Q&A

ResearchGate Q&A lets scientists and researchers exchange questions and answers relating to their research expertise, including areas such as techniques and methodologies.

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2
How can I perform butylamine ligand exchange on CdSe-OA Quantum dots?

I want to do ligand exchange, Oleic acid (OA) to butylamine.

Does any one knows the simplest way to do that?

I don't want to wast a lot of QDs.

Thanks

Hi Navid,

The common method for ligand exchange in QDs is just simply expose your nanoparticles to a high concentrated solution of your new ligand. Are you familiar with this method?

4
Students perspective: mid-term exam = copy - paste; final exam = cut - paste; where is the knowledge transfer?

Exam-oriented approach is a major threat to knowledge transfer and critical thinking?  It  stifles  students' imagination, creativity, and sense of self.What do you think?

I recall a student telling me once that memorizing was not learning.  This student only wanted to learn broad concepts rather than committing large amounts of information to memory. There are a number of different models, however, many people agree there are different levels of learning.  First, one must be able to put knowledge into long term memory in order to later be able to use it.  If one is not using open book tests, asking a student to recite what has been learned is a basic first level of learning.  Second, one might move on to analyzing a case situation. One needs to already have certain basic knowledge in order to do this analysis well.  Third, one can move on to creating something new. For example, I would teach my graduate students how to do fieldwork.  After they had learned the basic methods involved, I would send them out to create their own case study.  Another example of advancing knowledge is the thesis and dissertation work that many graduate students do.  I suppose it would be nice to skip mastering steps one and two and just jump to step three.  However, this is not really very realistic.  Have you ever heard of "distributed learning?"  One should not try to push young people too far too fast.  Good luck with your work, Bruce

1
What are the benefits of nutritional supplements in pressure ulcer management?

what supplements are essential for pressure ulcer healing?

Life saving. Patients need whey protein TID. Multivits & vit C.

Zinc bit contriversial.

But unless they have adequate protein they will never heal. Some bad cases might even need Fresh Frozen Plasma.

10
Is there any relation between iflammation and cytotoxicity of nanoparticles?

I have methods to check antiinflammatory activity (decrease in inflammatory markers in bloods) of nanoaparticles? Can I predict toxicity of nanoparticles by same methods i.e. inflammatory markers appear in blood or not?

Dear Mubashar Rehman

My experience is that when nanoparticles enter the airways produce an inflammatory reaction. This inflammatory response is due to the attack by macrophages to nanoparticles adhering to the lung surface. Probably unable to engulf all nanoparticles, occurs oxidative stress, which causes macrophages release inflammatory mediators that produce the inflammation.

4
What is the relationship between complex modulus and relaxation modulus?

In the book of Findley titled "Creep and relaxation of nonlinear viscoelastic materials: with an introduction to linear viscoelasticity", he had a section talking about the relationship between complex modulus and relaxation modulus. He could calculate this relationship using the following formula:

E*(w)=iwL{E(t)}s=iw

where 'w' is the frequency and 'i' is a complex number.

I am trying to use the same formula, but with considering E(t) to be as follows:

E(t)= Einf + Ee-(t/k)

While Einf, E1, and k are known fitting parameters from the relaxation test.

My questions are:

1. What does it mean when we have s=iw next to Laplace transform brackets? and how we implement it in our calculation?
2. I would appreciate if someone can help me solve this Laplace transform to be able to calculate the complex modulus at a certain frequency (w).

Thank you..

+ 1 more attachment

I think, (6.34) is wrong. This is easily seen since kappa has the dimension of time (the same as t). But then, it is dimensionally impossible that omega*kappa^2 has dimension 1, as (6.34) would imply. A simple calculation indeed gives a different result for E^* (see the attached file). Here, the answer depends only on the dimensionless quantity omega*kappa.

99+
What are the best cognitive tests for detecting early changes prior to the onset of dementia?
A traditional approach is to use tests of global cognitive function such as the Mini-Mental State Exam (MMSE: Folstein et al., 1975) or the Blessed-Information-Memory-Concentration Test (BIMC: Blessed et al., 1968) to assess the severity of cognitive impairment (Tombaugh and McIntyre, 1992). But are these tests sensitive enough? Most studies show either ceiling or floor effects according to the time progression into disease.

