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  • Pierre Claudy added an answer in TGA/DSC:
    Does anyone have idea that if particle size would impact the melting point measured by DSC?

    The particle size was reduced from about 100 micronmeter to 10 micrometer, however, the melting signal on DSC shifted to higher temperature.

    Pierre Claudy

    Then the size is not responsible for this behavior. Other experimental parameters have to be considered. How are you decreasing the size? Possible change of your product ? Oxydation ? Crystal structure ? ...

  • Yousef Amini added an answer in PLGA Nanoparticles:
    Any advice on why I cannot calculate protein encapsulation in PLGA nanoparticles?

    my blank NP absorbency in BCA method is higher than NP contain protein. it s maybe because PVA in blank NP or i dont have protein encapsulation. i confuse, also i used NaoH 1M and urea 10M+ SDS 2% and pbs for dissolve protein in pellet. please guide me if you have same experience,

    Yousef Amini

    my protein concentration is 3mg per ml. no i didnt tried bradford but my colleague used and obtain same results .

  • Elshaimaa Abumandour added an answer in Ionic Liquids:
    Which families of ionic liquids amongst the extensively used in research studies are more corrosive?

    What is the reason of the corrosion of the ionic liquids.

    I am trying to find the probability of ionic liquids to damage pipelines by their corrosive nature.


    Elshaimaa Abumandour

    I think the probable reason that ILs can be corrosive is their decomposition byproduct when temperature increases or when mixed with solvents such as water. alkylsulfate based ILs can be corrosive when mixed with water.

  • Gunjan Mansingh added an answer in Money:
    Does the Kenyan M-Pesa mobile money model points to the Future of Money ?

    The M-Pesa model demonstrates the beneficial impacts to society (government, firms and households) through reduced costs for financial intermediation, improved efficiencies in service delivery to the bottom of the pyramid, the productivity implications, the security benefits of going cashless, efficiencies in tax collection and  the facilitation in spurring related innovations.

    see video


    Despite the overwhelming  success in Kenya, similar successes has not been translated in other overseas jurisdictions.  What are the barriers to successful diffusion in other jurisdictions ?  Is the lack of success due to the resistance of the incumbent banking sector, the conservatism of the regulators, the different local cultures, the density / ubiquity of the smart phone penetration ?


    Gunjan Mansingh

    You might find this link interetsing.


  • Constantin Bratianu added an answer in Knowledge Management:
    I am interested in reading more about Knowledge Management Maturity Models - KMMM. Who worked with such models?

    The evolution of a Knowledge Management System can be measured by using some Maturity Models. I am interested in reading more about any experience in using such KMMM. I would appreciate sending me some papers in this domain.

    Constantin Bratianu

    Dear John,

    I got your answer and the paper attached.

    Many thanks!


  • Narendra Kumar Chunduri added an answer in Chromatin:
    Could someone answer some questions on chromatin accessibility by DNase1?

    I would like to investigate the chromatin state (open or closed) at defined locus using DNase1 in my cell lines. I performed this experiment a couple of times and I have some questions concerning this.

    1.       To what extent should I digest the chromatin? Generally I digest in such a way that I do not see any undigested genomic DNA. I use about 20-50 U for 3 million cells. Is this optimal?

    2.       Experimentally, what are the most critical steps that would affect the outcome of experiment?

    3.       What is the best way to isolate genomic DNA? I always use phenol chloroform method. It works very well with my digested samples. But I find it difficult to use with undigested samples as the DNA is quite sticky and difficult to separate from interphase.

    Any suggestions would be appreciated. Thank you!

    Narendra Kumar Chunduri

    Dear Carmelo,

    Thanks for your suggestions.

    -Concerning point 1, I have tested various concentrations and i have decided to use 20U or 50U. But my question is to what extent should i digest the DNA? Should i aim for complete digestion such that i do not see any undigested genomic DNA on agarose gel or mild digestion (Smear of DNA) should do?

  • Ulf Nobbmann added an answer in Dynamic Light Scattering:
    Can someone help with size measurement of blood microparticles (microvesicles) using dynamic light scattering?

