37960673

RESUMEN

As was shown in the previous part of the study, windshields are an important part of the passive safety means of modern low-floor trams with an extraordinary effect on pedestrian safety in a pedestrian-tram collisions. Therefore, maximum attention must be paid to the definition of tram windshield characteristics. This article describes a windshield crash test, from which data are obtained to verify the feasibility of the applied computational approaches. A developed analytical model is utilised for a simple description of the energy balance during collision with an illustrative definition of the important parameters of laminated glass as well as their clear physical interpretations. The finite element analysis (FEA) performed in Ansys software using two versions of material definition, namely a simpler (*MAT_ELASTIC with nonlocal failure criterion) and a more complex (*MAT_GLASS with brittle stress-state-dependent failure) material model, which are presented as suitable for obtaining a detailed description of the shattering process of laminated glass, which can also be used effectively in windshield engineering.

6.
Vet Med (Praha) ; 68(9): 349-358, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37981944

RESUMEN

Tail biting in pigs represents a very serious problem in modern pig farming, particularly with the intensification of the industry. It is considered a multifactorial syndrome and can be caused by various factors, leading to significant economic losses through reduced weight gain and partial or total condemnation of slaughtered carcasses due to secondary bacterial infections. The aim of this article is to summarise the current knowledge regarding tail biting in pigs, with a primary focus on the use of slaughterhouses for evaluating tail lesions and monitoring their prevalence. The introduction addresses the factors influencing the incidence of tail biting in pig farms and prevention strategies. Subsequent sections cover topics such as tail docking, the negative effects of pig tail biting, the advantages and drawbacks of examining tail lesions in slaughterhouses, and the methodical procedure for evaluating such lesions. Additionally, the article discusses the relationship between tail lesions and meat inspection findings, as well as the prevalence of tail lesions in various European countries.

7.
Vet Med (Praha) ; 68(4): 145-151, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37982086

RESUMEN

The aim of the study was to compare the efficacy of the intranasal and parenteral administration of azaperone in order to achieve pig sedation. A total of 32 weaned piglets divided into 4 groups (8 piglets in each group) were used. Group A was injected intramuscularly (i.m.) with azaperone (Stresnil®, 40 mg/ml inj.; Elanco Animal Health) at a dose of 2 mg/kg of body weight (b.w.). Group B received a dose of 2 mg/kg b.w. of azaperone intranasally. Group C was given azaperone intranasally at a dose of 4 mg/kg b.w. Group D was given 1 ml of saline intranasally and served as the control group. The response to the defined stimulus (a blunt blow of a metal rod into a metal edge of a pen), the degree of salivation, movement level, body temperature and serum azaperone concentration were included in the trial. We found that in order to induce an adequate level of sedation comparable to the standard method of application, i.e., 2 mg/kg b.w. i.m., the intranasal administration of azaperone at a dose of 4 mg/kg body weight is required.

8.
Vet Med (Praha) ; 68(8): 299-312, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37982122

RESUMEN

The present review deals with a particularly important topic: the use of functional amino acids in different categories of pigs. It is especially relevant in the context of the current efforts to reduce the use of antibiotics in pig farming and the search for possible alternatives to replace them. The review is based on the definition that functional amino acids (FAAs) are classified as dispensable amino acids, but with additional biological functions, i.e., not only are they used for protein formation, but they are also involved in regulating essential metabolic pathways to improve health, survival, growth, and development. We describe the mechanism of action of individual FAAs and their potential use in pigs, including glutamate, glutamine, arginine, branched-chain amino acids (i.e., leucine, isoleucine, and valine), tryptophan and glycine. The work is divided into three parts. The first part deals with the FAAs and their role in the overall health of sows and their offspring. The second part describes the use of functional amino acids in piglets after weaning. Part three examines the use of functional amino acids in growing and fattening pigs and their impact on meat quality.

