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  • Is intrinsic sympathomimetic activity has any role on β blockers?

    Many β blockers have different intrinsic sympathomimetic activity, could any one explain the role of on β blockers as anti-hypertensive drugs?

    Krishnan Umachandran · Professor

    Pindolol attenuates increases in heart rate, systolic blood pressure, and cardiac output resulting from exercise and isoproterenol administration, thus confirming its beta-blocking properties. The ISA or partial agonist activity of Pindolol is mediated directly at the adrenergic receptor sites and may be blocked by other beta-blockers. In catecholamine depleted animal experiments, ISA is manifested as an increase in the inotropic and chronotropic activity of the myocardium. In man, ISA is manifested by a smaller reduction in the resting heart rate (4 to 8 beats/min) than is seen with drugs lacking ISA. There is also a smaller reduction in resting cardiac output. The clinical significance of this observation has not been evaluated and there is no evidence, or reason to believe, that exercise cardiac output is less affected by Pindolol.

    Pindolol has been shown in controlled, double-blind clinical studies to be an effective antihypertensive agent when used as monotherapy, or when added to therapy with thiazide-type diuretics. Divided dosages in the range of 10 mg to 60 mg daily have been shown to be effective. As monotherapy, Pindolol is as effective as propranolol, α-methyldopa, hydrochlorothiazide, and chlorthalidone in reducing systolic and diastolic blood pressure. The effect on blood pressure is not orthostatic, i.e., Pindolol was equally effective in reducing the supine and standing blood pressure.

  • How can I solve my problem with Suzuki coupling?

    Hi !

    I am trying to couple a dibromoanthracene derivative with bishexyloxy benzene boronic acid using Suzuki coupling. [Please see to the attachment] The anthracene derivative is highly insoluble even in Chloroform and Toluene at reflux temperature and slightly soluble in DMF.

    I used Sodium carbonate, potassium carbonate and Potassium phosphate for the reactions in toluene, THF and DMF using Pd(PPh3)4 as the catalyst.

    The reaction either doesn't proceed (most of the time) or methyl esters convert to the acid.

    Which is the ideal Pd catalyst to carry out Suzuki reaction of reactants with poor solubility? What are other alternatives for this coupling? 

    Michel Rickhaus · Universität Basel

    Chlorinated aromatics (like chlorobenzene or 1,2 dichlorobenzene) often solubilize anthracene derivatives. Since the reactivities of chlorines can be well controlled with temperature, it should not pose a problem.

    Besides the already mentioned suggestions, please be aware of another issue: The boronic acid is better soluble than your starting material and I bet that most of the time you will see deborylation. It essentially means that the boronic moiety slowly degrades over time and cross coupling cannot take place anymore. Improving the catalyst will unfortunately also speed up deborylation (since it is present in a large excess over your starting material). The issue you need to talke first is solubility, maybe functionalize the anthracene (replace the methyl esters with tertButly or hexyl for instance should enhance solubilities greatly). Switching from Bromines to iodines can also help tremendously. The cleavage of esters can be prevented by using KF as base, but unfortunately often the reaction rates are diminished. In general, cleavage of acids is mediated in aqueous media (which unfortunately is also the best cosolvent in Suzuki reactions), switching to DMF can help.

  • René Dreos added an answer in Fusarium:
    Promoter and terminator of Fum 9 and Fum10 (Fusarium verticillioides)?

    I am trying to predict the promoter and terminator of Fum 9 and Fum10 (Fusarium verticillioides) with a software. I include 500bp upstream of ORF. Different promoter prediction softwares were tried but none of them worked. I am wondering how people normally predict the promoter sequence? Thank you very much.

    René Dreos · Swiss Institute of Bioinformatics

    Hi Nanxi,

    I just come across a new review about in-silico promoter identification that you might find useful for your analysis:

    In silico Identification of Eukaryotic Promoters
    VR Yella, M Bansal - Systems and Synthetic Biology, 2015

    Anyway, promoter prediction is a tricky business, good luck with your work!

  • What is the cheapest and easiest way to obtain periodic soil moisture measurements up to 10m depth without digging big soil pits?

    I want to estimate the soil moisture across several plots at one meter interval upto 10 m depth. Any good references are also welcome.

