Batch trials were carried out to determine the methane potential yields of some typical organic wastes generated in the region of Cantabria (Spain): cocoa shell, cheese whey and sludges from dairy industry. Anaerobic ...Batch trials were carried out to determine the methane potential yields of some typical organic wastes generated in the region of Cantabria (Spain): cocoa shell, cheese whey and sludges from dairy industry. Anaerobic co-digestion trials of these wastes with dairy manure were also investigated in batch at 35℃. Cheese whey obtained similar methane yields than dairy manure, between 17.5 and 19.3 L CH4kg-1 cheese whey compared with 18.0 L CH4kg-1 manure. Methane yields of various sludge samples collected from wastewater treatment facilities of dairy industries were influenced by its origin. Sludge samples from fat separation devices were the most productive in terms of specific methane yields compared with biological sludge from an aerobic reactor. Sludge samples from fat separator reached specific methane productivities of 350 and 388 L CH4kg-1 VS (10.5 and 24.1 L CH4kg-1 sludge), whereas biological sludge yielded 125 L CH4kg-1 VS (12.6 L CH4kg-1 sludge). The methane potential of sludge samples was influenced by solids content. Cocoa shell resulted to be an interesting waste for anaerobic digestion due to its high VS content, yielding 195 L CH4kg-1 cocoa shell. It is a waste that can considerably improve methane yields in anaerobic co-digestion with dairy manure. However, at proportions of 10% cocoa shell, the process was hindered by hydrolysis of particulate matter. Anaerobic digestion at higher temperatures (thermophilic range) could be a better option for this kind of waste. Co-digestion of 5% cocoa shell with 35% dairy sludge and 60% dairy manure resulted in 80.5% higher methane production compared to anaerobic digestion of dairy manure alone.展开更多
In order to satisfy the increasing demand on high performance planetary transmissions, an important line of research is focused on the understanding of some of the underlying phenomena involved in this mechanical syst...In order to satisfy the increasing demand on high performance planetary transmissions, an important line of research is focused on the understanding of some of the underlying phenomena involved in this mechanical system. Through the development of models capable of reproduce the system behavior, research in this area contributes to improve gear transmission insight, helping developing better maintenance practices and more efficient design processes. A planetary gear model used for the design of profile modifications ratio based on the levelling of the load sharing ratio is presented. The gear profile geometry definition, following a vectorial approach that mimics the real cutting process of gears, is thoroughly described. Teeth undercutting and hypotrochoid definition are implicitly considered, and a procedure for the incorporation of a rounding arc at the tooth tip in order to deal with corner contacts is described. A procedure for the modeling of profile deviations is presented, which can be used for the introduction of both manufacturing errors and designed profile modifications. An easy and flexible implementation of the profile deviation within the planetary model is accomplished based on the geometric overlapping. The contact force calculation and dynamic implementation used in the model are also introduced, and parameters from a real transmission for agricultural applications are presented for the application example. A set of reliefs is designed based on the levelling of the load sharing ratio for the example transmission, and finally some other important dynamic factors of the transmission are analyzed to assess the changes in the dynamic behavior with respect to the non-modified case. Thus, the main innovative aspect of the proposed planetary transmission model is the capacity of providing a simulated load sharing ratio which serves as design variable for the calculation of the tooth profile modifications.展开更多
This paper aims to study the shear interaction mechanism of one of the critical geosynthetic interfaces,the geotextile/geomembrane, typically used for lined containment facilities such as landfills. A largedirect shea...This paper aims to study the shear interaction mechanism of one of the critical geosynthetic interfaces,the geotextile/geomembrane, typically used for lined containment facilities such as landfills. A largedirect shear machine is used to carry out 90 geosynthetic interface tests. The test results show a strainsoftening behavior with a very small dilatancy （〈0.5 mm） and nonlinear failure envelopes at a normalstress range of 25e450 kPa. The influences of the micro-level structure of these geosynthetics on themacro-level interface shear behavior are discussed in detail. This study has generated several practicalrecommendations to help professionals to choose what materials are more adequate. From the threegeotextiles tested, the thermally bonded monofilament exhibits the best interface shear strength underhigh normal stress. For low normal stress, however, needle-punched monofilaments are recommended.For the regular textured geomembranes tested, the space between the asperities is an important factor.The closer these asperities are, the better the result achieves. For the irregular textured geomembranestested, the nonwoven geotextiles made of monofilaments produce the largest interface shear strength.展开更多
Mesenchymal stem cells(MSCs)are the most frequently used stem cells in clinical trials due to their easy isolation from various adult tissues,their ability of homing to injury sites and their potential to differentiat...Mesenchymal stem cells(MSCs)are the most frequently used stem cells in clinical trials due to their easy isolation from various adult tissues,their ability of homing to injury sites and their potential to differentiate into multiple cell types.However,the realization that the beneficial effect of MSCs relies mainly on their paracrine action,rather than on their engraftment in the recipient tissue and subsequent differentiation,has opened the way to cell-free therapeutic strategies in regenerative medicine.All the soluble factors and vesicles secreted by MSCs are commonly known as secretome.MSCs secretome has a key role in cell-to-cell communication and has been proven to be an active mediator of immunemodulation and regeneration both in vitro and in vivo.Moreover,the use of secretome has key advantages over cell-based therapies,such as a lower immunogenicity and easy production,handling and storage.Importantly,MSCs can be modulated to alter their secretome composition to better suit specific therapeutic goals,thus,opening a large number of possibilities.Altogether these advantages now place MSCs secretome at the center of an important number of investigations in different clinical contexts,enabling rapid scientific progress in this field.展开更多