    I am trying to measure size distribution of my microparticles samples isolated from blood and synovial fluid using Dynamic Light scattering (Malvern ZetaSizer, Nanotrack Wave). Refractive index (RI) and absorbance rate needs to be entered for each sample in order to do the analysis. In the literature, RI for microvesicles are given as a range 1.35-1.45. Tried to use RI from 1.35 to 1.45, the measurements give very different size for each RI in this range. There are many papers that have used Malvern ZetaSizer and Nanotrack Wave for size distribution analysis of both microvesicles and exosomes, but non of them mention what RI and absorbance are used in their analysis. Any suggestion and advise is appreciated.




    Ulf Nobbmann

    The intensity based size does not depend on the refractive index you enter for the vesicles, it is only the volume or number based distribution that you try to derive from that intensity based distribution. So, as a first step look at the intensity based results: z-average and intensity based particle size distribution. You probably are looking at the volume based distribution, and this will (especially for sizes larger than 100nm) change with the refractive index properties. In the attached publication, NTA was used to determine the refractive index for some vesicles that might be relevant for you.

    + 1 more attachment

  • Jose Rueff added an answer in SPSS:
    Could you tell me how to calculate the SNPs results with OR and compare the genotypic frequency of each SNPs type with SPSS?

    I have done the project about genetic polymorphism and now I face some problem about how to use the statistical analysis to evaluate my results. Could you give me some suggestion for SNPs interpretation?

    Jose Rueff

    Dear Methee,

    Although I'm not aware of the exact nature of your work, here are some general suggested informations which can be used if you are abour to determine ORs for a certain condition comparing patients wit age- and sex-matched controls (and please bear in mind that controls should be age-matched within at a maximum of 18 months interval of the date of birth. The Hardy-Weinberg frequencies for all alleles in patients and controls should be analyzed using exact probability tests available in Mendel software (V5.7.2).The Kolmogorov-Smirnov and Shapiro-Wilk tests should be used to verify the normality of continuous variables and the Levene test to analyze the homogeneity of variances. Differences in genotype frequency, age class and gender distributions between patients and controls should be evaluated by the χ2 test. Adjusted odds ratio (OR) and corresponding 95% confidence interval (CI) should be calculated using unconditional multiple logistic regression. The model for adjusted OR should  include terms for sex, age at diagnosis (e.g., ≤30, 31-39, 40-49, 50-59, 60-69 and ≥70 years). The reference groups for these variables should be clearly set. All analyses can be performed using SPSS 15.0 (SPSS, Inc.).

    Jose Rueff

  • Anders Lanzén added an answer in DNA Sequence Analysis:
    Can anyone provide the method for improving the sequence quality of low quality sequence?

    I have done 16SrDNA sequencing. The sequences obtained are of low quality which gives a problem in obtaining accession number. Can anyone suggest me the methods to improve the sequence quality?

    Anders Lanzén

    Can you explain what you mean with "problem in obtaining accession number"? Are you trying to submit your low-quality sequences to Genbank (or similar) and they do not let you due to low quality? Or are you trying to run a similarity search (e.g. BLAST) and are getting no hits to public sequences (which have accession numbers...)?

  • Harekrishna Misra added an answer in Climate:
    How to increase preventive thinking and research?

    The climate summit in Paris shows: earlier preventive thinking and research was 1) to slow and 2) couldn´t be put in practice in time.

    As for the preventions in politics - some kind of clearly future-oriented ruling of the daily business from a wider perspective, we have the general one regarding the specific countries, provinces and cities - but as well the institutional ones.

    In some part - sooner or later - they are linked.

    So how about your personal experiences, to influence yourself the direction in respect to a prevention supporting research?

    And how can it be inhanced for a better future?

    Harekrishna Misra

    The question is quite timely! But we always do not learn from our mistakes. The situation that we face today is because of systematic failure of the warning given by nature with sytemic indications over ages. The situation will continue. 

  • Pierre Devaux added an answer in Restoration:
    Is it wise and scientific to perform only one cross between a CMS line and a restorer line to find the genes restoring fertiliy in the F1?

    Or do I need to perform several cross between CMS and restorer lines with different genotypes?