9.
Chemistry ; 29(34): e202300435, 2023 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-37026531

RESUMEN

As the first known example of ring-opening cross metathesis (ROCM) of polyfluorinated strained cyclobutenes, ROCM of 3,3,4,4-tetrafluorocyclobutene with electronically rich alkenes, catalyzed by Grubbs or Hoveyda-Grubbs 2nd generation precatalysts, gave a small library of non-symmetrical isolated dienes bearing a tetrafluoroethylene spacer between the double bonds. 1-Butoxy-3,3,4,4-tetrafluorohexa-1,5-diene thus formed underwent subsequent regioselective cross metathesis (CM) with a series of styrenes, catalyzed by Hoveyda-Grubbs 2nd generation precatalyst, leading to non-symmetrically substituted dienes. 6,6-Dibutoxy-3,3,4,4-tetrafluorohex-1-ene, formed by regioselective butoxylation of 1-butoxy-3,3,4,4-tetrafluorohexa-1,5-diene, was dihydroxylated and cyclized to the corresponding 3,3,4,4-tetrafluorohexopyranose.

10.
J Gastrointest Cancer ; 54(2): 528-535, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35524090

RESUMEN

PURPOSE: It is still unclear if pathological complete response (pCR) after neoadjuvant chemoradiotherapy (CRT) in patients treated for rectal cancer causes worse postoperative outcomes, especially after transanal total mesorectal excision (TaTME). Worse postoperative outcomes might be an argument for an organ preserving watch and wait strategy in fragile patients and patients with comorbidities. The aim of this study is to evaluate whether patients treated for rectal cancer who had pCR to neoadjuvant therapy develop worse postoperative outcomes after TaTME than patients without complete response. METHODS: Comparative retrospective analysis (with nearest neighbor matching algorithm) of postoperative outcomes in two groups of patients, with pCR, n = 15 and without pCR (non-pCR), n = 57. All patients were operated on only by one surgical approach, TaTME, for middle and distal rectal tumors. All procedures were performed by one surgical team between 2014 and 2020 at the University Hospital Brno in Czech Republic. RESULTS: Overall morbidity was comparable between the groups (pCR group - 53.8% vs. non-pCR - 38.6%, p = 0.381). Anastomotic leak (AL) was observed in 33.3% of patients with pCR and in 17.5% of patients in the non-pCR group without statistical significance (p = 0.281). CONCLUSION: In conclusion, pathological complete response after neoadjuvant therapy does not appear to affect postoperative morbidity in rectal cancer after TaTME. Therefore, in patients with complete response who are not adherent to W&W surveillance, surgical resection can be perform without increased postoperative complications.


Asunto(s)
Laparoscopía , Neoplasias del Recto , Humanos , Recto/cirugía , Recto/patología , Terapia Neoadyuvante , Estudios Retrospectivos , Neoplasias del Recto/cirugía , Neoplasias del Recto/patología , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Morbilidad , Laparoscopía/métodos , Resultado del Tratamiento
11.
Chemistry ; 28(31): e202200911, 2022 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-35355345

RESUMEN

5-(ß-d-Glucopyranosyloxymethyl)-2'-deoxyuridine and -cytidine 5'-O-triphosphates were prepared and used for polymerase-mediated (primer extension or PCR) synthesis of DNA containing glucosylated 5-hydroxymethyluracil (5hmU) or 5-hydroxymethyluracil (5hmC). The presence of any glucosylated pyrimidines fully protected DNA from cleavage by type II restriction endonucleases. On the other hand, while the presence of glucosylated 5hmU completely inhibited transcription by bacterial (Escherichia coli) RNA polymerase, the DNA containing the corresponding glucosylated 5hmC allowed a similar level of transcription as natural DNA. This suggests different roles of these hypermodified bases in the epigenetic regulation of transcription in bacteriophages or kinetoplastid parasites. Consequently, enzymatic glucosylation of 5hmC-containing DNA can be used for tuning of transcription activity.