Mesenchymal stem cells(MSCs)are promising candidates for bone regeneration therapies due to their plasticity and easiness of sourcing.MSC-based treatments are generally considered a safe procedure,however,the long-ter...Mesenchymal stem cells(MSCs)are promising candidates for bone regeneration therapies due to their plasticity and easiness of sourcing.MSC-based treatments are generally considered a safe procedure,however,the long-term results obtained up to now are far from satisfactory.The main causes of these therapeutic limitations are inefficient homing,engraftment,and osteogenic differentiation.Many studies have proposed modifications to improve MSC engraftment and osteogenic differentiation of the transplanted cells.Several strategies are aimed to improve cell resistance to the hostile microenvironment found in the recipient tissue and increase cell survival after transplantation.These strategies could range from a simple modification of the culture conditions,known as cell-preconditioning,to the genetic modification of the cells to avoid cellular senescence.Many efforts have also been done in order to enhance the osteogenic potential of the transplanted cells and induce bone formation,mainly by the use of bioactive or biomimetic scaffolds,although alternative approaches will also be discussed.This review aims to summarize several of the most recent approaches,providing an up-to-date view of the main developments in MSCbased regenerative techniques.展开更多
Among neurodegenerative diseases,amyotrophic lateral sclerosis(ALS)is the most frequent one involving motor neurons(MNs).ALS incidence varies throughout the world ranging from 0.7 to 4 cases per 100,000 habitants and ...Among neurodegenerative diseases,amyotrophic lateral sclerosis(ALS)is the most frequent one involving motor neurons(MNs).ALS incidence varies throughout the world ranging from 0.7 to 4 cases per 100,000 habitants and year(Riancho et al.,2016).This disease,which currently lacks an effective therapy,is characterized by a variable combination of upper and lower MN degeneration,leading to progressive muscle wasting which usually results in a terminal respiratory failure within 3 years after symptom onset(Zufiria et al.,2016).A small proportion of ALS cases show familial aggregation.These are related to mutations in specific causative genes(Cr9ORF72,TARDBP,FUS,SOD1 and others)which directly determine disease onset in carriers.By contrast,more than 90 percent of cases are considered to be sporadic,in which generally unknown environmental and internal factors interact with genetic predisposing factors finally leading to disease(Riancho et al.,2018).From a histopathological point of view,ALS is characterized by MN damage and loss.MNs from ALS sporadic and most of familial patients exhibit prominent transactive response DNA-binding protein 43(TDP-43)cytoplasmic aggregates which are considered as the“pathological hallmark”of the disease,excepting those related to SOD1 and FUS mutations(Zufiria et al.,2016).TDP-43 is a DNA/RNA binding protein encoded by the TARDBP gene that controls the expression of many different genes.展开更多
In this paper, the use of a signal to noise ratio (SNR) is proposed for the quantification of the goodness of some selected processing techniques of thermographic images, such as differentiated absolute contrast, skew...In this paper, the use of a signal to noise ratio (SNR) is proposed for the quantification of the goodness of some selected processing techniques of thermographic images, such as differentiated absolute contrast, skewness and kurtosis based algorithms, pulsed phase transform, principal component analysis and thermographic signal reconstruction. A new hybrid technique is also applied (PhAC—Phase absolute contrast), it combines three different processing techniques: phase absolute contrast, pulsed phase thermography and thermographic signal reconstruction. The quality of the results is established on the basis of the values of the parameter SNR, assessed for the present defects in the analyzed specimen, which enabled to quantify and compare their identification and the quality of the results of the employed technique.展开更多
According to the; energy equation, the relation between reflection and energy losses for short waves from mild beaches is established and analysed. A reflection coefficient varying with position and energy losses is p...According to the; energy equation, the relation between reflection and energy losses for short waves from mild beaches is established and analysed. A reflection coefficient varying with position and energy losses is proposed. Different reflection tests are conducted to check the theoretical analysis. A modified method to estimate the reflection coefficient at varied water depths is suggested based on the linear wave theory. The study indicates that the reflection coefficient from mild beaches has a changing trend for short waves approaching shoreline.展开更多
We introduce a new algebraic approach dealing with the problem of computing the topology of an arrangement of a finite set of real algebraic plane curves presented implicitly. The main achievement of the presented met...We introduce a new algebraic approach dealing with the problem of computing the topology of an arrangement of a finite set of real algebraic plane curves presented implicitly. The main achievement of the presented method is a complete avoidance of irrational numbers that appear when using the sweeping method in the classical way for solving the problem at hand. Therefore, it is worth mentioning that the efficiency of the proposed method is only assured for low-degree curves.展开更多
