Author Archives: nicole yipp

Happy Halloween: Beware of the caries!

Posted on October 31, 2016 | 3 comments

Halloween has approached us. Among the daunting horror films and scary costumes come the dreaded likelihood of cavities AKA dental caries (DUN DUN DUN)!

As a child I always wondered how cavities form, but I never looked into it because I didn’t want to face the awful truth that my beloved candy is actually plotting against me. But now that I am older, and hopefully wiser, I have figured out the true story of the candy cavity curse!

It begins the moment you present that delicious piece of candy to your mouth, and the simple sugars, specifically sucrose, are released into your oral cavity. The sugar feeds the already present bacteria on your teeth [1], which live in the plaque growing on the enamel. Plaque forms normally on your teeth by the combination of sucrose, and proteins from your saliva [2]. However unpreventable, it can be removed by frequent tooth-brushing. So bacteria such as Streptococcus mutans (S. mutans), which are round, cariogenic (causes tooth decay), and anaerobic, feed on the sucrose provided by the candy, to form lactic acid through glycolysis [2].

Glycolysis is an important process in which energy is produced. The process is outlined generally below.

Hydrolysis of Sucrose to form Glucose and Fructose Image Credit: Charles E Ophardt http://chemistry.elmhurst.edu/vchembook/548toothdecay.html

Hydrolysis of Sucrose to form Glucose and Fructose Image Credit: Charles E Ophardt http://chemistry.elmhurst.edu/vchembook/548toothdecay.html

Formation of Lactic Acid from Fructose via Glycolysis. Image Credit: Charles E Ophardt http://chemistry.elmhurst.edu/vchembook/548toothdecay.html

Formation of Lactic Acid from Fructose via Glycolysis. Image Credit: Charles E Ophardt http://chemistry.elmhurst.edu/vchembook/548toothdecay.html

S. mutans lives in the plaque trapped between your teeth, and lacks oxygen. Therefore it uses glycolysis to produce lactic acid under anaerobic conditions [3]. Lactic acid is very acidic. It has a pH level of 2 [4]. The added acidity decreases the pH of your mouth to initiate the dissolution of the calcium phosphate in your tooth enamel [3]. Thus, the start of a cavity. A description of the process is explained in the video below.

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Despite the terror inflicted on my teeth due to my obsession with candy, I refuse to deprive myself of the traditional Halloween treat. Although ceasing the intake of sugar would obviously decrease the production of lactic acid on my teeth, also decreasing cavity formation, there are other methods being investigated to protect our teeth.

For example, Shelby Kashket, and Dominick P. DePaola have studied the anticariogenic effects of cheese [5]! They researched that possibly due to the buffering effects of dairy proteins on the lactic acid formation, and increased salivation when eating cheese, this helps in battling the cariogenic effects of S. mutans!

Additionally, Chu-hong Hu et al. developed a way to make large quantities of Glycyrrhizol A, an extraction of licorice root, into a sugar-free lollipop which can kill the S. mutans bacteria [6]! Talk about fighting fire with fire, or in this case, fighting candy with candy!

Finally, you can also use toothpaste with sodium bicarbonate, which raises the pH level in your mouth and neutralizes the acid [1]. Or rinse with fluoride, which speeds up the remineralization of the enamel, too [7].

So, I guess what I’m saying is, long live candy! And, apparently, cheese!
…Just make sure you brush and floss often, as well.

Happy Halloween, everyone!

Nicole Yipp

References:

[1] Dr Chemical, http://drchemical.com.au/why-does-sugar-cause-tooth-decay (accessed Oct 31, 2016).

[2]Loesche WJ. Role of Streptococcus mutans in human dental decay. Microbiol Rev. 1986;50:353–380.

[3] Ophardt, C. E. Tooth Decay http://chemistry.elmhurst.edu/vchembook/548toothdecay.html (accessed Oct 31, 2016).

[4] Lactic acid; MSDS No. 9924447 [Online]; Science Lab; Houston, Texas, May 21, 2013, http://www.sciencelab.com/msds.php?msdsId=9924447 (accessed Oct 31, 2016).