    Shaban Ahmed Ali Abdel-Raheem · Agricultural Research Center, Egypt

    see

  • Luiza Dihoru added an answer in Foundation Design:
    What risk factors should be considered on pile foundation design ?

    Suggest me related documents. 

    Luiza Dihoru · University of Bristol

    Dear Monjurul,

    The relevant risk factors relate to the geotechnical conditions (ground response), the pile static and dynamic behaviour and the relationship between the two (soil-pile interaction). There is an extensive body of literature on the subject. Please see below a couple:

    "Pile Design and Construction Practice," Sixth Edition,7 Oct 2014
    by Michael Tomlinson and John Woodward

    and


    "Design Of Pile Foundations In Liquefiable Soils",15 Nov 2009
    by Gopal Madabhushi and Jonathan Knappett

    I hope this helps. Good luck!

    Luiza

  • Lingyu Kong asked a question in Chemical Reactions:
    Can HF:H2O2:H2O remove Nickel ? If yes, what will be the chemical equation for this reaction?

    Basically, I would like to know what is the chemical reaction equation for Ni in Etchants (HF:H2O2:H2O)

    Thanks

  • Where to find real data on decision making in natural disasters?

    I would like to model and to solve real scenarios related to natural disasters (e.g. floods, hurricanes), specially in the relief phase.

    Pavel Novoa-Hernández · Universidad de Holguín "Oscar Lucero Moya"

    An optimization one...

  • Mohamed Khalfaoui asked a question in N2 Adsorption:
    I am looking for a numerical code to apply NLDFT for calculating pore size distribution?

    It will be very helpfull  if one can provide me for example an excel sheet or like this showing how applying the NLDFT to calculate pore size distribution from experimental N2 adsorption isotherms ?

    Regards,

  • Citing Wikipedia?
    While Wikipedia is more and more popular with students, professors discourage them from using it and bar them from citing it. What are reasons (to cite or) not to cite Wikipedia?
    Jul 31, 2012
    Mahmoud Abdallah · College of Education, Assiut University, Egypt

    Ok. While Wikipedia is NOT currently recognized as an official academic source to cite form, it is becoming very common nowadays. Personally, I use it as a STARTING POINT whenever I meet a new term or acronym. At that stage, my target is to have a basic idea (account) on this new term. Besides, Wikipedia itself usually guides me into the most useful resources to consult in this regard, and help me with knowing the main authorities on the subject in the target field of study. As said above, never mind about accuracy of Wikipedia accounts. Whenever something wrong is found, it's usually amended/corrected within a few minutes (or even seconds). So, the information found there is quite reliable and accurate. The fact that anyone can edit anything on Wikipedia is a strong point in the same way that it is a weak one! The whole world community is using Wikipedia and thus experts are always there to amend anything wrong at anytime since we currently have millions of Wikipedia users. Some research conducted by a professor at an English university proves this. The professor intentionally edited an account and wrote the wrong information to see what would happen. Immediately within few seconds, it was corrected by some Wikipedia users. Besides, it is in our hands to double-check using other reliable resources.

  • Fernando Anaya Gámez added an answer in Music:
    Is there any recent research on reading music sheets software programs?

    How to improve sight reading (piano sheet music) skills for the beginners?

    Fernando Anaya Gámez · University of Malaga

    Another possibility could be:

    http://www.teoria.com/

  • Hamidreza Simchi added an answer in HOMO-LUMO:
    Why are two CdSe nanoclusters attracting and combining when I change molecular linker connecting them in DFT calculations?

    I am doing DFT calculations on CdSe clusters (Cd15Se15) connected with a molecular bridge. When I change the composition of the bridge, these clusters move close and merge. The linker is composed of an aromatic ligand that attaches to the particle (two, one for each) bridged with a linker to create a conjugated system. When I change the type of linker from the one containing C=C (double bond) to benzene ring, the clusters bend the linker and merge. With C=C linker, they just remain apart with the linker stretched out between them (distance is about 1.5nm, about twice the size of each cluster).

    I am guessing that introduction of benzene created strong electron coupling between clusters, but I am not sure. I will do TD-DFT on the system, but it will have to be single-point calculation, because I want to look at the separated particles. The values of HOMO-LUMO gap from these single-point calculations are very small (1.36eV for 2-particle system and 1.05eV for 3-particle system, compared to 2.92 for optimized single particle and 2.68 and 2.65 for optimized 2- and 3-particle systems with C=C linker, respectively), so I don't think they are a realistic representation of the band gap change. Although, these systems were created using optimized 2- and 3-particle systems with C=C linker, so they are as close to optimized structure I can get at this point.