BACKGROUND Liver transplant(LT)is a complex procedure with frequent postoperative complications.In other surgical procedures such as gastrectomy,esophagectomy or resection of liver metastases,these complications are a...BACKGROUND Liver transplant(LT)is a complex procedure with frequent postoperative complications.In other surgical procedures such as gastrectomy,esophagectomy or resection of liver metastases,these complications are associated with poorer long-term survival.It is possible this happens in LT but there are not enough data to establish this relationship.AIM To analyze the possible influence of postoperative complications on long-term survival and the ability of the comprehensive complication index(CCI)to predict this.METHODS Retrospective study in a tertiary-level university hospital.The 164 participants were all patients who received a LT from January 2012 to July 2019.The follow-up was done in the hospital until the end of the study or death.Comorbidity and risk after transplantation were calculated using the Charlson and balance of risk(BAR)scores,respectively.Postoperative complications were graded according to the Clavien-Dindo classification and the CCI.To assess the CCI cut-off value with greater prognostic accuracy a receiver operating characteristic(ROC)curve was built,with calculation of the area under the curve(AUC).Overall survival was estimated according to the Kaplan-Meier test and log-rank test.Groups were compared by the Mann-Whitney test.For the multivariable analysis the Cox regression was used.RESULTS The mean follow-up time of the cohort was 37.76(SD=24.5)mo.A ROC curve of CCI with 5-year survival was built.The AUC was 0.826(0.730-0.922),P<0.001.The cut-off was calculated by means of the Youden index with a result of 35.95.The sensitivity was 84.6%and the specificity 61.3%.Survival curves for comparison of patients with CCI score<36 vs≥36 were calculated.The estimated 5-year survival was 57.65 and 43.95 months,respectively(log-rank<0.001).This suggests that patients with more severe complications exhibit worse long-term survival.Other cut-off values were analysed.Comparison between patients with CCI<33.5 vs>33.5(33.5=median CCI value)showed estimated 5-year survival was 57.4 and 45.71 months,respectively(log-rank<0.0001).Dividing patients according to the mode CCI value(20.9)showed an estimated 5-year survival of 60 mo for a CCI below 20.9 vs 57 mo for a CCI above 20.9(log-rank=0.147).The univariate analysis did not show any association between individual complications and long-term survival.A multivariate analysis was carried out to analyse the possible influence of CCI,Charlson comorbidity index,BAR and hepatocellular carcinoma on survival.Only the CCI score showed significant influence on long-term survival.CONCLUSION A complicated postoperative period–well-defined by means of the CCI score–can influence not only short-term survival,but also long-term survival.展开更多
Lymphomatoid granulomatosis, currently called as extranodal angiocentric and angiodestructive immunoproliferative disorder, is a rare entity of unclear etiology. It involves most frequently lungs, central nervous syst...Lymphomatoid granulomatosis, currently called as extranodal angiocentric and angiodestructive immunoproliferative disorder, is a rare entity of unclear etiology. It involves most frequently lungs, central nervous system and skin. The clinical course is variable, but mortality is high. Today, it represents a diagnostic challenge because it can emulate autoimmunity, infection, and malignancy processes. Optimal therapy scheme is still unknown. We report the case of a 20 year-old man presenting with fever, weight loss, sweating, multiple bilateral lung nodules on the chest X-ray and cutaneous involvement.展开更多
Traditionally surgeons learned surgical techniques by training them directly in the patient by imitating the actions of the surgeon with more experience. Today this methodology is difficult to apply, since there are m...Traditionally surgeons learned surgical techniques by training them directly in the patient by imitating the actions of the surgeon with more experience. Today this methodology is difficult to apply, since there are multiple factors that hinder its use. The limited time of training systems, scarcity of resources, patient safety or the need to learn new techniques of minimally invasive surgery, make the training of surgeons require a different learning methodology. This study has designed a new methodology for the learning of surgical techniques that minimizes the impact of all the previous factors on the training of surgeons. Its effectiveness in the teaching of laparoscopic manual intestinal anastomosis is analyzed. It has been asked a group of 24 expert surgeons teaching in intestinal anastomoses, which are the steps that must include the teaching of the technique. The phases evaluated with the highest score were included in the methodology. Once the steps of the methodology were designed, 25 general surgeons were chosen and divided into three groups according to their level of experience (experts, trained and beginners). Each participant performed five training sessions following the new methodology. The technical quality of the anastomosis, the overall development of the operation, as well as the feedback developed between the participants and the instructor was analyzed. After analyzing the results it was observed that structured feedback between the instructor and the participant increases the involvement of the participant in the learning process and reduces the time needed to acquire the competence. With this methodology the inexperienced participants perform the fifth anastomosis with quality parameters close to those obtained by the expert participants. In addition, this methodology allows to individualize the learning according to the needs of each participant.展开更多
The carbon black has been used in military fabrics to comply with the color requirements and infrared radiation lessening criteria. Currently, military industries don’t distinguish between fabrics with carbon black f...The carbon black has been used in military fabrics to comply with the color requirements and infrared radiation lessening criteria. Currently, military industries don’t distinguish between fabrics with carbon black fibers or with carbon black into dyes or prints. The latter initially allows us to comply with the color specifications in the visible and infrared, but fabrics are degraded with use losing that initial capacity. The inclusion of carbon black in the fiber gets that the fabric doesn’t degrade with the wear, washed and dried, ensuring the accomplishment of the specifications all the time. The use of infrared imaging will allow us to define a method to discriminate those textiles with carbon black in their fibers from those which are dyed or printed.展开更多
This editorial describes the indications and technical aspects of the simultaneous retrieval of thoracic and abdominal organs in Maastricht III donors as well as the preservation of such organs until their implantation.