Asunto(s)
ADN , Epigénesis Genética , ARN Polimerasas Dirigidas por ADN , Reacción en Cadena de la Polimerasa
12.
Vet Med (Praha) ; 67(11): 553-561, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-38623478

RESUMEN

The aim of this study is to evaluate the possibility of achieving more effective and prolonged sedation in pigs by the oral administration of increased doses of azaperone and to evaluate its safety. This was performed through a prospective randomised and double blinded study. A total of 32 weaned piglets were divided into 4 groups (8 in each group). Group A was given 1 ml of saline orally and served as the control group. Group B received azaperone orally at a dose of 4 mg/kg b.w. Group C received azaperone orally at a dose of 8 mg/kg b.w. Group D was given azaperone orally at a dose of 12 mg/kg b.w. The response to the defined stimulus, movement level, degree of salivation, body temperature, respiratory frequency, blood plasma azaperone concentration and biochemical variables were included in the trial. We found that by increasing the dose of the orally administered azaperone, the onset of the sedation is faster, the end of the sedation starts later and the sedation time is longer. However, the use of higher doses of oral azaperone is not suitable for piglets because the doses negatively affect the respiratory rate, body temperature, some biochemical parameters and cause the immobility of the piglets.

13.
Eur Phys J E Soft Matter ; 44(11): 134, 2021 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-34731339

RESUMEN

Shear strain localization into shear bands is associated with velocity weakening instabilities and earthquakes. Here, we simulate steady-state plane-shear flow of numerical granular material (gouge), confined between parallel surfaces. Both constant shear stress and constant strain-rate boundary conditions are tested, and the two types of boundary conditions are found to yield distinct velocity profiles and friction laws. The inertial number, I, exerts the largest control on the layers' behavior, but additional dependencies of friction on normal stress and thickness of the layer are observed under constant stress boundary condition. We find that shear-band localization, which is present in the quasistatic regime ([Formula: see text]) in rate-controlled shear, is absent under stress-controlled loading. In the latter case, flow ceases when macroscopic friction coefficient approaches the quasistatic friction value. The inertial regime that occurs at higher inertial numbers ([Formula: see text]) is associated with distributed shear, and friction and porosity that increase with shear rate (rate-strengthening regime). The finding that shear under constant stress boundary condition produces the inertial, distributed shear but never quasistatic, localized deformation is rationalized based on low fluctuations of shear forces in granular contacts for stress-controlled loading. By examining porosity within and outside a shear band, we also provide a mechanical reason why the transition between quasistatic and inertial shear coincides with the transition between localized and distributed strain.

14.
Soft Matter ; 17(43): 9967-9984, 2021 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-34704992

RESUMEN

Bilayers, self-assembled by cationic surfactants and fatty alcohols in water, are the basic units of lamellar gel networks - creamy formulations extensively used in cosmetics and pharmaceutics. Mesoscopic modelling and study of the bilayers formed by single- or double-tail cationic surfactants (CTAC or DHDAC), and fatty alcohols (FAs) in the lamellar fluid and gel phases were employed. Fatty alcohols with alkyl tail equal to or greater than the surfactant alkyl tail, i.e., C16FA or C18FA and C22FA, were considered. A model formulation was explored with the FA concentration greater than that of the surfactant and the structure of the fluid and gel bilayers in tensionless state characterised via the density profiles across the bilayers, orientational order parameters of the surfactant and FA chains, intrinsic analysis of the bilayer interfaces, and bending rigidity. The intrinsic analysis allows identification and quantification of the coexistence of the interdigitated and non-interdigitated phases present within the gel bilayers. The FA chains were found to conform the primary scaffolding of the bilayers while the surfactant chains tessellate bilayer monolayers from their water-hydrophobic interface. Further, the overlap of the FA chains from the apposed monolayers of the fluid bilayers rises with increasing FA length. Finally, the prevalence of the non-interdigitated phase over the interdigitated phase within the gel bilayers becomes enhanced upon the FA length increase with a preference of the surfactant chains to reside in the non-interdigitated phase rather than the interdigitated phase.