    Any advice on this would be much appreciated.

    Hamidreza Simchi · Iran University of Science and Technology

    Hi!

    Thanks a lot for providing the figures us. I think we are discussing about three subjects as below:

    1-Confguration of linked system should be stable i.e., it cohesive energy should be negative. If you calculate the cohesive energy of linked system in both cases i.e., different linkers, it means that they are stable and can be found it nature. But bigger absolute value cohesive energy shows more stable configuration.

    2-It should be noted that when the size of system decreases the Kohn-Sham band gap, Eg,  (LUMO-HOMO energies)  increases due to the size quantiztion (confinement) effects. By changing the linker the size is changed and it is expected that Eg changes.

    3-Using DFT calculation you can find HOMO and LUMO energies and therefore Eg. By using TD-DFT you can find singlet and triplet excited states, How they are made by single states, the occupation probability of each excited state and the photon energy which is necessary for doing the excitation. Therefore,one should not confuse Kohn-Sham band gap and the photon energy. I do not know what is happened for spin configuration of the system when the linker is changed. May be in some cases multiplicity is zero (2S+1=0) and in other 2S+1=1. It can change the photon energy.

    If you use Gaussian Code you can check all of them and we can judge. If we know the values of binding energy, the effect of size, the effect of multiplicity, and the excited states (photon energies) we can draw a complete picture about the physics of the problem.

    Best Regards

    H.Simchi

  • E. M. Shishonok added an answer in Nanoparticles:
    Why have I got broadened peaks for my XRD graph?

    I have slightly sharp peaks. Can anyone tell me from my graph whether my particles are nanoparticles or of amorphous nature? I have attached my file herewith.

    Some say that that my particles are amorphous. Is there any criteria for FWHM values?

    E. M. Shishonok · Belarusian State Technological University

    Exactly, you have mostly nanostructured sample. In the case of an amorphous sample  its XRD patterns don't show peaks. Nanostructured samples always have broadened peaks in XRD patterns.

    I agree with Alberto Martinelli . The low angle peak can be convoluted. 

    In the case of one phase sample, additional peaks can prove distortions of  the related crystal lattice.

    About the amorphous state. Its input can be seen from  background  intensity  increase in low angles region of XRD patterns. The background in your case  is increased a little. But the same result can prove a solid solution formation if some additional impurities are introduced into  the crystal lattice.  Such impurities can result the top mentioned distortions as well. 

  • Luiza Dihoru added an answer in Particle Size:
    What is the difference between grain size and particles size?

    is there any difference between particle and grain?

    Luiza Dihoru · University of Bristol

    Hi Abhijit,

    A 'particle' is usually  defined as a small object that behaves as a whole unit in terms of its transport and properties.  A 'grain' is , again, one of the basic concepts in the solid state physics.It is also termed as crystallite. It is a domain of a solid state matter that has the same structure as a single crystal. In nanotechnology, for example, the 'particle' and 'grain' are very distinct things. However, in areas such as powder technology, the two definitions often overlap, with 'particle size' and 'grain size' being the same thing.

    Rigorously though, a “grain” is a region of many particles, with an uninterrupted crystal structure (characterized by a repeating unit cell). 

    I hope this helps. Good luck!

    Luiza

  • Marco Marano added an answer in QRS:
    What QRS duration should be considered abnormal?

    A recent recommendation indicates that the QRS complex on routine ECG should be considered abnormal is its duration is of 120ms or more. I saw a young women of 150cm height and 45kg weight with the QRS duration of 110ms and a men of 195cm height and 100kg weight with the QRS duration of 120ms. Actually, who of them had abnormal QRS duration?

    Marco Marano · Maria Rosaria Clinic Pompeii Italy

    As QRS lenght is not the same in all leads, a question arise: should be the largest one to consider?

  • Alex Ignatov added an answer in Sequest:
    Can bacteria sequester atmospheric carbon rapidly?

    Some researchers told that Pseudomonas sp. can do it to some extent. Do you have more idea or references in support of your answer. Please add your valuable thoughts.