Olfactory testing uses extended to Alzheimer’s disease
Published on November 20, 2015 at 5:15 PM · No Comments

inShare0

By Eleanor McDermid, Senior medwireNews Reporter

A simple olfactory test may help to identify people at increased risk of developing Alzheimer’s disease (AD) dementia, suggest findings from a population-based study.

Olfactory dysfunction, already considered a strong risk indicator for Parkinson’s disease, significantly predicted both amnestic mild cognitive impairment (MCI) and further progression to AD dementia among 1430 cognitively normal people aged an average of 79.5 years.

Rosebud Roberts (Mayo Clinic, Rochester, Minnesota, USA) and study co-authors suggest that “odor identification tests may have use for early detection of persons at risk of cognitive outcomes.”

59
Are there any specific or general biomarkers for following up Alzheimer's Disease treatment?
The measurement of biomarkers will be useful for grading disease response to treatment.

Olfactory testing uses extended to Alzheimer’s disease
Published on November 20, 2015 at 5:15 PM · No Comments

inShare0

By Eleanor McDermid, Senior medwireNews Reporter

A simple olfactory test may help to identify people at increased risk of developing Alzheimer’s disease (AD) dementia, suggest findings from a population-based study.

Olfactory dysfunction, already considered a strong risk indicator for Parkinson’s disease, significantly predicted both amnestic mild cognitive impairment (MCI) and further progression to AD dementia among 1430 cognitively normal people aged an average of 79.5 years.

Rosebud Roberts (Mayo Clinic, Rochester, Minnesota, USA) and study co-authors suggest that “odor identification tests may have use for early detection of persons at risk of cognitive outcomes.”

1
Can BCG be used as a therapeutic vaccine ? Can booster shots be used ?

Very rare studies are reported that have investigated role of BCG as therapeutic vaccine after TB infection. Can Single or booster dose of BCG be used as therapeutic vaccine alone with drug combination?

Dear Aliabbas,

The use of BCG to treat diseases:

Mycobacteria
Leprosy: BCG has a protective effect against leprosy in the range of 26 to 41% based on controlled trials. The protective effect is somewhat larger based on case control and cohort studies—about 60%.[18][19] However BCG vaccine is not used specifically to control leprosy.
Buruli ulcer: BCG may protect against or delay the onset of Buruli ulcer.[20]
Cancer immunotherapy
Micrograph showing granulomatousinflammation of bladder neck tissue due to Bacillus Calmette-Guérin used to treat bladder cancer, H&E stain
A number of cancer vaccines use BCG as an adjuvant to provide an initial stimulation of the persons` immune systems.
BCG is used in the treatment of superficial forms of bladder cancer. Since the late 1970s, evidence has become available that instillation of BCG into the bladder is an effective form of immunotherapy in this disease.[21] While the mechanism is unclear, it appears a local immune reaction is mounted against the tumor. Immunotherapy with BCG prevents recurrence in up to 67% of cases of superficial bladder cancer.
Colorectal cancer[22]
Lung cancer[23]
Melanoma[24]
MPNST[25]
Equine sarcoid (in horses)
Type I diabetes
Diabetes, type 1: Clinical trials based on the work of Denise Faustman use BCG to induce production of TNF-α, which can kill the T-cells responsible for type 1 diabetes. In a Phase I, double-blind, placebo-controlled trial, two doses of the BCG vaccine were administered to three adults with long-term type 1 diabetes, resulting in elimination of the pancreas-harming cells, induction of regulatory T cells (Tregs) and a transient rise in C-peptide levels, suggestive of temporarily restored insulin production.[26]