A Bayesian network approach is presented for probabilistic safety analysis(PSA)of railway lines.The idea consists of identifying and reproducing all the elements that the train encounters when circulating along a rail...A Bayesian network approach is presented for probabilistic safety analysis(PSA)of railway lines.The idea consists of identifying and reproducing all the elements that the train encounters when circulating along a railway line,such as light and speed limit signals,tunnel or viaduct entries or exits,cuttings and embankments,acoustic sounds received in the cabin,curves,etc.In addition,since the human error is very relevant for safety evaluation,the automatic train protection(ATP)systems and the driver behaviour and its time evolution are modelled and taken into account to determine the probabilities of human errors.The nodes of the Bayesian network,their links and the associated probability tables are automatically constructed based on the line data that need to be carefully given.The conditional probability tables are reproduced by closed formulas,which facilitate the modelling and the sensitivity analysis.A sorted list of the most dangerous elements in the line is obtained,which permits making decisions about the line safety and programming maintenance operations in order to optimize them and reduce the maintenance costs substantially.The proposed methodology is illustrated by its application to several cases that include real lines such as the Palencia-Santander and the Dublin-Belfast lines.展开更多
Multiple myeloma(MM)is a hematological malignancy characterized by the accumulation of immunoglobulin-secreting clonal plasma cells at the bone marrow(BM).The interaction between MM cells and the BM microenvironment,a...Multiple myeloma(MM)is a hematological malignancy characterized by the accumulation of immunoglobulin-secreting clonal plasma cells at the bone marrow(BM).The interaction between MM cells and the BM microenvironment,and specifically BM mesenchymal stem cells(BM-MSCs),has a key role in the pathophysiology of this disease.Multiple data support the idea that BM-MSCs not only enhance the proliferation and survival of MM cells but are also involved in the resistance of MM cells to certain drugs,aiding the progression of this hematological tumor.The relation of MM cells with the resident BM-MSCs is a two-way interaction.MM modulate the behavior of BM-MSCs altering their expression profile,proliferation rate,osteogenic potential,and expression of senescence markers.In turn,modified BM-MSCs can produce a set of cytokines that would modulate the BM microenvironment to favor disease progression.The interaction between MM cells and BM-MSCs can be mediated by the secretion of a variety of soluble factors and extracellular vesicles carrying microRNAs,long non-coding RNAs or other molecules.However,the communication between these two types of cells could also involve a direct physical interaction through adhesion molecules or tunneling nanotubes.Thus,understanding the way this communication works and developing strategies to interfere in the process,would preclude the expansion of the MM cells and might offer alternative treatments for this incurable disease.展开更多
The information society depends increasingly on risk assessment and management systems as means to adequately protect its key information assets.The availability of these systems is now vital for the protection and ev...The information society depends increasingly on risk assessment and management systems as means to adequately protect its key information assets.The availability of these systems is now vital for the protection and evolution of companies.However,several factors have led to an increasing need for more accurate risk analysis approaches.These are:the speed at which technologies evolve,their global impact and the growing requirement for companies to collaborate.Risk analysis processes must consequently adapt to these new circumstances and new technological paradigms.The objective of this paper is,therefore,to present the results of an exhaustive analysis of the techniques and methods offered by the scientific community with the aim of identifying their main weaknesses and providing a new risk assessment and management process.This analysis was carried out using the systematic review protocol and found that these proposals do not fully meet these new needs.The paper also presents a summary of MARISMA,the risk analysis and management framework designed by our research group.The basis of our framework is the main existing risk standards and proposals,and it seeks to address the weaknesses found in these proposals.MARISMA is in a process of continuous improvement,as is being applied by customers in several European and American countries.It consists of a risk data management module,a methodology for its systematic application and a tool that automates the process.展开更多
Laparoscopic surgery is applied today worldwide to most digestive procedures. In some of them, such as cholecystectomy, Nissen's fundoplication or obesity surgery, laparoscopy has become the standard in practice. ...Laparoscopic surgery is applied today worldwide to most digestive procedures. In some of them, such as cholecystectomy, Nissen's fundoplication or obesity surgery, laparoscopy has become the standard in practice. In others, such as colon or gastric resection, the laparoscopic approach is frequently used and its usefulness is unquestionable. More complex procedures, such as esophageal, liver or pancreatic resections are, however, more infrequently performed, due to the high grade of skill necessary. As a result, there is less clinical evidence to support its implementation. In the recent years, robot-assisted laparoscopic surgery has been increasingly applied, again with little evidence for comparison with the conventional laparoscopic approach. This review will focus on the complex digestive procedures as well as those whose use in standard practice could be more controversial. Also novel robot-assisted procedures will be updated.展开更多