    Alex Ignatov · Russian Academy of Sciences

    Sure, some bacteria really can accumulate storage carbohydrates that are not used by other microbes immediately. But, comparing to green plants that produce cellulose and lignin, the amount of bacterial storage carbohydrates is very small.

  • Houda Ghédir added an answer in Consanguinity:
    Is consanguineous marriage one of the causative agent of human infertility?

    Some of our researchers believe that consanguinity is one of the causative agent of human infertility. Is it possible or not? If the consanguinity is the causative agent, then what is the reason behind that? What kind of changes take place due to consanguinity?  

    Houda Ghédir · Centre Hôpital Universitaire Farhat Hached

    i hope it helps !

  • Can anyone give me information about the design patterns for the Internet of Things (IoT)?

    Currently, I am doing the research on the modelling of design patterns using OWL. For the application, I have considered IOT. 

    Enterprise Integration Patterns is a good start: http://www.enterpriseintegrationpatterns.com/toc.html

    Typically you are looking at Remote invocation, Distributed Tracking, Discovery protocols and Message etc. 

    • System Integration patterns
    • Messaging patterns
    • Routing patterns
    • Transformation patterns
    • Distributed Coordination patterns
  • Elena Yu. Filinova added an answer in Bacteria:
    Is the Eppendorf Multiporator suitable for Eukaryotic Cells?

    We have an Eppendorf Multiporator labeled Bacteria Module 4308 805.005.

    Dose it suitable for Eukaryoktic Cells electrotransformation?

    Or we need buy a eukaryote module?

    Elena Yu. Filinova · Advanced Biomedical Research Laboratory, RF; Vidipharm Gmbh, Austria

    Dear Du Xiang,

    Electroporation for eukaryotes is being done in voltage diapason of 50-500 mV, for bacterial electrotransformation you would need 1000-3000 mV range. Electroporator itself is a strong/heavy enough transformator which transfers our 110-220 V from electric supply into necessary range. Normally producers of such instruments make different modules for eukaryotic and prokaryotic electroporation. But if other adjustments functions are reduced it is possible to make machine in one module. So, to unswer your question for Eppendorf multiporator you should read technical details on the backside of machine or in instruction for these mullivoltage ranges. I suppose "Bacterial module" is this one with higher voltage, so for eukaryotes you would need so called "Mammalian module"

    The other thing which is differ is volume of steril cuvettes. I normally use ones of 800-1000 mkl for human cells fusion/transfection and 100-200 mkl for E.coli transformations. And Harvard Apparatus 830 instrument.

  • How can one synthesize artificial HDL?

    I am trying to synthesize artificial HDL. Does anyone have references to papers or know how this is done?

    Taralina Gaee Atefi · Griffith University

    Interesting interest to synthesise HDL....i will look into it too. Thank you collegues!!!

  • Fatima Razavi added an answer in Persian Language:
    Is difference between women's writing and men's in textual cohesion and coherence based on Halliday and Hasan's theory?

    I got MA in Persian language and literature. My dissertation is about differences between women and men's writing. I'm searching in gender linguistics and studies and I'm interesting in knowing more about this field.

    Fatima Razavi · Ferdowsi University Of Mashhad

    Thank you  Aysha. I'll inform you

  • Kevin Perreaut added an answer in Deafness:
    How can deaf student develop like normal student?

    This question aims to point out the difficulties that hearing impaired face in social life, in despite all the efforts made and different approaches taken to help them. Emphasizing the necessity of self-reliance of the hearing-impaired in social life and their substantial participation in the sustainable development of community, this question introduces.

    Kevin Perreaut · University of Lyon

    Hi,

    it depends of severals factors like the type the level and laterality of deafness. It will also depends of associated handicaps.

    Can you be more precise ?

  • Faik Hamad added an answer in Numerical Modeling:
    Is the Grid Independency Test (GIT) a must for complex numerical models?

    In complex numerical models having mesh elements nearing a million, its highly impossible for GIT due to time and constraints. So is GIT necessary or is there any alternate option?