[18] Setia MS, Steinmaus C, Ho CS, Rutherford GW. (2006). "The role of BCG in prevention of leprosy: a meta-analysis". Lancet Infect Dis 6 (3): 162–70. doi:10.1016/S1473-3099(06)70412-1. PMID 16500597.
[19] Merle, Corinne SC; Cunha, Sergio S; Rodrigues, Laura C (2010). "BCG vaccination and leprosy protection: Review of current evidence and status of BCG in leprosy control". Expert Review of Vaccines 9 (2): 209–22. doi:10.1586/ERV.09.161. PMID 20109030.
[20] Tanghe, A., J. Content, J. P. Van Vooren, F. Portaels, and K. Huygen (2001). "Protective efficacy of a DNA vaccine encoding antigen 85A from Mycobacterium bovis BCG against Buruli ulcer". Infection and Immunity 69 (9): 5403–11. doi:10.1128/IAI.69.9.5403-5411.2001. PMC 98650. PMID 11500410.
[21] Lamm DL, Blumenstein BA, Crawford ED (1991). "A randomized trial of intravesical doxorubicin and immunotherapy with bacille Calmette-Guerin for transitional-cell carcinoma of the bladder". N Engl J Med 325 (2): 1205–9. doi:10.1056/NEJM199110243251703. PMC 1164610. PMID 1922207.
[22] Mosolits S, Nilsson B, Mellstedt H. (2005). "Towards therapeutic vaccines for colorectal carcinoma: a review of clinical trials". Expert Rev Vaccines 4 (3): 329–50. doi:10.1586/14760584.4.3.329. PMID 16026248.
[23] NAOTO MIYAZAWA; KEIICHI SUEMASU; TOSHIRO OGATA; TAKESHI YONEYAMA; TSUGUO NARUKE; RYOSUKE TSUCHIYA (1979). "BCG Immunotherapy as an Adjuvant to Surgery in Lung Cancer: A Randomized Prospective Clinical Trial". Jpn. J. Clin. Oncol. 9 (1): 19–26.
[24] Lu, CY; Lin, GC; Gu, JZ; Zhou, GY; Cao, Y (Sep 1994). "[A preliminary study of BCG adjuvant therapy in oral and maxillofacial malignant melanoma.].". Shanghai kou qiang yi xue = Shanghai journal of stomatology 3 (3): 144–5. PMID 16538310.
[25] Sari, Aysegul; Bal, Kaan; Tunakan, Mine; Ozturk, Cemil. "A case of a sporadic malignant peripheral nerve sheath tumor of the urinary bladder with concomitant in situ urothelial carcinoma treated by transuretheral resection". Indian Journal of Pathology and Microbiology 54 (1): 147. doi:10.4103/0377-4929.77376.
[26]  Faustman, DL; Wang L; Okubo Y; Burger D; Ban L; Man G; Zheng H; Schoenfeld D; Pompei R; Avruch J; Nathan D (Aug 2012). Doherty, T. Mark, ed. "Proof-of-Concept, Randomized, Controlled Clinical Trial of Bacillus-Calmette-Guerin for Treatment of Long-Term Type 1 Diabetes". PLoS ONE 7 (8): e41756. doi:10.1371/journal.pone.0041756. PMC 3414482. PMID 22905105.

Rafik

1
Is there any protocol related to chromosome/DNA damaging?

Hello all researcher.I have some  metal stress plants and i have done stress enzyme analysis via spectrophotometer.

I want to ask Is there any technique/Protocol/methodology through which i analysed chromosomal/DNA damaging via spectrophotometer.I don't have any idea related to this.Please guide me and suggest me.

Only via spectrophometer directly I think no, but in this article below describes the other methods to do it.

http://www.excli.de/vol7/sinha02-08/kumari04-03proof.pdf

10
Is probability of error better than signal to noise ratio, How ?

I know that probability of error is monotonically inversely proportional to singal-to-noise ratio. But if weights are assigned to probability of error as how it is done to signal-to-noise ratio, will it give any better results?

Nice words of wisdom are definitely found in this thread.