The present article proposes a climatic approach to the study of the interaction between influenza spreading and climatic and meteorological factors in different climatic domains of the Iberian Peninsula. This associa...The present article proposes a climatic approach to the study of the interaction between influenza spreading and climatic and meteorological factors in different climatic domains of the Iberian Peninsula. This association can be used to help in the prevention and mitigation of influenza epidemics. A biometeorological index has been defined and applied to the epidemic periods that took place in the Iberian Peninsula between 2000 and 2009 considering its climatic domains.展开更多
文摘Batch trials were carried out to determine the methane potential yields of some typical organic wastes generated in the region of Cantabria (Spain): cocoa shell, cheese whey and sludges from dairy industry. Anaerobic co-digestion trials of these wastes with dairy manure were also investigated in batch at 35℃. Cheese whey obtained similar methane yields than dairy manure, between 17.5 and 19.3 L CH4kg-1 cheese whey compared with 18.0 L CH4kg-1 manure. Methane yields of various sludge samples collected from wastewater treatment facilities of dairy industries were influenced by its origin. Sludge samples from fat separation devices were the most productive in terms of specific methane yields compared with biological sludge from an aerobic reactor. Sludge samples from fat separator reached specific methane productivities of 350 and 388 L CH4kg-1 VS (10.5 and 24.1 L CH4kg-1 sludge), whereas biological sludge yielded 125 L CH4kg-1 VS (12.6 L CH4kg-1 sludge). The methane potential of sludge samples was influenced by solids content. Cocoa shell resulted to be an interesting waste for anaerobic digestion due to its high VS content, yielding 195 L CH4kg-1 cocoa shell. It is a waste that can considerably improve methane yields in anaerobic co-digestion with dairy manure. However, at proportions of 10% cocoa shell, the process was hindered by hydrolysis of particulate matter. Anaerobic digestion at higher temperatures (thermophilic range) could be a better option for this kind of waste. Co-digestion of 5% cocoa shell with 35% dairy sludge and 60% dairy manure resulted in 80.5% higher methane production compared to anaerobic digestion of dairy manure alone.
基金Supported by the Project DPI2013-44860 funded by the Spanish Ministry of Science and Technology
文摘In order to satisfy the increasing demand on high performance planetary transmissions, an important line of research is focused on the understanding of some of the underlying phenomena involved in this mechanical system. Through the development of models capable of reproduce the system behavior, research in this area contributes to improve gear transmission insight, helping developing better maintenance practices and more efficient design processes. A planetary gear model used for the design of profile modifications ratio based on the levelling of the load sharing ratio is presented. The gear profile geometry definition, following a vectorial approach that mimics the real cutting process of gears, is thoroughly described. Teeth undercutting and hypotrochoid definition are implicitly considered, and a procedure for the incorporation of a rounding arc at the tooth tip in order to deal with corner contacts is described. A procedure for the modeling of profile deviations is presented, which can be used for the introduction of both manufacturing errors and designed profile modifications. An easy and flexible implementation of the profile deviation within the planetary model is accomplished based on the geometric overlapping. The contact force calculation and dynamic implementation used in the model are also introduced, and parameters from a real transmission for agricultural applications are presented for the application example. A set of reliefs is designed based on the levelling of the load sharing ratio for the example transmission, and finally some other important dynamic factors of the transmission are analyzed to assess the changes in the dynamic behavior with respect to the non-modified case. Thus, the main innovative aspect of the proposed planetary transmission model is the capacity of providing a simulated load sharing ratio which serves as design variable for the calculation of the tooth profile modifications.
基金an extensive research project sponsored by the Company Ferrovial S.A.(Spain)conducted by the Geotechnical Group at the School of Civil Engineering,the University of Cantabria(Spain)
文摘This paper aims to study the shear interaction mechanism of one of the critical geosynthetic interfaces,the geotextile/geomembrane, typically used for lined containment facilities such as landfills. A largedirect shear machine is used to carry out 90 geosynthetic interface tests. The test results show a strainsoftening behavior with a very small dilatancy （〈0.5 mm） and nonlinear failure envelopes at a normalstress range of 25e450 kPa. The influences of the micro-level structure of these geosynthetics on themacro-level interface shear behavior are discussed in detail. This study has generated several practicalrecommendations to help professionals to choose what materials are more adequate. From the threegeotextiles tested, the thermally bonded monofilament exhibits the best interface shear strength underhigh normal stress. For low normal stress, however, needle-punched monofilaments are recommended.For the regular textured geomembranes tested, the space between the asperities is an important factor.The closer these asperities are, the better the result achieves. For the irregular textured geomembranestested, the nonwoven geotextiles made of monofilaments produce the largest interface shear strength.
基金Supported by Spanish Ministerio de Economía y competitividad,No.RTI2018-097324Predoctoral program in Biomedicine from the University of Cantabria and the Instituto de Investigación Valdecilla(IDIVAL),No.PREVAL 19/02 and PREVAL 20/01.