    Pierre Devaux

    Hi Anik,

    I understand your concern, budget and time have to be considered of course! Two F2 populations sound fine to me and definitely more robust that a single one. The procedure seems also fine. Too bad that you don't time enough to generate RILs or DHs as mapping populations if there were possible to get in your species. Is that wheat you are dealing with as you are from Hohenheim :-)?  Best regards and good luck!


  • Alberto Battistelli added an answer in Tomato:
    Is it possible to include green (premature) fruits in the total yield of tomato?

    I conducted a variety trial of tomato. However, due to early frost period, I decided to harvest all mature fruits and cut the plants to determine plant biomass while there was some premature fruits (green fruits) which was also weighted separately from plant biomass. I am wondering if it makes sense to include these premature fruits as yield? The proportion of the remaining fruits was about from 10-20% comparing to the harvested mature fruits.

    Alberto Battistelli

    If your aim is physiology, you might consider the immature fruit as a sink. If it is productivity you can consider the immature fruit as a non-edible biomass because you would not send it to the market. Furthermore, by including the immature fruit in the yield you might very likely decrease quality and value related parameters of your produce, like average size of fruit, lycopene content , sugar content and so on.

    But what is the problem to consider two classes of fruit?

  • David A Rowe added an answer in Physical Activity:
    How many steps mean a clinically relevant increase in activity in chronic patients such as COPD?

    Recommendations give 30 minutes of moderate activity on 5 days a week from. An objective indication of amounts to 7000 steps per day. When can you say that it is a significant improvement? Even if a patient improved from 3000 to 4000 steps / day? Is there information on the responsiveness?

    David A Rowe

    Gilbert, if you mean an objective measure, I am not sure there are any low-cost alternatives. The activPAL is generally looked upon as the gold standard measure but they are not cheap. Some questionnaires (e.g., IPAQ) include sitting time estimates but I am not sure they are accurate enough to detect sensitivity to change in individuals, more intended for general population surveillance.

  • Ita Widowati added an answer in H&E:
    Can any histological resercher help me with the scoring of artemia tissue with H&E?

    I'm using H&E.

    Ita Widowati

    H&E is a simple tissue coloration, just to colour the topography of the tissue,  not to scale the degree of contents (like coloration used in histochemical : Alkaline phospatase , acid phosphatase, etc). By using the  histochemical for example, we could see the level of content by regarding the colour and it make it possible to scale (semiquantitatif study).

    So, please define what do you want to score? and on  which part of tissue of Artemia? 

    Hoping to hear you soon.


  • Oksana Tuchina added an answer in Oligodendrocytes:
    Could anyone please suggest me good antibodies to check different glial populations by immunohistochemistry?

    Hi, I am trying to find the best antibodies to perform immunohistochemistry and check neurons, oligodendrocytes, astrocytes and microglial populations. I know that will be tough to check everything at the same time because of color-dye combinations. I have some in mind, but I will really appreciate expertise input before buying them. 

    Thanks a lot!!

    Oksana Tuchina

    Hi Sergio,

    Are you going to do IHC on fixed brain sections?

    Then my advice is to use GFAP (for astrocytes), NeuN or TUJ1 (for neurons) and Iba1 (for microglia) - all antibodies from Abcam. I havent done any IHC with oligodendrocytes, so I cannot advice anything. But you can use 3, 4 or more antibodies at the same time. Just check your overlapping spectra.

  • David F. Nettleton asked a question in Numerics:
    Data modeling techniques for multiple input and multiple output continuous data values?

    I am looking for some machine learning/statistical techniques/algorithms/functions with the following capabilities:

    - can be called as an api from c++
    - can model multiple numerical outputs for calibration modeling*

    * For example, I have an industrial process which fabricates a high precision component (numerically controlled machine) which has two inputs
    (temperature, tension) and two outputs (friction, radius), all of which are continuous numerical values. So, for a diversity of input configurations, I want to model what the outputs will be.

    Also, I would like to model the reverse, that is, given some output values (friction, radius), I would like to know what the input values should be to obtain those output values.

  • Georgina Boyd added an answer in Domestic Violence:
    Is there a relationship between familism and acculturation in disclosure and help-seeking for domestic violence and abuse among immigrant communities?