But I think, the easiest way to show the relation between the Signal-to-Noise Ratio (SNR) and its corresponding Bit Error Rate (BER) would be for the case of Binary Phase Key Shifting and is given by:

${\text{BER}} = \frac{1}{2}{\text{erfc}}\left[ {\sqrt {\frac{1}{2}SNR} } \right]$

where ${\text{erfc}}\left( x \right)$ function is the complementary error function, which is actually:

${\text{erfc}}\left( x \right) \equiv \frac{2}{{\sqrt \pi }}\int\limits_x^\infty {{e^{ - {t^2}}}dt}$

2
How can all possible 22 digit binary numbers can be generated?

I am in a situation where all the possible 22 digit binary number are required. Also, the number must be sorted from smallest to largest.

Kindly, suggest me the fast and the efficient way to get this all the binary numbers.

I mean to get the list of all the binary strings between

00 0000 0000 0000 0000 0000

to

11 1111 1111 1111 1111 1111

Dear sir,

I prefer MATLAB programming. Even C++ will be good for me.  Anyway, I am just interested to know all those binary numbers, not specific about programming language.

10
Does anyone know what is the ideal (optimum) ratio of fine aggregates to coarse aggregates in a standard concrete mix?

Any tips or pointers greatly appreciated. Papers, documents, own findings, etc. are all welcome.

Many thanks Ali for your answer. It is really very helpful. It seems that there are simply too many parameters that can affect the answer.

I am finding more papers on the topic, which is good.

2
What is the most efficent way to postprocess UEL in Abaqus ?

Hello Abaqus user,

As you all aware the visualization of results associated with user elements is not supported by abaqus viewer. I tried to follow the guidelines provided in Abaqus manual to access the results file but no success so far.

Method -1

I used fortran interface (attached -source : http://forum.cadec-online.com) to read the results from the .fil-file with ABQmain subroutine.

abaqus make job=filToBin.f

This provides me filToBin.o file with the Note: declarations in dependent base » cow_Btree < odb_String , odb_Instance > " could not be found

Method-2

Other tricky way which i figured out is  to superimpose another element on the UEL element. which runs on UMAT.   UMAT communicates with UEL via  COMMOM statement  and solution dependent variables (SDV).

I am more interested to visualize my element using Method-1. Is there any detail explanation to do so ?  can somebody guide me please?

The second method you mentioned is also called dummy element. As far as I can see this way is even simpler and efficient. If you also know a little bit about how to use Python, then you can develop your own small program for post-processing.

• Liz Memun asked a question in Cell Line:
New
Which rat cell line expresses TNFa in a constitutive manner ?

I need a rat cell line that expresses TNFa in a constitutive manner to use its ARN as a positive control in RT-PCR.

Anyone knows about TNFa expression in PC12  ?

5
Prodromic and early Alzheimer´s disease detection using MRI...What do you think?
Creating a mathematical model of the brain changes across time from the evolution of 116 anatomical structures from more than 2100 MRI studies of Alzheimer´s disease patients (CDR=0.5) and healthy subjects showing the possibility of an early detection of this disease since it is possible to describe the neurodegenerative pattern.

Instead of MRI could be used just olfactorial testing

Olfactory testing uses extended to Alzheimer’s disease
Published on November 20, 2015 at 5:15 PM · No Comments

inShare0

By Eleanor McDermid, Senior medwireNews Reporter

A simple olfactory test may help to identify people at increased risk of developing Alzheimer’s disease (AD) dementia, suggest findings from a population-based study.

Olfactory dysfunction, already considered a strong risk indicator for Parkinson’s disease, significantly predicted both amnestic mild cognitive impairment (MCI) and further progression to AD dementia among 1430 cognitively normal people aged an average of 79.5 years.

Rosebud Roberts (Mayo Clinic, Rochester, Minnesota, USA) and study co-authors suggest that “odor identification tests may have use for early detection of persons at risk of cognitive outcomes.”

8
What kind of concentration dependence exists for the activation energy?

Dear Colleagues! We are interested in the concentration dependence of the activation energy. For example, the activation energy of viscosity or conductivity of solutions. However, we can not find publications on this topic. Tell me please!

Dear Colleagues! Thank you very much for your answers, in particular, for the reminder about the works of Erdey-Gruz.