文摘Mesenchymal stem cells(MSCs)are the most frequently used stem cells in clinical trials due to their easy isolation from various adult tissues,their ability of homing to injury sites and their potential to differentiate into multiple cell types.However,the realization that the beneficial effect of MSCs relies mainly on their paracrine action,rather than on their engraftment in the recipient tissue and subsequent differentiation,has opened the way to cell-free therapeutic strategies in regenerative medicine.All the soluble factors and vesicles secreted by MSCs are commonly known as secretome.MSCs secretome has a key role in cell-to-cell communication and has been proven to be an active mediator of immunemodulation and regeneration both in vitro and in vivo.Moreover,the use of secretome has key advantages over cell-based therapies,such as a lower immunogenicity and easy production,handling and storage.Importantly,MSCs can be modulated to alter their secretome composition to better suit specific therapeutic goals,thus,opening a large number of possibilities.Altogether these advantages now place MSCs secretome at the center of an important number of investigations in different clinical contexts,enabling rapid scientific progress in this field.
文摘Mesenchymal stem cells(MSCs)are promising candidates for bone regeneration therapies due to their plasticity and easiness of sourcing.MSC-based treatments are generally considered a safe procedure,however,the long-term results obtained up to now are far from satisfactory.The main causes of these therapeutic limitations are inefficient homing,engraftment,and osteogenic differentiation.Many studies have proposed modifications to improve MSC engraftment and osteogenic differentiation of the transplanted cells.Several strategies are aimed to improve cell resistance to the hostile microenvironment found in the recipient tissue and increase cell survival after transplantation.These strategies could range from a simple modification of the culture conditions,known as cell-preconditioning,to the genetic modification of the cells to avoid cellular senescence.Many efforts have also been done in order to enhance the osteogenic potential of the transplanted cells and induce bone formation,mainly by the use of bioactive or biomimetic scaffolds,although alternative approaches will also be discussed.This review aims to summarize several of the most recent approaches,providing an up-to-date view of the main developments in MSCbased regenerative techniques.
文摘Among neurodegenerative diseases,amyotrophic lateral sclerosis(ALS)is the most frequent one involving motor neurons(MNs).ALS incidence varies throughout the world ranging from 0.7 to 4 cases per 100,000 habitants and year(Riancho et al.,2016).This disease,which currently lacks an effective therapy,is characterized by a variable combination of upper and lower MN degeneration,leading to progressive muscle wasting which usually results in a terminal respiratory failure within 3 years after symptom onset(Zufiria et al.,2016).A small proportion of ALS cases show familial aggregation.These are related to mutations in specific causative genes(Cr9ORF72,TARDBP,FUS,SOD1 and others)which directly determine disease onset in carriers.By contrast,more than 90 percent of cases are considered to be sporadic,in which generally unknown environmental and internal factors interact with genetic predisposing factors finally leading to disease(Riancho et al.,2018).From a histopathological point of view,ALS is characterized by MN damage and loss.MNs from ALS sporadic and most of familial patients exhibit prominent transactive response DNA-binding protein 43(TDP-43)cytoplasmic aggregates which are considered as the“pathological hallmark”of the disease,excepting those related to SOD1 and FUS mutations(Zufiria et al.,2016).TDP-43 is a DNA/RNA binding protein encoded by the TARDBP gene that controls the expression of many different genes.
文摘In this paper, the use of a signal to noise ratio (SNR) is proposed for the quantification of the goodness of some selected processing techniques of thermographic images, such as differentiated absolute contrast, skewness and kurtosis based algorithms, pulsed phase transform, principal component analysis and thermographic signal reconstruction. A new hybrid technique is also applied (PhAC—Phase absolute contrast), it combines three different processing techniques: phase absolute contrast, pulsed phase thermography and thermographic signal reconstruction. The quality of the results is established on the basis of the values of the parameter SNR, assessed for the present defects in the analyzed specimen, which enabled to quantify and compare their identification and the quality of the results of the employed technique.
文摘According to the; energy equation, the relation between reflection and energy losses for short waves from mild beaches is established and analysed. A reflection coefficient varying with position and energy losses is proposed. Different reflection tests are conducted to check the theoretical analysis. A modified method to estimate the reflection coefficient at varied water depths is suggested based on the linear wave theory. The study indicates that the reflection coefficient from mild beaches has a changing trend for short waves approaching shoreline.
基金Project (No. MTM2005-08690-C02-02) partially supported by the Spanish Ministry of Science and Innovation Grant
文摘We introduce a new algebraic approach dealing with the problem of computing the topology of an arrangement of a finite set of real algebraic plane curves presented implicitly. The main achievement of the presented method is a complete avoidance of irrational numbers that appear when using the sweeping method in the classical way for solving the problem at hand. Therefore, it is worth mentioning that the efficiency of the proposed method is only assured for low-degree curves.