    Faik Hamad · Teesside University

    •Numerical errors.
    –Solving equations on a computer invariably introduces numerical errors.
    –Round-off error: due to representation of numbers with a finite number of digits (significant digits).
    –Truncation error: due to approximations in the numerical models. 

    the mesh refinement is very useful. Using experimental data for simple case will help to select the mesh  

  • Valerii K. Kononenko added an answer in Laser:
    Why we have increase in output power by increasing pump current in diode laser?

    By increasing the pump current in diode laser, we see increasing in output power.

    This relation is linear.

    Why we have this?

    Valerii K. Kononenko · Belarusian State University

    It is rather simple. See, please, general description in a reference.

  • Anush Arunachalam added an answer in Abaqus:
    How can I connect the zero thickness cohesive element to the finite element in abaqus?

    Hello, Everyone,

    I am using zero-thickness cohesive element and traction-separation
    technique to model the delamination process. I have looked through this
    forum and Abaqus document but I still unable to get it in the following
    issues:

    I have generated orphan mesh from a neighboring finite element, that
    seems the cohesive element sharing node with the finite element on one
    side, but how to connect the cohesive element to the finite element on
    other side, use tie method?

    I will be very grateful if someone can help.

    Anush Arunachalam · Indian Institute of Technology Madras

    Hi Deepak,

                         Thanks for your valuable advice. I have one more doubt in connecting cohesive elements to surrounding material.

    I have to model shearing of  two blocks with one block fixed to ground , the interface between these two blocks is the cohesive element(with definite thickness). I have tied the cohesive elements with the fixed block , so what should i do on the other side plz suggest

  • Geno Villafano added an answer in Primer:
    How can I clone a PCR generated 9 kb amplicon in a 7.8kb vector?

    I am trying to clone a full length gene with flanking sequences (a total size of 9 kb) in the Drosophila expression vector pCaSpeR4. I had constructed primers with sites for BamHI and KpnI in the Forward and Reverse primers respectively to clone the gene directionally. On lack of results, I tried non-directional cloning using primers bearing restriction sites for the same enzyme, but in vain. My inserts and vectors are both clean, and ratios of vector : insert which I have tried are 1:1, 1:3, 1:5, 1:10. Is it a ligation problem?

    Geno Villafano · Jacobs University

    Instead of non-directional cloning perhaps you could try blunt cloning directly out of the PCR mix. Purify the PCR product, blunt it with an excess of dNTPs and some klenow fragment (or a dedicated blunting enzyme) and ligate into a blunt vector as Fabian has mentioned. Then once in this blunt shuttle vector isolate a large amount and do a very clean digestion with your two restriction enzymes and gel purify before trying to do directional cloning.

    I recently cloned a few very AT rich ~6kb genes into a 7.6kb vector this way and it worked well. In our lab we use pJET1.2 blunt vector for a shuttle. We do all the sequencing while it is in pJET1.2 and only after transfer it to our expression vectors. pJET1.2 has the nice advantage of having a kill gene if it is empty when it closes, so it makes screening much faster. 

    Best of luck with everything. 

  • Has there been research to show that with increasing education, there has been improved ethics in a community?

    'Students often know the right thing to do. How can schools help them to do it?

    The numbers are in and they don't look good." That was the assessment of the Josephson Institute of Ethics last October, when they conducted a survey about the moral standards of more than 20,000 middle and high school students. Almost half the young people reported stealing something from a store in the previous 12 months. In the same period, seven out of 10 cheated on an exam.
    Should we be worried? Many observers say that we should. We see evidence of more antisocial behavior than ever among our youth—a sort of divorce between personal ethics and everyday behavior.'

    Has there been research to show that with increasing education, there has been improved ethics in a community?  Can you share, give some evidence? Thanks.

    Dr. Nizar Matar · An-Najah National University

    Had there been a research which concluded that increasing education has led to improvement of ethics, I shall put question marks about it. It is obvious that the teachers are ordered to concentrate on the subjects they teach & to cover the whole chapters of the textbook. If, e.g., a chemistry teacher “digresses” into talking about ethics, then s/he will be reported to the “big brothers”. The big brothers, in turn, will accuse him/her of wasting time of lectures or periods. This has meant that no ethics are taught so the students will be similar to illiterates in terms of ethics. What is more painful is that the methods of cheating by students become more elaborate than the ordinary layman.
    It is time to have a worldwide “revolution” in the systems of education in order to produce “honest” graduates with the proper qualifications.