But again I formulate the question: We have the results of own electrical conductivity measurements of the activation energy concentration dependence for the proton-conductive solutions: water+glycerol, water+ethylene glycol, water+diethylene glycol, DMSO+glycerol, DMSO+ethylene glycol... We have the results for more complex systems [see example "Synthesis and properties of novel polyurethanes based on amino ethers of boron acid for gas separation membranes", RSC Advances 5(81), DOI: 10.1039/C5RA11417A].

The next step - an analytical description of this dependence. We had an idea how to describe this dependence. Then we began to look for similar works. I found only one work [Journal of Structural Chemistry. Vol. 44, No. 6, pp. 995-1000, 2003], where it is shown that similar dependence for has a minimum. Other works we have not found.

It is possible that in our system of concentration dependence of activation energy (conductivity)  has a minimum, too, but it is so weak that I can not definitely say. It's one of the problems.

Therefore, I am interested in work in this area, but I can not find them.

Thanks again.

3
Anyone familiar with structure learning in Bayesian Networks and Markov equivalence class?

When learning the structure from data in a Bayesian network and due to the Markov equivalence class, how can directions in the DAG be inferred for the non-v structures?

Dear Francisco,

They are interpreted not as causal but they indicate that there exist a relation between the two variables (dependence)

5
Is there any effect of sound and its extent on animal behavior?

In fact I am very much interested to know, about the effect of sound ad it's extent on behavior change, particularly decision making.
.
If any one got a related paper......please attach that for me

Thank you sir sir

New
Can we further increasing efficiency of energy tapping from Wind?

As of now heavy windmill is designed to run at slower speed with large torque and gear drive mechanism/belt drive is used to drive the electric generator at high speed to produce electricity. Depending on the wind velocity availability, high torque persists for short time and large portion of wind energy (at low pressure) remains untapped. I think if we change the design  to tap wind energy at varied speeds at varied torque by using multiples windmills mounted on the same tower having varied blade sizes (heavy,medium and light weight) with separate generator for each one (with different voltage ratings). This may increase overall tapping of the wind energy and further improve the efficiency of the overall setup. Yes, this may add extra first cost. What is your opinion?

With best regards,

• Zsuzsanna Bordan asked a question in Lentivirus:
New
Does anyone have any experience to purify or/and concentrate lentivirus supernatant?

Does anyone have experience with Lenti-X concentrator (Clonetech) / Fast-Trap Lentivirus Purification and Concentration Kit (Millipore) / Lenti-Pac Lentivirus Concentration Solution (Gene Copoeia) / PEG (System Biosciences), ultracentrigutaion to purify or/and concentrate lentivirus supernatant?

I am working with the second generation lentivirus plasmids. The transfer plasmid has RFP and I got some bright red cells with the non-concentrated viral supernatant. I wanted to concentrate it to increase the transduction efficiency, but unfortunately the PEG was not working for me. The cells had an interesting shape, they had interesting "appendum", because PEG does induce cell fusion...(http://www.ncbi.nlm.nih.gov/pubmed/16761719) ?

That's why I am thinking about another options to concentrate the supernatants.

8
Can anybody provide me the sources of R, G,B, NIR band satellite images of urban areas having resolution less than 5 m?

I required R, G,B, NIR band satellite images of urban areas having resolution less than 5 m for my research work. if somebody have any links then kindly provide me

How to do Gap filling in image processing

7
Is there any established way of detecting alzheimer by analyzing blood, serum or any physiological components?
.

Olfactory testing uses extended to Alzheimer’s disease
Published on November 20, 2015 at 5:15 PM · No Comments

inShare0

By Eleanor McDermid, Senior medwireNews Reporter

A simple olfactory test may help to identify people at increased risk of developing Alzheimer’s disease (AD) dementia, suggest findings from a population-based study.

Olfactory dysfunction, already considered a strong risk indicator for Parkinson’s disease, significantly predicted both amnestic mild cognitive impairment (MCI) and further progression to AD dementia among 1430 cognitively normal people aged an average of 79.5 years.

Rosebud Roberts (Mayo Clinic, Rochester, Minnesota, USA) and study co-authors suggest that “odor identification tests may have use for early detection of persons at risk of cognitive outcomes.”