    I am developing a thesis on the role of familism and acculturation on the disclosure and help-seeking practices of immigrant women, and I am looking to see whether familism and acculturation maybe linked

    Georgina Boyd

    This is an interesting question and one which we examined in college the sociological make up of families has a lot to do with attitudes to domestic violence. It also has a cultural basis which is based up the roles of men and women within relationshiips. In some cultures women are not permitted to be seen by male doctors without their husbands present  if domestic violence is taking place their is not  avenue available for that woman to make a disclosure even if the GP suspects its the case. If marriage and family are a core cultural value the woman may perceive the violence reigned upon her as a sign of her failure to fulfill her marriage and support her husband and that this is the reason she is receiving this treatment from him. Having worked a short period with DVAS it is also important to realise that despite how multicultural our society is each person within their own culture speaks their own native language first with english sometimes coming a poor second. The ability to read and understand English results in an inability by many women from other ethnic minorities being unable to access supports or services. Their is also the fear that if they do access the services of a Domestic Violence Advocacy SErvice some one will see them and tell their husband, For many its a case of suffering in silence however the women are not the only one suffering its the children and the long term psychological impact on the children where continuation of domestic violence can be a learned thing leading to the continuation of the circle of  violence..

  • Jessica Grant added an answer in siRNA:
    Can I use a Lipofectamine® RNAiMAX kit to transfect nematodes (parasitic) with siRNA to knockdown genes?

    I want to knock down my genes of interest in parasitic nematode using siRNA in larval stages. For now I want to use Lipofectamine® RNAiMAX kit for transfection, could someone out there who used this kit either in C.elegans or other nematode give me an idea or tips on this kit? Or is there any other better cationic molecules to for transfecting siRNA in nematodes? Thanks in advance!

    Jessica Grant

    Cool, thank you!  I'm working primarily with Brugia malayi.  I've spent the past few years in front of a computer, so getting back to the bench is pretty exciting.

  • Jette Mebrouk added an answer in Hospitals:
    Does anybody have experiences with the implementation of SBAR in hospitals and would like to share her/his expertise?

    We would like to implement SBAR communication in a German Hospital. We are thankful for all advices, hints or literature tips: What are the main obstacles? What structures do we need for successful implementation? How should a SBAR training look like? How should we evaluate the effects of SBAR? etc.

    Jette Mebrouk

    Changing practice is challenging, even when all the evidence is there to support it. I think one of the reasons has to do with the constant flow of new initiatives, while at the same time having to work in an increasingly complex setting, providing quality care. This is not to give (good or poor) excuses, but merely to share my experience.

    Having clinical staff involved in the decision making and implementation stages is very important, it takes it far ahead on the success ladder (at least that is what I think).

    We also had small cards with a brief overview. They easily get lost (our ID badge system does not hang in a string where the card could be attached). The problem with these cards is also that there are so many other cards, and there is a limit to how many you can carry around.

    Definitely: Go for the poster in the rest room. Great idea.

  • Curtis Takahashi added an answer in Beetles:
    Can anybody determine this Cerambycid beetle?

    Determination only with pictures is difficult or impossible, I know.

    I thought, it is Acmaeops septentrionis, but I am not sure.

    Germany, Bayerischer Wald, 320 m, Meadow in a small river valley, 2009-05-17

    Thank you for your help!

    Rudolf Ritt

    + 1 more attachment

    Curtis Takahashi

    My suggestion is to get a series.  You'll have a better chance at species identification.  Some characters tend to be variable (ie:  "ususally", "sometimes", "often" being not uncommon in keys).

  • Marleen Hanelt added an answer in Macrophage:
    How can I normalize my seahorse bioscience assays?

    Hello everyone,

    I want to do assays using a Seahorse Flux analyzer (96well, mostly mitostress test) with primary macrophages and I wonder, how I can normalize the results for the cell number per well after the run (I plate a defined cell number, but there can be still differences in cell survival or proliferation). Has anyone done such an assay with macrophages and could help me with that issue?

    Thanks in advance,


    Marleen Hanelt

    Thanks everyone. The answers are very helpful.

    Philip, do you centrifuge the plate between the PBS washing steps?