文摘BACKGROUND Liver transplant(LT)is a complex procedure with frequent postoperative complications.In other surgical procedures such as gastrectomy,esophagectomy or resection of liver metastases,these complications are associated with poorer long-term survival.It is possible this happens in LT but there are not enough data to establish this relationship.AIM To analyze the possible influence of postoperative complications on long-term survival and the ability of the comprehensive complication index(CCI)to predict this.METHODS Retrospective study in a tertiary-level university hospital.The 164 participants were all patients who received a LT from January 2012 to July 2019.The follow-up was done in the hospital until the end of the study or death.Comorbidity and risk after transplantation were calculated using the Charlson and balance of risk(BAR)scores,respectively.Postoperative complications were graded according to the Clavien-Dindo classification and the CCI.To assess the CCI cut-off value with greater prognostic accuracy a receiver operating characteristic(ROC)curve was built,with calculation of the area under the curve(AUC).Overall survival was estimated according to the Kaplan-Meier test and log-rank test.Groups were compared by the Mann-Whitney test.For the multivariable analysis the Cox regression was used.RESULTS The mean follow-up time of the cohort was 37.76(SD=24.5)mo.A ROC curve of CCI with 5-year survival was built.The AUC was 0.826(0.730-0.922),P<0.001.The cut-off was calculated by means of the Youden index with a result of 35.95.The sensitivity was 84.6%and the specificity 61.3%.Survival curves for comparison of patients with CCI score<36 vs≥36 were calculated.The estimated 5-year survival was 57.65 and 43.95 months,respectively(log-rank<0.001).This suggests that patients with more severe complications exhibit worse long-term survival.Other cut-off values were analysed.Comparison between patients with CCI<33.5 vs>33.5(33.5=median CCI value)showed estimated 5-year survival was 57.4 and 45.71 months,respectively(log-rank<0.0001).Dividing patients according to the mode CCI value(20.9)showed an estimated 5-year survival of 60 mo for a CCI below 20.9 vs 57 mo for a CCI above 20.9(log-rank=0.147).The univariate analysis did not show any association between individual complications and long-term survival.A multivariate analysis was carried out to analyse the possible influence of CCI,Charlson comorbidity index,BAR and hepatocellular carcinoma on survival.Only the CCI score showed significant influence on long-term survival.CONCLUSION A complicated postoperative period–well-defined by means of the CCI score–can influence not only short-term survival,but also long-term survival.
文摘Lymphomatoid granulomatosis, currently called as extranodal angiocentric and angiodestructive immunoproliferative disorder, is a rare entity of unclear etiology. It involves most frequently lungs, central nervous system and skin. The clinical course is variable, but mortality is high. Today, it represents a diagnostic challenge because it can emulate autoimmunity, infection, and malignancy processes. Optimal therapy scheme is still unknown. We report the case of a 20 year-old man presenting with fever, weight loss, sweating, multiple bilateral lung nodules on the chest X-ray and cutaneous involvement.
文摘Traditionally surgeons learned surgical techniques by training them directly in the patient by imitating the actions of the surgeon with more experience. Today this methodology is difficult to apply, since there are multiple factors that hinder its use. The limited time of training systems, scarcity of resources, patient safety or the need to learn new techniques of minimally invasive surgery, make the training of surgeons require a different learning methodology. This study has designed a new methodology for the learning of surgical techniques that minimizes the impact of all the previous factors on the training of surgeons. Its effectiveness in the teaching of laparoscopic manual intestinal anastomosis is analyzed. It has been asked a group of 24 expert surgeons teaching in intestinal anastomoses, which are the steps that must include the teaching of the technique. The phases evaluated with the highest score were included in the methodology. Once the steps of the methodology were designed, 25 general surgeons were chosen and divided into three groups according to their level of experience (experts, trained and beginners). Each participant performed five training sessions following the new methodology. The technical quality of the anastomosis, the overall development of the operation, as well as the feedback developed between the participants and the instructor was analyzed. After analyzing the results it was observed that structured feedback between the instructor and the participant increases the involvement of the participant in the learning process and reduces the time needed to acquire the competence. With this methodology the inexperienced participants perform the fifth anastomosis with quality parameters close to those obtained by the expert participants. In addition, this methodology allows to individualize the learning according to the needs of each participant.
文摘The carbon black has been used in military fabrics to comply with the color requirements and infrared radiation lessening criteria. Currently, military industries don’t distinguish between fabrics with carbon black fibers or with carbon black into dyes or prints. The latter initially allows us to comply with the color specifications in the visible and infrared, but fabrics are degraded with use losing that initial capacity. The inclusion of carbon black in the fiber gets that the fabric doesn’t degrade with the wear, washed and dried, ensuring the accomplishment of the specifications all the time. The use of infrared imaging will allow us to define a method to discriminate those textiles with carbon black in their fibers from those which are dyed or printed.
文摘This editorial describes the indications and technical aspects of the simultaneous retrieval of thoracic and abdominal organs in Maastricht III donors as well as the preservation of such organs until their implantation.