[5] Kashket, S.; Depaola, D. P. Nutrition Reviews 2002, 60 (4), 97–103.

[6] Hu, C. H.; He, J.; Eckert, R.; Wu, X. Y.; Li, L. N.; Tian, Y.; Lux, R.; Shuffer, J. A.; Gelman, F.; Mentes, J.; Spackman, S.; Bauer, J.; Anderson, M. H.; Shi, W. Y. International Journal of Oral Science 2011, 3 (1), 13–20.

[7] Fluoride And Your Teeth http://www.colgate.com/en/us/oc/oral-health/basics/fluoride/article/fluoride-and-your-teeth (accessed Oct 31, 2016).

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Winter is coming.

Posted on October 10, 2016 | 5 comments

Let’s face it; summer is over. The cold months approach us, and unfortunately so do the infamous waves of common colds and viruses, too. Time to prepare for battle. But don’t worry; the fight against illness isn’t actually as vigorous as you might think. All we have to do is—pause for dramatic effect—wash our hands! It sounds too easy, doesn’t it? Well, luckily for everyone—for once in our undergraduate lives—it really is as easy as it seems!

At the University of Colorado, a study involving 430 students from 4 different residence halls investigated the efficacy of a hand-washing campaign as well as the use of alcohol gel hand-sanitizer in the fight against upper-respiratory illness (1). According to MedicineNet.com, upper-respiratory illness includes symptoms such as sneezing, nasal congestion, a runny nose, fever, and a sore throat, to name a few (2).  The study involved dividing the students into control and product groups, and statistically analyzed them for differences in illness rates, symptoms, and the number of absences from classes.  For the product groups, alcohol gel hand–sanitizer dispensers were mounted in every room, bathroom, and dining hall, and a hand washing message campaign covered bulletin boards throughout the residence halls, which carried weekly messages regarding hand washing hygiene. The control group was told they were participating in a wellness study but received no sanitizer dispensers or campaigning bulletin boards.

The study presented significant results. Although the data consisted of only self-reported symptoms and not clinically obtained information, the results displayed a recognizable increase in hand-washing and use of hand-sanitizer from the product groups, and thence a noticeable decrease in the amount of illness, absences, and symptoms of upper-respiratory illness as well.

Additionally, a study performed on children in Karachi, Pakistan also resulted with respiratory infections substantially decreasing after months of promoted hand washing (3).

Another article, in The New England Journal of Medicine, researched the transmission of rhinovirus infections (4). Rhinovirus infections cause 1/3 or more of the common colds, and proliferates primarily in the nose. Fortunately, the symptoms that arise are unlike the cartoon shown.

The investigation found that the virus is spread from the hands of the infected individual to either direct contact with another individual’s hands, or indirect contact via an intermediate surface. The recipient unknowingly spreads the infection by touching their face, eyes, or mouth, and contracts the virus. This video explains how the common cold works.

The moral of this story is to wash your hands before ever touching your face, eyes, or mouth!

However, squeezing soap on your hands and rinsing it off doesn’t suffice. In order to fully remove the bacteria, you must be thorough. Fortunately, some public washrooms show you how! An example of a sign showing efficient hand washing procedure is depicted below.

There you have it, folks. Keep it clean. Wash your hands as often as necessary; it’s probably the easiest way to fight against that nasty cold we all dread!

References:

  1. White, C.; Kolble, R.; Carlson, R.; Lipson, N. Journal of American College Health 2005, 53 (4), 175–181.
  2. FACEP, J. R. B. D. O.; MPH, S. N. N. M. D. Upper Respiratory Tract Infection Symptoms and Treatment http://www.medicinenet.com/upper_respiratory_infection/article.htm (accessed Oct 11, 2016).
  3. Luby, S. P.; Agboatwalla, M.; Feikin, D. R.; Painter, J.; Billhimer, W.; Altaf, A.; Hoekstra, R. M. The Lancet 2005, 366 (9481), 225–233.
  4. Hendley, J. O.; Wenzel, R. P.; Gwaltney, J. M. New England Journal of Medicine 1973, 288 (26), 1361–1364.

