85 research outputs found

    3D printable acrylate polydimethylsiloxane resins for cell culture and drug testing

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    Nowadays, most of the microfluidic devices for biological applications are fabricated with only few well-established materials. Among these, polydimethylsiloxane (PDMS) is the most used and known. However, it has many limitations, like the operator dependent and time-consuming manufacturing technique and the high molecule retention. TEGORad or Acrylate PDMS is an acrylate polydimethylsiloxane copolymer that can be 3D printed through Digital Light Processing (DLP), a technology that can boast reduction of waste products and the possibility of low cost and rapid manufacturing of complex components. Here, we developed 3D printed Acrylate PDMS-based devices for cell culture and drug testing. Our in vitro study shows that Acrylate PDMS can sustain cell growth of lung and skin epithelium, both of great interest for in vitro drug testing, without causing any genotoxic effect. Moreover, flow experiments with a drug-like solution (Rhodamine 6G) show that Acrylate PDMS drug retention is negligible unlike the high signal shown by PDMS. In conclusion, the study demonstrates that this acrylate resin can be an excellent alternative to PDMS to design stretchable platforms for cell culture and drug testing

    Microwave-assisted methacrylation of chitosan for 3D printable hydrogels in tissue engineering

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    Light processable natural polymers are highly attractive for 3D printing of biomedical hydrogels with defined geometries and sizes. However, functionalization with photo-curable groups, such as methacrylate or acrylate groups, is required. Here, we investigated a microwave-assisted process for methacrylation of chitosan to replace conventional methacrylation processes that can be time consuming and tedious. The microwave-assisted methacrylation reaction was optimized by varying the synthesis parameters such as the molar ratio of chitosan to the methacrylic agent, the launch and reaction times and process temperature. The optimized process was fast and efficient and allowed tuning of the degree of substitution and thereby the final hydrogel properties. The successful methacrylation and degree of substitution were verified by H-1 NMR and attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). The influence of the degree of methacrylation on photo-rheology, mechanical stiffness, swelling degree and gel content was evaluated. Furthermore, favourable 3D printability, enzymatic degradability, biocompatibility, cell migration and proliferation were demonstrated giving promise for further applications in tissue engineering

    Biomimetic hybrid nanoconstructs for cancer therapy

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    Water retentivity and environmental impact assessment in the headwaters of the Chambira micro-watershed, San Martin region

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    The study found that maximum precipitation and water retention occur in February for the Cacao sector and in October and February for the Caliza sector, with minimum values in July. The correlation between precipitation and temperature is −0.43 for both sectors, while the negative correlation between retentivity and temperature is stronger in the Caliza sector (−0.467) than in the Cacao sector (−0.096). Precipitation explains 82.07% and 89.92% of the variability in retentivity for the Cacao and Caliza sectors, respectively, according to the R2 coefficients. The environmental impact analysis indicates a medium impact with a value of 5.6

    Assessment of Patient Satisfaction Using a New Augmented Reality Simulation Software for Breast Augmentation: A Prospective Study

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    Background: Breast augmentation is one of the most frequently performed plastic surgery procedures. Providing patients with realistic 3D simulations of breast augmentation outcomes is becoming increasingly common. Until recently, such programs were expensive and required significant equipment, training, and office space. New simple user-friendly programs have been developed, but to date there remains a paucity of objective evidence comparing these 3D simulations with post-operative outcomes. The aim of this study is to assess the aesthetic similarity between a preoperative 3D simulation generated using Arbrea breast simulation software and real post-operative outcomes, with a focus on patient satisfaction. Methods: The authors conducted a prospective study of patients requiring breast augmentation. Patients were asked to assess how realistic the simulation was compared to the one-year post-operative result using the authors’ grading scale for breast augmentation simulation assessment. Patient satisfaction with the simulations was assessed using a satisfaction visual analogue scale (VAS) ranging from 0 (not at all satisfied) to 10 (very satisfied). Patient satisfaction with the surgical outcome was assessed using the BREAST-Q Augmentation Module. Results: All patients were satisfied with the simulations and with the attained breast volume, with a mean VAS score of 8.2   1.2. The mean simulation time took 90 s on average. The differences between the pre-operative and one-year post-operative values of the three BREAST-Q assessments were found to be statistically significant (p < 0.001). Conclusions: Three-dimensional simulation is becoming increasingly common in pre-operative planning for breast augmentation. The present study aimed to assess the degree of similarity of three-dimensional simulations generated using Arbrea Breast Software and found that the use of the software provided a very satisfying representation for patients undergoing breast augmentation. However, we recommend informing patients that only the volume simulation is extremely accurate. On the other hand, it is necessary to not guarantee an absolute correspondence regarding the breast shape between the simulation and the post-operative result