文摘A Bayesian network approach is presented for probabilistic safety analysis(PSA)of railway lines.The idea consists of identifying and reproducing all the elements that the train encounters when circulating along a railway line,such as light and speed limit signals,tunnel or viaduct entries or exits,cuttings and embankments,acoustic sounds received in the cabin,curves,etc.In addition,since the human error is very relevant for safety evaluation,the automatic train protection(ATP)systems and the driver behaviour and its time evolution are modelled and taken into account to determine the probabilities of human errors.The nodes of the Bayesian network,their links and the associated probability tables are automatically constructed based on the line data that need to be carefully given.The conditional probability tables are reproduced by closed formulas,which facilitate the modelling and the sensitivity analysis.A sorted list of the most dangerous elements in the line is obtained,which permits making decisions about the line safety and programming maintenance operations in order to optimize them and reduce the maintenance costs substantially.The proposed methodology is illustrated by its application to several cases that include real lines such as the Palencia-Santander and the Dublin-Belfast lines.
基金Supported by The“Instituto de Salud Carlos III,No.PI22/00264A Predoctoral Program in Biomedicine from The University of Cantabria and The Instituto de Investigación Valdecilla-IDIVAL(Alberto González-González and Daniel García-Sánchez),No.PREVAL19/02,and No.PREVAL20/01“Investigo Program”,part of the“Plan Nacional de Recuperación,Transformación y Resiliencia”from The Spanish Government(Mónica del Dujo-Gutiérrez).
文摘Multiple myeloma(MM)is a hematological malignancy characterized by the accumulation of immunoglobulin-secreting clonal plasma cells at the bone marrow(BM).The interaction between MM cells and the BM microenvironment,and specifically BM mesenchymal stem cells(BM-MSCs),has a key role in the pathophysiology of this disease.Multiple data support the idea that BM-MSCs not only enhance the proliferation and survival of MM cells but are also involved in the resistance of MM cells to certain drugs,aiding the progression of this hematological tumor.The relation of MM cells with the resident BM-MSCs is a two-way interaction.MM modulate the behavior of BM-MSCs altering their expression profile,proliferation rate,osteogenic potential,and expression of senescence markers.In turn,modified BM-MSCs can produce a set of cytokines that would modulate the BM microenvironment to favor disease progression.The interaction between MM cells and BM-MSCs can be mediated by the secretion of a variety of soluble factors and extracellular vesicles carrying microRNAs,long non-coding RNAs or other molecules.However,the communication between these two types of cells could also involve a direct physical interaction through adhesion molecules or tunneling nanotubes.Thus,understanding the way this communication works and developing strategies to interfere in the process,would preclude the expansion of the MM cells and might offer alternative treatments for this incurable disease.
基金the AETHERUCLM(PID2020-112540RB-C42)funded by MCIN/AEI/10.13039/501100011033,SpainALBA-UCLM(TED2021-130355B-C31,id.4809130355-130355-28-521)+1 种基金ALBA-UC(TED2021-130355B-C33,id.3611130630-130630-28-521)funded by the“Ministerio de Ciencia e Innovacion”,Spainsupported by the European Union’s Horizon 2020 Project“CyberSANE”under Grant Agreement No.833683.
文摘The information society depends increasingly on risk assessment and management systems as means to adequately protect its key information assets.The availability of these systems is now vital for the protection and evolution of companies.However,several factors have led to an increasing need for more accurate risk analysis approaches.These are:the speed at which technologies evolve,their global impact and the growing requirement for companies to collaborate.Risk analysis processes must consequently adapt to these new circumstances and new technological paradigms.The objective of this paper is,therefore,to present the results of an exhaustive analysis of the techniques and methods offered by the scientific community with the aim of identifying their main weaknesses and providing a new risk assessment and management process.This analysis was carried out using the systematic review protocol and found that these proposals do not fully meet these new needs.The paper also presents a summary of MARISMA,the risk analysis and management framework designed by our research group.The basis of our framework is the main existing risk standards and proposals,and it seeks to address the weaknesses found in these proposals.MARISMA is in a process of continuous improvement,as is being applied by customers in several European and American countries.It consists of a risk data management module,a methodology for its systematic application and a tool that automates the process.
文摘Laparoscopic surgery is applied today worldwide to most digestive procedures. In some of them, such as cholecystectomy, Nissen's fundoplication or obesity surgery, laparoscopy has become the standard in practice. In others, such as colon or gastric resection, the laparoscopic approach is frequently used and its usefulness is unquestionable. More complex procedures, such as esophageal, liver or pancreatic resections are, however, more infrequently performed, due to the high grade of skill necessary. As a result, there is less clinical evidence to support its implementation. In the recent years, robot-assisted laparoscopic surgery has been increasingly applied, again with little evidence for comparison with the conventional laparoscopic approach. This review will focus on the complex digestive procedures as well as those whose use in standard practice could be more controversial. Also novel robot-assisted procedures will be updated.
文摘The present article proposes a climatic approach to the study of the interaction between influenza spreading and climatic and meteorological factors in different climatic domains of the Iberian Peninsula. This association can be used to help in the prevention and mitigation of influenza epidemics. A biometeorological index has been defined and applied to the epidemic periods that took place in the Iberian Peninsula between 2000 and 2009 considering its climatic domains.