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Waste not, want not!

Posted on September 19, 2016 | Leave a comment

Value Chain Management International published a report stating that food waste costs Canada $31 billion a year. The report found food waste accumulating in restaurants, retail stores, domestic homes, restaurants, hotels, food processing factories, farms, and many more. Unfortunately the report says the amount of food wasted can actually increase the cost of food by 10 percent or more! Peers, I don’t know about you, but as a full time student, passionate eater, and no-time employee, I am not interested in forking up any percent more money to feed my persistent stomach, or else my face will look just like this baby.

uhoh

Image Credits: Elizabeth Delisi elizabethdelisi.blogspot.com

Luckily for us, Huaichen Zhang et al. at the Eindhoven University of Technology in the Netherlands, are developing a possible method to use sugar alcohols to store solar, and wind energy. The study uses naturally occurring xylitol and erythritol (molecular structures shown below). Both of which are often used as natural sweeteners. They investigated nanoscale heat transfer (NHT) across carbon structures dissolved in these compounds. The researchers used several sizes of carbon nanotubes (cylindrical forms of carbon depicted in the image below) submerged in the sugar alcohols, and employed various analytical techniques, and computer simulations, to observe the movements of the molecules and quantify the thermal conductance across them.

Structure of Xylitol. Image Credits: Century Stone Dental http://www.centurystonedental.com/blog/health-benefits-of-xylitol/

Structure of Erythritol. Image Credits: Wikipedia https://en.wikipedia.org/wiki/Erythritol

Structure of Erythritol. Image Credits: Wikipedia https://en.wikipedia.org/wiki/Erythritol

Carbon Nanotube. Image Credits: Gaia Technologies http://www.gaia3d.co.uk/3d-models/3d-chemistry/carbon-nanotube/Nanotube

Carbon Nanotube. Image Credits: Gaia Technologies http://www.gaia3d.co.uk/3d-models/3d-chemistry/carbon-nanotube/Nanotube

Most people are familiar with macroscale heat transfer: conduction, radiation, and convection. NHT on the other hand, is at a much smaller scale; it deals with heat transfer across atoms and molecules, as opposed to larger macroscopic objects. To put it into perspective, nano typically means 1 x 10-9.

NHT can be applied to modern technology. This includes improving the efficiency of energy conversion and storage. Alan McGaughey, a professor at Carnegie University, studies NHT, and thermal conductivity. He shows the importance of understanding heat transfer at the atomic level in order to advance technology and science. For example, further research of NHT could improve the energy conversion of light to electricity in LEDs.

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In conclusion of the Netherlands study, they found that smaller diameters of the nanotubes led to less heat transfer within the mixture. However, higher density combinations of the mixtures led to more heat transfer!

If Zhang, et al. can investigate the use of carbon and sugar alcohols in NHT to improve thermal storage, there may be hope for the food waste problem. The sugars and materials found in food waste could potentially be the key to better thermal energy storage, and therefore it wouldn’t really be considered waste after all!

This research contributes to a stronger understanding of the conductivity of carbon nanotubes, significance of nanoscale heat transfer, possible applications of these understandings, and most importantly brings forward a way to use all of the waste our species is contributing to the world!

Hooray for science!

– Nicole Yipp

References:

  1. Huaichen Zhang, Camilo C. M. Rindt, David M. J. Smeulders, Silvia V. Nedea. Nanoscale Heat Transfer in Carbon Nanotubes – Sugar Alcohol Composite as Heat Storage Materials. The Journal of Physical Chemistry C, 2016; DOI:10.1021/acs.jpcc.6b05466
  1. Luo, T.; Chen, G. Physical Chemistry Chemical Physics 2013, 15 (10), 3389.
  2. Chen, G.; Borca-Tasciuc, D.; Yang, R. G. Encyclopedia of Nanoscience and Nanotechnology 2004, 7, 429–459
  1. American Chemical Society (ACS). “Food waste could store solar, wind energy.” ScienceDaily. www.sciencedaily.com/releases/2016/09/160915133240.htm (accessed October 3, 2016)

 

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