Asunto(s)
Alcoholes Grasos , Membrana Dobles de Lípidos , Interacciones Hidrofóbicas e Hidrofílicas , Tensoactivos , Agua
15.
Materials (Basel) ; 14(18)2021 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-34576583

RESUMEN

The aim of this work is to verify the presence of deformation in the metal specimen from the material AISI 316L by means of lock-in thermography. The specimen was cyclically loaded by the three-point bending in the fatigue testing machine. A response of the specimen to such excitation can be detected in the infrared spectrum and to determine temperature changes during a loading cycle. By means of the lock-in method, an increased signal to noise ratio (radiation energy detected by an infrared camera) was achieved. Besides, the temperature changes were determined on the basis of amplitudes of radiant energy changes detected by the camera. The temperature change (all radiant energy) corresponds with the first invariant of the tensor of deformation and, after a calculation and regarding the material parameters, also the invariant of the stress tensor. The proportionality between the signal from the camera and the first deformation invariant is achieved if the specimen load is an adiabatic event. This process is achieved by choosing a sufficiently high load frequency. In case of a presence origin of plastic deformations, there takes place only part of radiant energy. When we accept the hypothesis of a presence of just elastic deformations and plastic deformation is also present in the monitored process, then the evaluated thermograms based on the assumption of the presence of elastic deformation present anomalies in a distribution of the determined tensor invariant of deformations. These anomalies are caused by a presence of plastic deformations. Based on the anomalies, plastic deformation can be detected and subsequently analyzed. For the tested specimen and the applied load, the calculation of stress tensor was performed. It confirmed a congruence of results obtained by the analysis of the physical process in the infrared spectrum of the mid-wave infrared camera.

16.
Microorganisms ; 9(9)2021 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-34576832

RESUMEN

Wohlfahrtiimonas chitiniclastica are bacteria that cause rare infections, typically associated with the infestation of an open wound with fly larvae. Here, we present a unique case report of the first W. chitiniclastica isolation from a burn wound with accidental myiasis in a 63-year-old homeless man and a literature review focused on human infections caused by these bacteria. So far, 23 cases of infection with W. chitiniclastica have been reported; in 52% of these, larvae were found in the wound area. Most of these cases suffered from chronic non-healing wound infections but none of these were burn injuries. The overall fatality rate associated directly with W. chitiniclastica in these cases was 17%. Infections with parasitic larvae occur in moderate climates (especially in people living in poor conditions); therefore, an infection with rare bacteria associated with accidental myiasis, such as W. chitiniclastica, can be expected to become more common there. Thus, in view of the absence of recommendations regarding the treatment of patients with accidental myiasis and, therefore, the risk of infection with W. chitiniclastica or other rare pathogens, we provide a list of recommendations for the treatment of such patients. The importance of meticulous microbial surveillance using molecular biological methods to facilitate the detection of rare pathogens is emphasized.

17.
Sensors (Basel) ; 21(11)2021 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-34199638

RESUMEN

The article deals with the measurement of dynamic effects that are transmitted to the driver (passenger) when driving in a car over obstacles. The measurements were performed in a real environment on a defined track at different driving speeds and different distributions of obstacles on the road. The reaction of the human organism, respectively the load of the cervical vertebrae and the heads of the driver and passenger, was measured. Experimental measurements were performed for different variants of driving conditions on a 28-year-old and healthy man. The measurement's main objective was to determine the acceleration values of the seats in the vehicle in the vertical movement of parts of the vehicle cabin and to determine the dynamic effects that are transmitted to the driver and passenger in a car when driving over obstacles. The measurements were performed in a real environment on a defined track at various driving speeds and diverse distributions of obstacles on the road. The acceleration values on the vehicle's axles and the structure of the driver's and front passenger's seats, under the buttocks, at the top of the head (Vertex Parietal Bone) and the C7 cervical vertebra (Vertebra Cervicales), were measured. The result of the experiment was to determine the maximum magnitudes of acceleration in the vertical direction on the body of the driver and the passenger of the vehicle when passing a passenger vehicle over obstacles. The analysis of the experiment's results is the basis for determining the future direction of the research.