• Ysabel Huaccallo asked a question in Reactors:
New
How can I start to design a biodisk reactor, and a composting reactor and an Ludzack and Ettinger modify reactor?

Hello everybody,

I am interested about to design differents reactors to treat wastewater so as knowing which calculus I must do.

Ysabel

4
What is the rate of bilateral internal thoracic artery (BITA) used at your institution?

I would like to perform a little survey as the use of BITA grafting formyocardial revascularization.

Hi Guiseppe. I would like to contribute to your research. Just let me know what you want to learn.

2
How do I calculate the index of cognitive activity (ICA)?

I have ICA (Index of Cognitive Activity) data exported from BeGaze (earlier collected with SMI eyetracker 60 Hz and computed with support of Eyeworks). And now is the question. Should I do any additional calculations on the ICA data obtained from BeGaze/Eyeworks or should I interpret it directly from the output file (for example just by calculating mean ICA from the specified time period)? In other words, whether the data from BeGaze/Eyeworks is raw and requires some further transformations or it is just ready to interpretation? I have got ICA in decimal values, but Marshall says about ICA values ranging from 0 to 20.... Hence I'm not sure whether I should transform the ICA (raw?) data somehow (if so – how it shall be done?)?

some related papers from our research group

best,

+ 1 more attachment

8
Which are the current guidelines for Alzheimer 's disease diagnosis?
New serum tests are used in clinical practice

Olfactory testing uses extended to Alzheimer’s disease
Published on November 20, 2015 at 5:15 PM · No Comments

inShare0

By Eleanor McDermid, Senior medwireNews Reporter

A simple olfactory test may help to identify people at increased risk of developing Alzheimer’s disease (AD) dementia, suggest findings from a population-based study.

Olfactory dysfunction, already considered a strong risk indicator for Parkinson’s disease, significantly predicted both amnestic mild cognitive impairment (MCI) and further progression to AD dementia among 1430 cognitively normal people aged an average of 79.5 years.

Rosebud Roberts (Mayo Clinic, Rochester, Minnesota, USA) and study co-authors suggest that “odor identification tests may have use for early detection of persons at risk of cognitive outcomes.”

6
What are the differential features between Plasmodium ovale and P. vivax?

Plasmodium specie in the thick and thin films are somehow difficult to differentiate.

If you see what Anil referred to (the appearance of parasitized erythrocytes), that is very helpful for diagnosing P. ovale infections. Bear in mind that P. ovale is not always the only species of Plasmodium present in the patient, although often (if not usually) it is.

7
Detection of Alzheimer
Is there any process by which we can detect early stages of Alzheimer?

Olfactory testing uses extended to Alzheimer’s disease
Published on November 20, 2015 at 5:15 PM · No Comments

inShare0

By Eleanor McDermid, Senior medwireNews Reporter

A simple olfactory test may help to identify people at increased risk of developing Alzheimer’s disease (AD) dementia, suggest findings from a population-based study.

Olfactory dysfunction, already considered a strong risk indicator for Parkinson’s disease, significantly predicted both amnestic mild cognitive impairment (MCI) and further progression to AD dementia among 1430 cognitively normal people aged an average of 79.5 years.

Rosebud Roberts (Mayo Clinic, Rochester, Minnesota, USA) and study co-authors suggest that “odor identification tests may have use for early detection of persons at risk of cognitive outcomes.”

26
Are vernacular names a clue to scientific identity of plants?

No doubt vernacular names are useful in identifying the plant scientifically but it is not always possible since a single vernacular name may refer to different plants in different area. Moreover a single plant is variously named by different community/tribes.

After more than seven months discussing if vernacular names are a clue to scientific identity I would like to ask to Dr. Bussmann if there is  a scientific paper about the toxicity of Gentianella thyrsoidea?. Thank you in advance.

5
What is the most suitable means of inferring meaning and function for rock art?

How much weight should be placed on ethnographic analogy?

Direct interpretation of subject matter?

Cross cultural studies of rock art?

Cognitive neuroscience?

Semiotics?

Comparative religion?

Other?