    Julie, have you ever tried transfering everything to a new 96 well plate instead of tubes (that could safe a lot of time, I assume) and spin it down in between each step?

    Thanks for your help.



  • Thomas Walther added an answer in Tungsten:
    How can i measure and locate Cavities clusters in under and overfocused TEM picture in irradiated sample?

    Hi everyone.

    I have irradiated tungsten sample and i'm looking to find and measure the cavity size in TEM pictures. For now, i located cavities manualy one by one. And i'm looking for a software that can do it automatically.

    Thank you very much

    Thomas Walther

    The larger cluster should not pose a problem, I guess. The 1-2nm clusters should be more difficult, in particular if they overlap and your sample surface is not perfectly flat.  Have you tried to increase overall contrast by EFTEM (try 8eV slits around 0eV, 23eV and 45eV ) or DF?

  • Clifford Morris added an answer in Liposomes:
    Can anyone please help me with liposome preparation?!!


    I am currently working on a project involving the observation of Beta-amyloid 1-40 peptide via ThT kinetics assay compared to that of some Mutant AB1-40 species I have synthesized too. We observed the peptide kinetics using ThT fluorescence assay and the results showed a difference in aggregation. Now, we want to use POPG and POPC phospholipid liposomes in order to take advantage of the different properties of the mutants and observe their kinetics now in the presence of liposomes. I have previously done this but I have a few questions to validate my methods.

    My previous method is as follows:

    The lipids were co-dissolved and mixed at the appropriate ratios in chloroform/methanol 1:1 v/v and the solvent removed by rotary evaporation at 45°C to obtain a thin lipid film. Phosphate buffer (50 mM Na-phosphate, 150 mM NaCl, pH 7.4) (PBS) was preheated to 45°C and added to rehydrate and the lipids to a final concentration of 0.4mg/mL (500μM) and the vessel vigorously agitated on a rotary mixer at a temperature above the transition temperature of the specific lipid (45°C for POPC/G) in a hot water bath for 1 hour to produce multilamellar vesicles (MLVs).

    Size Reduction of Liposomes: 

    Liposomes can be downsized by either bath sonication or probe tip sonication. For this study, a probe tip sonication cycle was used to produce Large Unilamellar Vesicles (LUVs). Original liposome MLV samples were placed in a water bath to maintain a stable temperature (40-45°C) during sonication, as the probe tip is susceptible to large heat generation, especially in small samples. A Microson Ultrasonic Cell Disruptor (Misonix, NY) was used to perform the sonication at a 30% duty cycle for 3 x 20 second pulses with 1 minute intervals between pulses. Following sonication, LUVs were annealed at 45°C for 60 minutes to increase sample homogeneity. “Liposomes can be stored at 4°C without an appreciable change in size for up to one month.”

    Then, DLS by Malvern nanosizer showed I got consistent samples around 100-200nm Diameter, with quite decent sample size distribution population. (See attached DLS results from). Previously I attempted a bath sonication method but was not strong enough to downsize liposomes to a size smaller than ~500nm so I used a probe-tip sonicator instead and provides decent results.

    For this new project. I will be preparing three samples of liposomes. 1) 100% POPG. 2)50/50% POPG/POPC and 3) 100% POPC.

    Does anyone have any suggestions for me to improve my methodology of liposome preparation?

    Specifically I would like to ask:

    1)    When downsizing using sonication, what temperature should this be done at? Above the phase transition temperature correct? I want to ensure best formation of SUV’s from the LMV’s and LUV’s. Ideally, I want to make SUV’s in the 50-100nm range, but anything up to 200nm liposome size is ok for my application, since we just want to observe the effect of adding liposomes into the in-vitro environment of the ThT assay.

    2)    Is it possible to “over-sonicate” by sonicating for too long or too strong intensity? Will this result in destruction of liposomes or will it rather produce better, more homogenous SUV’s?

    3)    To ensure correct storage of liposomes, is it ok to store them in 4C fridge then use a couple days later? What is the time limit on storage of liposomes?  Before use, should I sonicate again and bring to 45C before using in my ThT assay (37C).

    4) Do you recommend adding cholesterol to increase the robust of my liposomes due to the fact that they undergo mechanical downsizing by sonication? 