Asunto(s)
Conducción de Automóvil , Automóviles , Aceleración , Accidentes de Tránsito , Adulto , Vértebras Cervicales , Humanos , Masculino
18.
Beilstein J Org Chem ; 16: 2757-2768, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33224302

RESUMEN

The prochiral 4-(allyloxy)hepta-1,6-diynes, optionally modified in the positions 1 and 7 with an alkyl or ester group, undergo a chemoselective ring-closing enyne metathesis yielding racemic 4-alkenyl-2-alkynyl-3,6-dihydro-2H-pyrans. Among the catalysts tested, Grubbs 1st generation precatalyst in the presence of ethene (Mori conditions) gave superior results compared to the more stable Grubbs or Hoveyda-Grubbs 2nd generation precatalysts. This is probably caused by a suppression of the subsequent side-reactions of the enyne metathesis product with ethene. On the other hand, the 2nd generation precatalysts gave better yields in the absence of ethene. The metathesis products, containing both a triple bond and a conjugated system, can be successfully orthogonally modified. For example, the metathesis product of 5-(allyloxy)nona-2,7-diyne reacted chemo- and stereoselectively in a Diels-Alder reaction with N-phenylmaleimide affording the tricyclic products as a mixture of two separable diastereoisomers, the configuration of which was estimated by DFT computations. The reported enediyne metathesis paves the way to the enantioselective enyne metathesis yielding chiral building blocks for compounds with potential biological activity, e.g., norsalvinorin or cacospongionolide B.

19.
Comput Struct Biotechnol J ; 17: 537-560, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31049165

RESUMEN

The sphingolipid and lysophosphatidate regulatory networks impact diverse mechanisms attributed to cancer cells and the tumor immune microenvironment. Deciphering the complexity demands implementation of a holistic approach combined with higher-resolution techniques. We implemented a multi-modular integrative approach consolidating the latest accomplishments in gene expression profiling, prognostic/predictive modeling, next generation digital pathology, and systems biology for epithelial ovarian cancer. We assessed patient-specific transcriptional profiles using the sphingolipid/lysophosphatidate/immune-associated signature. This revealed novel sphingolipid/lysophosphatidate-immune gene-gene associations and distinguished tumor subtypes with immune high/low context. These were characterized by robust differences in sphingolipid-/lysophosphatidate-related checkpoints and the drug response. The analysis also nominates novel survival models for stratification of patients with CD68, LPAR3, SMPD1, PPAP2B, and SMPD2 emerging as the most prognostically important genes. Alignment of proprietary data with curated transcriptomic data from public databases across a variety of malignancies (over 600 categories; over 21,000 arrays) showed specificity for ovarian carcinoma. Our systems approach identified novel sphingolipid-lysophosphatidate-immune checkpoints and networks underlying tumor immune heterogeneity and disease outcomes. This holds great promise for delivering novel stratifying and targeting strategies.

20.
J Nanosci Nanotechnol ; 19(5): 2943-2949, 2019 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-30501804

RESUMEN

We use dissipative particle dynamics to simulate the controlled transport of flexible polymers through coated slit and cylindrical pores. Pores are coated inside with solvent-sensitive polymer brushes. Stretch-to-collapse transition then controls the permeability of the coated pores. We change the solvent quality with respect to the polymer brushes and study the flow of flexible polymers through the pores. We show that stretched brush chains close the pores and compress the polymers in the centre of the pores. The collapsed brush chains relieve compression and rapid change in permeability is observed. In open pore state, polymers partially accommodate on the brush layer and partially migrate towards the center of the pores, where the flux is maximal. Finally, we observe that polymers tend to align in the direction of the flow.

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