    Islet transplantation and insulin administration relieve long-term complications and rescue the residual endogenous pancreatic cells

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    Islet transplantation is a poorly investigated Long-term strategy for insulin replacement and for treatment of complications in patients with diabetes. We investigated whether islet transplantation and insulin treatment can relieve diabetic neuropathy and rescue the residual endogenous pancreatic beta cells. We used a multimodal approach, with five groups of Sprague-Dawley rats studied for 8 months: control rats, diabetic rats, insulin-treated diabetic rats with moderate or mild hyperglycemia, and diabetic rats transplanted with microencapsulated islets. Islet transplantation normalized glycemia and increased body and muscle weight; it was also effective in reducing proteinuria and altered liver function. Transplantation significantly improved tail nerve conduction velocity, Na+-K+-ATPase activity, and morphological alterations in the sciatic nerve as evidenced by decrease in g-ratio; it also restored thermal and ameliorated mechanical nociceptive thresholds. Morphometric analysis of pancreas indicated a significant beta-cell volume increase in transplanted rats, compared with mildly and moderately hyperglycemic rats. Thus, allogeneic islet transplantation had a positive systemic effect in diabetic rats and induced regression of the established neuropathy and restitution of the typical characteristics of the islets. These findings strongly reinforce the need for improving glycemic control, not only to reverse established diabetic complications but also to improve beta-cell status in diabetic pancreas

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Clinical autonomic nervous system laboratories in Europe. A joint survey of the European Academy of Neurology and the European Federation of Autonomic Societies

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    Background and purpose: Disorders of the autonomic nervous system (ANS) are common conditions, but it is unclear whether access to ANS healthcare provision is homogeneous across European countries. The aim of this study was to identify neurology-driven or interdisciplinary clinical ANS laboratories in Europe, describe their characteristics and explore regional differences. Methods: We contacted the European national ANS and neurological societies, as well as members of our professional network, to identify clinical ANS laboratories in each country and invite them to answer a web-based survey. Results: We identified 84 laboratories in 22 countries and 46 (55%) answered the survey. All laboratories perform cardiovascular autonomic function tests, and 83% also perform sweat tests. Testing for catecholamines and autoantibodies are performed in 63% and 56% of laboratories, and epidermal nerve fiber density analysis in 63%. Each laboratory is staffed by a median of two consultants, one resident, one technician and one nurse. The median (interquartile range [IQR]) number of head-up tilt tests/laboratory/year is 105 (49–251). Reflex syncope and neurogenic orthostatic hypotension are the most frequently diagnosed cardiovascular ANS disorders. Thirty-five centers (76%) have an ANS outpatient clinic, with a median (IQR) of 200 (100–360) outpatient visits/year; 42 centers (91%) also offer inpatient care (median 20 [IQR 4–110] inpatient stays/year). Forty-one laboratories (89%) are involved in research activities. We observed a significant difference in the geographical distribution of ANS services among European regions: 11 out of 12 countries from North/West Europe have at least one ANS laboratory versus 11 out of 21 from South/East/Greater Europe (p = 0.021). Conclusions: This survey highlights disparities in the availability of healthcare services for people with ANS disorders across European countries, stressing the need for improved access to specialized care in South, East and Greater Europe
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