    Clifford Morris

    Dear all,

    Thank you very much for you contributions to this discussion. 

    Taking from what you have said, I will make the following adjustments to my procedure:

    1) Room temperature preparation 

    2) Use membrane extrusion device 

    I will let you know how the results turn out. I will be performing AFM studies on the samples too which are always very interesting! 



  • Michael Bitar asked a question in Surface Antigens:
    Why is percent of T-bet always low, not more 4%, although CXCR3 +CCR6- CD4+ is 25% ?

    I try to establishment a Panel TH1 cells
    by surface antigen CXCR3 + CCR6- and transcription Factor T-bet
    But the problem is always the percentage of T-bet low(3-4%)
    I hope someone can help me

  • Jim Euchner added an answer in Business Ethics:
    Could any colleague provide me with good articles or e-book about morality or business ethics?

    Could any colleague provide me with good articles or e-book about morality or business ethics?

    Jim Euchner

    Servant Leadership, by Robert Greenleaf is good. So is The Human Side of Enterprise, by Douglas McGregor. 

  • Shankar Ekkanath Madathil added an answer in Sentaurus:
    Can anyone help with a Sentaurus GaN HEMT Self Heating Problem?

    Hi, we are using the Caughey Thomas model in Sentaurus to simulate the electro-thermal characteristics of a one channel GaN HEMT and we made the simulation succesfully converged with hydro; but we could not see the current drop with high drain voltages in drain current, that is self heating effect. We also tried different approaches like using the both first and second formula in Canali model. However, none of these attemtps were enough to see the current drop at high drain voltages. What other model(s) can be used to see the self heating effects for GaN HEMTs in Sentaurus TCAD?  

  • Qian Zhao added an answer in Heat Stress:
    Does anyone know about c. elegans heat stress?

    if  we would to conduct heat stress experiment to c.elegans,normally we use 30 degree.

    So if 25 degree is also a heat stress condition to c.elgans? 

    Qian Zhao

     Hi Jie,

    Thank you for your answer,actually 25 degree is also a normal growth condition to c.elegans, even though the c.elegans always grow under 20 degree. and also from the papers , if people do the heat stress all of them using 30 degree.

    But, most of  researchers conduct the experiment under 20 degree, and comparing to this 25 degree is higher.

    That is my confusion

  • Oleg Suslov added an answer in Aptamers:
    is there a method for aptamer-gold conjugation?

    What is more efficient method of conjugation of an aptamer to 40nm gold nanoparticles: using the thiolated aptamer or polyA one?

    Thank you.

    Oleg Suslov

    Thank you Haroon.

  • Martin Beaulieu added an answer in Chitosan:
    How can i make my low molecular weight chitosan hydrogel behave same as medium molecular weight chitosan hydrogel?

    I can't prepare the hydrogel using low MW CS of (pH, gelation point etc.) with the same protocol as I was getting with Medium MW CS. Should i reduce the concentration of CS and reduce the conc. of acid solution for dissolving CS and also suggest how cross linker concentration will vary in case of low MW CS? Thanks!

    Martin Beaulieu

    When I have done a chitosan with a low MW, I've maintained the same concentration of acid and chitosan but I have increase the time of hydrolysis at 80°C.

    When you produce a chitosan with low MW, you increase the probability to cut a cross linker, so I think that the cross linker will be lower.

  • Sayed Mukit Hossain added an answer in Reinforced Concrete:
    Is there adequate literature on load transfer mechanism of inclined reinforced concrete column between two floor plan?

    I am not getting any literature on this topic. As I want to do research on load transfer mechanism so I need some literature on inclined column research?

    Also I want to know the scope of future research on this topic

    Please help me in this regard

    Sayed Mukit Hossain
    Conventionally, for designing any column with inclination, one needs to 1st resolve the forces on the inclined column. The column would be designed for a force which is resolved along its longitudinal axis and the moments if any. (the regular method of column design)

    So, when you are analyzing this inclined column in Staad, program automatically determines the additional moment due to eccentricity and all the resolved forces developed along the column axis. Now, use the DESIGN COLUMN command to design by the same column design approach.